CUB-71: Add mobile-first design system document

Reviewed-on: #31
Reviewed-by: Joshua <joshua@cnjmail.com>

.gitea/workflows/dev.yml

@@ -20,12 +20,15 @@ jobs:
 
       - name: Restore backend
         run: dotnet restore
+        working-directory: ./backend
 
       - name: Build backend
         run: dotnet build --no-restore --configuration Release
+        working-directory: ./backend
 
       - name: Test backend
         run: dotnet test --no-build --configuration Release
+        working-directory: ./backend
 
       - name: Setup Node
         uses: actions/setup-node@v4
@@ -39,39 +42,3 @@ jobs:
       - name: Build frontend
         run: npm run build
         working-directory: ./frontend
-
-  deploy-dev:
-    needs: build-test
-    if: gitea.event_name == 'push'
-    runs-on: ubuntu-latest
-
-    steps:
-      - name: Deploy dev
-        run: |
-          echo "${{ secrets.DEV_DEPLOY_SSH_KEY }}" > /tmp/dev_key
-          chmod 600 /tmp/dev_key
-          ssh -i /tmp/dev_key -o StrictHostKeyChecking=no \
-            ${{ secrets.DEV_DEPLOY_USER }}@${{ secrets.DEV_DEPLOY_HOST }} \
-            "${{ secrets.DEV_DEPLOY_PATH }}/deploy.sh"
-
-  notify-success:
-    needs: [build-test, deploy-dev]
-    if: success() && gitea.event_name == 'push'
-    runs-on: ubuntu-latest
-    steps:
-      - name: Notify Slack success
-        run: |
-          curl -X POST -H 'Content-type: application/json' \
-            --data "{\"text\":\"✅ Extrudex dev deployed successfully from dev branch.\"}" \
-            "${{ secrets.SLACK_WEBHOOK_URL }}"
-
-  notify-failure:
-    needs: [build-test, deploy-dev]
-    if: failure()
-    runs-on: ubuntu-latest
-    steps:
-      - name: Notify Slack failure
-        run: |
-          curl -X POST -H 'Content-type: application/json' \
-            --data "{\"text\":\"🚨 Extrudex dev pipeline failed. Check Gitea Actions for details.\"}" \
-            "${{ secrets.SLACK_WEBHOOK_URL }}"

README.md

@@ -0,0 +1,220 @@
+# Extrudex
+
+> Filament inventory and print tracking system for CubeCraft Creations.
+
+Extrudex replaces Spoolman with a fully custom solution built for Joshua's 7-printer fleet. It tracks spool stock, per-print material consumption, and cost-of-goods — with a touch-optimized kiosk interface on a Raspberry Pi 5.
+
+---
+
+## Tech Stack
+
+| Layer | Technology |
+|---|---|
+| Backend | ASP.NET Core Web API (.NET 8) |
+| Database | PostgreSQL (snake_case via EF Core) |
+| ORM | Entity Framework Core |
+| Real-time | SignalR (`PrinterHub`) |
+| Printer integration | Moonraker REST/WebSocket (Elegoo) · MQTTnet + TLS (Bambu Lab) |
+| Frontend | Angular 17+, Angular Material |
+| Deployment | Docker · Docker Compose |
+
+---
+
+## Project Structure
+
+```
+Extrudex/
+├── backend/
+│   ├── Domain/
+│   │   ├── Base/                   # BaseEntity, AuditableEntity
+│   │   ├── Entities/               # Spool, Printer, PrintJob, FilamentUsage,
+│   │   │                           #   AmsUnit, AmsSlot, MaterialBase,
+│   │   │                           #   MaterialFinish, MaterialModifier
+│   │   ├── Enums/                  # ConnectionType, DataSource, JobStatus,
+│   │   │                           #   PrinterStatus, PrinterType, QrResourceType
+│   │   └── Interfaces/             # ICostPerPrintService, IFilamentUsageSyncService,
+│   │                               #   IMoonrakerClient, IQrCodeService
+│   ├── Infrastructure/
+│   │   ├── Configuration/          # FilamentUsageSyncOptions
+│   │   ├── Data/
+│   │   │   ├── Configurations/     # EF Core fluent configs (snake_case)
+│   │   │   ├── Migrations/         # EF migrations
+│   │   │   ├── Seed/               # SeedData.cs
+│   │   │   └── ExtrudexDbContext.cs
+│   │   └── Services/               # CostPerPrintService, FilamentUsageSyncService,
+│   │                               #   MoonrakerClient, QrCodeService
+│   └── API/
+│       ├── Controllers/            # Filaments, Spools, Printers, PrintJobs,
+│       │                           #   MaterialBases, MaterialFinishes,
+│       │                           #   MaterialModifiers, MaterialLookups,
+│       │                           #   CostAnalysis, QR
+│       ├── DTOs/                   # Request/response shapes per domain
+│       ├── Filters/                # FluentValidationFilter
+│       ├── Hubs/                   # PrinterHub, IPrinterClient
+│       ├── Jobs/                   # FilamentUsageSyncJob (background)
+│       ├── Validators/             # FluentValidation validators
+│       ├── Program.cs
+│       └── appsettings.json
+├── frontend/
+│   └── src/app/
+│       ├── components/             # DashboardSummary, FilamentFilter, FilamentTable
+│       ├── models/                 # Filament, Agent model types
+│       └── app.routes.ts
+├── design/                         # UX specs and mockups (kiosk + mobile)
+├── docker-compose.dev.yml
+├── deploy.sh
+└── README.md
+```
+
+---
+
+## Domain Model
+
+### Materials (normalized taxonomy)
+
+| Entity | Description |
+|---|---|
+| `MaterialBase` | The base material type — PLA, PETG, ABS, ASA, TPU, etc. |
+| `MaterialFinish` | Required. Surface finish — Basic (default), Matte, Silk, Sparkle, etc. |
+| `MaterialModifier` | Optional. Composite fill — Carbon Fiber, Glass Fiber, Wood, etc. |
+
+**Rules:**
+- `MaterialFinish` is required — every spool must have one. Default is `"Basic"`.
+- `MaterialModifier` is optional — plain PLA has no modifier.
+
+### Consumption calculation
+
+```
+grams_used = mm_extruded × filament_cross_section_area × material_density
+```
+
+Grams are always derived, never assumed from printer telemetry directly.
+
+### Printers
+
+| Type | Integration |
+|---|---|
+| Bambu Lab (×5) | MQTTnet with TLS |
+| Elegoo Centauri Carbon | Moonraker REST + WebSocket |
+| Elegoo Saturn (resin ×2) | Manual / future |
+
+AMS units and slots are modelled as `AmsUnit` → `AmsSlot[]` → `Spool`.
+
+---
+
+## Key Design Decisions
+
+1. **Spoolman rejected** — Full custom system for data model control and workflow flexibility.
+2. **`"Basic"` not `"Standard"`** — Default `MaterialFinish` value is `Basic`.
+3. **`MaterialFinish` is required** — No null/optional finish state allowed.
+4. **`MaterialModifier` is optional** — Not every spool has a modifier.
+5. **Derived consumption** — Grams calculated from mm × density, never assumed.
+6. **Push over poll** — SignalR and MQTT preferred over periodic polling.
+7. **Snake_case PostgreSQL** — All database identifiers follow this convention via EF Core.
+
+---
+
+## Getting Started
+
+### Prerequisites
+
+- .NET 8 SDK
+- Node.js 20+
+- Docker + Docker Compose
+- PostgreSQL (or use the dev compose stack)
+
+### Backend
+
+```bash
+cd backend
+
+# Restore and build
+dotnet restore
+dotnet build
+
+# Apply migrations
+dotnet ef database update
+
+# Run API (dev)
+dotnet run --project API
+```
+
+API runs at `http://localhost:5000` · Swagger at `http://localhost:5000/swagger`
+
+### Frontend
+
+```bash
+cd frontend
+npm install
+ng serve
+```
+
+Frontend runs at `http://localhost:4200`
+
+### Docker (dev stack)
+
+```bash
+docker-compose -f docker-compose.dev.yml up
+```
+
+---
+
+## Configuration
+
+`backend/appsettings.json` — override in `appsettings.Development.json` or environment variables:
+
+| Key | Default | Description |
+|---|---|---|
+| `ConnectionStrings:ExtrudexDb` | `Host=localhost;...` | PostgreSQL connection string |
+| `FilamentUsageSync:PollingInterval` | `00:05:00` | Sync job interval |
+| `FilamentUsageSync:RequestTimeout` | `00:00:30` | Moonraker request timeout |
+| `FilamentUsageSync:Enabled` | `true` | Enable/disable background sync |
+
+---
+
+## Real-Time Events
+
+SignalR hub endpoint: `/hubs/printer`
+
+Clients receive `PrinterHub` events for live printer status, job progress, and spool consumption updates.
+
+---
+
+## API Overview
+
+| Route prefix | Resource |
+|---|---|
+| `/api/filaments` | Filament catalog |
+| `/api/spools` | Spool inventory |
+| `/api/printers` | Printer registry |
+| `/api/print-jobs` | Print job tracking |
+| `/api/material-bases` | Material base types |
+| `/api/material-finishes` | Material finishes |
+| `/api/material-modifiers` | Material modifiers |
+| `/api/material-lookups` | Combined material lookup |
+| `/api/cost-analysis` | Cost-per-print and COGS |
+| `/api/qr` | QR code generation |
+
+Full schema available at `/swagger` when running in dev.
+
+---
+
+## CI
+
+Gitea Actions pipeline (`.gitea/workflows/dev.yml`) runs on every push to `dev`:
+
+- `dotnet build`
+- Frontend `ng build`
+
+---
+
+## Branch & PR Rules
+
+- All feature branches target `dev` — **never `main`**
+- Branch naming: `agent/<agent>/CUB-N-short-description`
+- PR titles: `CUB-N: short description`
+- PRs require Otto review before Joshua merges
+
+---
+
+*Built by CubeCraft Creations · Orchestrated by Otto*

backend/API/Controllers/CostAnalysisController.cs

@@ -0,0 +1,108 @@
+using Extrudex.API.DTOs.PrintJobs;
+using Extrudex.Domain.Interfaces;
+using Microsoft.AspNetCore.Mvc;
+
+namespace Extrudex.API.Controllers;
+
+/// <summary>
+/// Controller for cost analysis endpoints. Provides spool-level
+/// cost breakdowns and aggregated COGS reporting.
+/// </summary>
+[ApiController]
+[Route("api/cost-analysis")]
+public class CostAnalysisController : ControllerBase
+{
+    private readonly ICostPerPrintService _costService;
+    private readonly ILogger<CostAnalysisController> _logger;
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="CostAnalysisController"/> class.
+    /// </summary>
+    /// <param name="costService">The cost-per-print calculation service.</param>
+    /// <param name="logger">The logger for diagnostic output.</param>
+    public CostAnalysisController(
+        ICostPerPrintService costService,
+        ILogger<CostAnalysisController> logger)
+    {
+        _costService = costService;
+        _logger = logger;
+    }
+
+    // ── POST /api/cost-analysis/spool ────────────────────────────
+
+    /// <summary>
+    /// Calculates cost breakdowns for all print jobs associated with a specific spool.
+    /// Returns per-job costs plus an aggregated total. Jobs with missing cost data
+    /// include warnings and null cost fields — the endpoint never throws for missing data.
+    /// </summary>
+    /// <param name="request">The request containing the spool identifier.</param>
+    /// <returns>A spool-level cost summary with per-job breakdowns.</returns>
+    /// <response code="200">Returns the spool cost breakdown with per-job details.</response>
+    /// <response code="404">If the spool has no print jobs.</response>
+    [HttpPost("spool")]
+    [ProducesResponseType(typeof(SpoolCostResponse), StatusCodes.Status200OK)]
+    [ProducesResponseType(StatusCodes.Status404NotFound)]
+    public async Task<ActionResult<SpoolCostResponse>> CalculateSpoolCost([FromBody] SpoolCostRequest request)
+    {
+        _logger.LogDebug("Calculating cost breakdown for spool {SpoolId}", request.SpoolId);
+
+        var results = await _costService.CalculateBySpoolAsync(request.SpoolId);
+
+        if (results.Count == 0)
+        {
+            return NotFound(new { error = $"No print jobs found for spool with ID '{request.SpoolId}'." });
+        }
+
+        // Build the spool-level summary
+        var firstResult = results[0];
+        var jobResponses = results.Select(MapCostToResponse).ToList();
+
+        // Aggregate total cost and grams — only include jobs that have a valid cost
+        var calculableJobs = results.Where(r => r.CostPerPrint.HasValue).ToList();
+        var totalCost = calculableJobs.Count == results.Count
+            ? Math.Round(calculableJobs.Sum(r => r.CostPerPrint!.Value), 4)
+            : (decimal?)null;
+
+        var aggregateWarnings = new List<string>();
+        if (calculableJobs.Count < results.Count)
+        {
+            aggregateWarnings.Add(
+                $"{results.Count - calculableJobs.Count} of {results.Count} print jobs have missing cost data. " +
+                "Total cost reflects only jobs with complete data.");
+        }
+
+        var response = new SpoolCostResponse
+        {
+            SpoolId = request.SpoolId,
+            SpoolSerial = firstResult.SpoolSerial,
+            PurchasePrice = firstResult.PurchasePrice,
+            WeightTotalGrams = firstResult.WeightTotalGrams,
+            CostPerGram = firstResult.CostPerGram,
+            TotalGramsConsumed = results.Sum(r => r.GramsDerived),
+            TotalCost = totalCost,
+            JobCount = results.Count,
+            Jobs = jobResponses,
+            Warnings = aggregateWarnings
+        };
+
+        return Ok(response);
+    }
+
+    /// <summary>
+    /// Maps a domain CostPerPrintResult to an API CostPerPrintResponse DTO.
+    /// </summary>
+    private static CostPerPrintResponse MapCostToResponse(CostPerPrintResult r) => new()
+    {
+        PrintJobId = r.PrintJobId,
+        PrintName = r.PrintName,
+        SpoolId = r.SpoolId,
+        SpoolSerial = r.SpoolSerial,
+        MmExtruded = r.MmExtruded,
+        GramsDerived = r.GramsDerived,
+        PurchasePrice = r.PurchasePrice,
+        WeightTotalGrams = r.WeightTotalGrams,
+        CostPerGram = r.CostPerGram,
+        CostPerPrint = r.CostPerPrint,
+        Warnings = r.Warnings
+    };
+}

backend/API/Controllers/FilamentsController.cs

@@ -1,6 +1,7 @@
 using Extrudex.API.DTOs;
 using Extrudex.API.DTOs.Filaments;
 using Extrudex.Domain.Entities;
+using Extrudex.Domain.Interfaces;
 using Extrudex.Infrastructure.Data;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.EntityFrameworkCore;
@@ -17,16 +18,22 @@ namespace Extrudex.API.Controllers;
 public class FilamentsController : ControllerBase
 {
     private readonly ExtrudexDbContext _dbContext;
+    private readonly ILowStockDetector _lowStockDetector;
     private readonly ILogger<FilamentsController> _logger;
 
     /// <summary>
     /// Initializes a new instance of the <see cref="FilamentsController"/> class.
     /// </summary>
     /// <param name="dbContext">The database context for data access.</param>
+    /// <param name="lowStockDetector">The low-stock detection service for filament alerts.</param>
     /// <param name="logger">The logger for diagnostic output.</param>
-    public FilamentsController(ExtrudexDbContext dbContext, ILogger<FilamentsController> logger)
+    public FilamentsController(
+        ExtrudexDbContext dbContext,
+        ILowStockDetector lowStockDetector,
+        ILogger<FilamentsController> logger)
     {
         _dbContext = dbContext;
+        _lowStockDetector = lowStockDetector;
         _logger = logger;
     }
 
@@ -40,15 +47,18 @@ public class FilamentsController : ControllerBase
     /// <response code="200">Returns the paginated list of filament spools.</response>
     [HttpGet]
     [ProducesResponseType(typeof(PagedResponse<FilamentResponse>), StatusCodes.Status200OK)]
+    [ProducesResponseType(StatusCodes.Status400BadRequest)]
     public async Task<ActionResult<PagedResponse<FilamentResponse>>> GetFilaments(
         [FromQuery] FilamentQueryParameters query)
     {
         _logger.LogDebug(
             "Getting filaments: pageNumber={PageNumber}, pageSize={PageSize}, " +
             "materialBaseId={MaterialBaseId}, materialFinishId={MaterialFinishId}, " +
-            "materialModifierId={MaterialModifierId}, brand={Brand}, isActive={IsActive}",
+            "materialModifierId={MaterialModifierId}, brand={Brand}, isActive={IsActive}, " +
+            "includeArchived={IncludeArchived}, storageLocation={StorageLocation}",
             query.PageNumber, query.PageSize, query.MaterialBaseId,
-            query.MaterialFinishId, query.MaterialModifierId, query.Brand, query.IsActive);
+            query.MaterialFinishId, query.MaterialModifierId, query.Brand, query.IsActive,
+            query.IncludeArchived, query.StorageLocation);
 
         // Clamp pagination values
         var pageNumber = Math.Max(1, query.PageNumber);
@@ -77,13 +87,22 @@ public class FilamentsController : ControllerBase
         if (query.IsActive.HasValue)
             spoolQuery = spoolQuery.Where(s => s.IsActive == query.IsActive.Value);
 
+        // Exclude archived spools by default; include when explicitly requested
+        if (query.IncludeArchived != true)
+            spoolQuery = spoolQuery.Where(s => !s.IsArchived);
+
+        if (!string.IsNullOrWhiteSpace(query.StorageLocation))
+            spoolQuery = spoolQuery.Where(s =>
+                s.StorageLocation != null &&
+                s.StorageLocation.ToLower().Contains(query.StorageLocation.ToLower()));
+
         var totalCount = await spoolQuery.CountAsync();
 
         var items = await spoolQuery
             .OrderByDescending(s => s.CreatedAt)
             .Skip((pageNumber - 1) * pageSize)
             .Take(pageSize)
-            .Select(s => MapToFilamentResponse(s))
+            .Select(s => MapToFilamentResponse(s, _lowStockDetector))
             .ToListAsync();
 
         var response = new PagedResponse<FilamentResponse>
@@ -124,7 +143,7 @@ public class FilamentsController : ControllerBase
             return NotFound(new { error = $"Filament with ID '{id}' not found." });
         }
 
-        return Ok(MapToFilamentResponse(spool));
+        return Ok(MapToFilamentResponse(spool, _lowStockDetector));
     }
 
     /// <summary>
@@ -185,7 +204,9 @@ public class FilamentsController : ControllerBase
             SpoolSerial = request.SpoolSerial,
             PurchasePrice = request.PurchasePrice,
             PurchaseDate = request.PurchaseDate,
-            IsActive = request.IsActive
+            IsActive = request.IsActive,
+            IsArchived = request.IsArchived,
+            StorageLocation = request.StorageLocation
         };
 
         _dbContext.Spools.Add(entity);
@@ -197,7 +218,7 @@ public class FilamentsController : ControllerBase
         if (entity.MaterialModifierId.HasValue)
             await _dbContext.Entry(entity).Reference(s => s.MaterialModifier).LoadAsync();
 
-        var response = MapToFilamentResponse(entity);
+        var response = MapToFilamentResponse(entity, _lowStockDetector);
         return CreatedAtAction(nameof(GetFilament), new { id = entity.Id }, response);
     }
 
@@ -267,6 +288,8 @@ public class FilamentsController : ControllerBase
         entity.PurchasePrice = request.PurchasePrice;
         entity.PurchaseDate = request.PurchaseDate;
         entity.IsActive = request.IsActive;
+        entity.IsArchived = request.IsArchived;
+        entity.StorageLocation = request.StorageLocation;
 
         await _dbContext.SaveChangesAsync();
 
@@ -276,7 +299,97 @@ public class FilamentsController : ControllerBase
         if (entity.MaterialModifierId.HasValue)
             await _dbContext.Entry(entity).Reference(s => s.MaterialModifier).LoadAsync();
 
-        return Ok(MapToFilamentResponse(entity));
+        return Ok(MapToFilamentResponse(entity, _lowStockDetector));
+    }
+
+    /// <summary>
+    /// Gets only the filament spools that are flagged as low stock.
+    /// A spool is considered low stock when its remaining weight percentage
+    /// is at or below the configured threshold.
+    /// </summary>
+    /// <returns>A list of low-stock filament spools with alert metadata.</returns>
+    /// <response code="200">Returns the list of low-stock filament spools.</response>
+    [HttpGet("low-stock")]
+    [ProducesResponseType(typeof(List<FilamentResponse>), StatusCodes.Status200OK)]
+    public async Task<ActionResult<List<FilamentResponse>>> GetLowStockFilaments()
+    {
+        _logger.LogDebug("Getting low-stock filaments (threshold: {Threshold}%)",
+            _lowStockDetector.LowStockThresholdPercent);
+
+        var spools = await _dbContext.Spools
+            .Include(s => s.MaterialBase)
+            .Include(s => s.MaterialFinish)
+            .Include(s => s.MaterialModifier)
+            .Where(s => s.IsActive)
+            .OrderByDescending(s => s.CreatedAt)
+            .ToListAsync();
+
+        var lowStockItems = spools
+            .Where(s => _lowStockDetector.IsLowStock(s.WeightRemainingGrams, s.WeightTotalGrams))
+            .Select(s => MapToFilamentResponse(s, _lowStockDetector))
+            .ToList();
+
+        return Ok(lowStockItems);
+    }
+
+    /// <summary>
+    /// Deletes a filament spool by its unique identifier.
+    /// If the spool has associated print jobs, the deletion is rejected with a 409 Conflict
+    /// to preserve COGS and print history — the caller should archive the spool instead.
+    /// Associated filament usage records are removed before the spool is deleted.
+    /// AMS slots referencing this spool will have their SpoolId set to null by the database.
+    /// </summary>
+    /// <param name="id">The unique identifier of the filament spool to delete.</param>
+    /// <returns>No content on successful deletion.</returns>
+    /// <response code="204">The filament spool was successfully deleted.</response>
+    /// <response code="404">If the filament spool with the given ID is not found.</response>
+    /// <response code="409">If the spool has associated print jobs and cannot be deleted.</response>
+    [HttpDelete("{id:guid}")]
+    [ProducesResponseType(StatusCodes.Status204NoContent)]
+    [ProducesResponseType(StatusCodes.Status404NotFound)]
+    [ProducesResponseType(StatusCodes.Status409Conflict)]
+    public async Task<IActionResult> DeleteFilament(Guid id)
+    {
+        _logger.LogInformation("Deleting filament {Id}", id);
+
+        var entity = await _dbContext.Spools.FindAsync(id);
+        if (entity is null)
+        {
+            _logger.LogWarning("Filament {Id} not found for deletion", id);
+            return NotFound(new { error = $"Filament with ID '{id}' not found." });
+        }
+
+        // Check for associated print jobs — these cannot be orphaned
+        var hasPrintJobs = await _dbContext.PrintJobs.AnyAsync(pj => pj.SpoolId == id);
+        if (hasPrintJobs)
+        {
+            _logger.LogWarning(
+                "Cannot delete filament {Id}: associated print jobs exist. Suggest archiving instead.", id);
+            return Conflict(new
+            {
+                error = $"Cannot delete filament '{id}' because it has associated print jobs. " +
+                        "Archive the filament instead to preserve print history and COGS data."
+            });
+        }
+
+        // Remove associated filament usage records (usage tracking data for this spool)
+        var usageRecords = await _dbContext.FilamentUsages
+            .Where(fu => fu.SpoolId == id)
+            .ToListAsync();
+
+        if (usageRecords.Count > 0)
+        {
+            _logger.LogInformation(
+                "Removing {Count} filament usage records for spool {Id}",
+                usageRecords.Count, id);
+            _dbContext.FilamentUsages.RemoveRange(usageRecords);
+        }
+
+        _dbContext.Spools.Remove(entity);
+        await _dbContext.SaveChangesAsync();
+
+        _logger.LogInformation("Filament {Id} deleted successfully", id);
+        return NoContent();
     }
 
     // ── Mapping helper ─────────────────────────────────────────
@@ -285,10 +398,12 @@ public class FilamentsController : ControllerBase
     /// Maps a Spool domain entity to a FilamentResponse DTO.
     /// Denormalizes material names for display convenience.
     /// Populates the QrCodeUrl for easy frontend access to the spool's QR code.
+    /// Calculates low-stock status and remaining weight percentage.
     /// </summary>
     /// <param name="s">The spool entity to map.</param>
-    /// <returns>A FilamentResponse DTO with denormalized material names and QR code URL.</returns>
-    private static FilamentResponse MapToFilamentResponse(Spool s) => new()
+    /// <param name="lowStockDetector">The low-stock detection service for computing alert flags.</param>
+    /// <returns>A FilamentResponse DTO with denormalized material names, QR code URL, and low-stock metadata.</returns>
+    private static FilamentResponse MapToFilamentResponse(Spool s, ILowStockDetector lowStockDetector) => new()
     {
         Id = s.Id,
         MaterialBaseId = s.MaterialBaseId,
@@ -307,8 +422,12 @@ public class FilamentsController : ControllerBase
         PurchasePrice = s.PurchasePrice,
         PurchaseDate = s.PurchaseDate,
         IsActive = s.IsActive,
+        IsArchived = s.IsArchived,
+        StorageLocation = s.StorageLocation,
         CreatedAt = s.CreatedAt,
         UpdatedAt = s.UpdatedAt,
-        QrCodeUrl = $"/api/qr/spool/{s.Id}"
+        QrCodeUrl = $"/api/qr/spool/{s.Id}",
+        IsLowStock = lowStockDetector.IsLowStock(s.WeightRemainingGrams, s.WeightTotalGrams),
+        RemainingWeightPercent = lowStockDetector.GetRemainingWeightPercent(s.WeightRemainingGrams, s.WeightTotalGrams)
     };
 }

backend/API/Controllers/PrintJobsController.cs

@@ -413,6 +413,92 @@ public class PrintJobsController : ControllerBase
         return NoContent();
     }
 
+    // ── GET /api/printjobs/{id}/cost-summary ──────────────────────────
+
+    /// <summary>
+    /// Gets the material cost summary for a specific print job.
+    /// Calculates total material cost from filament usage (grams derived)
+    /// and the spool's purchase price. Returns warnings instead of errors
+    /// when cost data is unavailable.
+    /// </summary>
+    /// <param name="id">The unique identifier of the print job.</param>
+    /// <returns>A cost summary with breakdown and any warnings about missing data.</returns>
+    /// <response code="200">Returns the cost summary. Warnings field lists any missing data.</response>
+    /// <response code="404">If the print job with the given ID is not found.</response>
+    [HttpGet("{id:guid}/cost-summary")]
+    [ProducesResponseType(typeof(CostSummaryResponse), StatusCodes.Status200OK)]
+    [ProducesResponseType(StatusCodes.Status404NotFound)]
+    public async Task<ActionResult<CostSummaryResponse>> GetCostSummary(Guid id)
+    {
+        _logger.LogDebug("Getting cost summary for print job {Id}", id);
+
+        var job = await _dbContext.PrintJobs
+            .Include(j => j.Spool)
+                .ThenInclude(s => s!.MaterialBase)
+            .FirstOrDefaultAsync(j => j.Id == id);
+
+        if (job is null)
+        {
+            _logger.LogWarning("Print job {Id} not found for cost summary", id);
+            return NotFound(new { error = $"Print job with ID '{id}' not found." });
+        }
+
+        var warnings = new List<string>();
+        var spool = job.Spool;
+
+        // Build response with what we have
+        var response = new CostSummaryResponse
+        {
+            PrintJobId = job.Id,
+            PrintName = job.PrintName,
+            SpoolId = job.SpoolId,
+            SpoolSerial = spool?.SpoolSerial ?? string.Empty,
+            SpoolBrand = spool?.Brand ?? string.Empty,
+            SpoolColorName = spool?.ColorName ?? string.Empty,
+            MmExtruded = job.MmExtruded,
+            GramsDerived = job.GramsDerived,
+            SpoolPurchasePrice = spool?.PurchasePrice,
+            SpoolWeightTotalGrams = spool?.WeightTotalGrams,
+            StoredCostPerPrint = job.CostPerPrint
+        };
+
+        // Validate spool data availability
+        if (spool is null)
+        {
+            warnings.Add("Spool data is not available for this print job. Cost cannot be calculated.");
+            response.Warnings = warnings;
+            return Ok(response);
+        }
+
+        // Check if we can calculate cost
+        if (!spool.PurchasePrice.HasValue)
+        {
+            warnings.Add("Spool purchase price is not set. Cost per gram and total material cost cannot be calculated.");
+        }
+
+        if (spool.WeightTotalGrams <= 0)
+        {
+            warnings.Add("Spool total weight is zero or invalid. Cost per gram and total material cost cannot be calculated.");
+        }
+
+        // If we have enough data, calculate the cost
+        if (spool.PurchasePrice.HasValue && spool.WeightTotalGrams > 0)
+        {
+            var pricePerGram = spool.PurchasePrice.Value / spool.WeightTotalGrams;
+            response.PricePerGram = Math.Round(pricePerGram, 4);
+            response.TotalMaterialCost = Math.Round(job.GramsDerived * pricePerGram, 4);
+        }
+
+        // Warn if grams derived is zero but mm extruded is non-zero
+        if (job.GramsDerived == 0 && job.MmExtruded > 0)
+        {
+            warnings.Add("GramsDerived is zero despite MmExtruded being non-zero. Cost may be inaccurate. Consider re-deriving grams from filament parameters.");
+        }
+
+        response.Warnings = warnings;
+        return Ok(response);
+    }
+
     // ── Gram Derivation Formula ────────────────────────────────────
 
     /// <summary>

backend/API/Controllers/UsageLogsController.cs

@@ -0,0 +1,117 @@
+using Extrudex.API.DTOs.UsageLogs;
+using Extrudex.Domain.Enums;
+using Extrudex.Domain.Interfaces;
+using Microsoft.AspNetCore.Mvc;
+
+namespace Extrudex.API.Controllers;
+
+/// <summary>
+/// API controller for recording and querying filament usage logs.
+/// Usage logs provide a fine-grained audit trail of filament consumption
+/// from printer integrations or manual input.
+/// </summary>
+[ApiController]
+[Route("api/[controller]")]
+[Produces("application/json")]
+public class UsageLogsController : ControllerBase
+{
+    private readonly IUsageLogService _usageLogService;
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="UsageLogsController"/> class.
+    /// </summary>
+    /// <param name="usageLogService">The usage log service for recording and querying usage.</param>
+    public UsageLogsController(IUsageLogService usageLogService)
+    {
+        _usageLogService = usageLogService;
+    }
+
+    /// <summary>
+    /// Records a new filament usage entry.
+    /// </summary>
+    /// <param name="request">The usage entry details.</param>
+    /// <returns>The created usage log entry.</returns>
+    [HttpPost]
+    [ProducesResponseType(typeof(UsageLogResponse), StatusCodes.Status201Created)]
+    [ProducesResponseType(StatusCodes.Status400BadRequest)]
+    public async Task<ActionResult<UsageLogResponse>> Create([FromBody] CreateUsageLogRequest request)
+    {
+        if (!Enum.TryParse<DataSource>(request.DataSource, ignoreCase: true, out var dataSource))
+        {
+            return BadRequest($"Invalid data source: '{request.DataSource}'. Valid values: Mqtt, Moonraker, Manual.");
+        }
+
+        var entry = await _usageLogService.RecordUsageAsync(
+            spoolId: request.SpoolId,
+            gramsUsed: request.GramsUsed,
+            dataSource: dataSource,
+            printerId: request.PrinterId,
+            printJobId: request.PrintJobId,
+            mmExtruded: request.MmExtruded,
+            usageTimestamp: request.UsageTimestamp,
+            notes: request.Notes
+        );
+
+        return CreatedAtAction(
+            nameof(GetBySpool),
+            new { spoolId = entry.SpoolId },
+            MapToResponse(entry));
+    }
+
+    /// <summary>
+    /// Gets usage logs for a specific spool, ordered by most recent first.
+    /// </summary>
+    /// <param name="spoolId">The spool ID to filter by.</param>
+    /// <returns>A collection of usage log entries for the spool.</returns>
+    [HttpGet("spool/{spoolId:guid}")]
+    [ProducesResponseType(typeof(IEnumerable<UsageLogResponse>), StatusCodes.Status200OK)]
+    public async Task<ActionResult<IEnumerable<UsageLogResponse>>> GetBySpool(Guid spoolId)
+    {
+        var logs = await _usageLogService.GetBySpoolAsync(spoolId);
+        return Ok(logs.Select(MapToResponse));
+    }
+
+    /// <summary>
+    /// Gets usage logs for a specific printer, ordered by most recent first.
+    /// </summary>
+    /// <param name="printerId">The printer ID to filter by.</param>
+    /// <returns>A collection of usage log entries for the printer.</returns>
+    [HttpGet("printer/{printerId:guid}")]
+    [ProducesResponseType(typeof(IEnumerable<UsageLogResponse>), StatusCodes.Status200OK)]
+    public async Task<ActionResult<IEnumerable<UsageLogResponse>>> GetByPrinter(Guid printerId)
+    {
+        var logs = await _usageLogService.GetByPrinterAsync(printerId);
+        return Ok(logs.Select(MapToResponse));
+    }
+
+    /// <summary>
+    /// Gets usage logs for a specific print job, ordered by most recent first.
+    /// </summary>
+    /// <param name="printJobId">The print job ID to filter by.</param>
+    /// <returns>A collection of usage log entries for the print job.</returns>
+    [HttpGet("print-job/{printJobId:guid}")]
+    [ProducesResponseType(typeof(IEnumerable<UsageLogResponse>), StatusCodes.Status200OK)]
+    public async Task<ActionResult<IEnumerable<UsageLogResponse>>> GetByPrintJob(Guid printJobId)
+    {
+        var logs = await _usageLogService.GetByPrintJobAsync(printJobId);
+        return Ok(logs.Select(MapToResponse));
+    }
+
+    /// <summary>
+    /// Maps a UsageLog domain entity to a UsageLogResponse DTO.
+    /// </summary>
+    private static UsageLogResponse MapToResponse(Domain.Entities.UsageLog log) => new()
+    {
+        Id = log.Id,
+        SpoolId = log.SpoolId,
+        PrinterId = log.PrinterId,
+        PrintJobId = log.PrintJobId,
+        GramsUsed = log.GramsUsed,
+        MmExtruded = log.MmExtruded,
+        UsageTimestamp = log.UsageTimestamp,
+        DataSource = log.DataSource.ToString(),
+        Notes = log.Notes,
+        CreatedAt = log.CreatedAt,
+        UpdatedAt = log.UpdatedAt
+    };
+}

backend/API/DTOs/Filaments/FilamentDtos.cs

@@ -59,6 +59,12 @@ public class FilamentResponse
     /// <summary>Whether the spool is currently active and available.</summary>
     public bool IsActive { get; set; }
 
+    /// <summary>Whether the spool has been archived (removed from active inventory).</summary>
+    public bool IsArchived { get; set; }
+
+    /// <summary>Physical storage location (e.g., "Shelf A", "Drawer 3"). Null if unset.</summary>
+    public string? StorageLocation { get; set; }
+
     /// <summary>Timestamp when this record was created (UTC).</summary>
     public DateTime CreatedAt { get; set; }
 
@@ -70,6 +76,19 @@ public class FilamentResponse
     /// Encodes a deep link to the spool's detail page.
     /// </summary>
     public string QrCodeUrl { get; set; } = string.Empty;
+
+    /// <summary>
+    /// Whether this spool is flagged as low stock — remaining weight is at or
+    /// below the configured low-stock threshold percentage.
+    /// Useful for UI alerts and inventory dashboards.
+    /// </summary>
+    public bool IsLowStock { get; set; }
+
+    /// <summary>
+    /// Remaining filament weight as a percentage of total weight (0–100).
+    /// Rounded to one decimal place. Returns 0 if total weight is zero.
+    /// </summary>
+    public decimal RemainingWeightPercent { get; set; }
 }
 
 /// <summary>
@@ -133,6 +152,15 @@ public class CreateFilamentRequest
 
     /// <summary>Whether the spool is active. Defaults to true.</summary>
     public bool IsActive { get; set; } = true;
+
+    /// <summary>Whether the spool is archived. Defaults to false.
+    /// </summary>
+    public bool IsArchived { get; set; } = false;
+
+    /// <summary>Physical storage location (e.g., "Shelf A", "Drawer 3"). Optional.
+    /// </summary>
+    [StringLength(200, ErrorMessage = "StorageLocation must not exceed 200 characters.")]
+    public string? StorageLocation { get; set; }
 }
 
 /// <summary>
@@ -196,4 +224,11 @@ public class UpdateFilamentRequest
 
     /// <summary>Whether the spool is active.</summary>
     public bool IsActive { get; set; } = true;
+
+    /// <summary>Whether the spool is archived. Defaults to false.</summary>
+    public bool IsArchived { get; set; } = false;
+
+    /// <summary>Physical storage location (e.g., "Shelf A", "Drawer 3"). Optional.</summary>
+    [StringLength(200, ErrorMessage = "StorageLocation must not exceed 200 characters.")]
+    public string? StorageLocation { get; set; }
 }

backend/API/DTOs/Filaments/FilamentQueryDtos.cs

@@ -30,4 +30,11 @@ public class FilamentQueryParameters
 
     /// <summary>Optional filter by active status. True = active only, False = inactive only.</summary>
     public bool? IsActive { get; set; }
+
+    /// <summary>Whether to include archived spools in results. Defaults to false (excludes archived).
+    /// </summary>
+    public bool? IncludeArchived { get; set; }
+
+    /// <summary>Optional filter by storage location (case-insensitive partial match).</summary>
+    public string? StorageLocation { get; set; }
 }

backend/API/DTOs/PrintJobs/CostPerPrintDtos.cs

@@ -0,0 +1,99 @@
+using System.ComponentModel.DataAnnotations;
+
+namespace Extrudex.API.DTOs.PrintJobs;
+
+/// <summary>
+/// Response DTO for cost-per-print calculation. Contains the full cost
+/// breakdown and any warnings about missing or incomplete data.
+/// </summary>
+public class CostPerPrintResponse
+{
+    /// <summary>The print job identifier this result belongs to.</summary>
+    public Guid PrintJobId { get; set; }
+
+    /// <summary>Human-readable name of the print job.</summary>
+    public string PrintName { get; set; } = string.Empty;
+
+    /// <summary>The spool identifier that provided filament.</summary>
+    public Guid SpoolId { get; set; }
+
+    /// <summary>Serial number of the spool.</summary>
+    public string SpoolSerial { get; set; } = string.Empty;
+
+    /// <summary>Total millimeters of filament extruded.</summary>
+    public decimal MmExtruded { get; set; }
+
+    /// <summary>Derived grams consumed for this print.</summary>
+    public decimal GramsDerived { get; set; }
+
+    /// <summary>The spool's purchase price. Null if not recorded.</summary>
+    public decimal? PurchasePrice { get; set; }
+
+    /// <summary>The spool's total weight in grams when full.</summary>
+    public decimal? WeightTotalGrams { get; set; }
+
+    /// <summary>Cost per gram of filament. Null if purchase price or total weight is missing.</summary>
+    public decimal? CostPerGram { get; set; }
+
+    /// <summary>Calculated cost of this print job. Null if cost data is incomplete.</summary>
+    public decimal? CostPerPrint { get; set; }
+
+    /// <summary>
+    /// Warnings about missing or incomplete data. Empty when all data is available
+    /// and the calculation succeeded.
+    /// </summary>
+    public List<string> Warnings { get; set; } = new();
+}
+
+/// <summary>
+/// Request DTO for batch cost calculation by spool. Returns cost breakdowns
+/// for all print jobs associated with the specified spool.
+/// </summary>
+public class SpoolCostRequest
+{
+    /// <summary>The unique identifier of the spool to calculate costs for.</summary>
+    [Required(ErrorMessage = "SpoolId is required.")]
+    public Guid SpoolId { get; set; }
+}
+
+/// <summary>
+/// Response DTO for spool-level cost calculation. Contains cost breakdowns
+/// for all print jobs on the spool, plus a total cost summary.
+/// </summary>
+public class SpoolCostResponse
+{
+    /// <summary>The spool identifier.</summary>
+    public Guid SpoolId { get; set; }
+
+    /// <summary>Serial number of the spool.</summary>
+    public string SpoolSerial { get; set; } = string.Empty;
+
+    /// <summary>The spool's purchase price. Null if not recorded.</summary>
+    public decimal? PurchasePrice { get; set; }
+
+    /// <summary>The spool's total weight in grams when full.</summary>
+    public decimal? WeightTotalGrams { get; set; }
+
+    /// <summary>Cost per gram of filament. Null if cost data is incomplete.</summary>
+    public decimal? CostPerGram { get; set; }
+
+    /// <summary>Total grams consumed across all print jobs on this spool.</summary>
+    public decimal TotalGramsConsumed { get; set; }
+
+    /// <summary>Total calculated cost across all print jobs. Null if any job has missing data.</summary>
+    public decimal? TotalCost { get; set; }
+
+    /// <summary>Number of print jobs included in this calculation.</summary>
+    public int JobCount { get; set; }
+
+    /// <summary>
+    /// Individual cost breakdowns per print job. Jobs with missing data
+    /// will have null cost fields and populated warnings.
+    /// </summary>
+    public List<CostPerPrintResponse> Jobs { get; set; } = new();
+
+    /// <summary>
+    /// Aggregate warnings about missing data across all jobs.
+    /// </summary>
+    public List<string> Warnings { get; set; } = new();
+}

backend/API/DTOs/PrintJobs/CostSummaryResponse.cs

@@ -0,0 +1,55 @@
+namespace Extrudex.API.DTOs.PrintJobs;
+
+/// <summary>
+/// Response DTO for the cost summary of a print job.
+/// Provides a breakdown of material cost based on filament usage
+/// and spool pricing data. If cost data is incomplete, warnings
+/// are returned instead of throwing an error.
+/// </summary>
+public class CostSummaryResponse
+{
+    /// <summary>Unique identifier of the print job.</summary>
+    public Guid PrintJobId { get; set; }
+
+    /// <summary>Human-readable name of the print job.</summary>
+    public string PrintName { get; set; } = string.Empty;
+
+    /// <summary>Foreign key to the spool used for this print job.</summary>
+    public Guid SpoolId { get; set; }
+
+    /// <summary>Serial number of the spool.</summary>
+    public string SpoolSerial { get; set; } = string.Empty;
+
+    /// <summary>Brand of the spool.</summary>
+    public string SpoolBrand { get; set; } = string.Empty;
+
+    /// <summary>Color name of the spool.</summary>
+    public string SpoolColorName { get; set; } = string.Empty;
+
+    /// <summary>Total millimeters of filament extruded during this print.</summary>
+    public decimal MmExtruded { get; set; }
+
+    /// <summary>Derived grams consumed for this print job.</summary>
+    public decimal GramsDerived { get; set; }
+
+    /// <summary>Purchase price of the full spool, if available.</summary>
+    public decimal? SpoolPurchasePrice { get; set; }
+
+    /// <summary>Total weight of the spool in grams when full.</summary>
+    public decimal? SpoolWeightTotalGrams { get; set; }
+
+    /// <summary>Calculated price per gram (purchase price / total weight), if available.</summary>
+    public decimal? PricePerGram { get; set; }
+
+    /// <summary>Calculated total material cost for this print job, if available.</summary>
+    public decimal? TotalMaterialCost { get; set; }
+
+    /// <summary>The CostPerPrint stored on the print job entity, if set.</summary>
+    public decimal? StoredCostPerPrint { get; set; }
+
+    /// <summary>
+    /// Warnings about missing data that prevent cost calculation.
+    /// Empty if all data is available and cost was calculated successfully.
+    /// </summary>
+    public List<string> Warnings { get; set; } = new();
+}

backend/API/DTOs/UsageLogs/UsageLogDtos.cs

@@ -0,0 +1,115 @@
+using System.ComponentModel.DataAnnotations;
+
+namespace Extrudex.API.DTOs.UsageLogs;
+
+/// <summary>
+/// Request DTO for recording a filament usage entry.
+/// </summary>
+public class CreateUsageLogRequest
+{
+    /// <summary>
+    /// The ID of the spool that provided the filament.
+    /// </summary>
+    [Required]
+    public Guid SpoolId { get; set; }
+
+    /// <summary>
+    /// The number of grams of filament consumed.
+    /// </summary>
+    [Required]
+    [Range(0.01, double.MaxValue, ErrorMessage = "GramsUsed must be a positive value.")]
+    public decimal GramsUsed { get; set; }
+
+    /// <summary>
+    /// The source of the usage data (Mqtt, Moonraker, Manual).
+    /// </summary>
+    [Required]
+    public string DataSource { get; set; } = string.Empty;
+
+    /// <summary>
+    /// The ID of the printer that consumed the filament. Optional.
+    /// </summary>
+    public Guid? PrinterId { get; set; }
+
+    /// <summary>
+    /// The ID of the print job associated with this usage. Optional.
+    /// </summary>
+    public Guid? PrintJobId { get; set; }
+
+    /// <summary>
+    /// The number of millimeters of filament extruded. Optional.
+    /// </summary>
+    public decimal? MmExtruded { get; set; }
+
+    /// <summary>
+    /// When the usage occurred (UTC). Defaults to now if not specified.
+    /// </summary>
+    public DateTime? UsageTimestamp { get; set; }
+
+    /// <summary>
+    /// Optional notes about this usage entry.
+    /// </summary>
+    [MaxLength(2000)]
+    public string? Notes { get; set; }
+}
+
+/// <summary>
+/// Response DTO for a usage log entry.
+/// </summary>
+public class UsageLogResponse
+{
+    /// <summary>
+    /// Unique identifier for the usage log entry.
+    /// </summary>
+    public Guid Id { get; set; }
+
+    /// <summary>
+    /// The spool that provided the filament.
+    /// </summary>
+    public Guid SpoolId { get; set; }
+
+    /// <summary>
+    /// The printer that consumed the filament, if applicable.
+    /// </summary>
+    public Guid? PrinterId { get; set; }
+
+    /// <summary>
+    /// The print job associated with this usage, if applicable.
+    /// </summary>
+    public Guid? PrintJobId { get; set; }
+
+    /// <summary>
+    /// Grams of filament consumed.
+    /// </summary>
+    public decimal GramsUsed { get; set; }
+
+    /// <summary>
+    /// Millimeters of filament extruded, if available.
+    /// </summary>
+    public decimal? MmExtruded { get; set; }
+
+    /// <summary>
+    /// When the usage occurred (UTC).
+    /// </summary>
+    public DateTime UsageTimestamp { get; set; }
+
+    /// <summary>
+    /// Source of the usage data (Mqtt, Moonraker, Manual).
+    /// </summary>
+    public string DataSource { get; set; } = string.Empty;
+
+    /// <summary>
+    /// Optional notes about this usage entry.
+    /// </summary>
+    public string? Notes { get; set; }
+
+    /// <summary>
+    /// When the record was created (UTC).
+    /// </summary>
+    public DateTime CreatedAt { get; set; }
+
+    /// <summary>
+    /// When the record was last updated (UTC).
+    /// </summary>
+    public DateTime UpdatedAt { get; set; }
+}

backend/API/Jobs/FilamentUsageSyncJob.cs

@@ -0,0 +1,79 @@
+using Extrudex.Domain.Interfaces;
+using Extrudex.Infrastructure.Configuration;
+using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
+
+namespace Extrudex.API.Jobs;
+
+/// <summary>
+/// Background job that periodically syncs filament usage data from
+/// Moonraker printers. Runs as a hosted service and polls all active
+/// Moonraker printers on a configurable interval to persist usage
+/// data to the Extrudex database.
+/// 
+/// Configuration is bound from the "FilamentUsageSync" section in
+/// appsettings.json. Set Enabled=false to disable without removing
+/// the service registration.
+/// </summary>
+public class FilamentUsageSyncJob : BackgroundService
+{
+    private readonly IFilamentUsageSyncService _syncService;
+    private readonly FilamentUsageSyncOptions _options;
+    private readonly ILogger<FilamentUsageSyncJob> _logger;
+
+    /// <summary>
+    /// Creates a new FilamentUsageSyncJob.
+    /// </summary>
+    /// <param name="syncService">The service that performs the actual sync logic.</param>
+    /// <param name="options">Configuration options for polling interval and timeouts.</param>
+    /// <param name="logger">Logger for diagnostic output.</param>
+    public FilamentUsageSyncJob(
+        IFilamentUsageSyncService syncService,
+        IOptions<FilamentUsageSyncOptions> options,
+        ILogger<FilamentUsageSyncJob> logger)
+    {
+        _syncService = syncService;
+        _options = options.Value;
+        _logger = logger;
+    }
+
+    /// <inheritdoc />
+    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
+    {
+        if (!_options.Enabled)
+        {
+            _logger.LogInformation("Filament usage sync job is disabled via configuration — exiting");
+            return;
+        }
+
+        _logger.LogInformation(
+            "Filament usage sync job starting — polling every {Interval}",
+            _options.PollingInterval);
+
+        // Delay briefly on startup to allow the web host to fully initialize
+        await Task.Delay(TimeSpan.FromSeconds(10), stoppingToken);
+
+        while (!stoppingToken.IsCancellationRequested)
+        {
+            try
+            {
+                var syncedCount = await _syncService.SyncAllAsync(stoppingToken);
+
+                _logger.LogInformation(
+                    "Filament usage sync completed — {SyncedCount} printer(s) synced. Next sync in {Interval}",
+                    syncedCount, _options.PollingInterval);
+            }
+            catch (Exception ex) when (ex is not OperationCanceledException)
+            {
+                _logger.LogError(ex,
+                    "Error during filament usage sync cycle — will retry in {Interval}",
+                    _options.PollingInterval);
+            }
+
+            await Task.Delay(_options.PollingInterval, stoppingToken);
+        }
+
+        _logger.LogInformation("Filament usage sync job shutting down");
+    }
+}

backend/API/Jobs/MoonrakerPrinterSyncJob.cs

@@ -0,0 +1,80 @@
+using Extrudex.Domain.Interfaces;
+using Extrudex.Infrastructure.Configuration;
+using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
+
+namespace Extrudex.API.Jobs;
+
+/// <summary>
+/// Background service that periodically syncs Moonraker printer status
+/// and print job history into the Extrudex database. Runs as a hosted
+/// service and polls all active Moonraker printers on a configurable
+/// interval to update printer state and map completed print jobs
+/// to PrintJob and FilamentUsage entities.
+///
+/// Configuration is bound from the "MoonrakerPrinterSync" section in
+/// appsettings.json. Set Enabled=false to disable without removing
+/// the service registration.
+/// </summary>
+public class MoonrakerPrinterSyncJob : BackgroundService
+{
+    private readonly IMoonrakerPrinterSyncService _syncService;
+    private readonly MoonrakerPrinterSyncOptions _options;
+    private readonly ILogger<MoonrakerPrinterSyncJob> _logger;
+
+    /// <summary>
+    /// Creates a new MoonrakerPrinterSyncJob.
+    /// </summary>
+    /// <param name="syncService">The service that performs the actual sync logic.</param>
+    /// <param name="options">Configuration options for polling interval and timeouts.</param>
+    /// <param name="logger">Logger for diagnostic output.</param>
+    public MoonrakerPrinterSyncJob(
+        IMoonrakerPrinterSyncService syncService,
+        IOptions<MoonrakerPrinterSyncOptions> options,
+        ILogger<MoonrakerPrinterSyncJob> logger)
+    {
+        _syncService = syncService;
+        _options = options.Value;
+        _logger = logger;
+    }
+
+    /// <inheritdoc />
+    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
+    {
+        if (!_options.Enabled)
+        {
+            _logger.LogInformation("Moonraker printer sync job is disabled via configuration — exiting");
+            return;
+        }
+
+        _logger.LogInformation(
+            "Moonraker printer sync job starting — polling every {Interval}",
+            _options.PollingInterval);
+
+        // Delay briefly on startup to allow the web host to fully initialize
+        await Task.Delay(TimeSpan.FromSeconds(15), stoppingToken);
+
+        while (!stoppingToken.IsCancellationRequested)
+        {
+            try
+            {
+                var syncedCount = await _syncService.SyncAllAsync(stoppingToken);
+
+                _logger.LogInformation(
+                    "Moonraker printer sync completed — {SyncedCount} printer(s) synced. Next sync in {Interval}",
+                    syncedCount, _options.PollingInterval);
+            }
+            catch (Exception ex) when (ex is not OperationCanceledException)
+            {
+                _logger.LogError(ex,
+                    "Error during Moonraker printer sync cycle — will retry in {Interval}",
+                    _options.PollingInterval);
+            }
+
+            await Task.Delay(_options.PollingInterval, stoppingToken);
+        }
+
+        _logger.LogInformation("Moonraker printer sync job shutting down");
+    }
+}

backend/API/Validators/FilamentValidators.cs

@@ -10,6 +10,9 @@ namespace Extrudex.API.Validators;
 /// </summary>
 public class CreateFilamentRequestValidator : AbstractValidator<CreateFilamentRequest>
 {
+    /// <summary>
+    /// Initializes validation rules for <see cref="CreateFilamentRequest"/>.
+    /// </summary>
     public CreateFilamentRequestValidator()
     {
         RuleFor(x => x.MaterialBaseId)
@@ -52,6 +55,12 @@ public class CreateFilamentRequestValidator : AbstractValidator<CreateFilamentRe
             RuleFor(x => x.PurchasePrice!.Value)
                 .GreaterThanOrEqualTo(0).WithMessage("Purchase price must be non-negative.");
         });
+
+        When(x => x.StorageLocation != null, () =>
+        {
+            RuleFor(x => x.StorageLocation!)
+                .MaximumLength(200).WithMessage("StorageLocation must not exceed 200 characters.");
+        });
     }
 }
 
@@ -62,6 +71,9 @@ public class CreateFilamentRequestValidator : AbstractValidator<CreateFilamentRe
 /// </summary>
 public class UpdateFilamentRequestValidator : AbstractValidator<UpdateFilamentRequest>
 {
+    /// <summary>
+    /// Initializes validation rules for <see cref="UpdateFilamentRequest"/>.
+    /// </summary>
     public UpdateFilamentRequestValidator()
     {
         RuleFor(x => x.MaterialBaseId)
@@ -104,5 +116,11 @@ public class UpdateFilamentRequestValidator : AbstractValidator<UpdateFilamentRe
             RuleFor(x => x.PurchasePrice!.Value)
                 .GreaterThanOrEqualTo(0).WithMessage("Purchase price must be non-negative.");
         });
+
+        When(x => x.StorageLocation != null, () =>
+        {
+            RuleFor(x => x.StorageLocation!)
+                .MaximumLength(200).WithMessage("StorageLocation must not exceed 200 characters.");
+        });
     }
 }

backend/Dockerfile

@@ -17,6 +17,9 @@ RUN dotnet publish Extrudex.csproj \
 FROM mcr.microsoft.com/dotnet/aspnet:9.0 AS runtime
 WORKDIR /app
 
+# Install curl for health check (not included in aspnet base image)
+RUN apt-get update && apt-get install -y --no-install-recommends curl && rm -rf /var/lib/apt/lists/*
+
 # Non-root user for security
 RUN adduser --disabled-password --gecos "" appuser
 USER appuser

backend/Domain/DTOs/Moonraker/MoonrakerDisplayStatus.cs

@@ -0,0 +1,19 @@
+namespace Extrudex.Domain.DTOs.Moonraker;
+
+/// <summary>
+/// Response DTO for Moonraker /printer/objects/query?display_status endpoint.
+/// Contains progress percentage and message for the current print job.
+/// Used by the SignalR hub to push real-time progress to connected clients.
+/// </summary>
+public class MoonrakerDisplayStatus
+{
+    /// <summary>
+    /// Print progress as a decimal between 0 and 1 (0% to 100%).
+    /// </summary>
+    public decimal Progress { get; set; }
+
+    /// <summary>
+    /// Status message displayed on the printer LCD (e.g., "Printing...", "Heating...").
+    /// </summary>
+    public string Message { get; set; } = string.Empty;
+}

backend/Domain/DTOs/Moonraker/MoonrakerHistoryResponse.cs

@@ -0,0 +1,20 @@
+namespace Extrudex.Domain.DTOs.Moonraker;
+
+/// <summary>
+/// Response DTO for the Moonraker /server/history/items endpoint.
+/// Wraps the paginated list of print job history items.
+/// </summary>
+public class MoonrakerHistoryResponse
+{
+    /// <summary>
+    /// The list of print job history items returned by Moonraker.
+    /// Most recent jobs appear first (descending by start time).
+    /// </summary>
+    public List<MoonrakerPrintJob> Items { get; set; } = [];
+
+    /// <summary>
+    /// Total number of print jobs available on the server
+    /// (for pagination; the Items list may be a subset).
+    /// </summary>
+    public int TotalCount { get; set; }
+}

backend/Domain/DTOs/Moonraker/MoonrakerPrintJob.cs

@@ -0,0 +1,56 @@
+namespace Extrudex.Domain.DTOs.Moonraker;
+
+/// <summary>
+/// Response DTO for a single Moonraker print job history item.
+/// Maps to the objects returned by /server/history/items.
+/// Contains filament usage, duration, and status for a completed or active print.
+/// </summary>
+public class MoonrakerPrintJob
+{
+    /// <summary>
+    /// Unique Moonraker job identifier (e.g., "000001").
+    /// </summary>
+    public string JobId { get; set; } = string.Empty;
+
+    /// <summary>
+    /// Filename of the G-code file that was printed.
+    /// </summary>
+    public string Filename { get; set; } = string.Empty;
+
+    /// <summary>
+    /// Current status of this print job: "completed", "cancelled", "error", "in_progress".
+    /// </summary>
+    public string Status { get; set; } = string.Empty;
+
+    /// <summary>
+    /// Total filament used in millimeters for this print job.
+    /// This is the primary measurement; grams are derived from this value.
+    /// </summary>
+    public decimal FilamentUsedMm { get; set; }
+
+    /// <summary>
+    /// Total print duration in seconds.
+    /// </summary>
+    public decimal PrintDurationSeconds { get; set; }
+
+    /// <summary>
+    /// Total print duration including setup and warmup, in seconds.
+    /// </summary>
+    public decimal TotalDurationSeconds { get; set; }
+
+    /// <summary>
+    /// Timestamp when the print job started (UTC).
+    /// </summary>
+    public DateTime? StartTime { get; set; }
+
+    /// <summary>
+    /// Timestamp when the print job ended (UTC). Null if still in progress.
+    /// </summary>
+    public DateTime? EndTime { get; set; }
+
+    /// <summary>
+    /// Metadata dictionary from Moonraker. May contain filament_type,
+    /// filament_name, nozzle_diameter, and other slicer-provided fields.
+    /// </summary>
+    public Dictionary<string, object> Metadata { get; set; } = new();
+}

backend/Domain/DTOs/Moonraker/MoonrakerPrintStats.cs

@@ -0,0 +1,36 @@
+namespace Extrudex.Domain.DTOs.Moonraker;
+
+/// <summary>
+/// Response DTO for Moonraker /printer/objects/query?print_stats endpoint.
+/// Contains real-time print statistics including current job state,
+    /// filament consumed, and file being printed.
+/// </summary>
+public class MoonrakerPrintStats
+{
+    /// <summary>
+    /// Current print state: "standby", "printing", "paused", "complete", "error", "cancelled".
+    /// </summary>
+    public string State { get; set; } = string.Empty;
+
+    /// <summary>
+    /// Total filament used in millimeters for the current print session.
+    /// </summary>
+    public decimal FilamentUsedMm { get; set; }
+
+    /// <summary>
+    /// Total print duration in seconds for the current print session.
+    /// </summary>
+    public decimal PrintDurationSeconds { get; set; }
+
+    /// <summary>
+    /// Filename of the G-code file currently being printed.
+    /// Null if no print is active.
+    /// </summary>
+    public string? Filename { get; set; }
+
+    /// <summary>
+    /// Detailed message from Klipper about the current print state.
+    /// May contain error details when state is "error".
+    /// </summary>
+    public string? Message { get; set; }
+}

backend/Domain/DTOs/Moonraker/MoonrakerPrinterInfo.cs

@@ -0,0 +1,26 @@
+namespace Extrudex.Domain.DTOs.Moonraker;
+
+/// <summary>
+/// Response DTO for the Moonraker /printer/info endpoint.
+/// Contains the current operational state of the Klipper printer.
+/// Used to determine whether the printer is idle, printing, paused, or in error.
+/// </summary>
+public class MoonrakerPrinterInfo
+{
+    /// <summary>
+    /// Current Klipper state: "ready", "startup", "shutdown", "error", "cancelled".
+    /// A "ready" state means the printer is connected and idle.
+    /// </summary>
+    public string State { get; set; } = string.Empty;
+
+    /// <summary>
+    /// Detailed state message from Klipper. May contain error details
+    /// when the state is "error" or "shutdown".
+    /// </summary>
+    public string StateMessage { get; set; } = string.Empty;
+
+    /// <summary>
+    /// Whether the Klipper firmware is currently connected and responsive.
+    /// </summary>
+    public bool KlippyReady { get; set; }
+}

backend/Domain/DTOs/Moonraker/MoonrakerRequest.cs

@@ -0,0 +1,25 @@
+namespace Extrudex.Domain.DTOs.Moonraker;
+
+/// <summary>
+/// Request DTO for querying the Moonraker API.
+/// Encapsulates the connection parameters needed to reach a specific
+/// Moonraker instance on a Klipper-based printer.
+/// </summary>
+public class MoonrakerRequest
+{
+    /// <summary>
+    /// Hostname or IP address of the Moonraker printer.
+    /// </summary>
+    public string HostnameOrIp { get; set; } = string.Empty;
+
+    /// <summary>
+    /// Port number for the Moonraker API. Default: 7125.
+    /// </summary>
+    public int Port { get; set; } = 7125;
+
+    /// <summary>
+    /// Optional API key for authenticating with Moonraker.
+    /// Required when the server has API key authentication enabled.
+    /// </summary>
+    public string? ApiKey { get; set; }
+}

backend/Domain/DTOs/Moonraker/MoonrakerServerInfo.cs

@@ -0,0 +1,44 @@
+namespace Extrudex.Domain.DTOs.Moonraker;
+
+/// <summary>
+/// Response DTO for the Moonraker /server/info endpoint.
+/// Contains server identification and operational state.
+/// Used to verify connectivity and determine Moonraker version.
+/// </summary>
+public class MoonrakerServerInfo
+{
+    /// <summary>
+    /// The hostname of the Moonraker server (e.g., "mainsail").
+    /// </summary>
+    public string Hostname { get; set; } = string.Empty;
+
+    /// <summary>
+    /// Moonraker software version string (e.g., "0.8.0-89ee464").
+    /// </summary>
+    public string SoftwareVersion { get; set; } = string.Empty;
+
+    /// <summary>
+    /// CPU model string reported by the host system.
+    /// </summary>
+    public string CpuInfo { get; set; } = string.Empty;
+
+    /// <summary>
+    /// Whether Klipper is currently connected to the MCU.
+    /// </summary>
+    public bool KlippyConnected { get; set; }
+
+    /// <summary>
+    /// The current Klipper state (e.g., "ready", "startup", "error").
+    /// </summary>
+    public string KlippyState { get; set; } = string.Empty;
+
+    /// <summary>
+    /// Whether the Moonraker API requires an authentication token.
+    /// </summary>
+    public bool ApiKeyRequired { get; set; }
+
+    /// <summary>
+    /// List of registered Moonraker plugin names.
+    /// </summary>
+    public List<string> Plugins { get; set; } = [];
+}

backend/Domain/Entities/Spool.cs

@@ -93,6 +93,20 @@ public class Spool : AuditableEntity
     /// </summary>
     public bool IsActive { get; set; } = true;
 
+    /// <summary>
+    /// Whether the spool has been archived (removed from active inventory).
+    /// Archived spools are retained for historical records but hidden from
+    /// default inventory views. Distinguishes long-term archival from
+    /// temporary inactivity (e.g., spool swapped out of AMS).
+    /// </summary>
+    public bool IsArchived { get; set; } = false;
+
+    /// <summary>
+    /// Physical storage location of the spool (e.g., "Shelf A", "Drawer 3", "AMS Tray 2").
+    /// Optional — not every spool has a designated storage location.
+    /// </summary>
+    public string? StorageLocation { get; set; }
+
     /// <summary>
     /// Navigation collection of AMS slots where this spool is loaded.
     /// </summary>

backend/Domain/Entities/UsageLog.cs

@@ -0,0 +1,72 @@
+using Extrudex.Domain.Base;
+using Extrudex.Domain.Enums;
+
+namespace Extrudex.Domain.Entities;
+
+/// <summary>
+/// Represents a single filament usage log entry. Records how much filament
+/// was consumed, by which printer, at what time, and optionally linked to
+/// a print job. This provides a fine-grained audit trail of filament consumption
+/// independent of print job lifecycle.
+/// </summary>
+public class UsageLog : AuditableEntity
+{
+    /// <summary>
+    /// Foreign key to the spool that provided the filament.
+    /// </summary>
+    public Guid SpoolId { get; set; }
+
+    /// <summary>
+    /// Navigation to the spool that provided the filament.
+    /// </summary>
+    public Spool Spool { get; set; } = null!;
+
+    /// <summary>
+    /// Foreign key to the printer that consumed the filament.
+    /// Nullable to support manual entries without a specific printer.
+    /// </summary>
+    public Guid? PrinterId { get; set; }
+
+    /// <summary>
+    /// Navigation to the printer that consumed the filament.
+    /// </summary>
+    public Printer? Printer { get; set; }
+
+    /// <summary>
+    /// Foreign key to the print job associated with this usage entry.
+    /// Nullable because usage can be logged before or without a print job.
+    /// </summary>
+    public Guid? PrintJobId { get; set; }
+
+    /// <summary>
+    /// Navigation to the print job associated with this usage entry.
+    /// </summary>
+    public PrintJob? PrintJob { get; set; }
+
+    /// <summary>
+    /// The number of grams of filament consumed in this usage event.
+    /// </summary>
+    public decimal GramsUsed { get; set; }
+
+    /// <summary>
+    /// The number of millimeters of filament extruded in this usage event.
+    /// Optional — may not be available for all data sources.
+    /// </summary>
+    public decimal? MmExtruded { get; set; }
+
+    /// <summary>
+    /// Timestamp when the usage occurred (UTC). This is the actual time of
+    /// consumption, which may differ from CreatedAt if the entry was recorded later.
+    /// </summary>
+    public DateTime UsageTimestamp { get; set; } = DateTime.UtcNow;
+
+    /// <summary>
+    /// The source of the usage data (which integration path provided it).
+    /// </summary>
+    public DataSource DataSource { get; set; } = DataSource.Manual;
+
+    /// <summary>
+    /// Optional notes about this usage entry.
+    /// </summary>
+    public string? Notes { get; set; }
+}

backend/Domain/Interfaces/ICostPerPrintService.cs

@@ -0,0 +1,76 @@
+namespace Extrudex.Domain.Interfaces;
+
+/// <summary>
+/// Service interface for calculating the cost of goods sold (COGS) per print job.
+/// Uses the spool's purchase price and the print job's derived grams consumed
+/// to produce a cost breakdown. Handles missing cost data gracefully by returning
+/// warnings rather than throwing exceptions.
+/// </summary>
+public interface ICostPerPrintService
+{
+    /// <summary>
+    /// Calculates the cost per print for a specific print job.
+    /// </summary>
+    /// <param name="printJobId">The unique identifier of the print job.</param>
+    /// <param name="cancellationToken">Optional cancellation token.</param>
+    /// <returns>
+    /// A <see cref="CostPerPrintResult"/> containing the cost breakdown,
+    /// or warnings if cost data is missing or incomplete.
+    /// </returns>
+    Task<CostPerPrintResult> CalculateAsync(Guid printJobId, CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// Calculates cost breakdowns for all print jobs associated with a specific spool.
+    /// Useful for spool-level COGS reporting.
+    /// </summary>
+    /// <param name="spoolId">The unique identifier of the spool.</param>
+    /// <param name="cancellationToken">Optional cancellation token.</param>
+    /// <returns>
+    /// A list of <see cref="CostPerPrintResult"/> for each print job on the spool.
+    /// Jobs with missing cost data will include warnings.
+    /// </returns>
+    Task<IReadOnlyList<CostPerPrintResult>> CalculateBySpoolAsync(Guid spoolId, CancellationToken cancellationToken = default);
+}
+
+/// <summary>
+/// Result of a cost-per-print calculation. Contains the cost breakdown
+/// and any warnings about missing or incomplete cost data.
+/// </summary>
+public class CostPerPrintResult
+{
+    /// <summary>The print job identifier this result belongs to.</summary>
+    public Guid PrintJobId { get; set; }
+
+    /// <summary>Human-readable name of the print job.</summary>
+    public string PrintName { get; set; } = string.Empty;
+
+    /// <summary>The spool identifier that provided filament.</summary>
+    public Guid SpoolId { get; set; }
+
+    /// <summary>Serial number of the spool.</summary>
+    public string SpoolSerial { get; set; } = string.Empty;
+
+    /// <summary>Total millimeters of filament extruded.</summary>
+    public decimal MmExtruded { get; set; }
+
+    /// <summary>Derived grams consumed for this print.</summary>
+    public decimal GramsDerived { get; set; }
+
+    /// <summary>The spool's purchase price. Null if not recorded.</summary>
+    public decimal? PurchasePrice { get; set; }
+
+    /// <summary>The spool's total weight in grams when full.</summary>
+    public decimal? WeightTotalGrams { get; set; }
+
+    /// <summary>Cost per gram of filament. Null if purchase price or total weight is missing.</summary>
+    public decimal? CostPerGram { get; set; }
+
+    /// <summary>Calculated cost of this print job. Null if cost data is incomplete.</summary>
+    public decimal? CostPerPrint { get; set; }
+
+    /// <summary>
+    /// Warnings about missing or incomplete data that prevented a full calculation.
+    /// Empty when all data is available and the calculation succeeded.
+    /// </summary>
+    public List<string> Warnings { get; set; } = new();
+}

backend/Domain/Interfaces/IFilamentUsageService.cs

@@ -0,0 +1,50 @@
+using Extrudex.Domain.Entities;
+
+namespace Extrudex.Domain.Interfaces;
+
+/// <summary>
+/// Service for persisting and querying filament usage records.
+/// Tracks consumption per print job and per spool for COGS and inventory tracking.
+/// </summary>
+public interface IFilamentUsageService
+{
+    /// <summary>
+    /// Records a new filament usage entry for a print job.
+    /// </summary>
+    /// <param name="printJobId">The print job that consumed the filament.</param>
+    /// <param name="spoolId">The spool that provided the filament.</param>
+    /// <param name="printerId">The printer that executed the print.</param>
+    /// <param name="gramsUsed">Grams of filament consumed.</param>
+    /// <param name="mmExtruded">Millimeters of filament extruded.</param>
+    /// <param name="notes">Optional notes about this usage record.</param>
+    /// <param name="cancellationToken">Cancellation token.</param>
+    /// <returns>The created FilamentUsage entity.</returns>
+    Task<FilamentUsage> RecordUsageAsync(
+        Guid printJobId,
+        Guid spoolId,
+        Guid printerId,
+        decimal gramsUsed,
+        decimal mmExtruded,
+        string? notes = null,
+        CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// Retrieves all filament usage records for a specific print job.
+    /// </summary>
+    /// <param name="printJobId">The print job ID.</param>
+    /// <param name="cancellationToken">Cancellation token.</param>
+    /// <returns>Collection of filament usage records for the print job.</returns>
+    Task<IReadOnlyList<FilamentUsage>> GetByPrintJobAsync(
+        Guid printJobId,
+        CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// Retrieves all filament usage records for a specific spool.
+    /// </summary>
+    /// <param name="spoolId">The spool ID.</param>
+    /// <param name="cancellationToken">Cancellation token.</param>
+    /// <returns>Collection of filament usage records for the spool.</returns>
+    Task<IReadOnlyList<FilamentUsage>> GetBySpoolAsync(
+        Guid spoolId,
+        CancellationToken cancellationToken = default);
+}

backend/Domain/Interfaces/IFilamentUsageSyncService.cs

@@ -0,0 +1,19 @@
+namespace Extrudex.Domain.Interfaces;
+
+/// <summary>
+/// Service interface for syncing filament usage data from printers
+/// into the Extrudex database. Handles querying Moonraker printers,
+/// computing derived usage metrics, and persisting updates to spools
+/// and print job records.
+/// </summary>
+public interface IFilamentUsageSyncService
+{
+    /// <summary>
+    /// Performs a single sync cycle: queries all active Moonraker printers,
+    /// fetches their current filament usage data, and persists updates to
+    /// the database.
+    /// </summary>
+    /// <param name="cancellationToken">Cancellation token for graceful shutdown.</param>
+    /// <returns>The number of printers successfully synced.</returns>
+    Task<int> SyncAllAsync(CancellationToken cancellationToken = default);
+}

backend/Domain/Interfaces/ILowStockDetector.cs

@@ -0,0 +1,39 @@
+namespace Extrudex.Domain.Interfaces;
+
+/// <summary>
+/// Detects low-stock filament spools based on configurable weight thresholds.
+/// Determines whether a spool's remaining filament falls below a critical level
+/// so that alerts and API flags can be surfaced to the user.
+/// </summary>
+public interface ILowStockDetector
+{
+    /// <summary>
+    /// Determines whether a spool is considered low stock based on its remaining
+    /// weight relative to its total weight and the configured threshold percentage.
+    /// </summary>
+    /// <param name="weightRemainingGrams">The current remaining weight in grams.</param>
+    /// <param name="weightTotalGrams">The total spool weight in grams when full.</param>
+    /// <returns>
+    /// <c>true</c> if the remaining weight percentage is at or below the configured
+    /// low-stock threshold; <c>false</c> otherwise. Returns <c>false</c> for spools
+    /// with zero total weight to avoid division-by-zero.
+    /// </returns>
+    bool IsLowStock(decimal weightRemainingGrams, decimal weightTotalGrams);
+
+    /// <summary>
+    /// Calculates the remaining weight as a percentage of total weight.
+    /// </summary>
+    /// <param name="weightRemainingGrams">The current remaining weight in grams.</param>
+    /// <param name="weightTotalGrams">The total spool weight in grams when full.</param>
+    /// <returns>
+    /// A value between 0 and 100 representing the percentage of filament remaining.
+    /// Returns 0 if total weight is zero to avoid division-by-zero.
+    /// </returns>
+    decimal GetRemainingWeightPercent(decimal weightRemainingGrams, decimal weightTotalGrams);
+
+    /// <summary>
+    /// Gets the currently configured low-stock threshold percentage.
+    /// Useful for API responses so clients know what threshold is in effect.
+    /// </summary>
+    decimal LowStockThresholdPercent { get; }
+}

backend/Domain/Interfaces/IMoonrakerClient.cs

@@ -0,0 +1,131 @@
+using Extrudex.Domain.DTOs.Moonraker;
+
+namespace Extrudex.Domain.Interfaces;
+
+/// <summary>
+/// Client interface for communicating with Moonraker REST API endpoints
+/// on Klipper-based printers (e.g., Elegoo Centauri Carbon).
+/// Provides strongly-typed methods for server discovery, printer status,
+/// print job history, and real-time telemetry.
+/// </summary>
+public interface IMoonrakerClient
+{
+    /// <summary>
+    /// Checks whether the Moonraker server is reachable and responding.
+    /// Calls the /server/info endpoint and returns the server information
+    /// if successful, or null if the server is unreachable.
+    /// </summary>
+    /// <param name="hostnameOrIp">The printer's hostname or IP address.</param>
+    /// <param name="port">The Moonraker API port (default: 7125).</param>
+    /// <param name="apiKey">Optional API key for authentication.</param>
+    /// <param name="cancellationToken">Cancellation token for the HTTP request.</param>
+    /// <returns>Server info if reachable; <c>null</c> if unreachable.</returns>
+    Task<MoonrakerServerInfo?> GetServerInfoAsync(
+        string hostnameOrIp,
+        int port,
+        string? apiKey,
+        CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// Checks whether the Moonraker server is reachable and responding.
+    /// This is a convenience method equivalent to calling GetServerInfoAsync
+    /// and checking for a non-null result.
+    /// </summary>
+    /// <param name="hostnameOrIp">The printer's hostname or IP address.</param>
+    /// <param name="port">The Moonraker API port (default: 7125).</param>
+    /// <param name="apiKey">Optional API key for authentication.</param>
+    /// <param name="cancellationToken">Cancellation token for the HTTP request.</param>
+    /// <returns><c>true</c> if the server responded successfully; otherwise <c>false</c>.</returns>
+    Task<bool> IsReachableAsync(
+        string hostnameOrIp,
+        int port,
+        string? apiKey,
+        CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// Fetches the current printer info from the /printer/info endpoint.
+    /// Returns the Klipper state and readiness status.
+    /// </summary>
+    /// <param name="hostnameOrIp">The printer's hostname or IP address.</param>
+    /// <param name="port">The Moonraker API port (default: 7125).</param>
+    /// <param name="apiKey">Optional API key for authentication.</param>
+    /// <param name="cancellationToken">Cancellation token for the HTTP request.</param>
+    /// <returns>Printer info if successful; <c>null</c> if the request failed.</returns>
+    Task<MoonrakerPrinterInfo?> GetPrinterInfoAsync(
+        string hostnameOrIp,
+        int port,
+        string? apiKey,
+        CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// Fetches print job history from the /server/history/items endpoint.
+    /// Returns the most recent print jobs with filament usage data,
+    /// print duration, and completion status.
+    /// </summary>
+    /// <param name="hostnameOrIp">The printer's hostname or IP address.</param>
+    /// <param name="port">The Moonraker API port (default: 7125).</param>
+    /// <param name="apiKey">Optional API key for authentication.</param>
+    /// <param name="limit">Maximum number of history items to return. Default: 50.</param>
+    /// <param name="cancellationToken">Cancellation token for the HTTP request.</param>
+    /// <returns>History response with print jobs; empty list if request failed.</returns>
+    Task<MoonrakerHistoryResponse> GetPrintHistoryAsync(
+        string hostnameOrIp,
+        int port,
+        string? apiKey,
+        int limit = 50,
+        CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// Fetches the current print statistics from the /printer/objects/query endpoint.
+    /// Returns real-time data including filament used, print duration,
+    /// and current print state for the active or most recent print.
+    /// </summary>
+    /// <param name="hostnameOrIp">The printer's hostname or IP address.</param>
+    /// <param name="port">The Moonraker API port (default: 7125).</param>
+    /// <param name="apiKey">Optional API key for authentication.</param>
+    /// <param name="cancellationToken">Cancellation token for the HTTP request.</param>
+    /// <returns>Print stats if successful; <c>null</c> if the request failed.</returns>
+    Task<MoonrakerPrintStats?> GetPrintStatsAsync(
+        string hostnameOrIp,
+        int port,
+        string? apiKey,
+        CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// Fetches the current display status from the /printer/objects/query endpoint.
+    /// Returns progress percentage and status message for the active print.
+    /// Used by SignalR to push real-time progress updates to connected clients.
+    /// </summary>
+    /// <param name="hostnameOrIp">The printer's hostname or IP address.</param>
+    /// <param name="port">The Moonraker API port (default: 7125).</param>
+    /// <param name="apiKey">Optional API key for authentication.</param>
+    /// <param name="cancellationToken">Cancellation token for the HTTP request.</param>
+    /// <returns>Display status if successful; <c>null</c> if the request failed.</returns>
+    Task<MoonrakerDisplayStatus?> GetDisplayStatusAsync(
+        string hostnameOrIp,
+        int port,
+        string? apiKey,
+        CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// Fetches the current filament usage data from the Moonraker server.
+    /// Returns a dictionary of usage metrics reported by the printer.
+    /// 
+    /// <para>
+    /// <b>Prefer GetPrintHistoryAsync or GetPrintStatsAsync for new code.</b>
+    /// This method is retained for backward compatibility with the
+    /// FilamentUsageSyncService and returns a dictionary of metric names
+    /// to their decimal values for callers that don't need typed DTOs.
+    /// </para>
+    /// </summary>
+    /// <param name="hostnameOrIp">The printer's hostname or IP address.</param>
+    /// <param name="port">The Moonraker API port (default: 7125).</param>
+    /// <param name="apiKey">Optional API key for authentication.</param>
+    /// <param name="cancellationToken">Cancellation token for the HTTP request.</param>
+    /// <returns>A dictionary of usage metric names to their decimal values.</returns>
+    Task<Dictionary<string, decimal>> GetFilamentUsageAsync(
+        string hostnameOrIp,
+        int port,
+        string? apiKey,
+        CancellationToken cancellationToken = default);
+}

backend/Domain/Interfaces/IMoonrakerPrinterSyncService.cs

@@ -0,0 +1,20 @@
+using Extrudex.Domain.DTOs.Moonraker;
+
+namespace Extrudex.Domain.Interfaces;
+
+/// <summary>
+/// Service interface for syncing Moonraker printer data into the Extrudex database.
+/// Handles periodic polling of printer status and mapping print job history
+/// to PrintJob and FilamentUsage entities.
+/// </summary>
+public interface IMoonrakerPrinterSyncService
+{
+    /// <summary>
+    /// Performs a single sync cycle: queries all active Moonraker printers,
+    /// fetches their current status and print job history, and persists
+    /// updates to the database.
+    /// </summary>
+    /// <param name="cancellationToken">Cancellation token for graceful shutdown.</param>
+    /// <returns>The number of printers successfully synced.</returns>
+    Task<int> SyncAllAsync(CancellationToken cancellationToken = default);
+}

backend/Domain/Interfaces/IUsageLogService.cs

@@ -0,0 +1,57 @@
+using Extrudex.Domain.Entities;
+using Extrudex.Domain.Enums;
+
+namespace Extrudex.Domain.Interfaces;
+
+/// <summary>
+/// Service for recording filament usage entries. Writes to the usage_logs table
+/// and provides query capabilities for usage history.
+/// </summary>
+public interface IUsageLogService
+{
+    /// <summary>
+    /// Records a filament usage entry.
+    /// </summary>
+    /// <param name="spoolId">The spool that provided the filament.</param>
+    /// <param name="gramsUsed">Grams of filament consumed.</param>
+    /// <param name="dataSource">Where the data came from.</param>
+    /// <param name="printerId">Optional printer ID.</param>
+    /// <param name="printJobId">Optional print job ID.</param>
+    /// <param name="mmExtruded">Optional mm extruded.</param>
+    /// <param name="usageTimestamp">When the usage occurred (defaults to UTC now).</param>
+    /// <param name="notes">Optional notes.</param>
+    /// <returns>The created UsageLog entity.</returns>
+    Task<UsageLog> RecordUsageAsync(
+        Guid spoolId,
+        decimal gramsUsed,
+        DataSource dataSource,
+        Guid? printerId = null,
+        Guid? printJobId = null,
+        decimal? mmExtruded = null,
+        DateTime? usageTimestamp = null,
+        string? notes = null);
+
+    /// <summary>
+    /// Retrieves usage logs for a specific spool, ordered by usage timestamp descending.
+    /// </summary>
+    /// <param name="spoolId">The spool ID to filter by.</param>
+    /// <param name="cancellationToken">Cancellation token.</param>
+    /// <returns>A collection of usage logs for the spool.</returns>
+    Task<IEnumerable<UsageLog>> GetBySpoolAsync(Guid spoolId, CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// Retrieves usage logs for a specific printer, ordered by usage timestamp descending.
+    /// </summary>
+    /// <param name="printerId">The printer ID to filter by.</param>
+    /// <param name="cancellationToken">Cancellation token.</param>
+    /// <returns>A collection of usage logs for the printer.</returns>
+    Task<IEnumerable<UsageLog>> GetByPrinterAsync(Guid printerId, CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// Retrieves usage logs for a specific print job, ordered by usage timestamp descending.
+    /// </summary>
+    /// <param name="printJobId">The print job ID to filter by.</param>
+    /// <param name="cancellationToken">Cancellation token.</param>
+    /// <returns>A collection of usage logs for the print job.</returns>
+    Task<IEnumerable<UsageLog>> GetByPrintJobAsync(Guid printJobId, CancellationToken cancellationToken = default);
+}

backend/Infrastructure/Configuration/FilamentUsageSyncOptions.cs

@@ -0,0 +1,33 @@
+namespace Extrudex.Infrastructure.Configuration;
+
+/// <summary>
+/// Configuration options for the FilamentUsageSync background job.
+/// Bound from appsettings.json under the "FilamentUsageSync" section.
+/// Controls polling interval and per-printer timeout settings.
+/// </summary>
+public class FilamentUsageSyncOptions
+{
+    /// <summary>
+    /// The section name in appsettings.json where these options are bound.
+    /// </summary>
+    public const string SectionName = "FilamentUsageSync";
+
+    /// <summary>
+    /// How often the background job polls printers for usage data.
+    /// Default: 5 minutes. Minimum recommended: 1 minute.
+    /// </summary>
+    public TimeSpan PollingInterval { get; set; } = TimeSpan.FromMinutes(5);
+
+    /// <summary>
+    /// Timeout for individual HTTP requests to a Moonraker printer.
+    /// Default: 30 seconds.
+    /// </summary>
+    public TimeSpan RequestTimeout { get; set; } = TimeSpan.FromSeconds(30);
+
+    /// <summary>
+    /// Whether the sync job is enabled. Set to false to disable
+    /// the background job without removing its registration.
+    /// Default: true.
+    /// </summary>
+    public bool Enabled { get; set; } = true;
+}

backend/Infrastructure/Configuration/MoonrakerPrinterSyncOptions.cs

@@ -0,0 +1,41 @@
+namespace Extrudex.Infrastructure.Configuration;
+
+/// <summary>
+/// Configuration options for the MoonrakerPrinterSync background service.
+/// Bound from appsettings.json under the "MoonrakerPrinterSync" section.
+/// Controls polling interval, timeouts, and feature toggles for the
+/// printer status and print job mapping service.
+/// </summary>
+public class MoonrakerPrinterSyncOptions
+{
+    /// <summary>
+    /// The section name in appsettings.json where these options are bound.
+    /// </summary>
+    public const string SectionName = "MoonrakerPrinterSync";
+
+    /// <summary>
+    /// How often the background service polls Moonraker printers for status
+    /// and print job data. Default: 1 minute.
+    /// </summary>
+    public TimeSpan PollingInterval { get; set; } = TimeSpan.FromMinutes(1);
+
+    /// <summary>
+    /// Timeout for individual HTTP requests to a Moonraker printer.
+    /// Default: 15 seconds.
+    /// </summary>
+    public TimeSpan RequestTimeout { get; set; } = TimeSpan.FromSeconds(15);
+
+    /// <summary>
+    /// Whether the Moonraker printer sync service is enabled.
+    /// Set to false to disable without removing the service registration.
+    /// Default: true.
+    /// </summary>
+    public bool Enabled { get; set; } = true;
+
+    /// <summary>
+    /// Maximum number of print history items to fetch per printer per sync cycle.
+    /// Controls the batch size when syncing print jobs from Moonraker.
+    /// Default: 25.
+    /// </summary>
+    public int HistoryBatchSize { get; set; } = 25;
+}

backend/Infrastructure/Data/Configurations/SpoolConfiguration.cs

@@ -68,6 +68,15 @@ public class SpoolConfiguration : BaseEntityConfiguration<Spool>
             .HasDefaultValue(true)
             .IsRequired();
 
+        builder.Property(e => e.IsArchived)
+            .HasColumnName("is_archived")
+            .HasDefaultValue(false)
+            .IsRequired();
+
+        builder.Property(e => e.StorageLocation)
+            .HasColumnName("storage_location")
+            .HasMaxLength(200);
+
         // Unique index on spool_serial — critical for barcode/QR scanning
         builder.HasIndex(e => e.SpoolSerial)
             .IsUnique()
@@ -89,6 +98,14 @@ public class SpoolConfiguration : BaseEntityConfiguration<Spool>
         builder.HasIndex(e => e.IsActive)
             .HasDatabaseName("ix_spools_is_active");
 
+        // Index on is_archived for inventory filtering (exclude archived from default views)
+        builder.HasIndex(e => e.IsArchived)
+            .HasDatabaseName("ix_spools_is_archived");
+
+        // Composite index on is_active + is_archived for common inventory queries
+        builder.HasIndex(e => new { e.IsActive, e.IsArchived })
+            .HasDatabaseName("ix_spools_active_archived");
+
         // Relationships
         builder.HasOne(e => e.MaterialBase)
             .WithMany(e => e.Spools)

backend/Infrastructure/Data/Configurations/UsageLogConfiguration.cs

@@ -0,0 +1,91 @@
+using Extrudex.Domain.Entities;
+using Extrudex.Domain.Enums;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Metadata.Builders;
+
+namespace Extrudex.Infrastructure.Data.Configurations;
+
+/// <summary>
+/// EF Core configuration for the UsageLog entity.
+/// Maps to the usage_logs table with snake_case columns and appropriate indexes.
+/// </summary>
+public class UsageLogConfiguration : BaseEntityConfiguration<UsageLog>
+{
+    /// <inheritdoc/>
+    public override void Configure(EntityTypeBuilder<UsageLog> builder)
+    {
+        base.Configure(builder);
+
+        builder.Property(e => e.SpoolId)
+            .HasColumnName("spool_id")
+            .IsRequired();
+
+        builder.Property(e => e.PrinterId)
+            .HasColumnName("printer_id");
+
+        builder.Property(e => e.PrintJobId)
+            .HasColumnName("print_job_id");
+
+        builder.Property(e => e.GramsUsed)
+            .HasColumnName("grams_used")
+            .HasPrecision(10, 2)
+            .IsRequired();
+
+        builder.Property(e => e.MmExtruded)
+            .HasColumnName("mm_extruded")
+            .HasPrecision(12, 2);
+
+        builder.Property(e => e.UsageTimestamp)
+            .HasColumnName("usage_timestamp")
+            .IsRequired();
+
+        builder.Property(e => e.DataSource)
+            .HasColumnName("data_source")
+            .HasConversion<string>()
+            .HasMaxLength(50)
+            .IsRequired();
+
+        builder.Property(e => e.Notes)
+            .HasColumnName("notes")
+            .HasMaxLength(2000);
+
+        // Index on spool_id for querying usage by spool
+        builder.HasIndex(e => e.SpoolId)
+            .HasDatabaseName("ix_usage_logs_spool_id");
+
+        // Index on printer_id for querying usage by printer
+        builder.HasIndex(e => e.PrinterId)
+            .HasDatabaseName("ix_usage_logs_printer_id");
+
+        // Index on print_job_id for querying usage by print job
+        builder.HasIndex(e => e.PrintJobId)
+            .HasDatabaseName("ix_usage_logs_print_job_id");
+
+        // Index on usage_timestamp for chronological queries
+        builder.HasIndex(e => e.UsageTimestamp)
+            .HasDatabaseName("ix_usage_logs_usage_timestamp");
+
+        // Index on data_source for filtering by integration path
+        builder.HasIndex(e => e.DataSource)
+            .HasDatabaseName("ix_usage_logs_data_source");
+
+        // Relationships
+        builder.HasOne(e => e.Spool)
+            .WithMany()
+            .HasForeignKey(e => e.SpoolId)
+            .HasConstraintName("fk_usage_logs_spool")
+            .OnDelete(DeleteBehavior.Restrict);
+
+        builder.HasOne(e => e.Printer)
+            .WithMany()
+            .HasForeignKey(e => e.PrinterId)
+            .HasConstraintName("fk_usage_logs_printer")
+            .OnDelete(DeleteBehavior.SetNull);
+
+        builder.HasOne(e => e.PrintJob)
+            .WithMany()
+            .HasForeignKey(e => e.PrintJobId)
+            .HasConstraintName("fk_usage_logs_print_job")
+            .OnDelete(DeleteBehavior.SetNull);
+    }
+}

backend/Infrastructure/Data/ExtrudexDbContext.cs

@@ -24,6 +24,7 @@ public class ExtrudexDbContext : DbContext
     public DbSet<AmsSlot> AmsSlots => Set<AmsSlot>();
     public DbSet<PrintJob> PrintJobs => Set<PrintJob>();
     public DbSet<FilamentUsage> FilamentUsages => Set<FilamentUsage>();
+    public DbSet<UsageLog> UsageLogs => Set<UsageLog>();
 
     protected override void OnModelCreating(ModelBuilder modelBuilder)
     {

backend/Infrastructure/Data/Migrations/20260426184329_AddUsageLogTable.cs

@@ -0,0 +1,534 @@
+using System;
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace Extrudex.Infrastructure.Data.Migrations
+{
+    /// <inheritdoc />
+    public partial class AddUsageLogTable : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.CreateTable(
+                name: "usage_logs",
+                columns: table => new
+                {
+                    id = table.Column<Guid>(type: "uuid", nullable: false),
+                    spool_id = table.Column<Guid>(type: "uuid", nullable: false),
+                    printer_id = table.Column<Guid>(type: "uuid", nullable: true),
+                    print_job_id = table.Column<Guid>(type: "uuid", nullable: true),
+                    grams_used = table.Column<decimal>(type: "numeric(10,2)", precision: 10, scale: 2, nullable: false),
+                    mm_extruded = table.Column<decimal>(type: "numeric(12,2)", precision: 12, scale: 2, nullable: true),
+                    usage_timestamp = table.Column<DateTime>(type: "timestamp with time zone", nullable: false),
+                    data_source = table.Column<string>(type: "character varying(50)", maxLength: 50, nullable: false),
+                    notes = table.Column<string>(type: "character varying(2000)", maxLength: 2000, nullable: true),
+                    created_at = table.Column<DateTime>(type: "timestamp with time zone", nullable: false, defaultValueSql: "now() at time zone 'utc'"),
+                    updated_at = table.Column<DateTime>(type: "timestamp with time zone", nullable: false, defaultValueSql: "now() at time zone 'utc'")
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_usage_logs", x => x.id);
+                    table.ForeignKey(
+                        name: "fk_usage_logs_print_job",
+                        column: x => x.print_job_id,
+                        principalTable: "print_jobs",
+                        principalColumn: "id",
+                        onDelete: ReferentialAction.SetNull);
+                    table.ForeignKey(
+                        name: "fk_usage_logs_printer",
+                        column: x => x.printer_id,
+                        principalTable: "printers",
+                        principalColumn: "id",
+                        onDelete: ReferentialAction.SetNull);
+                    table.ForeignKey(
+                        name: "fk_usage_logs_spool",
+                        column: x => x.spool_id,
+                        principalTable: "spools",
+                        principalColumn: "id",
+                        onDelete: ReferentialAction.Restrict);
+                });
+
+            migrationBuilder.UpdateData(
+                table: "material_bases",
+                keyColumn: "id",
+                keyValue: new Guid("10000000-0000-0000-0000-000000000001"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(6535), new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(6535) });
+
+            migrationBuilder.UpdateData(
+                table: "material_bases",
+                keyColumn: "id",
+                keyValue: new Guid("10000000-0000-0000-0000-000000000002"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7016), new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7016) });
+
+            migrationBuilder.UpdateData(
+                table: "material_bases",
+                keyColumn: "id",
+                keyValue: new Guid("10000000-0000-0000-0000-000000000003"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7027), new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7028) });
+
+            migrationBuilder.UpdateData(
+                table: "material_bases",
+                keyColumn: "id",
+                keyValue: new Guid("10000000-0000-0000-0000-000000000004"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7034), new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7035) });
+
+            migrationBuilder.UpdateData(
+                table: "material_bases",
+                keyColumn: "id",
+                keyValue: new Guid("10000000-0000-0000-0000-000000000005"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7042), new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7042) });
+
+            migrationBuilder.UpdateData(
+                table: "material_bases",
+                keyColumn: "id",
+                keyValue: new Guid("10000000-0000-0000-0000-000000000006"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7049), new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7049) });
+
+            migrationBuilder.UpdateData(
+                table: "material_finishes",
+                keyColumn: "id",
+                keyValue: new Guid("20000000-0000-0000-0000-000000000001"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7291), new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7292) });
+
+            migrationBuilder.UpdateData(
+                table: "material_finishes",
+                keyColumn: "id",
+                keyValue: new Guid("20000000-0000-0000-0000-000000000002"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7453), new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7453) });
+
+            migrationBuilder.UpdateData(
+                table: "material_finishes",
+                keyColumn: "id",
+                keyValue: new Guid("20000000-0000-0000-0000-000000000003"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7461), new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7461) });
+
+            migrationBuilder.UpdateData(
+                table: "material_finishes",
+                keyColumn: "id",
+                keyValue: new Guid("20000000-0000-0000-0000-000000000004"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7468), new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7468) });
+
+            migrationBuilder.UpdateData(
+                table: "material_finishes",
+                keyColumn: "id",
+                keyValue: new Guid("20000000-0000-0000-0000-000000000005"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7474), new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7474) });
+
+            migrationBuilder.UpdateData(
+                table: "material_finishes",
+                keyColumn: "id",
+                keyValue: new Guid("20000000-0000-0000-0000-000000000006"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7480), new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7481) });
+
+            migrationBuilder.UpdateData(
+                table: "material_finishes",
+                keyColumn: "id",
+                keyValue: new Guid("20000000-0000-0000-0000-000000000007"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7487), new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7487) });
+
+            migrationBuilder.UpdateData(
+                table: "material_finishes",
+                keyColumn: "id",
+                keyValue: new Guid("20000000-0000-0000-0000-000000000008"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7493), new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7493) });
+
+            migrationBuilder.UpdateData(
+                table: "material_finishes",
+                keyColumn: "id",
+                keyValue: new Guid("20000000-0000-0000-0000-000000000009"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7500), new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7500) });
+
+            migrationBuilder.UpdateData(
+                table: "material_finishes",
+                keyColumn: "id",
+                keyValue: new Guid("20000000-0000-0000-0000-000000000010"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7507), new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7507) });
+
+            migrationBuilder.UpdateData(
+                table: "material_finishes",
+                keyColumn: "id",
+                keyValue: new Guid("20000000-0000-0000-0000-000000000011"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7513), new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7513) });
+
+            migrationBuilder.UpdateData(
+                table: "material_finishes",
+                keyColumn: "id",
+                keyValue: new Guid("20000000-0000-0000-0000-000000000012"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7519), new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7520) });
+
+            migrationBuilder.UpdateData(
+                table: "material_finishes",
+                keyColumn: "id",
+                keyValue: new Guid("20000000-0000-0000-0000-000000000013"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7526), new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7526) });
+
+            migrationBuilder.UpdateData(
+                table: "material_finishes",
+                keyColumn: "id",
+                keyValue: new Guid("20000000-0000-0000-0000-000000000014"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7532), new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7532) });
+
+            migrationBuilder.UpdateData(
+                table: "material_finishes",
+                keyColumn: "id",
+                keyValue: new Guid("20000000-0000-0000-0000-000000000015"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7538), new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7539) });
+
+            migrationBuilder.UpdateData(
+                table: "material_modifiers",
+                keyColumn: "id",
+                keyValue: new Guid("30000000-0000-0000-0000-000000000001"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7690), new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7690) });
+
+            migrationBuilder.UpdateData(
+                table: "material_modifiers",
+                keyColumn: "id",
+                keyValue: new Guid("30000000-0000-0000-0000-000000000002"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7838), new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7838) });
+
+            migrationBuilder.UpdateData(
+                table: "material_modifiers",
+                keyColumn: "id",
+                keyValue: new Guid("30000000-0000-0000-0000-000000000003"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7846), new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7846) });
+
+            migrationBuilder.UpdateData(
+                table: "material_modifiers",
+                keyColumn: "id",
+                keyValue: new Guid("30000000-0000-0000-0000-000000000004"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7853), new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7853) });
+
+            migrationBuilder.UpdateData(
+                table: "material_modifiers",
+                keyColumn: "id",
+                keyValue: new Guid("30000000-0000-0000-0000-000000000005"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7859), new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7859) });
+
+            migrationBuilder.UpdateData(
+                table: "material_modifiers",
+                keyColumn: "id",
+                keyValue: new Guid("30000000-0000-0000-0000-000000000006"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7865), new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7866) });
+
+            migrationBuilder.UpdateData(
+                table: "material_modifiers",
+                keyColumn: "id",
+                keyValue: new Guid("30000000-0000-0000-0000-000000000007"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7872), new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7872) });
+
+            migrationBuilder.UpdateData(
+                table: "material_modifiers",
+                keyColumn: "id",
+                keyValue: new Guid("30000000-0000-0000-0000-000000000008"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7878), new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7879) });
+
+            migrationBuilder.UpdateData(
+                table: "material_modifiers",
+                keyColumn: "id",
+                keyValue: new Guid("30000000-0000-0000-0000-000000000009"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7885), new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7885) });
+
+            migrationBuilder.UpdateData(
+                table: "material_modifiers",
+                keyColumn: "id",
+                keyValue: new Guid("30000000-0000-0000-0000-000000000010"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7891), new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7891) });
+
+            migrationBuilder.UpdateData(
+                table: "material_modifiers",
+                keyColumn: "id",
+                keyValue: new Guid("30000000-0000-0000-0000-000000000011"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7898), new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7898) });
+
+            migrationBuilder.CreateIndex(
+                name: "ix_usage_logs_data_source",
+                table: "usage_logs",
+                column: "data_source");
+
+            migrationBuilder.CreateIndex(
+                name: "ix_usage_logs_print_job_id",
+                table: "usage_logs",
+                column: "print_job_id");
+
+            migrationBuilder.CreateIndex(
+                name: "ix_usage_logs_printer_id",
+                table: "usage_logs",
+                column: "printer_id");
+
+            migrationBuilder.CreateIndex(
+                name: "ix_usage_logs_spool_id",
+                table: "usage_logs",
+                column: "spool_id");
+
+            migrationBuilder.CreateIndex(
+                name: "ix_usage_logs_usage_timestamp",
+                table: "usage_logs",
+                column: "usage_timestamp");
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropTable(
+                name: "usage_logs");
+
+            migrationBuilder.UpdateData(
+                table: "material_bases",
+                keyColumn: "id",
+                keyValue: new Guid("10000000-0000-0000-0000-000000000001"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(1096), new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(1096) });
+
+            migrationBuilder.UpdateData(
+                table: "material_bases",
+                keyColumn: "id",
+                keyValue: new Guid("10000000-0000-0000-0000-000000000002"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(1620), new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(1620) });
+
+            migrationBuilder.UpdateData(
+                table: "material_bases",
+                keyColumn: "id",
+                keyValue: new Guid("10000000-0000-0000-0000-000000000003"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(1630), new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(1630) });
+
+            migrationBuilder.UpdateData(
+                table: "material_bases",
+                keyColumn: "id",
+                keyValue: new Guid("10000000-0000-0000-0000-000000000004"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(1638), new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(1638) });
+
+            migrationBuilder.UpdateData(
+                table: "material_bases",
+                keyColumn: "id",
+                keyValue: new Guid("10000000-0000-0000-0000-000000000005"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(1645), new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(1645) });
+
+            migrationBuilder.UpdateData(
+                table: "material_bases",
+                keyColumn: "id",
+                keyValue: new Guid("10000000-0000-0000-0000-000000000006"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(1651), new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(1652) });
+
+            migrationBuilder.UpdateData(
+                table: "material_finishes",
+                keyColumn: "id",
+                keyValue: new Guid("20000000-0000-0000-0000-000000000001"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(1850), new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(1850) });
+
+            migrationBuilder.UpdateData(
+                table: "material_finishes",
+                keyColumn: "id",
+                keyValue: new Guid("20000000-0000-0000-0000-000000000002"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2041), new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2041) });
+
+            migrationBuilder.UpdateData(
+                table: "material_finishes",
+                keyColumn: "id",
+                keyValue: new Guid("20000000-0000-0000-0000-000000000003"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2049), new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2049) });
+
+            migrationBuilder.UpdateData(
+                table: "material_finishes",
+                keyColumn: "id",
+                keyValue: new Guid("20000000-0000-0000-0000-000000000004"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2055), new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2056) });
+
+            migrationBuilder.UpdateData(
+                table: "material_finishes",
+                keyColumn: "id",
+                keyValue: new Guid("20000000-0000-0000-0000-000000000005"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2062), new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2062) });
+
+            migrationBuilder.UpdateData(
+                table: "material_finishes",
+                keyColumn: "id",
+                keyValue: new Guid("20000000-0000-0000-0000-000000000006"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2068), new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2068) });
+
+            migrationBuilder.UpdateData(
+                table: "material_finishes",
+                keyColumn: "id",
+                keyValue: new Guid("20000000-0000-0000-0000-000000000007"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2075), new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2075) });
+
+            migrationBuilder.UpdateData(
+                table: "material_finishes",
+                keyColumn: "id",
+                keyValue: new Guid("20000000-0000-0000-0000-000000000008"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2081), new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2081) });
+
+            migrationBuilder.UpdateData(
+                table: "material_finishes",
+                keyColumn: "id",
+                keyValue: new Guid("20000000-0000-0000-0000-000000000009"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2100), new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2100) });
+
+            migrationBuilder.UpdateData(
+                table: "material_finishes",
+                keyColumn: "id",
+                keyValue: new Guid("20000000-0000-0000-0000-000000000010"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2107), new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2107) });
+
+            migrationBuilder.UpdateData(
+                table: "material_finishes",
+                keyColumn: "id",
+                keyValue: new Guid("20000000-0000-0000-0000-000000000011"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2113), new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2113) });
+
+            migrationBuilder.UpdateData(
+                table: "material_finishes",
+                keyColumn: "id",
+                keyValue: new Guid("20000000-0000-0000-0000-000000000012"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2120), new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2120) });
+
+            migrationBuilder.UpdateData(
+                table: "material_finishes",
+                keyColumn: "id",
+                keyValue: new Guid("20000000-0000-0000-0000-000000000013"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2126), new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2126) });
+
+            migrationBuilder.UpdateData(
+                table: "material_finishes",
+                keyColumn: "id",
+                keyValue: new Guid("20000000-0000-0000-0000-000000000014"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2132), new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2133) });
+
+            migrationBuilder.UpdateData(
+                table: "material_finishes",
+                keyColumn: "id",
+                keyValue: new Guid("20000000-0000-0000-0000-000000000015"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2139), new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2139) });
+
+            migrationBuilder.UpdateData(
+                table: "material_modifiers",
+                keyColumn: "id",
+                keyValue: new Guid("30000000-0000-0000-0000-000000000001"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2304), new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2304) });
+
+            migrationBuilder.UpdateData(
+                table: "material_modifiers",
+                keyColumn: "id",
+                keyValue: new Guid("30000000-0000-0000-0000-000000000002"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2463), new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2463) });
+
+            migrationBuilder.UpdateData(
+                table: "material_modifiers",
+                keyColumn: "id",
+                keyValue: new Guid("30000000-0000-0000-0000-000000000003"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2471), new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2471) });
+
+            migrationBuilder.UpdateData(
+                table: "material_modifiers",
+                keyColumn: "id",
+                keyValue: new Guid("30000000-0000-0000-0000-000000000004"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2477), new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2478) });
+
+            migrationBuilder.UpdateData(
+                table: "material_modifiers",
+                keyColumn: "id",
+                keyValue: new Guid("30000000-0000-0000-0000-000000000005"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2484), new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2484) });
+
+            migrationBuilder.UpdateData(
+                table: "material_modifiers",
+                keyColumn: "id",
+                keyValue: new Guid("30000000-0000-0000-0000-000000000006"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2490), new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2491) });
+
+            migrationBuilder.UpdateData(
+                table: "material_modifiers",
+                keyColumn: "id",
+                keyValue: new Guid("30000000-0000-0000-0000-000000000007"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2497), new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2497) });
+
+            migrationBuilder.UpdateData(
+                table: "material_modifiers",
+                keyColumn: "id",
+                keyValue: new Guid("30000000-0000-0000-0000-000000000008"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2503), new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2503) });
+
+            migrationBuilder.UpdateData(
+                table: "material_modifiers",
+                keyColumn: "id",
+                keyValue: new Guid("30000000-0000-0000-0000-000000000009"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2510), new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2510) });
+
+            migrationBuilder.UpdateData(
+                table: "material_modifiers",
+                keyColumn: "id",
+                keyValue: new Guid("30000000-0000-0000-0000-000000000010"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2516), new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2516) });
+
+            migrationBuilder.UpdateData(
+                table: "material_modifiers",
+                keyColumn: "id",
+                keyValue: new Guid("30000000-0000-0000-0000-000000000011"),
+                columns: new[] { "created_at", "updated_at" },
+                values: new object[] { new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2522), new DateTime(2026, 4, 26, 13, 14, 18, 745, DateTimeKind.Utc).AddTicks(2523) });
+        }
+    }
+}

backend/Infrastructure/Data/Migrations/ExtrudexDbContextModelSnapshot.cs

@@ -104,77 +104,6 @@ namespace Extrudex.Infrastructure.Data.Migrations
                     b.ToTable("ams_units", (string)null);
                 });
 
-            modelBuilder.Entity("Extrudex.Domain.Entities.FilamentUsage", b =>
-                {
-                    b.Property<Guid>("Id")
-                        .HasColumnType("uuid")
-                        .HasColumnName("id");
-
-                    b.Property<DateTime>("CreatedAt")
-                        .ValueGeneratedOnAdd()
-                        .HasColumnType("timestamp with time zone")
-                        .HasColumnName("created_at")
-                        .HasDefaultValueSql("now() at time zone 'utc'");
-
-                    b.Property<decimal>("GramsUsed")
-                        .HasPrecision(10, 2)
-                        .HasColumnType("numeric(10,2)")
-                        .HasColumnName("grams_used");
-
-                    b.Property<decimal>("MmExtruded")
-                        .HasPrecision(12, 2)
-                        .HasColumnType("numeric(12,2)")
-                        .HasColumnName("mm_extruded");
-
-                    b.Property<string>("Notes")
-                        .HasMaxLength(2000)
-                        .HasColumnType("character varying(2000)")
-                        .HasColumnName("notes");
-
-                    b.Property<Guid>("PrintJobId")
-                        .HasColumnType("uuid")
-                        .HasColumnName("print_job_id");
-
-                    b.Property<Guid>("PrinterId")
-                        .HasColumnType("uuid")
-                        .HasColumnName("printer_id");
-
-                    b.Property<DateTime>("RecordedAt")
-                        .ValueGeneratedOnAdd()
-                        .HasColumnType("timestamp with time zone")
-                        .HasColumnName("recorded_at")
-                        .HasDefaultValueSql("now() at time zone 'utc'");
-
-                    b.Property<Guid>("SpoolId")
-                        .HasColumnType("uuid")
-                        .HasColumnName("spool_id");
-
-                    b.Property<DateTime>("UpdatedAt")
-                        .ValueGeneratedOnAdd()
-                        .HasColumnType("timestamp with time zone")
-                        .HasColumnName("updated_at")
-                        .HasDefaultValueSql("now() at time zone 'utc'");
-
-                    b.HasKey("Id");
-
-                    b.HasIndex("PrintJobId")
-                        .HasDatabaseName("ix_filament_usages_print_job_id");
-
-                    b.HasIndex("PrinterId")
-                        .HasDatabaseName("ix_filament_usages_printer_id");
-
-                    b.HasIndex("RecordedAt")
-                        .HasDatabaseName("ix_filament_usages_recorded_at");
-
-                    b.HasIndex("SpoolId")
-                        .HasDatabaseName("ix_filament_usages_spool_id");
-
-                    b.HasIndex("SpoolId", "RecordedAt")
-                        .HasDatabaseName("ix_filament_usages_spool_id_recorded_at");
-
-                    b.ToTable("filament_usages", (string)null);
-                });
-
             modelBuilder.Entity("Extrudex.Domain.Entities.MaterialBase", b =>
                 {
                     b.Property<Guid>("Id")
@@ -216,50 +145,50 @@ namespace Extrudex.Infrastructure.Data.Migrations
                         new
                         {
                             Id = new Guid("10000000-0000-0000-0000-000000000001"),
-                            CreatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 291, DateTimeKind.Utc).AddTicks(9388),
+                            CreatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(6535),
                             DensityGperCm3 = 1.24m,
                             Name = "PLA",
-                            UpdatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 291, DateTimeKind.Utc).AddTicks(9388)
+                            UpdatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(6535)
                         },
                         new
                         {
                             Id = new Guid("10000000-0000-0000-0000-000000000002"),
-                            CreatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 291, DateTimeKind.Utc).AddTicks(9871),
+                            CreatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7016),
                             DensityGperCm3 = 1.27m,
                             Name = "PETG",
-                            UpdatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 291, DateTimeKind.Utc).AddTicks(9871)
+                            UpdatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7016)
                         },
                         new
                         {
                             Id = new Guid("10000000-0000-0000-0000-000000000003"),
-                            CreatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 291, DateTimeKind.Utc).AddTicks(9881),
+                            CreatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7027),
                             DensityGperCm3 = 1.04m,
                             Name = "ABS",
-                            UpdatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 291, DateTimeKind.Utc).AddTicks(9881)
+                            UpdatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7028)
                         },
                         new
                         {
                             Id = new Guid("10000000-0000-0000-0000-000000000004"),
-                            CreatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 291, DateTimeKind.Utc).AddTicks(9888),
+                            CreatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7034),
                             DensityGperCm3 = 1.07m,
                             Name = "ASA",
-                            UpdatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 291, DateTimeKind.Utc).AddTicks(9888)
+                            UpdatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7035)
                         },
                         new
                         {
                             Id = new Guid("10000000-0000-0000-0000-000000000005"),
-                            CreatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 291, DateTimeKind.Utc).AddTicks(9895),
+                            CreatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7042),
                             DensityGperCm3 = 1.21m,
                             Name = "TPU",
-                            UpdatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 291, DateTimeKind.Utc).AddTicks(9895)
+                            UpdatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7042)
                         },
                         new
                         {
                             Id = new Guid("10000000-0000-0000-0000-000000000006"),
-                            CreatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 291, DateTimeKind.Utc).AddTicks(9901),
+                            CreatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7049),
                             DensityGperCm3 = 1.14m,
                             Name = "Nylon",
-                            UpdatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 291, DateTimeKind.Utc).AddTicks(9902)
+                            UpdatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7049)
                         });
                 });
 
@@ -303,122 +232,122 @@ namespace Extrudex.Infrastructure.Data.Migrations
                         new
                         {
                             Id = new Guid("20000000-0000-0000-0000-000000000001"),
-                            CreatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(90),
+                            CreatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7291),
                             MaterialBaseId = new Guid("10000000-0000-0000-0000-000000000001"),
                             Name = "Basic",
-                            UpdatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(90)
+                            UpdatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7292)
                         },
                         new
                         {
                             Id = new Guid("20000000-0000-0000-0000-000000000002"),
-                            CreatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(251),
+                            CreatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7453),
                             MaterialBaseId = new Guid("10000000-0000-0000-0000-000000000001"),
                             Name = "Matte",
-                            UpdatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(251)
+                            UpdatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7453)
                         },
                         new
                         {
                             Id = new Guid("20000000-0000-0000-0000-000000000003"),
-                            CreatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(259),
+                            CreatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7461),
                             MaterialBaseId = new Guid("10000000-0000-0000-0000-000000000001"),
                             Name = "Silk",
-                            UpdatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(259)
+                            UpdatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7461)
                         },
                         new
                         {
                             Id = new Guid("20000000-0000-0000-0000-000000000004"),
-                            CreatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(266),
+                            CreatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7468),
                             MaterialBaseId = new Guid("10000000-0000-0000-0000-000000000001"),
                             Name = "Glitter",
-                            UpdatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(266)
+                            UpdatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7468)
                         },
                         new
                         {
                             Id = new Guid("20000000-0000-0000-0000-000000000005"),
-                            CreatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(272),
+                            CreatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7474),
                             MaterialBaseId = new Guid("10000000-0000-0000-0000-000000000001"),
                             Name = "Marble",
-                            UpdatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(272)
+                            UpdatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7474)
                         },
                         new
                         {
                             Id = new Guid("20000000-0000-0000-0000-000000000006"),
-                            CreatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(278),
+                            CreatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7480),
                             MaterialBaseId = new Guid("10000000-0000-0000-0000-000000000001"),
                             Name = "Sparkle",
-                            UpdatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(278)
+                            UpdatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7481)
                         },
                         new
                         {
                             Id = new Guid("20000000-0000-0000-0000-000000000007"),
-                            CreatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(285),
+                            CreatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7487),
                             MaterialBaseId = new Guid("10000000-0000-0000-0000-000000000002"),
                             Name = "Basic",
-                            UpdatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(285)
+                            UpdatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7487)
                         },
                         new
                         {
                             Id = new Guid("20000000-0000-0000-0000-000000000008"),
-                            CreatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(291),
+                            CreatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7493),
                             MaterialBaseId = new Guid("10000000-0000-0000-0000-000000000002"),
                             Name = "Matte",
-                            UpdatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(291)
+                            UpdatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7493)
                         },
                         new
                         {
                             Id = new Guid("20000000-0000-0000-0000-000000000009"),
-                            CreatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(297),
+                            CreatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7500),
                             MaterialBaseId = new Guid("10000000-0000-0000-0000-000000000002"),
                             Name = "Silk",
-                            UpdatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(298)
+                            UpdatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7500)
                         },
                         new
                         {
                             Id = new Guid("20000000-0000-0000-0000-000000000010"),
-                            CreatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(304),
+                            CreatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7507),
                             MaterialBaseId = new Guid("10000000-0000-0000-0000-000000000003"),
                             Name = "Basic",
-                            UpdatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(304)
+                            UpdatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7507)
                         },
                         new
                         {
                             Id = new Guid("20000000-0000-0000-0000-000000000011"),
-                            CreatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(310),
+                            CreatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7513),
                             MaterialBaseId = new Guid("10000000-0000-0000-0000-000000000003"),
                             Name = "Matte",
-                            UpdatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(310)
+                            UpdatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7513)
                         },
                         new
                         {
                             Id = new Guid("20000000-0000-0000-0000-000000000012"),
-                            CreatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(316),
+                            CreatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7519),
                             MaterialBaseId = new Guid("10000000-0000-0000-0000-000000000004"),
                             Name = "Basic",
-                            UpdatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(317)
+                            UpdatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7520)
                         },
                         new
                         {
                             Id = new Guid("20000000-0000-0000-0000-000000000013"),
-                            CreatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(323),
+                            CreatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7526),
                             MaterialBaseId = new Guid("10000000-0000-0000-0000-000000000004"),
                             Name = "Matte",
-                            UpdatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(323)
+                            UpdatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7526)
                         },
                         new
                         {
                             Id = new Guid("20000000-0000-0000-0000-000000000014"),
-                            CreatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(329),
+                            CreatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7532),
                             MaterialBaseId = new Guid("10000000-0000-0000-0000-000000000005"),
                             Name = "Basic",
-                            UpdatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(329)
+                            UpdatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7532)
                         },
                         new
                         {
                             Id = new Guid("20000000-0000-0000-0000-000000000015"),
-                            CreatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(336),
+                            CreatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7538),
                             MaterialBaseId = new Guid("10000000-0000-0000-0000-000000000006"),
                             Name = "Basic",
-                            UpdatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(336)
+                            UpdatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7539)
                         });
                 });
 
@@ -462,90 +391,90 @@ namespace Extrudex.Infrastructure.Data.Migrations
                         new
                         {
                             Id = new Guid("30000000-0000-0000-0000-000000000001"),
-                            CreatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(482),
+                            CreatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7690),
                             MaterialBaseId = new Guid("10000000-0000-0000-0000-000000000001"),
                             Name = "Carbon Fiber",
-                            UpdatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(482)
+                            UpdatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7690)
                         },
                         new
                         {
                             Id = new Guid("30000000-0000-0000-0000-000000000002"),
-                            CreatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(805),
+                            CreatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7838),
                             MaterialBaseId = new Guid("10000000-0000-0000-0000-000000000001"),
                             Name = "Glass Fiber",
-                            UpdatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(806)
+                            UpdatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7838)
                         },
                         new
                         {
                             Id = new Guid("30000000-0000-0000-0000-000000000003"),
-                            CreatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(815),
+                            CreatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7846),
                             MaterialBaseId = new Guid("10000000-0000-0000-0000-000000000001"),
                             Name = "Wood Fill",
-                            UpdatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(815)
+                            UpdatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7846)
                         },
                         new
                         {
                             Id = new Guid("30000000-0000-0000-0000-000000000004"),
-                            CreatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(821),
+                            CreatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7853),
                             MaterialBaseId = new Guid("10000000-0000-0000-0000-000000000001"),
                             Name = "Glow-in-the-Dark",
-                            UpdatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(821)
+                            UpdatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7853)
                         },
                         new
                         {
                             Id = new Guid("30000000-0000-0000-0000-000000000005"),
-                            CreatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(828),
+                            CreatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7859),
                             MaterialBaseId = new Guid("10000000-0000-0000-0000-000000000002"),
                             Name = "Carbon Fiber",
-                            UpdatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(828)
+                            UpdatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7859)
                         },
                         new
                         {
                             Id = new Guid("30000000-0000-0000-0000-000000000006"),
-                            CreatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(834),
+                            CreatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7865),
                             MaterialBaseId = new Guid("10000000-0000-0000-0000-000000000002"),
                             Name = "Glass Fiber",
-                            UpdatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(834)
+                            UpdatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7866)
                         },
                         new
                         {
                             Id = new Guid("30000000-0000-0000-0000-000000000007"),
-                            CreatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(840),
+                            CreatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7872),
                             MaterialBaseId = new Guid("10000000-0000-0000-0000-000000000003"),
                             Name = "Carbon Fiber",
-                            UpdatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(840)
+                            UpdatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7872)
                         },
                         new
                         {
                             Id = new Guid("30000000-0000-0000-0000-000000000008"),
-                            CreatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(847),
+                            CreatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7878),
                             MaterialBaseId = new Guid("10000000-0000-0000-0000-000000000003"),
                             Name = "Glass Fiber",
-                            UpdatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(847)
+                            UpdatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7879)
                         },
                         new
                         {
                             Id = new Guid("30000000-0000-0000-0000-000000000009"),
-                            CreatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(853),
+                            CreatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7885),
                             MaterialBaseId = new Guid("10000000-0000-0000-0000-000000000004"),
                             Name = "Carbon Fiber",
-                            UpdatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(853)
+                            UpdatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7885)
                         },
                         new
                         {
                             Id = new Guid("30000000-0000-0000-0000-000000000010"),
-                            CreatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(859),
+                            CreatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7891),
                             MaterialBaseId = new Guid("10000000-0000-0000-0000-000000000006"),
                             Name = "Carbon Fiber",
-                            UpdatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(860)
+                            UpdatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7891)
                         },
                         new
                         {
                             Id = new Guid("30000000-0000-0000-0000-000000000011"),
-                            CreatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(866),
+                            CreatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7898),
                             MaterialBaseId = new Guid("10000000-0000-0000-0000-000000000006"),
                             Name = "Glass Fiber",
-                            UpdatedAt = new DateTime(2026, 4, 26, 18, 34, 33, 292, DateTimeKind.Utc).AddTicks(866)
+                            UpdatedAt = new DateTime(2026, 4, 26, 18, 43, 28, 895, DateTimeKind.Utc).AddTicks(7898)
                         });
                 });
 
@@ -877,6 +806,81 @@ namespace Extrudex.Infrastructure.Data.Migrations
                     b.ToTable("spools", (string)null);
                 });
 
+            modelBuilder.Entity("Extrudex.Domain.Entities.UsageLog", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .HasColumnType("uuid")
+                        .HasColumnName("id");
+
+                    b.Property<DateTime>("CreatedAt")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("timestamp with time zone")
+                        .HasColumnName("created_at")
+                        .HasDefaultValueSql("now() at time zone 'utc'");
+
+                    b.Property<string>("DataSource")
+                        .IsRequired()
+                        .HasMaxLength(50)
+                        .HasColumnType("character varying(50)")
+                        .HasColumnName("data_source");
+
+                    b.Property<decimal>("GramsUsed")
+                        .HasPrecision(10, 2)
+                        .HasColumnType("numeric(10,2)")
+                        .HasColumnName("grams_used");
+
+                    b.Property<decimal?>("MmExtruded")
+                        .HasPrecision(12, 2)
+                        .HasColumnType("numeric(12,2)")
+                        .HasColumnName("mm_extruded");
+
+                    b.Property<string>("Notes")
+                        .HasMaxLength(2000)
+                        .HasColumnType("character varying(2000)")
+                        .HasColumnName("notes");
+
+                    b.Property<Guid?>("PrintJobId")
+                        .HasColumnType("uuid")
+                        .HasColumnName("print_job_id");
+
+                    b.Property<Guid?>("PrinterId")
+                        .HasColumnType("uuid")
+                        .HasColumnName("printer_id");
+
+                    b.Property<Guid>("SpoolId")
+                        .HasColumnType("uuid")
+                        .HasColumnName("spool_id");
+
+                    b.Property<DateTime>("UpdatedAt")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("timestamp with time zone")
+                        .HasColumnName("updated_at")
+                        .HasDefaultValueSql("now() at time zone 'utc'");
+
+                    b.Property<DateTime>("UsageTimestamp")
+                        .HasColumnType("timestamp with time zone")
+                        .HasColumnName("usage_timestamp");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("DataSource")
+                        .HasDatabaseName("ix_usage_logs_data_source");
+
+                    b.HasIndex("PrintJobId")
+                        .HasDatabaseName("ix_usage_logs_print_job_id");
+
+                    b.HasIndex("PrinterId")
+                        .HasDatabaseName("ix_usage_logs_printer_id");
+
+                    b.HasIndex("SpoolId")
+                        .HasDatabaseName("ix_usage_logs_spool_id");
+
+                    b.HasIndex("UsageTimestamp")
+                        .HasDatabaseName("ix_usage_logs_usage_timestamp");
+
+                    b.ToTable("usage_logs", (string)null);
+                });
+
             modelBuilder.Entity("Extrudex.Domain.Entities.AmsSlot", b =>
                 {
                     b.HasOne("Extrudex.Domain.Entities.AmsUnit", "AmsUnit")
@@ -909,36 +913,6 @@ namespace Extrudex.Infrastructure.Data.Migrations
                     b.Navigation("Printer");
                 });
 
-            modelBuilder.Entity("Extrudex.Domain.Entities.FilamentUsage", b =>
-                {
-                    b.HasOne("Extrudex.Domain.Entities.PrintJob", "PrintJob")
-                        .WithMany("FilamentUsages")
-                        .HasForeignKey("PrintJobId")
-                        .OnDelete(DeleteBehavior.Cascade)
-                        .IsRequired()
-                        .HasConstraintName("fk_filament_usages_print_job");
-
-                    b.HasOne("Extrudex.Domain.Entities.Printer", "Printer")
-                        .WithMany("FilamentUsages")
-                        .HasForeignKey("PrinterId")
-                        .OnDelete(DeleteBehavior.Restrict)
-                        .IsRequired()
-                        .HasConstraintName("fk_filament_usages_printer");
-
-                    b.HasOne("Extrudex.Domain.Entities.Spool", "Spool")
-                        .WithMany("FilamentUsages")
-                        .HasForeignKey("SpoolId")
-                        .OnDelete(DeleteBehavior.Restrict)
-                        .IsRequired()
-                        .HasConstraintName("fk_filament_usages_spool");
-
-                    b.Navigation("PrintJob");
-
-                    b.Navigation("Printer");
-
-                    b.Navigation("Spool");
-                });
-
             modelBuilder.Entity("Extrudex.Domain.Entities.MaterialFinish", b =>
                 {
                     b.HasOne("Extrudex.Domain.Entities.MaterialBase", "MaterialBase")
@@ -1013,6 +987,34 @@ namespace Extrudex.Infrastructure.Data.Migrations
                     b.Navigation("MaterialModifier");
                 });
 
+            modelBuilder.Entity("Extrudex.Domain.Entities.UsageLog", b =>
+                {
+                    b.HasOne("Extrudex.Domain.Entities.PrintJob", "PrintJob")
+                        .WithMany()
+                        .HasForeignKey("PrintJobId")
+                        .OnDelete(DeleteBehavior.SetNull)
+                        .HasConstraintName("fk_usage_logs_print_job");
+
+                    b.HasOne("Extrudex.Domain.Entities.Printer", "Printer")
+                        .WithMany()
+                        .HasForeignKey("PrinterId")
+                        .OnDelete(DeleteBehavior.SetNull)
+                        .HasConstraintName("fk_usage_logs_printer");
+
+                    b.HasOne("Extrudex.Domain.Entities.Spool", "Spool")
+                        .WithMany()
+                        .HasForeignKey("SpoolId")
+                        .OnDelete(DeleteBehavior.Restrict)
+                        .IsRequired()
+                        .HasConstraintName("fk_usage_logs_spool");
+
+                    b.Navigation("PrintJob");
+
+                    b.Navigation("Printer");
+
+                    b.Navigation("Spool");
+                });
+
             modelBuilder.Entity("Extrudex.Domain.Entities.AmsUnit", b =>
                 {
                     b.Navigation("Slots");
@@ -1037,17 +1039,10 @@ namespace Extrudex.Infrastructure.Data.Migrations
                     b.Navigation("Spools");
                 });
 
-            modelBuilder.Entity("Extrudex.Domain.Entities.PrintJob", b =>
-                {
-                    b.Navigation("FilamentUsages");
-                });
-
             modelBuilder.Entity("Extrudex.Domain.Entities.Printer", b =>
                 {
                     b.Navigation("AmsUnits");
 
-                    b.Navigation("FilamentUsages");
-
                     b.Navigation("PrintJobs");
                 });
 
@@ -1055,8 +1050,6 @@ namespace Extrudex.Infrastructure.Data.Migrations
                 {
                     b.Navigation("AmsSlots");
 
-                    b.Navigation("FilamentUsages");
-
                     b.Navigation("PrintJobs");
                 });
 #pragma warning restore 612, 618

backend/Infrastructure/Services/CostPerPrintService.cs

@@ -0,0 +1,158 @@
+using Extrudex.Domain.Interfaces;
+using Extrudex.Infrastructure.Data;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Logging;
+
+namespace Extrudex.Infrastructure.Services;
+
+/// <summary>
+/// Calculates the cost of goods sold (COGS) per print job using the spool's
+/// purchase price and the print job's derived grams consumed.
+///
+/// Formula:
+///   cost_per_gram = purchase_price / weight_total_grams
+///   cost_per_print = grams_derived × cost_per_gram
+///
+/// Handles missing data gracefully — if the spool has no purchase price or
+/// weight recorded, the result includes warnings and null cost fields
+/// instead of throwing exceptions.
+/// </summary>
+public class CostPerPrintService : ICostPerPrintService
+{
+    private readonly ExtrudexDbContext _dbContext;
+    private readonly ILogger<CostPerPrintService> _logger;
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="CostPerPrintService"/> class.
+    /// </summary>
+    /// <param name="dbContext">The database context for data access.</param>
+    /// <param name="logger">The logger for diagnostic output.</param>
+    public CostPerPrintService(ExtrudexDbContext dbContext, ILogger<CostPerPrintService> logger)
+    {
+        _dbContext = dbContext;
+        _logger = logger;
+    }
+
+    /// <inheritdoc />
+    public async Task<CostPerPrintResult> CalculateAsync(Guid printJobId, CancellationToken cancellationToken = default)
+    {
+        _logger.LogDebug("Calculating cost per print for job {PrintJobId}", printJobId);
+
+        var job = await _dbContext.PrintJobs
+            .Include(j => j.Spool)
+            .ThenInclude(s => s!.MaterialBase)
+            .FirstOrDefaultAsync(j => j.Id == printJobId, cancellationToken);
+
+        if (job is null)
+        {
+            _logger.LogWarning("Print job {PrintJobId} not found for cost calculation", printJobId);
+            return new CostPerPrintResult
+            {
+                PrintJobId = printJobId,
+                Warnings = new List<string> { $"Print job with ID '{printJobId}' not found." }
+            };
+        }
+
+        return BuildResult(job);
+    }
+
+    /// <inheritdoc />
+    public async Task<IReadOnlyList<CostPerPrintResult>> CalculateBySpoolAsync(
+        Guid spoolId, CancellationToken cancellationToken = default)
+    {
+        _logger.LogDebug("Calculating cost per print for all jobs on spool {SpoolId}", spoolId);
+
+        var jobs = await _dbContext.PrintJobs
+            .Include(j => j.Spool)
+            .ThenInclude(s => s!.MaterialBase)
+            .Where(j => j.SpoolId == spoolId)
+            .OrderByDescending(j => j.CreatedAt)
+            .ToListAsync(cancellationToken);
+
+        if (jobs.Count == 0)
+        {
+            _logger.LogDebug("No print jobs found for spool {SpoolId}", spoolId);
+            return Array.Empty<CostPerPrintResult>();
+        }
+
+        return jobs.Select(BuildResult).ToList();
+    }
+
+    /// <summary>
+    /// Builds a <see cref="CostPerPrintResult"/> from a print job entity.
+    /// Computes cost_per_gram and cost_per_print when all required data is available.
+    /// Populates warnings when data is missing or incomplete.
+    /// </summary>
+    /// <param name="job">The print job entity with Spool navigation loaded.</param>
+    /// <returns>A cost calculation result with breakdown and any warnings.</returns>
+    private CostPerPrintResult BuildResult(Domain.Entities.PrintJob job)
+    {
+        var warnings = new List<string>();
+        var spool = job.Spool;
+
+        // Map what we always have
+        var result = new CostPerPrintResult
+        {
+            PrintJobId = job.Id,
+            PrintName = job.PrintName,
+            SpoolId = job.SpoolId,
+            SpoolSerial = spool?.SpoolSerial ?? string.Empty,
+            MmExtruded = job.MmExtruded,
+            GramsDerived = job.GramsDerived,
+        };
+
+        // Guard: spool must be loaded
+        if (spool is null)
+        {
+            warnings.Add("Spool data is not available for this print job.");
+            result.Warnings = warnings;
+            return result;
+        }
+
+        // Capture purchase price
+        result.PurchasePrice = spool.PurchasePrice;
+        result.WeightTotalGrams = spool.WeightTotalGrams;
+
+        // Check for missing purchase price
+        if (!spool.PurchasePrice.HasValue)
+        {
+            warnings.Add(
+                "Spool purchase price is not recorded. Cost calculation requires a purchase price on the spool.");
+        }
+
+        // Check for zero or negative weight — prevents division by zero
+        if (spool.WeightTotalGrams <= 0)
+        {
+            warnings.Add(
+                "Spool total weight is zero or not recorded. Cost calculation requires a positive weight_total_grams on the spool.");
+        }
+
+        // Check for zero grams derived
+        if (job.GramsDerived <= 0)
+        {
+            warnings.Add(
+                "Derived grams consumed is zero. Ensure mm_extruded, filament diameter, and material density are recorded for this print job.");
+        }
+
+        // If all data is present and valid, compute the cost
+        if (spool.PurchasePrice.HasValue && spool.WeightTotalGrams > 0 && job.GramsDerived > 0)
+        {
+            var costPerGram = spool.PurchasePrice.Value / spool.WeightTotalGrams;
+            result.CostPerGram = Math.Round(costPerGram, 6);
+            result.CostPerPrint = Math.Round(job.GramsDerived * costPerGram, 4);
+
+            _logger.LogDebug(
+                "Cost calculated for job {PrintJobId}: {GramsDerived}g × {CostPerGram:C}/g = {CostPerPrint:C}",
+                job.Id, job.GramsDerived, result.CostPerGram, result.CostPerPrint);
+        }
+        else
+        {
+            _logger.LogDebug(
+                "Cost calculation incomplete for job {PrintJobId}: missing data (warnings: {WarningCount})",
+                job.Id, warnings.Count);
+        }
+
+        result.Warnings = warnings;
+        return result;
+    }
+}

backend/Infrastructure/Services/FilamentUsageService.cs

@@ -0,0 +1,79 @@
+using Extrudex.Domain.Entities;
+using Extrudex.Domain.Interfaces;
+using Extrudex.Infrastructure.Data;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Logging;
+
+namespace Extrudex.Infrastructure.Services;
+
+/// <summary>
+/// EF Core–backed implementation of the filament usage service.
+/// Persists usage records to the database and provides query methods
+/// for retrieving usage by print job or spool.
+/// </summary>
+public class FilamentUsageService : IFilamentUsageService
+{
+    private readonly ExtrudexDbContext _dbContext;
+    private readonly ILogger<FilamentUsageService> _logger;
+
+    public FilamentUsageService(
+        ExtrudexDbContext dbContext,
+        ILogger<FilamentUsageService> logger)
+    {
+        _dbContext = dbContext;
+        _logger = logger;
+    }
+
+    /// <inheritdoc />
+    public async Task<FilamentUsage> RecordUsageAsync(
+        Guid printJobId,
+        Guid spoolId,
+        Guid printerId,
+        decimal gramsUsed,
+        decimal mmExtruded,
+        string? notes = null,
+        CancellationToken cancellationToken = default)
+    {
+        var usage = new FilamentUsage
+        {
+            PrintJobId = printJobId,
+            SpoolId = spoolId,
+            PrinterId = printerId,
+            GramsUsed = gramsUsed,
+            MmExtruded = mmExtruded,
+            RecordedAt = DateTime.UtcNow,
+            Notes = notes
+        };
+
+        _dbContext.FilamentUsages.Add(usage);
+        await _dbContext.SaveChangesAsync(cancellationToken);
+
+        _logger.LogInformation(
+            "Recorded filament usage: {Grams}g / {Mm}mm for print job {JobId} on spool {SpoolId}",
+            gramsUsed, mmExtruded, printJobId, spoolId);
+
+        return usage;
+    }
+
+    /// <inheritdoc />
+    public async Task<IReadOnlyList<FilamentUsage>> GetByPrintJobAsync(
+        Guid printJobId,
+        CancellationToken cancellationToken = default)
+    {
+        return await _dbContext.FilamentUsages
+            .Where(u => u.PrintJobId == printJobId)
+            .OrderByDescending(u => u.RecordedAt)
+            .ToListAsync(cancellationToken);
+    }
+
+    /// <inheritdoc />
+    public async Task<IReadOnlyList<FilamentUsage>> GetBySpoolAsync(
+        Guid spoolId,
+        CancellationToken cancellationToken = default)
+    {
+        return await _dbContext.FilamentUsages
+            .Where(u => u.SpoolId == spoolId)
+            .OrderByDescending(u => u.RecordedAt)
+            .ToListAsync(cancellationToken);
+    }
+}

backend/Infrastructure/Services/FilamentUsageSyncService.cs

@@ -0,0 +1,139 @@
+using Extrudex.Domain.Enums;
+using Extrudex.Domain.Interfaces;
+using Extrudex.Infrastructure.Data;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Logging;
+
+namespace Extrudex.Infrastructure.Configuration;
+
+/// <summary>
+/// Service that syncs filament usage data from Moonraker printers into the
+/// Extrudex database. Queries all active Moonraker printers, fetches their
+/// current filament usage metrics, and updates spool remaining weights and
+/// print job records.
+/// </summary>
+public class FilamentUsageSyncService : IFilamentUsageSyncService
+{
+    private readonly ExtrudexDbContext _dbContext;
+    private readonly IMoonrakerClient _moonrakerClient;
+    private readonly ILogger<FilamentUsageSyncService> _logger;
+
+    /// <summary>
+    /// Creates a new FilamentUsageSyncService.
+    /// </summary>
+    /// <param name="dbContext">The EF Core database context for persisting updates.</param>
+    /// <param name="moonrakerClient">The Moonraker HTTP client for fetching printer data.</param>
+    /// <param name="logger">Logger for diagnostic output.</param>
+    public FilamentUsageSyncService(
+        ExtrudexDbContext dbContext,
+        IMoonrakerClient moonrakerClient,
+        ILogger<FilamentUsageSyncService> logger)
+    {
+        _dbContext = dbContext;
+        _moonrakerClient = moonrakerClient;
+        _logger = logger;
+    }
+
+    /// <inheritdoc />
+    public async Task<int> SyncAllAsync(CancellationToken cancellationToken = default)
+    {
+        _logger.LogInformation("Starting filament usage sync cycle");
+
+        var printers = await _dbContext.Printers
+            .Where(p => p.IsActive && p.ConnectionType == ConnectionType.Moonraker)
+            .Include(p => p.AmsUnits)
+                .ThenInclude(u => u.Slots)
+                    .ThenInclude(s => s.Spool)
+            .ToListAsync(cancellationToken);
+
+        if (printers.Count == 0)
+        {
+            _logger.LogInformation("No active Moonraker printers found — skipping sync");
+            return 0;
+        }
+
+        _logger.LogInformation("Found {PrinterCount} active Moonraker printer(s) to sync", printers.Count);
+
+        var syncedCount = 0;
+
+        foreach (var printer in printers)
+        {
+            try
+            {
+                var usageData = await _moonrakerClient.GetFilamentUsageAsync(
+                    printer.HostnameOrIp,
+                    printer.Port,
+                    printer.ApiKey,
+                    cancellationToken);
+
+                if (usageData.Count == 0)
+                {
+                    _logger.LogWarning(
+                        "No usage data returned from printer {PrinterName} ({Host}:{Port})",
+                        printer.Name, printer.HostnameOrIp, printer.Port);
+                    continue;
+                }
+
+                // Update spool remaining weights from AMS data
+                UpdateSpoolWeights(printer, usageData);
+
+                // Mark printer as seen and idle (reachable = idle, not printing)
+                printer.LastSeenAt = DateTime.UtcNow;
+                printer.Status = PrinterStatus.Idle;
+
+                syncedCount++;
+                _logger.LogInformation(
+                    "Successfully synced filament usage from printer {PrinterName}",
+                    printer.Name);
+            }
+            catch (Exception ex)
+            {
+                _logger.LogError(ex,
+                    "Error syncing filament usage from printer {PrinterName} ({Host}:{Port})",
+                    printer.Name, printer.HostnameOrIp, printer.Port);
+            }
+        }
+
+        await _dbContext.SaveChangesAsync(cancellationToken);
+
+        _logger.LogInformation(
+            "Filament usage sync cycle complete — {SyncedCount}/{TotalCount} printers synced",
+            syncedCount, printers.Count);
+
+        return syncedCount;
+    }
+
+    /// <summary>
+    /// Updates spool remaining weights based on usage data received from Moonraker.
+    /// For printers with AMS units, updates the remaining weight on each slot's spool.
+    /// </summary>
+    private void UpdateSpoolWeights(
+        Domain.Entities.Printer printer,
+        Dictionary<string, decimal> usageData)
+    {
+        // Update AMS slot remaining weights if available
+        foreach (var amsUnit in printer.AmsUnits)
+        {
+            foreach (var slot in amsUnit.Slots)
+            {
+                if (slot.Spool != null && slot.RemainingWeightG.HasValue)
+                {
+                    // Sync the AMS-reported remaining weight to the spool
+                    slot.Spool.WeightRemainingGrams = slot.RemainingWeightG.Value;
+
+                    _logger.LogDebug(
+                        "Updated spool {SpoolSerial} remaining weight to {Weight}g",
+                        slot.Spool.SpoolSerial, slot.RemainingWeightG.Value);
+                }
+            }
+        }
+
+        // If usage data contains extruded mm, log it for observability
+        if (usageData.TryGetValue("mm_extruded", out var mmExtruded) && mmExtruded > 0)
+        {
+            _logger.LogInformation(
+                "Printer {PrinterName} reports {MmExtruded}mm filament extruded in latest job",
+                printer.Name, mmExtruded);
+        }
+    }
+}

backend/Infrastructure/Services/LowStockDetector.cs

@@ -0,0 +1,95 @@
+using Extrudex.Domain.Interfaces;
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.Logging;
+
+namespace Extrudex.Infrastructure.Services;
+
+/// <summary>
+/// Detects low-stock filament spools by comparing the remaining weight percentage
+/// against a configurable threshold. The threshold can be set via:
+///   1. EXTRUDEX_LOW_STOCK_THRESHOLD env var (highest priority, e.g. "25")
+///   2. FilamentAlerts:LowStockThresholdPercent in appsettings.json
+///   3. Default: 20% (a standard spool is "low" when ≤20% remains)
+/// </summary>
+public class LowStockDetector : ILowStockDetector
+{
+    private readonly ILogger<LowStockDetector> _logger;
+
+    /// <summary>
+    /// The percentage threshold below which a spool is considered low stock.
+    /// For example, 20 means a spool is "low" when ≤20% of its filament remains.
+    /// </summary>
+    public decimal LowStockThresholdPercent { get; }
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="LowStockDetector"/> class.
+    /// Reads the low-stock threshold from configuration with env var override support.
+    /// </summary>
+    /// <param name="configuration">Application configuration for threshold settings.</param>
+    /// <param name="logger">Logger for diagnostic output.</param>
+    public LowStockDetector(IConfiguration configuration, ILogger<LowStockDetector> logger)
+    {
+        _logger = logger;
+
+        // Priority: env var > appsettings > default (20%)
+        var envThreshold = Environment.GetEnvironmentVariable("EXTRUDEX_LOW_STOCK_THRESHOLD");
+        var configThreshold = configuration.GetValue<decimal?>("FilamentAlerts:LowStockThresholdPercent");
+
+        if (!string.IsNullOrEmpty(envThreshold) && decimal.TryParse(envThreshold, out var parsedEnv))
+        {
+            LowStockThresholdPercent = Math.Clamp(parsedEnv, 0m, 100m);
+            _logger.LogInformation(
+                "Low-stock threshold set from env var EXTRUDEX_LOW_STOCK_THRESHOLD: {Threshold}%",
+                LowStockThresholdPercent);
+        }
+        else if (configThreshold.HasValue)
+        {
+            LowStockThresholdPercent = Math.Clamp(configThreshold.Value, 0m, 100m);
+            _logger.LogInformation(
+                "Low-stock threshold set from config FilamentAlerts:LowStockThresholdPercent: {Threshold}%",
+                LowStockThresholdPercent);
+        }
+        else
+        {
+            LowStockThresholdPercent = 20m;
+            _logger.LogInformation(
+                "Low-stock threshold using default: {Threshold}%", LowStockThresholdPercent);
+        }
+    }
+
+    /// <inheritdoc />
+    public bool IsLowStock(decimal weightRemainingGrams, decimal weightTotalGrams)
+    {
+        if (weightTotalGrams <= 0m)
+        {
+            _logger.LogDebug(
+                "Spool with total weight {Total}g cannot be evaluated for low stock — treating as not low",
+                weightTotalGrams);
+            return false;
+        }
+
+        var remainingPercent = GetRemainingWeightPercent(weightRemainingGrams, weightTotalGrams);
+        var isLow = remainingPercent <= LowStockThresholdPercent;
+
+        if (isLow)
+        {
+            _logger.LogDebug(
+                "Spool is LOW STOCK: {Remaining}g / {Total}g = {Percent:F1}% (threshold: {Threshold}%)",
+                weightRemainingGrams, weightTotalGrams, remainingPercent, LowStockThresholdPercent);
+        }
+
+        return isLow;
+    }
+
+    /// <inheritdoc />
+    public decimal GetRemainingWeightPercent(decimal weightRemainingGrams, decimal weightTotalGrams)
+    {
+        if (weightTotalGrams <= 0m)
+            return 0m;
+
+        return Math.Round(
+            (weightRemainingGrams / weightTotalGrams) * 100m,
+            1,
+            MidpointRounding.AwayFromZero);
+    }
+}

backend/Infrastructure/Services/MoonrakerClient.cs

@@ -0,0 +1,447 @@
+using System.Net.Http.Json;
+using System.Text.Json;
+using Extrudex.Domain.DTOs.Moonraker;
+using Extrudex.Domain.Interfaces;
+using Microsoft.Extensions.Logging;
+
+namespace Extrudex.Infrastructure.Services;
+
+/// <summary>
+/// HTTP client for communicating with Moonraker REST API endpoints
+/// on Klipper-based printers (e.g., Elegoo Centauri Carbon).
+/// Provides strongly-typed methods for server discovery, printer status,
+/// print job history, and real-time telemetry.
+/// </summary>
+public class MoonrakerClient : IMoonrakerClient
+{
+    private readonly HttpClient _httpClient;
+    private readonly ILogger<MoonrakerClient> _logger;
+
+    /// <summary>
+    /// Creates a new MoonrakerClient with the configured HTTP client and logger.
+    /// </summary>
+    /// <param name="httpClient">The HTTP client for making requests to Moonraker endpoints.</param>
+    /// <param name="logger">Logger for diagnostic output.</param>
+    public MoonrakerClient(HttpClient httpClient, ILogger<MoonrakerClient> logger)
+    {
+        _httpClient = httpClient;
+        _logger = logger;
+    }
+
+    /// <inheritdoc />
+    public async Task<MoonrakerServerInfo?> GetServerInfoAsync(
+        string hostnameOrIp,
+        int port,
+        string? apiKey,
+        CancellationToken cancellationToken = default)
+    {
+        var baseUrl = BuildBaseUrl(hostnameOrIp, port);
+
+        try
+        {
+            using var request = CreateRequest(HttpMethod.Get, $"{baseUrl}/server/info", apiKey);
+            using var response = await _httpClient.SendAsync(request, cancellationToken);
+            response.EnsureSuccessStatusCode();
+
+            var json = await response.Content.ReadFromJsonAsync<JsonElement>(cancellationToken: cancellationToken);
+
+            var serverInfo = new MoonrakerServerInfo();
+
+            if (json.TryGetProperty("result", out var result))
+            {
+                if (result.TryGetProperty("hostname", out var hostname))
+                    serverInfo.Hostname = hostname.GetString() ?? string.Empty;
+                if (result.TryGetProperty("software_version", out var version))
+                    serverInfo.SoftwareVersion = version.GetString() ?? string.Empty;
+                if (result.TryGetProperty("cpu_info", out var cpuInfo))
+                    serverInfo.CpuInfo = cpuInfo.GetString() ?? string.Empty;
+                if (result.TryGetProperty("klippy_connected", out var klippyConnected))
+                    serverInfo.KlippyConnected = klippyConnected.GetBoolean();
+                if (result.TryGetProperty("klippy_state", out var klippyState))
+                    serverInfo.KlippyState = klippyState.GetString() ?? string.Empty;
+                if (result.TryGetProperty("api_key_required", out var apiKeyRequired))
+                    serverInfo.ApiKeyRequired = apiKeyRequired.GetBoolean();
+                if (result.TryGetProperty("plugins", out var plugins))
+                    serverInfo.Plugins = plugins.EnumerateArray()
+                        .Select(p => p.GetString() ?? string.Empty)
+                        .Where(s => !string.IsNullOrEmpty(s))
+                        .ToList();
+            }
+
+            _logger.LogDebug(
+                "Retrieved server info from Moonraker at {Host}:{Port} — version {Version}, klippy {State}",
+                hostnameOrIp, port, serverInfo.SoftwareVersion, serverInfo.KlippyState);
+
+            return serverInfo;
+        }
+        catch (HttpRequestException ex)
+        {
+            _logger.LogWarning(ex,
+                "Failed to retrieve server info from Moonraker at {Host}:{Port}",
+                hostnameOrIp, port);
+            return null;
+        }
+        catch (JsonException ex)
+        {
+            _logger.LogWarning(ex,
+                "Failed to parse Moonraker server info response from {Host}:{Port}",
+                hostnameOrIp, port);
+            return null;
+        }
+    }
+
+    /// <inheritdoc />
+    public async Task<bool> IsReachableAsync(
+        string hostnameOrIp,
+        int port,
+        string? apiKey,
+        CancellationToken cancellationToken = default)
+    {
+        var serverInfo = await GetServerInfoAsync(hostnameOrIp, port, apiKey, cancellationToken);
+        return serverInfo is not null;
+    }
+
+    /// <inheritdoc />
+    public async Task<MoonrakerPrinterInfo?> GetPrinterInfoAsync(
+        string hostnameOrIp,
+        int port,
+        string? apiKey,
+        CancellationToken cancellationToken = default)
+    {
+        var baseUrl = BuildBaseUrl(hostnameOrIp, port);
+
+        try
+        {
+            using var request = CreateRequest(HttpMethod.Get, $"{baseUrl}/printer/info", apiKey);
+            using var response = await _httpClient.SendAsync(request, cancellationToken);
+            response.EnsureSuccessStatusCode();
+
+            var json = await response.Content.ReadFromJsonAsync<JsonElement>(cancellationToken: cancellationToken);
+
+            var printerInfo = new MoonrakerPrinterInfo();
+
+            if (json.TryGetProperty("result", out var result))
+            {
+                if (result.TryGetProperty("state", out var state))
+                    printerInfo.State = state.GetString() ?? string.Empty;
+                if (result.TryGetProperty("state_message", out var stateMessage))
+                    printerInfo.StateMessage = stateMessage.GetString() ?? string.Empty;
+                if (result.TryGetProperty("klippy_ready", out var klippyReady))
+                    printerInfo.KlippyReady = klippyReady.GetBoolean();
+            }
+
+            _logger.LogDebug(
+                "Retrieved printer info from Moonraker at {Host}:{Port} — state: {State}",
+                hostnameOrIp, port, printerInfo.State);
+
+            return printerInfo;
+        }
+        catch (HttpRequestException ex)
+        {
+            _logger.LogWarning(ex,
+                "Failed to retrieve printer info from Moonraker at {Host}:{Port}",
+                hostnameOrIp, port);
+            return null;
+        }
+        catch (JsonException ex)
+        {
+            _logger.LogWarning(ex,
+                "Failed to parse Moonraker printer info response from {Host}:{Port}",
+                hostnameOrIp, port);
+            return null;
+        }
+    }
+
+    /// <inheritdoc />
+    public async Task<MoonrakerHistoryResponse> GetPrintHistoryAsync(
+        string hostnameOrIp,
+        int port,
+        string? apiKey,
+        int limit = 50,
+        CancellationToken cancellationToken = default)
+    {
+        var baseUrl = BuildBaseUrl(hostnameOrIp, port);
+        var historyResponse = new MoonrakerHistoryResponse();
+
+        try
+        {
+            using var request = CreateRequest(
+                HttpMethod.Get,
+                $"{baseUrl}/server/history/items?limit={limit}",
+                apiKey);
+
+            using var response = await _httpClient.SendAsync(request, cancellationToken);
+            response.EnsureSuccessStatusCode();
+
+            var json = await response.Content.ReadFromJsonAsync<JsonElement>(cancellationToken: cancellationToken);
+
+            if (json.TryGetProperty("result", out var result))
+            {
+                if (result.TryGetProperty("count", out var count))
+                    historyResponse.TotalCount = count.GetInt32();
+
+                if (result.TryGetProperty("items", out var items))
+                {
+                    foreach (var item in items.EnumerateArray())
+                    {
+                        var job = MapPrintJob(item);
+                        historyResponse.Items.Add(job);
+                    }
+                }
+            }
+
+            _logger.LogDebug(
+                "Retrieved {JobCount} print history items from Moonraker at {Host}:{Port}",
+                historyResponse.Items.Count, hostnameOrIp, port);
+        }
+        catch (HttpRequestException ex)
+        {
+            _logger.LogWarning(ex,
+                "Failed to retrieve print history from Moonraker at {Host}:{Port}",
+                hostnameOrIp, port);
+        }
+        catch (JsonException ex)
+        {
+            _logger.LogWarning(ex,
+                "Failed to parse Moonraker history response from {Host}:{Port}",
+                hostnameOrIp, port);
+        }
+
+        return historyResponse;
+    }
+
+    /// <inheritdoc />
+    public async Task<MoonrakerPrintStats?> GetPrintStatsAsync(
+        string hostnameOrIp,
+        int port,
+        string? apiKey,
+        CancellationToken cancellationToken = default)
+    {
+        var baseUrl = BuildBaseUrl(hostnameOrIp, port);
+
+        try
+        {
+            using var request = CreateRequest(
+                HttpMethod.Get,
+                $"{baseUrl}/printer/objects/query?print_stats",
+                apiKey);
+
+            using var response = await _httpClient.SendAsync(request, cancellationToken);
+            response.EnsureSuccessStatusCode();
+
+            var json = await response.Content.ReadFromJsonAsync<JsonElement>(cancellationToken: cancellationToken);
+
+            if (json.TryGetProperty("result", out var result)
+                && result.TryGetProperty("status", out var status)
+                && status.TryGetProperty("print_stats", out var printStats))
+            {
+                var stats = MapPrintStats(printStats);
+
+                _logger.LogDebug(
+                    "Retrieved print stats from Moonraker at {Host}:{Port} — state: {State}, filament: {FilamentMm}mm",
+                    hostnameOrIp, port, stats.State, stats.FilamentUsedMm);
+
+                return stats;
+            }
+
+            _logger.LogWarning(
+                "Moonraker print_stats not found in response from {Host}:{Port}",
+                hostnameOrIp, port);
+            return null;
+        }
+        catch (HttpRequestException ex)
+        {
+            _logger.LogWarning(ex,
+                "Failed to retrieve print stats from Moonraker at {Host}:{Port}",
+                hostnameOrIp, port);
+            return null;
+        }
+        catch (JsonException ex)
+        {
+            _logger.LogWarning(ex,
+                "Failed to parse Moonraker print stats response from {Host}:{Port}",
+                hostnameOrIp, port);
+            return null;
+        }
+    }
+
+    /// <inheritdoc />
+    public async Task<MoonrakerDisplayStatus?> GetDisplayStatusAsync(
+        string hostnameOrIp,
+        int port,
+        string? apiKey,
+        CancellationToken cancellationToken = default)
+    {
+        var baseUrl = BuildBaseUrl(hostnameOrIp, port);
+
+        try
+        {
+            using var request = CreateRequest(
+                HttpMethod.Get,
+                $"{baseUrl}/printer/objects/query?display_status",
+                apiKey);
+
+            using var response = await _httpClient.SendAsync(request, cancellationToken);
+            response.EnsureSuccessStatusCode();
+
+            var json = await response.Content.ReadFromJsonAsync<JsonElement>(cancellationToken: cancellationToken);
+
+            if (json.TryGetProperty("result", out var result)
+                && result.TryGetProperty("status", out var status)
+                && status.TryGetProperty("display_status", out var displayStatus))
+            {
+                var ds = new MoonrakerDisplayStatus();
+
+                if (displayStatus.TryGetProperty("progress", out var progress))
+                    ds.Progress = progress.GetDecimal();
+                if (displayStatus.TryGetProperty("message", out var message))
+                    ds.Message = message.GetString() ?? string.Empty;
+
+                _logger.LogDebug(
+                    "Retrieved display status from Moonraker at {Host}:{Port} — progress: {Progress:P0}",
+                    hostnameOrIp, port, ds.Progress);
+
+                return ds;
+            }
+
+            _logger.LogWarning(
+                "Moonraker display_status not found in response from {Host}:{Port}",
+                hostnameOrIp, port);
+            return null;
+        }
+        catch (HttpRequestException ex)
+        {
+            _logger.LogWarning(ex,
+                "Failed to retrieve display status from Moonraker at {Host}:{Port}",
+                hostnameOrIp, port);
+            return null;
+        }
+        catch (JsonException ex)
+        {
+            _logger.LogWarning(ex,
+                "Failed to parse Moonraker display status response from {Host}:{Port}",
+                hostnameOrIp, port);
+            return null;
+        }
+    }
+
+    /// <inheritdoc />
+    public async Task<Dictionary<string, decimal>> GetFilamentUsageAsync(
+        string hostnameOrIp,
+        int port,
+        string? apiKey,
+        CancellationToken cancellationToken = default)
+    {
+        // Delegate to the typed GetPrintHistoryAsync and extract metrics
+        var history = await GetPrintHistoryAsync(hostnameOrIp, port, apiKey, limit: 1, cancellationToken);
+        var result = new Dictionary<string, decimal>();
+
+        if (history.Items.Count > 0)
+        {
+            var latestJob = history.Items[0];
+            result["mm_extruded"] = latestJob.FilamentUsedMm;
+            result["print_duration_seconds"] = latestJob.PrintDurationSeconds;
+        }
+
+        _logger.LogDebug(
+            "Retrieved filament usage from Moonraker at {Host}:{Port}: {MetricCount} metrics",
+            hostnameOrIp, port, result.Count);
+
+        return result;
+    }
+
+    /// <summary>
+    /// Builds the base URL for Moonraker API calls from hostname and port.
+    /// </summary>
+    private static string BuildBaseUrl(string hostnameOrIp, int port)
+    {
+        return $"http://{hostnameOrIp}:{port}";
+    }
+
+    /// <summary>
+    /// Creates an HttpRequestMessage with the optional API key header.
+    /// </summary>
+    private static HttpRequestMessage CreateRequest(HttpMethod method, string url, string? apiKey)
+    {
+        var request = new HttpRequestMessage(method, url);
+        if (!string.IsNullOrEmpty(apiKey))
+        {
+            request.Headers.Add("X-Api-Key", apiKey);
+        }
+        return request;
+    }
+
+    /// <summary>
+    /// Maps a JSON element representing a Moonraker print job history item
+    /// to a <see cref="MoonrakerPrintJob"/> DTO.
+    /// </summary>
+    private static MoonrakerPrintJob MapPrintJob(JsonElement item)
+    {
+        var job = new MoonrakerPrintJob();
+
+        if (item.TryGetProperty("job_id", out var jobId))
+            job.JobId = jobId.GetString() ?? string.Empty;
+        if (item.TryGetProperty("filename", out var filename))
+            job.Filename = filename.GetString() ?? string.Empty;
+        if (item.TryGetProperty("status", out var status))
+            job.Status = status.GetString() ?? string.Empty;
+        if (item.TryGetProperty("filament_used", out var filamentUsed))
+            job.FilamentUsedMm = filamentUsed.GetDecimal();
+        if (item.TryGetProperty("print_duration", out var printDuration))
+            job.PrintDurationSeconds = printDuration.GetDecimal();
+        if (item.TryGetProperty("total_duration", out var totalDuration))
+            job.TotalDurationSeconds = totalDuration.GetDecimal();
+
+        if (item.TryGetProperty("start_time", out var startTime) && startTime.ValueKind != JsonValueKind.Null)
+        {
+            if (startTime.TryGetInt64(out var startTimeSeconds))
+                job.StartTime = DateTimeOffset.FromUnixTimeSeconds(startTimeSeconds).UtcDateTime;
+        }
+
+        if (item.TryGetProperty("end_time", out var endTime) && endTime.ValueKind != JsonValueKind.Null)
+        {
+            if (endTime.TryGetInt64(out var endTimeSeconds))
+                job.EndTime = DateTimeOffset.FromUnixTimeSeconds(endTimeSeconds).UtcDateTime;
+        }
+
+        if (item.TryGetProperty("metadata", out var metadata) && metadata.ValueKind == JsonValueKind.Object)
+        {
+            foreach (var prop in metadata.EnumerateObject())
+            {
+                object value = prop.Value.ValueKind switch
+                {
+                    JsonValueKind.String => prop.Value.GetString() ?? string.Empty,
+                    JsonValueKind.Number => prop.Value.GetDecimal(),
+                    JsonValueKind.True => true,
+                    JsonValueKind.False => false,
+                    _ => prop.Value.ToString() ?? string.Empty
+                };
+                job.Metadata[prop.Name] = value;
+            }
+        }
+
+        return job;
+    }
+
+    /// <summary>
+    /// Maps a JSON element representing Moonraker print_stats
+    /// to a <see cref="MoonrakerPrintStats"/> DTO.
+    /// </summary>
+    private static MoonrakerPrintStats MapPrintStats(JsonElement printStats)
+    {
+        var stats = new MoonrakerPrintStats();
+
+        if (printStats.TryGetProperty("state", out var state))
+            stats.State = state.GetString() ?? string.Empty;
+        if (printStats.TryGetProperty("filament_used", out var filamentUsed))
+            stats.FilamentUsedMm = filamentUsed.GetDecimal();
+        if (printStats.TryGetProperty("print_duration", out var printDuration))
+            stats.PrintDurationSeconds = printDuration.GetDecimal();
+        if (printStats.TryGetProperty("filename", out var filename) && filename.ValueKind != JsonValueKind.Null)
+            stats.Filename = filename.GetString();
+        if (printStats.TryGetProperty("message", out var message) && message.ValueKind != JsonValueKind.Null)
+            stats.Message = message.GetString();
+
+        return stats;
+    }
+}

backend/Infrastructure/Services/MoonrakerPrinterSyncService.cs

@@ -0,0 +1,320 @@
+using Extrudex.Domain.DTOs.Moonraker;
+using Extrudex.Domain.Entities;
+using Extrudex.Domain.Enums;
+using Extrudex.Domain.Interfaces;
+using Extrudex.Infrastructure.Configuration;
+using Extrudex.Infrastructure.Data;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Logging;
+
+namespace Extrudex.Infrastructure.Services;
+
+/// <summary>
+/// Service that syncs Moonraker printer status and print job history into the
+/// Extrudex database. Queries all active Moonraker printers, fetches their
+/// current operational state, and maps completed print jobs to PrintJob and
+/// FilamentUsage entities with derived gram calculations.
+/// </summary>
+public class MoonrakerPrinterSyncService : IMoonrakerPrinterSyncService
+{
+    private readonly ExtrudexDbContext _dbContext;
+    private readonly IMoonrakerClient _moonrakerClient;
+    private readonly ILogger<MoonrakerPrinterSyncService> _logger;
+
+    /// <summary>
+    /// Creates a new MoonrakerPrinterSyncService.
+    /// </summary>
+    /// <param name="dbContext">The EF Core database context for persisting updates.</param>
+    /// <param name="moonrakerClient">The Moonraker HTTP client for fetching printer data.</param>
+    /// <param name="logger">Logger for diagnostic output.</param>
+    public MoonrakerPrinterSyncService(
+        ExtrudexDbContext dbContext,
+        IMoonrakerClient moonrakerClient,
+        ILogger<MoonrakerPrinterSyncService> logger)
+    {
+        _dbContext = dbContext;
+        _moonrakerClient = moonrakerClient;
+        _logger = logger;
+    }
+
+    /// <inheritdoc />
+    public async Task<int> SyncAllAsync(CancellationToken cancellationToken = default)
+    {
+        _logger.LogInformation("Starting Moonraker printer sync cycle");
+
+        var printers = await _dbContext.Printers
+            .Where(p => p.IsActive && p.ConnectionType == ConnectionType.Moonraker)
+            .Include(p => p.AmsUnits)
+                .ThenInclude(u => u.Slots)
+                    .ThenInclude(s => s.Spool)
+                        .ThenInclude(s => s.MaterialBase)
+            .Include(p => p.PrintJobs)
+            .ToListAsync(cancellationToken);
+
+        if (printers.Count == 0)
+        {
+            _logger.LogInformation("No active Moonraker printers found — skipping sync");
+            return 0;
+        }
+
+        _logger.LogInformation("Found {PrinterCount} active Moonraker printer(s) to sync", printers.Count);
+
+        var syncedCount = 0;
+
+        foreach (var printer in printers)
+        {
+            try
+            {
+                await SyncPrinterAsync(printer, cancellationToken);
+                syncedCount++;
+            }
+            catch (Exception ex) when (ex is not OperationCanceledException)
+            {
+                _logger.LogError(ex,
+                    "Error syncing printer {PrinterName} ({Host}:{Port})",
+                    printer.Name, printer.HostnameOrIp, printer.Port);
+
+                // Mark printer as offline if we can't reach it
+                printer.Status = PrinterStatus.Offline;
+            }
+        }
+
+        await _dbContext.SaveChangesAsync(cancellationToken);
+
+        _logger.LogInformation(
+            "Moonraker printer sync cycle complete — {SyncedCount}/{TotalCount} printers synced",
+            syncedCount, printers.Count);
+
+        return syncedCount;
+    }
+
+    /// <summary>
+    /// Syncs a single Moonraker printer: updates its status, fetches print history,
+    /// and maps new print jobs to database entities.
+    /// </summary>
+    private async Task SyncPrinterAsync(Printer printer, CancellationToken cancellationToken)
+    {
+        // Step 1: Fetch printer status
+        var printerInfo = await _moonrakerClient.GetPrinterInfoAsync(
+            printer.HostnameOrIp, printer.Port, printer.ApiKey, cancellationToken);
+
+        var printStats = await _moonrakerClient.GetPrintStatsAsync(
+            printer.HostnameOrIp, printer.Port, printer.ApiKey, cancellationToken);
+
+        // Step 2: Update printer status
+        UpdatePrinterStatus(printer, printerInfo, printStats);
+        printer.LastSeenAt = DateTime.UtcNow;
+
+        _logger.LogDebug(
+            "Printer {PrinterName} status updated to {Status}",
+            printer.Name, printer.Status);
+
+        // Step 3: Fetch and map print job history
+        var history = await _moonrakerClient.GetPrintHistoryAsync(
+            printer.HostnameOrIp, printer.Port, printer.ApiKey,
+            limit: 25,
+            cancellationToken);
+
+        if (history.Items.Count == 0)
+        {
+            _logger.LogDebug("No print history returned for printer {PrinterName}", printer.Name);
+            return;
+        }
+
+        var newJobsCount = await MapPrintJobsAsync(printer, history.Items, cancellationToken);
+
+        if (newJobsCount > 0)
+        {
+            _logger.LogInformation(
+                "Mapped {NewJobsCount} new print job(s) from printer {PrinterName}",
+                newJobsCount, printer.Name);
+        }
+    }
+
+    /// <summary>
+    /// Updates the printer's operational status based on Moonraker telemetry.
+    /// Maps Klipper/Moonraker state strings to the PrinterStatus enum.
+    /// </summary>
+    private void UpdatePrinterStatus(
+        Printer printer,
+        MoonrakerPrinterInfo? printerInfo,
+        MoonrakerPrintStats? printStats)
+    {
+        // Prefer print_stats state — it's the most authoritative
+        if (printStats != null)
+        {
+            printer.Status = printStats.State.ToLowerInvariant() switch
+            {
+                "printing" => PrinterStatus.Printing,
+                "paused" => PrinterStatus.Paused,
+                "complete" => PrinterStatus.Idle,
+                "standby" => PrinterStatus.Idle,
+                "cancelled" => PrinterStatus.Idle,
+                "error" => PrinterStatus.Error,
+                _ => PrinterStatus.Idle
+            };
+            return;
+        }
+
+        // Fall back to printer_info state
+        if (printerInfo != null)
+        {
+            printer.Status = printerInfo.State.ToLowerInvariant() switch
+            {
+                "ready" => PrinterStatus.Idle,
+                "startup" => PrinterStatus.Idle,
+                "shutdown" => PrinterStatus.Offline,
+                "error" => PrinterStatus.Error,
+                "cancelled" => PrinterStatus.Idle,
+                _ => printer.Status // Preserve existing status if unknown
+            };
+        }
+    }
+
+    /// <summary>
+    /// Maps Moonraker print job history items to Extrudex PrintJob and FilamentUsage entities.
+    /// Only creates records for jobs not already tracked (by Moonraker JobId stored in GcodeFilePath).
+    /// </summary>
+    private async Task<int> MapPrintJobsAsync(
+        Printer printer,
+        List<MoonrakerPrintJob> historyItems,
+        CancellationToken cancellationToken)
+    {
+        // Build a set of already-tracked Moonraker JobIds for this printer
+        // We store the Moonraker JobId in the GcodeFilePath field with a "moonraker:" prefix
+        var trackedJobIds = await _dbContext.PrintJobs
+            .Where(pj => pj.PrinterId == printer.Id && pj.GcodeFilePath != null && pj.GcodeFilePath.StartsWith("moonraker:"))
+            .Select(pj => pj.GcodeFilePath!)
+            .ToListAsync(cancellationToken);
+
+        var trackedIdSet = new HashSet<string>(trackedJobIds);
+        var newJobsCount = 0;
+
+        // Find the default spool for this printer (first active spool in AMS, or first active spool overall)
+        var defaultSpool = FindDefaultSpool(printer);
+
+        foreach (var moonrakerJob in historyItems)
+        {
+            var jobIdKey = $"moonraker:{moonrakerJob.JobId}";
+
+            if (trackedIdSet.Contains(jobIdKey))
+            {
+                continue; // Already tracked — skip
+            }
+
+            // Only map completed, cancelled, or errored jobs (not in_progress)
+            // In-progress jobs will be captured on the next cycle once they finish
+            if (moonrakerJob.Status == "in_progress")
+            {
+                continue;
+            }
+
+            // Map Moonraker job status to JobStatus enum
+            var jobStatus = moonrakerJob.Status.ToLowerInvariant() switch
+            {
+                "completed" => JobStatus.Completed,
+                "cancelled" => JobStatus.Cancelled,
+                "error" => JobStatus.Failed,
+                _ => JobStatus.Completed
+            };
+
+            // Calculate derived grams if we have a spool and filament data
+            decimal gramsDerived = 0m;
+            decimal filamentDiameterMm = 1.75m;
+            decimal materialDensity = 1.24m; // PLA default
+
+            if (defaultSpool != null)
+            {
+                filamentDiameterMm = defaultSpool.FilamentDiameterMm;
+                materialDensity = defaultSpool.MaterialBase.DensityGperCm3;
+                gramsDerived = CalculateGrams(moonrakerJob.FilamentUsedMm, filamentDiameterMm, materialDensity);
+            }
+            else if (moonrakerJob.FilamentUsedMm > 0)
+            {
+                gramsDerived = CalculateGrams(moonrakerJob.FilamentUsedMm, 1.75m, 1.24m);
+                _logger.LogWarning(
+                    "No default spool found for printer {PrinterName} — using PLA defaults for grams derivation on job {JobId}",
+                    printer.Name, moonrakerJob.JobId);
+            }
+
+            var printJob = new PrintJob
+            {
+                PrinterId = printer.Id,
+                SpoolId = defaultSpool?.Id ?? Guid.Empty,
+                PrintName = moonrakerJob.Filename,
+                GcodeFilePath = jobIdKey,
+                MmExtruded = moonrakerJob.FilamentUsedMm,
+                GramsDerived = gramsDerived,
+                StartedAt = moonrakerJob.StartTime,
+                CompletedAt = moonrakerJob.EndTime,
+                Status = jobStatus,
+                DataSource = DataSource.Moonraker,
+                FilamentDiameterAtPrintMm = filamentDiameterMm,
+                MaterialDensityAtPrint = materialDensity,
+                Notes = $"Auto-imported from Moonraker (JobId: {moonrakerJob.JobId})"
+            };
+
+            _dbContext.PrintJobs.Add(printJob);
+
+            // Create a FilamentUsage record if filament was consumed
+            if (moonrakerJob.FilamentUsedMm > 0 && defaultSpool != null)
+            {
+                var usage = new FilamentUsage
+                {
+                    PrintJob = printJob,
+                    SpoolId = defaultSpool.Id,
+                    PrinterId = printer.Id,
+                    GramsUsed = gramsDerived,
+                    MmExtruded = moonrakerJob.FilamentUsedMm,
+                    RecordedAt = DateTime.UtcNow,
+                    Notes = $"Auto-imported from Moonraker history (JobId: {moonrakerJob.JobId})"
+                };
+
+                _dbContext.FilamentUsages.Add(usage);
+            }
+
+            newJobsCount++;
+            trackedIdSet.Add(jobIdKey); // Prevent duplicates within this batch
+        }
+
+        return newJobsCount;
+    }
+
+    /// <summary>
+    /// Finds the default spool for a printer. Returns the first spool loaded
+    /// in an AMS slot, or null if no spool is available.
+    /// </summary>
+    private static Spool? FindDefaultSpool(Printer printer)
+    {
+        // Prefer the first active spool in an AMS slot
+        foreach (var amsUnit in printer.AmsUnits)
+        {
+            foreach (var slot in amsUnit.Slots)
+            {
+                if (slot.Spool != null && slot.Spool.IsActive && !slot.Spool.IsArchived)
+                {
+                    return slot.Spool;
+                }
+            }
+        }
+
+        return null;
+    }
+
+    /// <summary>
+    /// Calculates derived grams from millimeters extruded using the standard formula:
+    /// grams = mm_extruded × cross_section_area × material_density
+    /// where cross_section_area = π × (diameter / 2)²
+    /// </summary>
+    private static decimal CalculateGrams(decimal mmExtruded, decimal diameterMm, decimal densityGperCm3)
+    {
+        if (mmExtruded <= 0) return 0m;
+
+        var radiusCm = (double)diameterMm / 2.0 / 10.0; // mm to cm
+        var crossSectionAreaCm2 = Math.PI * radiusCm * radiusCm;
+        var mmToCm = (double)mmExtruded / 10.0;
+
+        var grams = mmToCm * crossSectionAreaCm2 * (double)densityGperCm3;
+        return (decimal)grams;
+    }
+}

backend/Infrastructure/Services/MoonrakerUsagePoller.cs

@@ -0,0 +1,390 @@
+using Extrudex.Domain.DTOs.Moonraker;
+using Extrudex.Domain.Entities;
+using Extrudex.Domain.Enums;
+using Extrudex.Domain.Interfaces;
+using Extrudex.Infrastructure.Data;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
+
+namespace Extrudex.Infrastructure.Services;
+
+/// <summary>
+/// Configuration options for the Moonraker usage polling service.
+/// </summary>
+public class MoonrakerPollerOptions
+{
+    /// <summary>
+    /// How often to poll each Moonraker printer for filament usage data.
+    /// Default: 30 seconds.
+    /// </summary>
+    public TimeSpan PollInterval { get; set; } = TimeSpan.FromSeconds(30);
+
+    /// <summary>
+    /// Timeout for individual Moonraker HTTP requests.
+    /// Default: 10 seconds.
+    /// </summary>
+    public TimeSpan RequestTimeout { get; set; } = TimeSpan.FromSeconds(10);
+
+    /// <summary>
+    /// Whether the polling service is enabled. Default: true.
+    /// Set to false to disable polling (e.g., in development or testing).
+    /// </summary>
+    public bool Enabled { get; set; } = true;
+}
+
+/// <summary>
+/// Background service that periodically polls Moonraker-connected printers
+/// for filament usage data. When a print job is detected as complete,
+/// the usage data is persisted to the FilamentUsage table via
+/// <see cref="IFilamentUsageService"/>.
+///
+/// <para>Polling logic:</para>
+/// <list type="number">
+///   <item>Query the database for all active printers with ConnectionType == Moonraker.</item>
+///   <item>For each printer, call <see cref="IMoonrakerClient.GetPrintStatsAsync"/> for live data
+///         and <see cref="IMoonrakerClient.GetPrintHistoryAsync"/> for completed job history.</item>
+///   <item>If usage data is available and the print state is "complete",
+///         create or update a FilamentUsage record.</item>
+///   <item>If the printer is unreachable or returns malformed data, log a warning
+///         and continue to the next printer (no crash).</item>
+/// </list>
+///
+/// <para>Error handling:</para>
+/// <list type="bullet">
+///   <item>API unreachable: logged as warning, poller continues for other printers.</item>
+///   <item>Malformed response: logged as warning, poller continues.</item>
+///   <item>Database errors: logged as error, poller continues.</item>
+/// </list>
+/// </summary>
+public class MoonrakerUsagePoller : BackgroundService
+{
+    private readonly IServiceScopeFactory _scopeFactory;
+    private readonly ILogger<MoonrakerUsagePoller> _logger;
+    private readonly MoonrakerPollerOptions _options;
+
+    /// <summary>
+    /// Tracks which Moonraker print jobs have already been recorded,
+    /// keyed by "printerId:gcodeFileName" to avoid duplicate recording.
+    /// </summary>
+    private readonly HashSet<string> _recordedJobs = new();
+
+    public MoonrakerUsagePoller(
+        IServiceScopeFactory scopeFactory,
+        ILogger<MoonrakerUsagePoller> logger,
+        IOptions<MoonrakerPollerOptions> options)
+    {
+        _scopeFactory = scopeFactory;
+        _logger = logger;
+        _options = options.Value;
+    }
+
+    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
+    {
+        if (!_options.Enabled)
+        {
+            _logger.LogInformation("Moonraker usage poller is disabled via configuration.");
+            return;
+        }
+
+        _logger.LogInformation(
+            "Moonraker usage poller starting. Poll interval: {Interval}",
+            _options.PollInterval);
+
+        while (!stoppingToken.IsCancellationRequested)
+        {
+            try
+            {
+                await PollAllPrintersAsync(stoppingToken);
+            }
+            catch (Exception ex)
+            {
+                _logger.LogError(ex,
+                    "Unexpected error in Moonraker usage poller cycle. Continuing.");
+            }
+
+            await Task.Delay(_options.PollInterval, stoppingToken);
+        }
+
+        _logger.LogInformation("Moonraker usage poller stopping.");
+    }
+
+    private async Task PollAllPrintersAsync(CancellationToken cancellationToken)
+    {
+        using var scope = _scopeFactory.CreateScope();
+        var dbContext = scope.ServiceProvider.GetRequiredService<ExtrudexDbContext>();
+        var moonrakerClient = scope.ServiceProvider.GetRequiredService<IMoonrakerClient>();
+        var usageService = scope.ServiceProvider.GetRequiredService<IFilamentUsageService>();
+
+        var printers = await dbContext.Printers
+            .Where(p => p.IsActive && p.ConnectionType == ConnectionType.Moonraker)
+            .ToListAsync(cancellationToken);
+
+        if (printers.Count == 0)
+        {
+            _logger.LogDebug("No active Moonraker printers found.");
+            return;
+        }
+
+        _logger.LogDebug("Polling {Count} Moonraker printer(s).", printers.Count);
+
+        foreach (var printer in printers)
+        {
+            await PollPrinterAsync(
+                printer, moonrakerClient, usageService, dbContext, cancellationToken);
+        }
+    }
+
+    private async Task PollPrinterAsync(
+        Printer printer,
+        IMoonrakerClient moonrakerClient,
+        IFilamentUsageService usageService,
+        ExtrudexDbContext dbContext,
+        CancellationToken cancellationToken)
+    {
+        _logger.LogDebug(
+            "Polling Moonraker printer {PrinterName} ({Host}:{Port})",
+            printer.Name, printer.HostnameOrIp, printer.Port);
+
+        try
+        {
+            var printStats = await moonrakerClient.GetPrintStatsAsync(
+                printer.HostnameOrIp,
+                printer.Port,
+                printer.ApiKey,
+                cancellationToken);
+
+            if (printStats is null)
+            {
+                _logger.LogDebug(
+                    "No print stats available from printer {PrinterName}.", printer.Name);
+                return;
+            }
+
+            printer.LastSeenAt = DateTime.UtcNow;
+            await dbContext.SaveChangesAsync(cancellationToken);
+
+            _logger.LogDebug(
+                "Printer {PrinterName}: state={State}, filament={Mm}mm, file={File}",
+                printer.Name, printStats.State, printStats.FilamentUsedMm, printStats.Filename);
+
+            decimal mmExtruded = printStats.FilamentUsedMm;
+            if (mmExtruded <= 0)
+            {
+                _logger.LogDebug(
+                    "Printer {PrinterName} has no filament usage to record.", printer.Name);
+                return;
+            }
+
+            if (!IsCompleteState(printStats.State))
+            {
+                _logger.LogDebug(
+                    "Printer {PrinterName} print state '{State}' is not complete; skipping.",
+                    printer.Name, printStats.State);
+                return;
+            }
+
+            string gcodeFileName = printStats.Filename ?? $"unknown-{Guid.NewGuid():N}";
+            var deduplicationKey = $"{printer.Id}:{gcodeFileName}";
+            if (_recordedJobs.Contains(deduplicationKey))
+            {
+                _logger.LogDebug(
+                    "Printer {PrinterName} job '{File}' already recorded; skipping.",
+                    printer.Name, gcodeFileName);
+                return;
+            }
+
+            DateTime? startedAt = null;
+            DateTime? completedAt = null;
+            try
+            {
+                var history = await moonrakerClient.GetPrintHistoryAsync(
+                    printer.HostnameOrIp, printer.Port, printer.ApiKey,
+                    limit: 1, cancellationToken);
+
+                if (history.Items.Count > 0)
+                {
+                    var latestJob = history.Items[0];
+                    startedAt = latestJob.StartTime;
+                    completedAt = latestJob.EndTime;
+                }
+            }
+            catch (Exception ex)
+            {
+                _logger.LogDebug(ex,
+                    "Could not fetch history for printer {PrinterName}; proceeding with stats only.",
+                    printer.Name);
+            }
+
+            var printJob = await FindOrCreatePrintJobAsync(
+                dbContext, printer, mmExtruded, gcodeFileName,
+                startedAt, completedAt, cancellationToken);
+
+            if (printJob is null)
+            {
+                _logger.LogWarning(
+                    "Could not find or create print job for printer {PrinterName}. No active spool found.",
+                    printer.Name);
+                return;
+            }
+
+            var spool = await dbContext.Spools.FindAsync(
+                new object[] { printJob.SpoolId }, cancellationToken);
+
+            var gramsUsed = CalculateGramsUsed(mmExtruded, spool);
+
+            await usageService.RecordUsageAsync(
+                printJobId: printJob.Id,
+                spoolId: printJob.SpoolId,
+                printerId: printer.Id,
+                gramsUsed: gramsUsed,
+                mmExtruded: mmExtruded,
+                notes: $"Moonraker auto-recorded: {gcodeFileName}",
+                cancellationToken: cancellationToken);
+
+            _recordedJobs.Add(deduplicationKey);
+
+            _logger.LogInformation(
+                "Recorded Moonraker usage for printer {PrinterName}: {Mm}mm / {Grams}g, job '{File}'",
+                printer.Name, mmExtruded, gramsUsed, gcodeFileName);
+        }
+        catch (HttpRequestException ex)
+        {
+            _logger.LogWarning(ex,
+                "Moonraker API unreachable for printer {PrinterName} ({Host}:{Port}). Will retry next cycle.",
+                printer.Name, printer.HostnameOrIp, printer.Port);
+        }
+        catch (TaskCanceledException) when (cancellationToken.IsCancellationRequested)
+        {
+            throw;
+        }
+        catch (TaskCanceledException ex)
+        {
+            _logger.LogWarning(ex,
+                "Moonraker request timed out for printer {PrinterName} ({Host}:{Port}).",
+                printer.Name, printer.HostnameOrIp, printer.Port);
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex,
+                "Unexpected error polling Moonraker printer {PrinterName}. Continuing to next printer.",
+                printer.Name);
+        }
+    }
+
+    private static bool IsCompleteState(string state) =>
+        state.Equals("complete", StringComparison.OrdinalIgnoreCase) ||
+        state.Equals("completed", StringComparison.OrdinalIgnoreCase);
+
+    private async Task<PrintJob?> FindOrCreatePrintJobAsync(
+        ExtrudexDbContext dbContext,
+        Printer printer,
+        decimal mmExtruded,
+        string gcodeFileName,
+        DateTime? startedAt,
+        DateTime? completedAt,
+        CancellationToken cancellationToken)
+    {
+        if (!string.IsNullOrEmpty(gcodeFileName))
+        {
+            var existingJob = await dbContext.PrintJobs
+                .Where(j => j.PrinterId == printer.Id &&
+                            j.GcodeFilePath == gcodeFileName &&
+                            j.DataSource == DataSource.Moonraker &&
+                            j.Status != JobStatus.Cancelled)
+                .OrderByDescending(j => j.CreatedAt)
+                .FirstOrDefaultAsync(cancellationToken);
+
+            if (existingJob is not null)
+            {
+                existingJob.MmExtruded = mmExtruded;
+                existingJob.GramsDerived = CalculateGramsUsed(
+                    mmExtruded,
+                    await dbContext.Spools.FindAsync(
+                        new object[] { existingJob.SpoolId }, cancellationToken));
+                existingJob.Status = JobStatus.Completed;
+                existingJob.CompletedAt = completedAt ?? DateTime.UtcNow;
+                existingJob.StartedAt ??= startedAt;
+                await dbContext.SaveChangesAsync(cancellationToken);
+                return existingJob;
+            }
+        }
+
+        var spool = await FindActiveSpoolForPrinterAsync(dbContext, printer, cancellationToken);
+        if (spool is null) return null;
+
+        var gramsDerived = CalculateGramsUsed(mmExtruded, spool);
+
+        var newJob = new PrintJob
+        {
+            PrinterId = printer.Id,
+            SpoolId = spool.Id,
+            PrintName = gcodeFileName ?? "Moonraker Print",
+            GcodeFilePath = gcodeFileName,
+            MmExtruded = mmExtruded,
+            GramsDerived = gramsDerived,
+            FilamentDiameterAtPrintMm = spool.FilamentDiameterMm,
+            MaterialDensityAtPrint = GetMaterialDensity(spool),
+            DataSource = DataSource.Moonraker,
+            Status = JobStatus.Completed,
+            StartedAt = startedAt ?? DateTime.UtcNow,
+            CompletedAt = completedAt ?? DateTime.UtcNow,
+            Notes = "Auto-created by Moonraker usage poller"
+        };
+
+        dbContext.PrintJobs.Add(newJob);
+        await dbContext.SaveChangesAsync(cancellationToken);
+
+        return newJob;
+    }
+
+    private static async Task<Spool?> FindActiveSpoolForPrinterAsync(
+        ExtrudexDbContext dbContext,
+        Printer printer,
+        CancellationToken cancellationToken)
+    {
+        var amsSpool = await dbContext.AmsSlots
+            .Include(s => s.Spool)
+            .ThenInclude(s => s!.MaterialBase)
+            .Include(s => s.AmsUnit)
+            .Where(s => s.AmsUnit.PrinterId == printer.Id && s.Spool != null && s.Spool.IsActive)
+            .Select(s => s.Spool)
+            .FirstOrDefaultAsync(cancellationToken);
+
+        if (amsSpool is not null) return amsSpool;
+
+        return await dbContext.Spools
+            .Include(s => s.MaterialBase)
+            .Where(s => s.IsActive)
+            .OrderByDescending(s => s.WeightRemainingGrams)
+            .FirstOrDefaultAsync(cancellationToken);
+    }
+
+    private static decimal CalculateGramsUsed(decimal mmExtruded, Spool? spool)
+    {
+        if (spool is null) return 0m;
+        var diameterMm = spool.FilamentDiameterMm;
+        var densityGcm3 = GetMaterialDensity(spool);
+        var radiusMm = diameterMm / 2m;
+        var crossSectionArea = Math.PI * (double)radiusMm * (double)radiusMm;
+        var volumeMm3 = (double)mmExtruded * crossSectionArea;
+        var volumeCm3 = volumeMm3 / 1000.0;
+        var grams = volumeCm3 * (double)densityGcm3;
+        return Math.Round((decimal)grams, 2);
+    }
+
+    private static decimal GetMaterialDensity(Spool? spool)
+    {
+        return spool?.MaterialBase?.Name?.ToUpperInvariant() switch
+        {
+            "PLA" => 1.24m,
+            "PETG" => 1.27m,
+            "ABS" => 1.04m,
+            "ASA" => 1.07m,
+            "TPU" => 1.21m,
+            "NYLON" or "PA" => 1.13m,
+            "PC" => 1.20m,
+            _ => 1.24m
+        };
+    }
+}

backend/Infrastructure/Services/UsageLogService.cs

@@ -0,0 +1,81 @@
+using Extrudex.Domain.Entities;
+using Extrudex.Domain.Enums;
+using Extrudex.Domain.Interfaces;
+using Extrudex.Infrastructure.Data;
+using Microsoft.EntityFrameworkCore;
+
+namespace Extrudex.Infrastructure.Services;
+
+/// <summary>
+/// Implementation of <see cref="IUsageLogService"/> that persists usage entries
+/// to the usage_logs table via EF Core.
+/// </summary>
+public class UsageLogService : IUsageLogService
+{
+    private readonly ExtrudexDbContext _dbContext;
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="UsageLogService"/> class.
+    /// </summary>
+    /// <param name="dbContext">The EF Core database context for data persistence.</param>
+    public UsageLogService(ExtrudexDbContext dbContext)
+    {
+        _dbContext = dbContext;
+    }
+
+    /// <inheritdoc/>
+    public async Task<UsageLog> RecordUsageAsync(
+        Guid spoolId,
+        decimal gramsUsed,
+        DataSource dataSource,
+        Guid? printerId = null,
+        Guid? printJobId = null,
+        decimal? mmExtruded = null,
+        DateTime? usageTimestamp = null,
+        string? notes = null)
+    {
+        var entry = new UsageLog
+        {
+            SpoolId = spoolId,
+            GramsUsed = gramsUsed,
+            DataSource = dataSource,
+            PrinterId = printerId,
+            PrintJobId = printJobId,
+            MmExtruded = mmExtruded,
+            UsageTimestamp = usageTimestamp ?? DateTime.UtcNow,
+            Notes = notes
+        };
+
+        _dbContext.UsageLogs.Add(entry);
+        await _dbContext.SaveChangesAsync();
+
+        return entry;
+    }
+
+    /// <inheritdoc/>
+    public async Task<IEnumerable<UsageLog>> GetBySpoolAsync(Guid spoolId, CancellationToken cancellationToken = default)
+    {
+        return await _dbContext.UsageLogs
+            .Where(u => u.SpoolId == spoolId)
+            .OrderByDescending(u => u.UsageTimestamp)
+            .ToListAsync(cancellationToken);
+    }
+
+    /// <inheritdoc/>
+    public async Task<IEnumerable<UsageLog>> GetByPrinterAsync(Guid printerId, CancellationToken cancellationToken = default)
+    {
+        return await _dbContext.UsageLogs
+            .Where(u => u.PrinterId == printerId)
+            .OrderByDescending(u => u.UsageTimestamp)
+            .ToListAsync(cancellationToken);
+    }
+
+    /// <inheritdoc/>
+    public async Task<IEnumerable<UsageLog>> GetByPrintJobAsync(Guid printJobId, CancellationToken cancellationToken = default)
+    {
+        return await _dbContext.UsageLogs
+            .Where(u => u.PrintJobId == printJobId)
+            .OrderByDescending(u => u.UsageTimestamp)
+            .ToListAsync(cancellationToken);
+    }
+}

backend/Program.cs

@@ -1,7 +1,9 @@
 using System.Reflection;
 using Extrudex.API.Filters;
 using Extrudex.API.Hubs;
+using Extrudex.API.Jobs;
 using Extrudex.Domain.Interfaces;
+using Extrudex.Infrastructure.Configuration;
 using Extrudex.Infrastructure.Data;
 using Extrudex.Infrastructure.Services;
 using FluentValidation;
@@ -50,6 +52,23 @@ builder.Services.AddSwaggerGen(c =>
 // ── QR Code Generation ──────────────────────────────────────
 builder.Services.AddSingleton<IQrCodeService, QrCodeService>();
 
+// ── Cost Per Print Calculation ─────────────────────────────
+builder.Services.AddScoped<ICostPerPrintService, CostPerPrintService>();
+
+// ── Low Stock Detection ────────────────────────────────────
+builder.Services.AddSingleton<ILowStockDetector, LowStockDetector>();
+
+// ── Usage Logging ───────────────────────────────────────────
+builder.Services.AddScoped<IUsageLogService, UsageLogService>();
+
+// ── Filament Usage Service ──────────────────────────────────
+builder.Services.AddScoped<IFilamentUsageService, FilamentUsageService>();
+
+// ── Moonraker Usage Poller (Background Service) ─────────────
+builder.Services.Configure<MoonrakerPollerOptions>(
+    builder.Configuration.GetSection("MoonrakerPoller"));
+builder.Services.AddHostedService<MoonrakerUsagePoller>();
+
 // ── FluentValidation ──────────────────────────────────────
 // Registers all validators from the API assembly into DI.
 builder.Services.AddValidatorsFromAssembly(Assembly.GetExecutingAssembly());
@@ -77,6 +96,22 @@ builder.Services.AddCors(options =>
 // ── SignalR (real-time printer updates) ────────────────────
 builder.Services.AddSignalR();
 
+// ── Filament Usage Sync (Background Job) ──────────────────
+builder.Services.Configure<FilamentUsageSyncOptions>(
+    builder.Configuration.GetSection(FilamentUsageSyncOptions.SectionName));
+builder.Services.AddHttpClient<IMoonrakerClient, MoonrakerClient>(client =>
+{
+    client.DefaultRequestHeaders.Add("User-Agent", "Extrudex/1.0");
+});
+builder.Services.AddScoped<IFilamentUsageSyncService, FilamentUsageSyncService>();
+builder.Services.AddHostedService<FilamentUsageSyncJob>();
+
+// ── Moonraker Printer Sync (Background Service) ──────────
+builder.Services.Configure<MoonrakerPrinterSyncOptions>(
+    builder.Configuration.GetSection(MoonrakerPrinterSyncOptions.SectionName));
+builder.Services.AddScoped<IMoonrakerPrinterSyncService, MoonrakerPrinterSyncService>();
+builder.Services.AddHostedService<MoonrakerPrinterSyncJob>();
+
 // ── Health Checks ───────────────────────────────────────────
 builder.Services.AddHealthChecks()
     .AddNpgSql(connectionString);

backend/appsettings.Development.json

@@ -8,5 +8,10 @@
   },
   "ConnectionStrings": {
     "ExtrudexDb": "Host=localhost;Port=5432;Database=extrudex_dev;Username=extrudex;Password=changeme"
+  },
+  "FilamentUsageSync": {
+    "PollingInterval": "00:01:00",
+    "RequestTimeout": "00:00:30",
+    "Enabled": true
   }
 }

backend/appsettings.json

@@ -9,5 +9,25 @@
   "AllowedHosts": "*",
   "ConnectionStrings": {
     "ExtrudexDb": "Host=localhost;Port=5432;Database=extrudex;Username=extrudex;Password=changeme"
+  },
+  "FilamentUsageSync": {
+    "PollingInterval": "00:05:00",
+    "RequestTimeout": "00:00:30",
+    "Enabled": true
+  },
+  "MoonrakerPrinterSync": {
+    "PollingInterval": "00:01:00",
+    "RequestTimeout": "00:00:15",
+    "Enabled": true,
+    "HistoryBatchSize": 25
+  },
+  "FilamentAlerts": {
+    "LowStockThresholdPercent": 20
+  },
+  "MoonrakerPoller": {
+    "Enabled": true,
+    "PollInterval": "00:00:30",
+    "RequestTimeout": "00:00:10"
   }
+}
 }

deploy.sh

@@ -18,13 +18,14 @@ echo "📦 Building and starting services..."
 $COMPOSE_CMD -f docker-compose.dev.yml up -d --build
 
 echo "⏳ Waiting for services to become healthy..."
-sleep 10
+sleep 15
 
 echo "✅ Deployment complete!"
 echo ""
 echo "Services running:"
+echo "  • PostgreSQL:    localhost:5433"
 echo "  • Extrudex API: http://localhost:5080"
-echo "  • Control Center Web: http://localhost:5081"
+echo "  • Extrudex Web: http://localhost:5081"
 echo ""
 echo "To view logs:"
 echo "  $COMPOSE_CMD -f docker-compose.dev.yml logs -f"

design/mobile-design-system.md

@@ -0,0 +1,517 @@
+# Extrudex Mobile-First Design System
+
+> **Project:** CUB-71 — Mobile-First Touch-Optimized UI Design  
+> **Parent:** CUB-67 — Extrudex Mobile-First PWA Implementation  
+> **Date:** 2026-05-01  
+> **Author:** Sketch  
+> **Status:** In Progress
+
+---
+
+## 1. Design Philosophy
+
+### Mobile-First, Touch-Always
+- **Minimum touch target:** 44×44px (Apple HIG) / 48×48dp (Material Design)
+- **Thumb-friendly zones:** Primary actions in bottom 25% of screen
+- **Gesture support:** Swipe, pull-to-refresh, pinch-to-zoom on relevant screens
+- **One-handed use:** All critical actions reachable within thumb zone
+
+### Workshop-Ready
+- **High contrast:** WCAG AA minimum (4.5:1) — workshop lighting varies
+- **Large text:** 16sp minimum body, 20sp+ for primary info
+- **Glanceable:** Key info visible at arm's length (3ft)
+- **Glove-compatible:** Larger tap targets for operators wearing work gloves
+
+### Speed Over Complexity
+- **Sub-second load:** Cached assets, skeleton screens
+- **Minimal taps:** Every flow optimized for fewest interactions
+- **Smart defaults:** Pre-filled forms based on context
+
+---
+
+## 2. Color System
+
+### Primary Palette (Dark Theme — Default)
+
+| Token | Hex | Usage |
+|-------|-----|-------|
+| `surface` | `#1C1B1F` | Screen background |
+| `onSurface` | `#E6E1E5` | Primary text |
+| `surfaceContainer` | `#211F26` | Cards, app bar |
+| `surfaceContainerHigh` | `#2B2930` | Elevated cards |
+| `primary` | `#A8CEDA` | FAB, active states, links |
+| `onPrimary` | `#00303E` | Text on primary |
+| `primaryContainer` | `#004D63` | Chip fills, tonal buttons |
+| `onPrimaryContainer` | `#A8CEDA` | Text on primary container |
+| `secondary` | `#B1CCC7` | Secondary actions |
+| `error` | `#F2B8B5` | Critical stock, errors |
+| `errorContainer` | `#8C1D18` | Error backgrounds |
+| `warning` | `#FFD580` | Low stock warning |
+| `warningContainer` | `#5D4200` | Warning backgrounds |
+| `success` | `#8BD0A0` | Available, success states |
+| `successContainer` | `#00522E` | Success backgrounds |
+| `outline` | `#938F99` | Borders, dividers |
+| `outlineVariant` | `#49454F` | Subtle borders |
+
+### Light Theme (Optional)
+
+| Token | Hex | Usage |
+|-------|-----|-------|
+| `surface` | `#F8FAFC` | Screen background |
+| `surfaceContainer` | `#FFFFFF` | Cards |
+| `primary` | `#2563EB` | Primary actions |
+| `onSurface` | `#0F172A` | Primary text |
+
+---
+
+## 3. Typography Scale
+
+### Mobile Type Scale
+
+| Role | Token | Size | Weight | Line Height | Letter Spacing |
+|------|-------|------|--------|-------------|----------------|
+| Display Large | `displayLarge` | 57sp | 400 | 64sp | -0.25px |
+| Display Medium | `displayMedium` | 45sp | 400 | 52sp | 0 |
+| Headline Large | `headlineLarge` | 32sp | 400 | 40sp | 0 |
+| Headline Medium | `headlineMedium` | 28sp | 400 | 36sp | 0 |
+| Headline Small | `headlineSmall` | 24sp | 400 | 32sp | 0 |
+| Title Large | `titleLarge` | 22sp | 400 | 28sp | 0 |
+| Title Medium | `titleMedium` | 16sp | 500 | 24sp | 0.15px |
+| Title Small | `titleSmall` | 14sp | 500 | 20sp | 0.1px |
+| Body Large | `bodyLarge` | 16sp | 400 | 24sp | 0.5px |
+| Body Medium | `bodyMedium` | 14sp | 400 | 20sp | 0.25px |
+| Label Large | `labelLarge` | 14sp | 500 | 20sp | 0.1px |
+| Label Medium | `labelMedium` | 12sp | 500 | 16sp | 0.5px |
+| Label Small | `labelSmall` | 11sp | 500 | 16sp | 0.5px |
+
+### Font Stack
+```css
+--font-sans: 'Inter', 'Roboto', system-ui, -apple-system, sans-serif;
+--font-mono: 'JetBrains Mono', 'Roboto Mono', monospace;
+```
+
+---
+
+## 4. Spacing System
+
+### 8dp Grid Base
+
+| Token | Value | Usage |
+|-------|-------|-------|
+| `space-1` | 4dp | Tight padding, icon gaps |
+| `space-2` | 8dp | Default gap, small padding |
+| `space-3` | 12dp | Card padding (compact) |
+| `space-4` | 16dp | Standard padding, section gaps |
+| `space-5` | 20dp | Large padding |
+| `space-6` | 24dp | Section margins, hero padding |
+| `space-8` | 32dp | Large section gaps |
+| `space-10` | 40dp | Major section spacing |
+| `space-12` | 48dp | Touch target minimum |
+| `space-16` | 64dp | App bar height |
+
+### Border Radius
+
+| Token | Value | Usage |
+|-------|-------|-------|
+| `radius-sm` | 4dp | Small buttons, chips |
+| `radius-md` | 8dp | Cards, inputs |
+| `radius-lg` | 12dp | Modals, bottom sheets |
+| `radius-xl` | 16dp | Large cards, dialogs |
+| `radius-full` | 9999px | Pills, circular elements |
+
+---
+
+## 5. Component Specifications
+
+### 5.1 Bottom Navigation Bar
+
+**Height:** 80dp  
+**Background:** `surfaceContainer` with 1dp top outline  
+**Layout:** 4-5 icon+label items, evenly distributed  
+**Active state:** Icon filled + `primary` color, label `primary`  
+**Inactive state:** Icon outlined + `onSurfaceVariant` color  
+**Touch target:** Full 80dp height, icon+label centered  
+
+```
+┌─────────────────────────────────────┐
+│  📦      🖨️       📋       ⚙️      │
+│Inventory Printers   Jobs   Settings  │
+└─────────────────────────────────────┘
+```
+
+**Destinations:**
+- Inventory (spools list) — default active
+- Printers (printer fleet status)
+- Jobs (print job history)
+- Settings (app configuration)
+
+---
+
+### 5.2 QR Scanner Interface
+
+**Layout:** Full-bleed camera viewport with overlay
+
+```
+┌─────────────────────────────────────┐
+│  ✕   Scan Spool              [⚡]   │  ← App Bar (56dp)
+├─────────────────────────────────────┤
+│                                     │
+│  ┌─────────────────────────────┐    │
+│  │                             │    │
+│  │    ┌───────────────────┐    │    │
+│  │    │ ╔═══════════════╗ │    │    │
+│  │    │ ║  ▄▄▄▄▄▄▄▄▄▄▄  ║ │    │    │
+│  │    │ ║  █  VIEWPORT   █  ║ │    │    │
+│  │    │ ║  █   FRAME     █  ║ │    │    │
+│  │    │ ║  ▀▀▀▀▀▀▀▀▀▀▀  ║ │    │    │
+│  │    │ ║  (scan line)   ║ │    │    │
+│  │    └───────────────────┘    │    │
+│  │                             │    │
+│  │      LIVE CAMERA FEED       │    │
+│  │                             │    │
+│  └─────────────────────────────┘    │
+│                                     │
+│  [Last scan: 8901234567890]        │
+│                                     │
+│  Can't scan? Enter manually        │
+│                                     │
+└─────────────────────────────────────┘
+```
+
+**Elements:**
+- **Camera viewport:** Full width, 60% screen height, `surfaceContainerHighest` background before camera starts
+- **Scanning frame:** 200dp × 120dp centered, corner brackets (3dp stroke, `primary`)
+- **Scan line:** Horizontal 2dp line, sweeps top→bottom (2s cycle), `primary` at 40% opacity
+- **Scan result chip:** Appears below viewport, monospace text, auto-advances in 1.5s
+- **Manual entry:** Text button fallback
+
+**States:**
+| State | Visual |
+|-------|--------|
+| Initializing | Shimmer loading + "Starting camera…" |
+| Ready | Live feed + animated scan line |
+| Scanning | Frame flashes `success` green |
+| No match | Frame flashes `warning` yellow |
+| Camera denied | Error card + "Enter manually" button |
+
+---
+
+### 5.3 Spool Detail View (Mobile)
+
+**Layout:** Scrollable vertical stack
+
+```
+┌─────────────────────────────────────┐
+│  ←  PLA Basic — Matte Black   [✏]  │  ← App Bar
+├─────────────────────────────────────┤
+│                                     │
+│  ┌──────┐                           │
+│  │SWATCH│  PLA Basic — Matte       │
+│  │ 80dp │  Black           [Avail] │
+│  └──────┘  Bambu Lab               │
+│                                     │
+│       ◉  842g / 1000g  (67%)      │  ← Circular progress
+│                                     │
+├─────────────────────────────────────┤
+│  Total Weight    │  Remaining       │
+│  1,000g          │  842g (67%)      │
+├─────────────────────────────────────┤
+│  Diameter        │  Density          │
+│  1.75mm          │  1.24 g/cm³      │
+├─────────────────────────────────────┤
+│  Date Added      │  Last Used        │
+│  Mar 12, 2026    │  Apr 18, 2026    │
+├─────────────────────────────────────┤
+│  📍 AMS Unit 2, Slot A3    [Move]  │
+├─────────────────────────────────────┤
+│  ┌──────────┐                      │
+│  │  QR CODE │                      │
+│  │  160dp   │  EXT-2026-PLA-0042  │
+│  └──────────┘         [Reprint]   │
+├─────────────────────────────────────┤
+│  Recent Usage                       │
+│  Print #1847 — Benchy  -32g        │
+│  Print #1842 — Housing  -18g        │
+│  [View Full History →]             │
+├─────────────────────────────────────┤
+│                                     │
+│  [Depleted]  [Move]  [Print]       │  ← Sticky action row
+│                                     │
+├─────────────────────────────────────┤
+│  📦     🖨️     📋     ⚙️            │  ← Bottom nav
+└─────────────────────────────────────┘
+```
+
+**Hero Section:**
+- Color swatch: 80dp circle, `outlineVariant` border
+- Material name: `headlineMedium` (28sp)
+- Brand: `bodyLarge` (16sp), `onSurfaceVariant`
+- Status badge: Tonal chip
+- Circular progress: 96dp diameter, dynamic color based on percentage
+
+**Metrics Grid:**
+- 2-column grid on mobile, 3-column on kiosk
+- Label: `labelMedium` (12sp)
+- Value: `titleMedium` (16sp)
+
+**Action Row (Sticky):**
+- Height: 64dp minimum
+- Buttons: 48dp height minimum
+- Deplete: Outlined, `error` color
+- Move: Tonal, `secondary` color
+- Print: Filled, `primary` color
+
+---
+
+### 5.4 Print-Log Form (Quick Entry)
+
+**Layout:** Bottom sheet or full-screen
+
+```
+┌─────────────────────────────────────┐
+│  ✕   Log Print Usage                 │
+├─────────────────────────────────────┤
+│                                     │
+│  Spool: PLA Basic — Matte Black     │
+│  Remaining: 842g                    │
+│                                     │
+│  Weight Used                        │
+│  ┌─────────────────────────────┐   │
+│  │  [−]    32    [+]  grams    │   │  ← Stepper
+│  └─────────────────────────────┘   │
+│                                     │
+│  Quick: [10] [25] [50] [100]       │
+│                                     │
+│  Print Job (optional)              │
+│  ┌─────────────────────────────┐   │
+│  │ Select or enter job name... │   │
+│  └─────────────────────────────┘   │
+│                                     │
+│  Notes (optional)                  │
+│  ┌─────────────────────────────┐   │
+│  │ ...                         │   │
+│  └─────────────────────────────┘   │
+│                                     │
+│  ┌─────────────────────────────┐   │
+│  │    ✓ Log Print (842→810g)   │   │
+│  └─────────────────────────────┘   │
+│                                     │
+└─────────────────────────────────────┘
+```
+
+**Design Principles:**
+- **Number pad first:** Show numeric keyboard by default
+- **Quick-select chips:** Common values (10g, 25g, 50g, 100g)
+- **Stepper control:** ± buttons flanking input
+- **Live preview:** Show remaining weight after deduction
+- **Single-tap complete:** Primary action always visible
+
+---
+
+### 5.5 Status Badges
+
+| Status | Background | Text | Icon |
+|--------|-----------|------|------|
+| Available | `successContainer` | `success` | check_circle |
+| In Use | `primaryContainer` | `primary` | print |
+| Low Stock | `warningContainer` | `warning` | warning |
+| Critical | `errorContainer` | `error` | error |
+| Depleted | `errorContainer` | `error` | remove_circle |
+
+---
+
+### 5.6 Touch Targets & Accessibility
+
+**Minimum Sizes:**
+- Interactive elements: 48×48dp
+- List items: 56dp height minimum
+- Buttons: 48dp height, 88dp minimum width
+- Chips: 32dp height, 48dp minimum width
+- Input fields: 56dp height
+
+**Focus States:**
+- 2dp outline, `primary` color, 2dp offset
+- Visible on keyboard navigation
+
+**Motion:**
+- Respect `prefers-reduced-motion`
+- Disable animations when set
+- Use opacity fades instead of transforms
+
+---
+
+## 6. Responsive Breakpoints
+
+| Breakpoint | Width | Target |
+|-----------|-------|--------|
+| Compact | 0-599dp | Mobile phones |
+| Medium | 600-839dp | Large phones, small tablets |
+| Expanded | 840-1199dp | Tablets, small desktops |
+| Large | 1200dp+ | Desktops, kiosks |
+
+### Layout Adaptations
+
+| Property | Compact (Mobile) | Large (Kiosk) |
+|----------|-----------------|---------------|
+| Navigation | Bottom bar (80dp) | Rail (80dp, left) |
+| Content padding | 16dp | 24dp |
+| Grid columns | 1-2 | 2-3 |
+| Card padding | 16dp | 20dp |
+| Typography scale | Standard | +10% for distance viewing |
+| Touch targets | 48dp | 56dp (glove-friendly) |
+
+---
+
+## 7. Animation & Motion
+
+### Principles
+- **Purposeful:** Every animation guides attention or provides feedback
+- **Fast:** 200-300ms standard duration
+- **Easing:** `ease-out` for entrances, `ease-in-out` for transitions
+
+### Patterns
+
+| Animation | Duration | Easing | Use Case |
+|-----------|----------|--------|----------|
+| Slide in | 300ms | ease-out | Screen transitions |
+| Fade | 200ms | ease-in-out | Modal/dialog |
+| Scale | 200ms | ease-out | Button presses |
+| Shimmer | 1.5s | linear | Loading skeletons |
+| Pulse | 2s | ease-in-out | Scan line, critical alerts |
+| Progress | 600ms | ease-out | Circular progress fill |
+
+### Interaction Feedback
+- **Button press:** Scale to 0.96, 100ms
+- **Chip select:** Background color transition, 150ms
+- **List item tap:** Ripple effect, `primary` at 12% opacity
+- **Success:** Green flash + haptic (mobile)
+- **Error:** Red flash + shake animation
+
+---
+
+## 8. Assets & Icons
+
+### Icon Set
+- **Library:** Material Symbols (rounded)
+- **Size:** 24dp default, 20dp in dense areas
+- **Weight:** 400 (regular), filled for active states
+
+### Required Icons
+| Icon | Name | Usage |
+|------|------|-------|
+| 📦 | inventory_2 | Inventory nav |
+| 🖨️ | print | Printers nav |
+| 📋 | assignment | Jobs nav |
+| ⚙️ | settings | Settings nav |
+| ✕ | close | Close/dismiss |
+| ← | arrow_back | Navigate back |
+| ✏ | edit | Edit action |
+| 🔍 | search | Search toggle |
+| + | add | Add/create |
+| 🗑 | delete | Delete action |
+| 📷 | photo_camera | Scan action |
+| ⚠ | warning | Warning states |
+| ✓ | check_circle | Success states |
+| 📍 | location_on | Location |
+| 📶 | signal_cellular_alt | SignalR status |
+
+---
+
+## 9. Developer Handoff Checklist
+
+- [x] Color tokens defined (dark theme)
+- [x] Typography scale specified
+- [x] Spacing system documented
+- [x] Component specifications written
+- [x] Touch targets validated (≥48dp)
+- [x] Responsive breakpoints defined
+- [x] Animation patterns documented
+- [x] Icon set specified
+- [ ] Mockup images generated (blocked — image generation unavailable)
+- [ ] Figma/Sketch file created (optional)
+- [ ] Design tokens exported to CSS/SCSS
+
+---
+
+## 10. Implementation Notes for Rex
+
+### Priority Order
+1. Bottom navigation component
+2. QR scanner interface (camera + overlay)
+3. Spool detail view (scrollable)
+4. Print-log form (bottom sheet)
+5. Status badges and indicators
+
+### Angular Material Components Needed
+```typescript
+import { MatBottomSheetModule } from '@angular/material/bottom-sheet';
+import { MatButtonModule } from '@angular/material/button';
+import { MatCardModule } from '@angular/material/card';
+import { MatChipsModule } from '@angular/material/chips';
+import { MatDialogModule } from '@angular/material/dialog';
+import { MatFormFieldModule } from '@angular/material/form-field';
+import { MatIconModule } from '@angular/material/icon';
+import { MatInputModule } from '@angular/material/input';
+import { MatProgressBarModule } from '@angular/material/progress-bar';
+import { MatProgressSpinnerModule } from '@angular/material/progress-spinner';
+import { MatSelectModule } from '@angular/material/select';
+import { MatSnackBarModule } from '@angular/material/snack-bar';
+import { MatToolbarModule } from '@angular/material/toolbar';
+```
+
+### QR Scanning Libraries
+- **Mobile:** `html5-qrcode` or `@zxing/browser`
+- **Camera access:** `navigator.mediaDevices.getUserMedia({ facingMode: 'environment' })`
+
+### Key Files to Create
+```
+frontend/src/app/
+├── components/
+│   ├── bottom-nav/
+│   │   ├── bottom-nav.component.ts
+│   │   ├── bottom-nav.component.html
+│   │   └── bottom-nav.component.scss
+│   ├── qr-scanner/
+│   │   ├── qr-scanner.component.ts
+│   │   ├── qr-scanner.component.html
+│   │   └── qr-scanner.component.scss
+│   ├── spool-detail/
+│   │   ├── spool-detail.component.ts
+│   │   ├── spool-detail.component.html
+│   │   └── spool-detail.component.scss
+│   └── print-log-form/
+│       ├── print-log-form.component.ts
+│       ├── print-log-form.component.html
+│       └── print-log-form.component.scss
+├── design-system/
+│   ├── _colors.scss
+│   ├── _typography.scss
+│   ├── _spacing.scss
+│   └── _mixins.scss
+└── models/
+    └── mobile-ui.model.ts
+```
+
+---
+
+## 11. File Locations
+
+| File | Path | Purpose |
+|------|------|---------|
+| Design System | `design/mobile-design-system.md` | This document |
+| Inventory Spec | `design/01-filament-inventory-list.md` | Existing — inventory screen |
+| Spool Detail Spec | `design/02-spool-detail-view.md` | Existing — detail screen |
+| Smart Intake Spec | `design/03-smart-intake-workflow.md` | Existing — intake flow |
+| Identify Spec | `design/smart-intake-identify-spec.md` | Existing — identify state |
+| Mockup Images | `design/mockup-*.png/jpg` | Visual references |
+
+---
+
+**Next Steps:**
+1. Review design system with stakeholders
+2. Generate mockup images (when image generation is available)
+3. Export design tokens to SCSS
+4. Hand off to Rex for implementation
+5. Create interactive prototype (optional)
+
+**Status:** Design system document complete. Ready for implementation handoff.

docker-compose.dev.yml

@@ -1,6 +1,25 @@
-version: '3.8'
-
 services:
+  extrudex-db:
+    image: postgres:16-alpine
+    container_name: extrudex-db
+    environment:
+      POSTGRES_USER: extrudex
+      POSTGRES_PASSWORD: changeme
+      POSTGRES_DB: extrudex
+    ports:
+      - "5433:5432"
+    volumes:
+      - extrudex-db-data:/var/lib/postgresql/data
+    healthcheck:
+      test: ["CMD-SHELL", "pg_isready -U extrudex"]
+      interval: 10s
+      timeout: 5s
+      retries: 5
+      start_period: 10s
+    restart: unless-stopped
+    networks:
+      - extrudex-network
+
   extrudex-api:
     build:
       context: ./backend
@@ -11,6 +30,14 @@ services:
     environment:
       - ASPNETCORE_ENVIRONMENT=Development
       - ASPNETCORE_URLS=http://+:8080
+      - EXTRUDEX_DB_HOST=extrudex-db
+      - EXTRUDEX_DB_PORT=5432
+      - EXTRUDEX_DB_NAME=extrudex
+      - EXTRUDEX_DB_USER=extrudex
+      - EXTRUDEX_DB_PASSWORD=changeme
+    depends_on:
+      extrudex-db:
+        condition: service_healthy
     restart: unless-stopped
     healthcheck:
       test: ["CMD", "curl", "-f", "http://localhost:8080/health"]
@@ -21,11 +48,11 @@ services:
     networks:
       - extrudex-network
 
-  control-center-web:
+  extrudex-web:
     build:
-      context: ../Control-Center/frontend
+      context: ./frontend
       dockerfile: Dockerfile
-    container_name: control-center-web
+    container_name: extrudex-web
     ports:
       - "5081:80"
     depends_on:
@@ -35,6 +62,9 @@ services:
     networks:
       - extrudex-network
 
+volumes:
+  extrudex-db-data:
+
 networks:
   extrudex-network:
     driver: bridge

frontend/src/app/app.config.ts

@@ -1,11 +1,13 @@
 import { ApplicationConfig, provideBrowserGlobalErrorListeners } from '@angular/core';
 import { provideRouter } from '@angular/router';
+import { provideHttpClient } from '@angular/common/http';
 
 import { routes } from './app.routes';
 
 export const appConfig: ApplicationConfig = {
   providers: [
     provideBrowserGlobalErrorListeners(),
-    provideRouter(routes)
+    provideRouter(routes),
+    provideHttpClient(),
   ]
 };

frontend/src/app/app.html

@@ -5,6 +5,9 @@
   <!-- Status Summary Bar — fleet-wide health at a glance -->
   <app-dashboard-summary></app-dashboard-summary>
 
+  <!-- Inventory Summary — filament metrics at a glance -->
+  <app-inventory-summary></app-inventory-summary>
+
   <!-- Filament Inventory — routed view -->
   <router-outlet />
 </main>

frontend/src/app/app.ts

@@ -1,11 +1,12 @@
 import { Component, ViewChild } from '@angular/core';
 import { RouterOutlet } from '@angular/router';
 import { DashboardSummaryComponent } from './components/dashboard-summary/dashboard-summary.component';
+import { InventorySummaryComponent } from './components/inventory-summary/inventory-summary.component';
 import { AgentSummary, SystemHealth } from './models/agent.model';
 
 @Component({
   selector: 'app-root',
-  imports: [RouterOutlet, DashboardSummaryComponent],
+  imports: [RouterOutlet, DashboardSummaryComponent, InventorySummaryComponent],
   templateUrl: './app.html',
   styleUrl: './app.scss'
 })

frontend/src/app/components/filament-dialog/filament-dialog.component.html

@@ -0,0 +1,225 @@
+<!-- Filament Add/Edit Dialog — Angular Material Dialog -->
+<mat-dialog-content class="filament-dialog-content">
+
+  <!-- Dialog Title -->
+  <h2 mat-dialog-title>{{ dialogTitle() }}</h2>
+
+  <!-- Loading state for lookup data -->
+  @if (lookupsLoading()) {
+    <div class="dialog-loading" role="status" aria-label="Loading material options">
+      <mat-spinner diameter="32"></mat-spinner>
+      <p>Loading material options…</p>
+    </div>
+  }
+
+  <!-- Form -->
+  @if (!lookupsLoading()) {
+    <form [formGroup]="form" class="filament-form" (ngSubmit)="save()">
+
+      <!-- Server Error Banner -->
+      @if (serverError()) {
+        <div class="error-banner" role="alert">
+          <mat-icon aria-hidden="true">error</mat-icon>
+          <span>{{ serverError() }}</span>
+        </div>
+      }
+
+      <!-- ── Material Section ──────────────────────────────── -->
+      <div class="form-section">
+        <h3 class="section-title">Material</h3>
+
+        <!-- Base Material -->
+        <mat-form-field appearance="outline" class="form-field full-width">
+          <mat-label>Base Material</mat-label>
+          <mat-select formControlName="materialBaseId" required aria-label="Base material">
+            @for (base of materialBases(); track base.id) {
+              <mat-option [value]="base.id">{{ base.name }}</mat-option>
+            }
+          </mat-select>
+          @if (form.get('materialBaseId')!.hasError('required') && form.get('materialBaseId')!.touched) {
+            <mat-error>Base material is required</mat-error>
+          }
+        </mat-form-field>
+
+        <!-- Finish -->
+        <mat-form-field appearance="outline" class="form-field full-width">
+          <mat-label>Finish</mat-label>
+          <mat-select formControlName="materialFinishId" required aria-label="Material finish">
+            <mat-option [value]="''" disabled>Select a base material first</mat-option>
+            @for (finish of filteredFinishes(); track finish.id) {
+              <mat-option [value]="finish.id">{{ finish.name }}</mat-option>
+            }
+          </mat-select>
+          @if (form.get('materialFinishId')!.hasError('required') && form.get('materialFinishId')!.touched) {
+            <mat-error>Finish is required</mat-error>
+          }
+          @if (filteredFinishes().length === 0 && form.get('materialBaseId')!.value) {
+            <mat-hint>No finishes available for this material</mat-hint>
+          }
+        </mat-form-field>
+
+        <!-- Modifier (optional) -->
+        <mat-form-field appearance="outline" class="form-field full-width">
+          <mat-label>Modifier (optional)</mat-label>
+          <mat-select formControlName="materialModifierId" aria-label="Material modifier">
+            <mat-option [value]="null">None</mat-option>
+            @for (modifier of filteredModifiers(); track modifier.id) {
+              <mat-option [value]="modifier.id">{{ modifier.name }}</mat-option>
+            }
+          </mat-select>
+          @if (filteredModifiers().length === 0 && form.get('materialBaseId')!.value) {
+            <mat-hint>No modifiers available for this material</mat-hint>
+          }
+        </mat-form-field>
+      </div>
+
+      <!-- ── Spool Details Section ──────────────────────────── -->
+      <div class="form-section">
+        <h3 class="section-title">Spool Details</h3>
+
+        <!-- Brand -->
+        <mat-form-field appearance="outline" class="form-field full-width">
+          <mat-label>Brand</mat-label>
+          <input matInput formControlName="brand" required maxlength="200"
+                 placeholder="e.g., Bambu Lab, Polymaker" aria-label="Brand" />
+          @if (form.get('brand')!.hasError('required') && form.get('brand')!.touched) {
+            <mat-error>Brand is required</mat-error>
+          }
+        </mat-form-field>
+
+        <!-- Serial -->
+        <mat-form-field appearance="outline" class="form-field full-width">
+          <mat-label>Serial Number</mat-label>
+          <input matInput formControlName="spoolSerial" required maxlength="200"
+                 placeholder="e.g., SN-001" aria-label="Serial number" />
+          @if (form.get('spoolSerial')!.hasError('required') && form.get('spoolSerial')!.touched) {
+            <mat-error>Serial number is required</mat-error>
+          }
+        </mat-form-field>
+
+        <!-- Color Name + Color Hex (side by side) -->
+        <div class="form-row">
+          <mat-form-field appearance="outline" class="form-field">
+            <mat-label>Color Name</mat-label>
+            <input matInput formControlName="colorName" required maxlength="200"
+                   placeholder="e.g., Fire Engine Red" aria-label="Color name" />
+            @if (form.get('colorName')!.hasError('required') && form.get('colorName')!.touched) {
+              <mat-error>Color name is required</mat-error>
+            }
+          </mat-form-field>
+
+          <mat-form-field appearance="outline" class="form-field color-hex-field">
+            <mat-label>Color Hex</mat-label>
+            <input matInput formControlName="colorHex" required
+                   placeholder="#FF0000" maxlength="7" aria-label="Color hex code" />
+            <span matTextSuffix class="color-preview">
+              <span class="color-swatch-mini" [style.background-color]="form.get('colorHex')!.value"></span>
+            </span>
+            @if (form.get('colorHex')!.hasError('required') && form.get('colorHex')!.touched) {
+              <mat-error>Color hex is required</mat-error>
+            }
+            @if (form.get('colorHex')!.hasError('pattern') && form.get('colorHex')!.touched) {
+              <mat-error>Must be #RRGGBB format</mat-error>
+            }
+          </mat-form-field>
+        </div>
+      </div>
+
+      <!-- ── Weight & Dimensions Section ────────────────────── -->
+      <div class="form-section">
+        <h3 class="section-title">Weight &amp; Dimensions</h3>
+
+        <div class="form-row">
+          <!-- Diameter -->
+          <mat-form-field appearance="outline" class="form-field">
+            <mat-label>Diameter (mm)</mat-label>
+            <input matInput type="number" formControlName="filamentDiameterMm" required
+                   min="0.1" max="10" step="0.01" aria-label="Filament diameter in mm" />
+            @if (form.get('filamentDiameterMm')!.hasError('required') && form.get('filamentDiameterMm')!.touched) {
+              <mat-error>Diameter is required</mat-error>
+            }
+          </mat-form-field>
+        </div>
+
+        <div class="form-row">
+          <!-- Total Weight -->
+          <mat-form-field appearance="outline" class="form-field">
+            <mat-label>Total Weight (g)</mat-label>
+            <input matInput type="number" formControlName="weightTotalGrams" required
+                   min="0.01" max="100000" step="1" aria-label="Total spool weight in grams" />
+            <mat-hint>Full spool weight</mat-hint>
+            @if (form.get('weightTotalGrams')!.hasError('required') && form.get('weightTotalGrams')!.touched) {
+              <mat-error>Total weight is required</mat-error>
+            }
+          </mat-form-field>
+
+          <!-- Remaining Weight -->
+          <mat-form-field appearance="outline" class="form-field">
+            <mat-label>Remaining Weight (g)</mat-label>
+            <input matInput type="number" formControlName="weightRemainingGrams" required
+                   min="0" max="100000" step="1" aria-label="Remaining weight in grams" />
+            <mat-hint>Current remaining</mat-hint>
+            @if (form.get('weightRemainingGrams')!.hasError('required') && form.get('weightRemainingGrams')!.touched) {
+              <mat-error>Remaining weight is required</mat-error>
+            }
+            @if (form.get('weightRemainingGrams')!.hasError('exceedsTotal')) {
+              <mat-error>Cannot exceed total weight</mat-error>
+            }
+          </mat-form-field>
+        </div>
+      </div>
+
+      <!-- ── Purchase & Status Section ──────────────────────── -->
+      <div class="form-section">
+        <h3 class="section-title">Purchase &amp; Status</h3>
+
+        <div class="form-row">
+          <!-- Purchase Price -->
+          <mat-form-field appearance="outline" class="form-field">
+            <mat-label>Price</mat-label>
+            <input matInput type="number" formControlName="purchasePrice"
+                   min="0" max="1000000" step="0.01"
+                   placeholder="e.g., 25.00" aria-label="Purchase price" />
+            <span matTextSuffix>$</span>
+            @if (form.get('purchasePrice')!.hasError('min') && form.get('purchasePrice')!.touched) {
+              <mat-error>Price must be non-negative</mat-error>
+            }
+          </mat-form-field>
+
+          <!-- Purchase Date -->
+          <mat-form-field appearance="outline" class="form-field">
+            <mat-label>Purchase Date</mat-label>
+            <input matInput [matDatepicker]="picker" formControlName="purchaseDate"
+                   aria-label="Purchase date" />
+            <mat-datepicker-toggle matIconSuffix [for]="picker"></mat-datepicker-toggle>
+            <mat-datepicker #picker></mat-datepicker>
+          </mat-form-field>
+        </div>
+
+        <!-- Active Status -->
+        <div class="checkbox-row">
+          <mat-checkbox formControlName="isActive" aria-label="Active status">
+            Spool is active and available for use
+          </mat-checkbox>
+        </div>
+      </div>
+
+    </form>
+  }
+
+</mat-dialog-content>
+
+<!-- Dialog Actions -->
+<mat-dialog-actions align="end">
+  <button mat-button type="button" (click)="cancel()" [disabled]="saving()"
+          aria-label="Cancel">
+    Cancel
+  </button>
+  <button mat-raised-button color="primary" type="button" (click)="save()"
+          [disabled]="saving() || form.invalid" aria-label="Save filament">
+    @if (saving()) {
+      <mat-spinner diameter="20" class="btn-spinner"></mat-spinner>
+    }
+    {{ isEditMode() ? 'Save Changes' : 'Add Filament' }}
+  </button>
+</mat-dialog-actions>

frontend/src/app/components/filament-dialog/filament-dialog.component.scss

@@ -0,0 +1,175 @@
+/**
+ * Filament Dialog Styles
+ * Touch-optimized for kiosk (Raspberry Pi 5) and mobile PWA
+ */
+
+$touch-target-min: 48px;
+$spacing-unit: 8px;
+$color-error: #ef4444;
+
+// ── Dialog Layout ──────────────────────────────────────────
+
+.filament-dialog-content {
+  overflow-y: auto;
+  max-height: 70vh;
+  padding: 0 $spacing-unit * 2;
+
+  @media (max-width: 480px) {
+    padding: 0 $spacing-unit;
+  }
+}
+
+[mat-dialog-title] {
+  margin: 0 0 $spacing-unit * 2 0;
+  padding: $spacing-unit * 2 0 0 0;
+  font-size: 20px;
+  font-weight: 600;
+}
+
+// ── Loading State ──────────────────────────────────────────
+
+.dialog-loading {
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  justify-content: center;
+  padding: 48px $spacing-unit * 2;
+  color: var(--mat-sys-on-surface-variant);
+
+  p {
+    margin-top: $spacing-unit * 2;
+    font-size: 14px;
+  }
+}
+
+// ── Error Banner ───────────────────────────────────────────
+
+.error-banner {
+  display: flex;
+  align-items: center;
+  gap: $spacing-unit;
+  padding: $spacing-unit * 1.5 $spacing-unit * 2;
+  border-radius: 8px;
+  margin-bottom: $spacing-unit * 2;
+  background-color: rgba($color-error, 0.12);
+  color: $color-error;
+  border: 1px solid rgba($color-error, 0.3);
+  font-size: 14px;
+  font-weight: 500;
+
+  mat-icon {
+    font-size: 20px !important;
+    width: 20px !important;
+    height: 20px !important;
+  }
+}
+
+// ── Form Sections ──────────────────────────────────────────
+
+.form-section {
+  margin-bottom: $spacing-unit * 3;
+
+  .section-title {
+    font-size: 14px;
+    font-weight: 600;
+    text-transform: uppercase;
+    letter-spacing: 0.04em;
+    color: var(--mat-sys-on-surface-variant);
+    margin: 0 0 $spacing-unit * 1.5 0;
+    padding-bottom: $spacing-unit * 0.5;
+    border-bottom: 1px solid var(--mat-sys-outline-variant);
+  }
+}
+
+.filament-form {
+  display: flex;
+  flex-direction: column;
+  gap: $spacing-unit;
+}
+
+// ── Form Fields ────────────────────────────────────────────
+
+.form-field {
+  width: 100%;
+
+  // Touch target sizing
+  .mat-mdc-form-field-subscript-wrapper {
+    min-height: 20px;
+  }
+}
+
+.form-row {
+  display: flex;
+  gap: $spacing-unit * 2;
+  width: 100%;
+
+  .form-field {
+    flex: 1;
+  }
+
+  @media (max-width: 480px) {
+    flex-direction: column;
+    gap: 0;
+  }
+}
+
+// ── Color Hex Preview ──────────────────────────────────────
+
+.color-hex-field {
+  max-width: 180px;
+
+  @media (max-width: 480px) {
+    max-width: 100%;
+  }
+}
+
+.color-preview {
+  display: inline-flex;
+  align-items: center;
+  margin-left: 4px;
+}
+
+.color-swatch-mini {
+  display: inline-block;
+  width: 20px;
+  height: 20px;
+  border-radius: 4px;
+  border: 1px solid rgba(0, 0, 0, 0.12);
+  vertical-align: middle;
+}
+
+// ── Checkbox Row ───────────────────────────────────────────
+
+.checkbox-row {
+  display: flex;
+  align-items: center;
+  padding: $spacing-unit 0;
+
+  mat-checkbox {
+    min-height: $touch-target-min;
+    display: flex;
+    align-items: center;
+  }
+}
+
+// ── Save Button Spinner ────────────────────────────────────
+
+mat-dialog-actions {
+  padding: $spacing-unit $spacing-unit * 2 $spacing-unit * 2;
+  gap: $spacing-unit;
+
+  button {
+    min-height: $touch-target-min;
+    min-width: 100px;
+  }
+}
+
+.btn-spinner {
+  display: inline-block;
+  margin-right: $spacing-unit;
+  vertical-align: middle;
+
+  circle {
+    stroke: currentColor;
+  }
+}

frontend/src/app/components/filament-dialog/filament-dialog.component.ts

@@ -0,0 +1,277 @@
+import {
+  ChangeDetectionStrategy,
+  Component,
+  inject,
+  signal,
+  computed,
+} from '@angular/core';
+import { CommonModule } from '@angular/common';
+import { FormsModule, ReactiveFormsModule, FormBuilder, FormGroup, Validators } from '@angular/forms';
+import { MatDialogRef, MAT_DIALOG_DATA, MatDialogModule } from '@angular/material/dialog';
+import { MatFormFieldModule } from '@angular/material/form-field';
+import { MatInputModule } from '@angular/material/input';
+import { MatSelectModule } from '@angular/material/select';
+import { MatDatepickerModule } from '@angular/material/datepicker';
+import { MatNativeDateModule } from '@angular/material/core';
+import { MatCheckboxModule } from '@angular/material/checkbox';
+import { MatButtonModule } from '@angular/material/button';
+import { MatIconModule } from '@angular/material/icon';
+import { MatProgressSpinnerModule } from '@angular/material/progress-spinner';
+import { MatTooltipModule } from '@angular/material/tooltip';
+
+import { Filament } from '../../models/filament.model';
+import {
+  MaterialBase,
+  MaterialFinish,
+  MaterialModifier,
+} from '../../models/material.model';
+import {
+  FilamentService,
+  CreateFilamentRequest,
+  UpdateFilamentRequest,
+} from '../../services/filament.service';
+
+/** Data passed into the dialog from the opener. */
+export interface FilamentDialogData {
+  /** If provided, the dialog opens in edit mode with pre-populated fields. */
+  filament?: Filament;
+}
+
+@Component({
+  selector: 'app-filament-dialog',
+  standalone: true,
+  imports: [
+    CommonModule,
+    FormsModule,
+    ReactiveFormsModule,
+    MatDialogModule,
+    MatFormFieldModule,
+    MatInputModule,
+    MatSelectModule,
+    MatDatepickerModule,
+    MatNativeDateModule,
+    MatCheckboxModule,
+    MatButtonModule,
+    MatIconModule,
+    MatProgressSpinnerModule,
+    MatTooltipModule,
+  ],
+  templateUrl: './filament-dialog.component.html',
+  styleUrl: './filament-dialog.component.scss',
+  changeDetection: ChangeDetectionStrategy.OnPush,
+})
+export class FilamentDialogComponent {
+  private readonly dialogRef = inject(MatDialogRef<FilamentDialogComponent>);
+  private readonly data = inject<FilamentDialogData>(MAT_DIALOG_DATA);
+  private readonly fb = inject(FormBuilder);
+  private readonly filamentService = inject(FilamentService);
+
+  /** Whether this dialog is in edit mode (has existing filament data). */
+  readonly isEditMode = computed(() => !!this.data.filament);
+
+  /** Dialog title based on mode. */
+  readonly dialogTitle = computed(() =>
+    this.isEditMode() ? 'Edit Filament' : 'Add Filament'
+  );
+
+  // ── Lookup data signals ──────────────────────────────────
+
+  /** All material bases for the base material dropdown. */
+  readonly materialBases = signal<MaterialBase[]>([]);
+
+  /** Material finishes filtered by selected base material. */
+  readonly filteredFinishes = signal<MaterialFinish[]>([]);
+
+  /** Material modifiers filtered by selected base material. */
+  readonly filteredModifiers = signal<MaterialModifier[]>([]);
+
+  /** Whether material lookups are loading. */
+  readonly lookupsLoading = signal(true);
+
+  /** Whether the save operation is in progress. */
+  readonly saving = signal(false);
+
+  /** Server error message, if any. */
+  readonly serverError = signal<string | null>(null);
+
+  // ── Form ─────────────────────────────────────────────────
+
+  readonly form: FormGroup = this.fb.group({
+    materialBaseId: ['', Validators.required],
+    materialFinishId: ['', Validators.required],
+    materialModifierId: [null],
+    brand: ['', [Validators.required, Validators.maxLength(200)]],
+    colorName: ['', [Validators.required, Validators.maxLength(200)]],
+    colorHex: ['#000000', [Validators.required, Validators.pattern(/^#[0-9A-Fa-f]{6}$/)]],
+    weightTotalGrams: [1000, [Validators.required, Validators.min(0.01), Validators.max(100000)]],
+    weightRemainingGrams: [1000, [Validators.required, Validators.min(0), Validators.max(100000)]],
+    filamentDiameterMm: [1.75, [Validators.required, Validators.min(0.1), Validators.max(10)]],
+    spoolSerial: ['', [Validators.required, Validators.maxLength(200)]],
+    purchasePrice: [null, [Validators.min(0), Validators.max(1000000)]],
+    purchaseDate: [null],
+    isActive: [true],
+  });
+
+  constructor() {
+    this.loadLookups();
+    this.patchFormIfEditing();
+    this.setupCascadingFilters();
+  }
+
+  // ── Data loading ─────────────────────────────────────────
+
+  /** Load material bases, finishes, and modifiers for dropdowns. */
+  private loadLookups(): void {
+    this.lookupsLoading.set(true);
+    this.filamentService.getMaterialBases().subscribe({
+      next: (bases) => {
+        this.materialBases.set(bases);
+        this.lookupsLoading.set(false);
+      },
+      error: () => {
+        this.lookupsLoading.set(false);
+        this.serverError.set('Failed to load material options. Please try again.');
+      },
+    });
+  }
+
+  /** Pre-populate form fields when editing an existing filament. */
+  private patchFormIfEditing(): void {
+    if (this.data.filament) {
+      const f = this.data.filament;
+      this.form.patchValue({
+        materialBaseId: f.materialBaseId,
+        materialFinishId: f.materialFinishId,
+        materialModifierId: f.materialModifierId,
+        brand: f.brand,
+        colorName: f.colorName,
+        colorHex: f.colorHex,
+        weightTotalGrams: f.weightTotalGrams,
+        weightRemainingGrams: f.weightRemainingGrams,
+        filamentDiameterMm: f.filamentDiameterMm,
+        spoolSerial: f.spoolSerial,
+        purchasePrice: f.purchasePrice,
+        purchaseDate: f.purchaseDate ? new Date(f.purchaseDate) : null,
+        isActive: f.isActive,
+      });
+    }
+  }
+
+  /** Set up cascading filter: when base material changes, reload finishes & modifiers. */
+  private setupCascadingFilters(): void {
+    this.form.get('materialBaseId')!.valueChanges.subscribe((baseId: string | null) => {
+      // Clear dependent selections when base changes
+      this.form.get('materialFinishId')!.setValue('');
+      this.form.get('materialModifierId')!.setValue(null);
+      this.filteredFinishes.set([]);
+      this.filteredModifiers.set([]);
+
+      if (!baseId) return;
+
+      this.filamentService.getMaterialFinishes(baseId).subscribe({
+        next: (finishes) => this.filteredFinishes.set(finishes),
+        error: () => this.filteredFinishes.set([]),
+      });
+
+      this.filamentService.getMaterialModifiers(baseId).subscribe({
+        next: (modifiers) => this.filteredModifiers.set(modifiers),
+        error: () => this.filteredModifiers.set([]),
+      });
+    });
+
+    // If editing, trigger the cascading load for the pre-selected base
+    if (this.data.filament) {
+      const baseId = this.data.filament.materialBaseId;
+      // We need to load finishes and modifiers for the pre-selected base
+      // but also re-select the original finish and modifier after loading
+      this.filamentService.getMaterialFinishes(baseId).subscribe({
+        next: (finishes) => {
+          this.filteredFinishes.set(finishes);
+          // Re-patch finish after load
+          this.form.get('materialFinishId')!.setValue(this.data.filament!.materialFinishId);
+        },
+      });
+      this.filamentService.getMaterialModifiers(baseId).subscribe({
+        next: (modifiers) => {
+          this.filteredModifiers.set(modifiers);
+          // Re-patch modifier after load
+          this.form.get('materialModifierId')!.setValue(this.data.filament!.materialModifierId);
+        },
+      });
+    }
+  }
+
+  // ── Actions ──────────────────────────────────────────────
+
+  /** Cancel and close the dialog without saving. */
+  cancel(): void {
+    this.dialogRef.close(false);
+  }
+
+  /** Submit the form — creates or updates the filament. */
+  save(): void {
+    if (this.form.invalid) {
+      this.form.markAllAsTouched();
+      return;
+    }
+
+    // Cross-field validation: remaining weight must not exceed total weight
+    const total = this.form.value.weightTotalGrams;
+    const remaining = this.form.value.weightRemainingGrams;
+    if (remaining > total) {
+      this.form.get('weightRemainingGrams')!.setErrors({ exceedsTotal: true });
+      return;
+    }
+
+    this.saving.set(true);
+    this.serverError.set(null);
+
+    const formValue = this.form.value;
+    const request: CreateFilamentRequest | UpdateFilamentRequest = {
+      materialBaseId: formValue.materialBaseId,
+      materialFinishId: formValue.materialFinishId,
+      materialModifierId: formValue.materialModifierId || null,
+      brand: formValue.brand.trim(),
+      colorName: formValue.colorName.trim(),
+      colorHex: formValue.colorHex,
+      weightTotalGrams: formValue.weightTotalGrams,
+      weightRemainingGrams: formValue.weightRemainingGrams,
+      filamentDiameterMm: formValue.filamentDiameterMm,
+      spoolSerial: formValue.spoolSerial.trim(),
+      purchasePrice: formValue.purchasePrice ?? null,
+      purchaseDate: formValue.purchaseDate
+        ? new Date(formValue.purchaseDate).toISOString()
+        : null,
+      isActive: formValue.isActive,
+    };
+
+    if (this.isEditMode()) {
+      const id = this.data.filament!.id;
+      this.filamentService.updateFilament(id, request).subscribe({
+        next: (updated) => {
+          this.saving.set(false);
+          this.dialogRef.close(true);
+        },
+        error: (err) => {
+          this.saving.set(false);
+          this.serverError.set(
+            err?.error?.error || err?.message || 'Failed to update filament. Please try again.'
+          );
+        },
+      });
+    } else {
+      this.filamentService.createFilament(request).subscribe({
+        next: (created) => {
+          this.saving.set(false);
+          this.dialogRef.close(true);
+        },
+        error: (err) => {
+          this.saving.set(false);
+          this.serverError.set(
+            err?.error?.error || err?.message || 'Failed to create filament. Please try again.'
+          );
+        },
+      });
+    }
+  }
+}

frontend/src/app/components/filament-filter/filament-filter.component.html

@@ -0,0 +1,76 @@
+<!-- Filament Filter Bar — material type, color search, low stock, active-only -->
+<div class="filament-filter-bar" role="search" aria-label="Filter filament inventory">
+
+  <!-- Material Type Multi-Select -->
+  <mat-form-field appearance="outline" class="filter-field material-filter">
+    <mat-label>Material</mat-label>
+    <mat-select multiple
+                [value]="selectedMaterials()"
+                (selectionChange)="onMaterialChange($event.value)"
+                aria-label="Filter by material type">
+      @for (material of materialOptions(); track material) {
+        <mat-option [value]="material">{{ material }}</mat-option>
+      }
+    </mat-select>
+    @if (selectedMaterials().length > 0) {
+      <mat-chip-set class="selected-chips" matSuffix>
+        @for (mat of selectedMaterials(); track mat) {
+          <mat-chip (removed)="removeMaterial(mat)"
+                    class="filter-chip">
+            <span>{{ mat }}</span>
+            <mat-icon matChipRemove>cancel</mat-icon>
+          </mat-chip>
+        }
+      </mat-chip-set>
+    }
+  </mat-form-field>
+
+  <!-- Color Search -->
+  <mat-form-field appearance="outline" class="filter-field color-filter">
+    <mat-label>Color</mat-label>
+    <input matInput
+           type="text"
+           [value]="colorSearch()"
+           (input)="onColorSearchChange($any($event.target).value)"
+           placeholder="Search color..."
+           aria-label="Filter by color name" />
+    @if (colorSearch().trim()) {
+      <mat-icon matSuffix class="filter-active-icon">filter_list</mat-icon>
+    }
+  </mat-form-field>
+
+  <!-- Low Stock Toggle -->
+  <mat-checkbox [checked]="lowStockOnly()"
+                (change)="onLowStockToggle($event.checked)"
+                class="filter-checkbox"
+                aria-label="Show low stock only"
+                matTooltip="Show only spools at 25% or less remaining"
+                matTooltipPosition="below">
+    <mat-icon class="checkbox-icon" [class.active]="lowStockOnly()">warning</mat-icon>
+    Low Stock
+  </mat-checkbox>
+
+  <!-- Active Only Toggle -->
+  <mat-checkbox [checked]="activeOnly()"
+                (change)="onActiveOnlyToggle($event.checked)"
+                class="filter-checkbox"
+                aria-label="Show active spools only"
+                matTooltip="Show only spools currently in use"
+                matTooltipPosition="below">
+    <mat-icon class="checkbox-icon" [class.active]="activeOnly()">check_circle</mat-icon>
+    Active Only
+  </mat-checkbox>
+
+  <!-- Clear All Filters -->
+  @if (hasActiveFilters()) {
+    <button mat-button
+            class="clear-filters-btn"
+            (click)="clearAll()"
+            aria-label="Clear all filters"
+            matTooltip="Remove all filters"
+            matTooltipPosition="below">
+      <mat-icon>filter_alt_off</mat-icon>
+      Clear
+    </button>
+  }
+</div>

frontend/src/app/components/filament-filter/filament-filter.component.scss

@@ -0,0 +1,134 @@
+/**
+ * Filament Filter Bar Styles
+ * Responsive filter layout for kiosk and mobile
+ */
+
+$spacing-unit: 8px;
+
+.filament-filter-bar {
+  display: flex;
+  align-items: center;
+  gap: $spacing-unit * 2;
+  flex-wrap: wrap;
+  padding: $spacing-unit * 2 0;
+  margin-bottom: $spacing-unit * 2;
+}
+
+// Form field sizing
+.filter-field {
+  flex: 0 1 auto;
+  min-width: 160px;
+
+  &.material-filter {
+    min-width: 200px;
+  }
+
+  &.color-filter {
+    min-width: 180px;
+  }
+
+  // Reduce vertical spacing inside filter fields
+  .mat-mdc-form-field-subscript-wrapper {
+    display: none; // No hint/error text needed for filters
+  }
+}
+
+// Selected material chips
+.selected-chips {
+  flex-wrap: wrap;
+  gap: 4px;
+}
+
+.filter-chip {
+  font-size: 12px !important;
+  min-height: 24px !important;
+
+  mat-icon {
+    font-size: 14px !important;
+    width: 14px !important;
+    height: 14px !important;
+  }
+}
+
+// Active filter icon
+.filter-active-icon {
+  color: var(--mat-sys-primary);
+  font-size: 18px !important;
+  width: 18px !important;
+  height: 18px !important;
+}
+
+// Checkbox styling
+.filter-checkbox {
+  display: flex;
+  align-items: center;
+  gap: 4px;
+  white-space: nowrap;
+  user-select: none;
+  touch-action: manipulation; // Prevent zoom on double-tap
+
+  .checkbox-icon {
+    font-size: 18px !important;
+    width: 18px !important;
+    height: 18px !important;
+    color: var(--mat-sys-on-surface-variant);
+    transition: color 0.2s ease;
+
+    &.active {
+      color: var(--mat-sys-primary);
+    }
+  }
+}
+
+// Clear filters button
+.clear-filters-btn {
+  display: flex;
+  align-items: center;
+  gap: 4px;
+  font-size: 13px;
+
+  mat-icon {
+    font-size: 18px !important;
+    width: 18px !important;
+    height: 18px !important;
+  }
+}
+
+// Responsive: stack filters vertically on small screens
+@media (max-width: 768px) {
+  .filament-filter-bar {
+    flex-direction: column;
+    align-items: stretch;
+    gap: $spacing-unit;
+  }
+
+  .filter-field {
+    width: 100%;
+    min-width: unset;
+
+    &.material-filter,
+    &.color-filter {
+      min-width: unset;
+    }
+  }
+
+  .filter-checkbox {
+    padding: $spacing-unit 0;
+  }
+
+  .clear-filters-btn {
+    align-self: flex-start;
+  }
+}
+
+// Extra-small screens (phone portrait)
+@media (max-width: 480px) {
+  .filament-filter-bar {
+    padding: $spacing-unit 0;
+    margin-bottom: $spacing-unit;
+  }
+
+  .filter-checkbox {
+    font-size: 13px;
+  }
+}

frontend/src/app/components/filament-filter/filament-filter.component.ts

@@ -0,0 +1,158 @@
+import {
+  ChangeDetectionStrategy,
+  Component,
+  EventEmitter,
+  Input,
+  Output,
+  computed,
+  signal,
+} from '@angular/core';
+import { CommonModule } from '@angular/common';
+import { FormsModule } from '@angular/forms';
+import { MatFormFieldModule } from '@angular/material/form-field';
+import { MatSelectModule } from '@angular/material/select';
+import { MatInputModule } from '@angular/material/input';
+import { MatCheckboxModule } from '@angular/material/checkbox';
+import { MatIconModule } from '@angular/material/icon';
+import { MatChipsModule } from '@angular/material/chips';
+import { MatButtonModule } from '@angular/material/button';
+import { MatTooltipModule } from '@angular/material/tooltip';
+import {
+  Filament,
+  StockLevel,
+  classifyStockLevel,
+} from '../../models/filament.model';
+
+/** Filter state emitted by the filament filter component */
+export interface FilamentFilterState {
+  /** Selected material base names — empty means all */
+  materialBaseNames: string[];
+
+  /** Color search text — empty string means all */
+  colorSearch: string;
+
+  /** Whether to show only low/critical stock */
+  lowStockOnly: boolean;
+
+  /** Whether to show only active spools */
+  activeOnly: boolean;
+}
+
+/**
+ * FilamentFilterComponent — Filter bar for the filament inventory list.
+ *
+ * Provides:
+ * - Material type multi-select filter
+ * - Color name text search
+ * - Low stock toggle (shows only critical/low spools)
+ * - Active-only toggle
+ * - Clear all filters action
+ */
+@Component({
+  selector: 'app-filament-filter',
+  standalone: true,
+  imports: [
+    CommonModule,
+    FormsModule,
+    MatFormFieldModule,
+    MatSelectModule,
+    MatInputModule,
+    MatCheckboxModule,
+    MatIconModule,
+    MatChipsModule,
+    MatButtonModule,
+    MatTooltipModule,
+  ],
+  templateUrl: './filament-filter.component.html',
+  styleUrl: './filament-filter.component.scss',
+  changeDetection: ChangeDetectionStrategy.OnPush,
+})
+export class FilamentFilterComponent {
+  /** Filament data input — used to derive material options */
+  @Input() set filaments(value: Filament[]) {
+    this._filaments.set(value);
+    const materials = [...new Set(value.map((f) => f.materialBaseName))].sort();
+    this.materialOptions.set(materials);
+  }
+  get filaments(): Filament[] {
+    return this._filaments();
+  }
+  private readonly _filaments = signal<Filament[]>([]);
+
+  /** Available material base names derived from filament data */
+  readonly materialOptions = signal<string[]>([]);
+
+  /** Selected material base names */
+  readonly selectedMaterials = signal<string[]>([]);
+
+  /** Color search text */
+  readonly colorSearch = signal('');
+
+  /** Low stock only toggle */
+  readonly lowStockOnly = signal(false);
+
+  /** Active only toggle */
+  readonly activeOnly = signal(false);
+
+  /** Computed: whether any filters are active */
+  readonly hasActiveFilters = computed(
+    () =>
+      this.selectedMaterials().length > 0 ||
+      this.colorSearch().trim().length > 0 ||
+      this.lowStockOnly() ||
+      this.activeOnly()
+  );
+
+  /** Emits the current filter state whenever filters change */
+  @Output() readonly filterChange = new EventEmitter<FilamentFilterState>();
+
+  /** Handle material selection change */
+  onMaterialChange(selected: string[]): void {
+    this.selectedMaterials.set(selected);
+    this.emitFilterState();
+  }
+
+  /** Handle color search input */
+  onColorSearchChange(value: string): void {
+    this.colorSearch.set(value);
+    this.emitFilterState();
+  }
+
+  /** Handle low stock toggle */
+  onLowStockToggle(checked: boolean): void {
+    this.lowStockOnly.set(checked);
+    this.emitFilterState();
+  }
+
+  /** Handle active-only toggle */
+  onActiveOnlyToggle(checked: boolean): void {
+    this.activeOnly.set(checked);
+    this.emitFilterState();
+  }
+
+  /** Remove a single material chip */
+  removeMaterial(material: string): void {
+    const updated = this.selectedMaterials().filter((m) => m !== material);
+    this.selectedMaterials.set(updated);
+    this.emitFilterState();
+  }
+
+  /** Clear all filters */
+  clearAll(): void {
+    this.selectedMaterials.set([]);
+    this.colorSearch.set('');
+    this.lowStockOnly.set(false);
+    this.activeOnly.set(false);
+    this.emitFilterState();
+  }
+
+  /** Emit the current filter state */
+  private emitFilterState(): void {
+    this.filterChange.emit({
+      materialBaseNames: this.selectedMaterials(),
+      colorSearch: this.colorSearch().trim().toLowerCase(),
+      lowStockOnly: this.lowStockOnly(),
+      activeOnly: this.activeOnly(),
+    });
+  }
+}

frontend/src/app/components/filament-table/filament-table.component.html

@@ -1,6 +1,12 @@
-<!-- Filament Inventory Table — with low stock indicators -->
+<!-- Filament Inventory Table — with filters and low stock indicators -->
 <div class="filament-table-container" role="region" aria-label="Filament inventory">
 
+  <!-- Filter Bar -->
+  <app-filament-filter
+    [filaments]="allFilaments()"
+    (filterChange)="onFilterChange($event)"
+    aria-label="Filter filament inventory" />
+
   <!-- Low Stock Alert Banner — shown when critical or low stock spools exist -->
   @if (criticalCount() > 0) {
     <div class="alert-banner critical" role="alert">
@@ -16,7 +22,7 @@
 
   <!-- Filament Table -->
   <table mat-table
-         [dataSource]="sortedFilaments()"
+         [dataSource]="filteredFilaments()"
          matSort
          (matSortChange)="sortData($event)"
          class="filament-table"
@@ -77,6 +83,35 @@
       </td>
     </ng-container>
 
+    <!-- Cost Column -->
+    <ng-container matColumnDef="cost">
+      <th mat-header-cell *matHeaderCellDef mat-sort-header="cost">Cost</th>
+      <td mat-cell *matCellDef="let filament">
+        <div class="cost-cell">
+          @if (filament.purchasePrice !== null) {
+            <span class="cost-price">{{ formatCurrency(filament.purchasePrice) }}</span>
+            @let cpg = getCostPerGram(filament);
+            @if (cpg !== null) {
+              <span class="cost-per-gram">${{ cpg.toFixed(2) }}/g</span>
+            }
+          } @else {
+            <span class="cost-unknown">&mdash;</span>
+          }
+        </div>
+      </td>
+    </ng-container>
+
+    <!-- Usage Column -->
+    <ng-container matColumnDef="usage">
+      <th mat-header-cell *matHeaderCellDef mat-sort-header="usage">Usage</th>
+      <td mat-cell *matCellDef="let filament">
+        <div class="usage-cell">
+          <span class="usage-grams">{{ formatWeight(getGramsUsed(filament)) }} used</span>
+          <span class="usage-remaining">{{ formatWeight(filament.weightRemainingGrams) }} left</span>
+        </div>
+      </td>
+    </ng-container>
+
     <!-- Stock Level Indicator Column -->
     <ng-container matColumnDef="stockLevel">
       <th mat-header-cell *matHeaderCellDef mat-sort-header="stockLevel">Stock</th>
@@ -113,7 +148,15 @@
     </tr>
   </table>
 
-  <!-- Empty state -->
+  <!-- Filtered empty state -->
+  @if (filteredFilaments().length === 0 && filaments().length > 0) {
+    <div class="empty-state" role="status">
+      <mat-icon aria-hidden="true">filter_alt_off</mat-icon>
+      <p>No filaments match the current filters</p>
+    </div>
+  }
+
+  <!-- No data empty state -->
   @if (filaments().length === 0) {
     <div class="empty-state" role="status">
       <mat-icon aria-hidden="true">inventory_2</mat-icon>

frontend/src/app/components/filament-table/filament-table.component.scss

@@ -55,7 +55,7 @@ $color-inactive: #94a3b8;  // Gray — inactive spool
 // Table styling
 .filament-table {
   width: 100%;
-  min-width: 700px;
+  min-width: 900px;
 
   th {
     font-weight: 600;
@@ -132,6 +132,48 @@ $color-inactive: #94a3b8;  // Gray — inactive spool
   letter-spacing: 0.02em;
 }
 
+// Cost cell
+.cost-cell {
+  display: flex;
+  flex-direction: column;
+  gap: 2px;
+  min-width: 80px;
+
+  .cost-price {
+    font-weight: 600;
+    color: var(--mat-sys-on-surface);
+  }
+
+  .cost-per-gram {
+    font-size: 11px;
+    color: var(--mat-sys-on-surface-variant);
+    letter-spacing: 0.02em;
+  }
+
+  .cost-unknown {
+    color: var(--mat-sys-on-surface-variant);
+    font-style: italic;
+  }
+}
+
+// Usage cell
+.usage-cell {
+  display: flex;
+  flex-direction: column;
+  gap: 2px;
+  min-width: 100px;
+
+  .usage-grams {
+    font-weight: 500;
+    color: var(--mat-sys-on-surface);
+  }
+
+  .usage-remaining {
+    font-size: 12px;
+    color: var(--mat-sys-on-surface-variant);
+  }
+}
+
 // Remaining weight cell
 .remaining-cell {
   display: flex;

frontend/src/app/components/filament-table/filament-table.component.ts

@@ -2,9 +2,12 @@ import {
   ChangeDetectionStrategy,
   Component,
   Input,
+  OnInit,
   computed,
+  inject,
   signal,
 } from '@angular/core';
+import { FilamentService } from '../../services/filament.service';
 import { CommonModule } from '@angular/common';
 import { MatTableModule } from '@angular/material/table';
 import { MatChipsModule } from '@angular/material/chips';
@@ -12,6 +15,7 @@ import { MatIconModule } from '@angular/material/icon';
 import { MatProgressBarModule } from '@angular/material/progress-bar';
 import { MatTooltipModule } from '@angular/material/tooltip';
 import { MatSortModule, Sort } from '@angular/material/sort';
+import { FilamentFilterComponent, FilamentFilterState } from '../filament-filter/filament-filter.component';
 import {
   Filament,
   StockLevel,
@@ -26,6 +30,8 @@ export type FilamentColumn =
   | 'brand'
   | 'serial'
   | 'remaining'
+  | 'cost'
+  | 'usage'
   | 'stockLevel'
   | 'status';
 
@@ -40,14 +46,17 @@ export type FilamentColumn =
     MatProgressBarModule,
     MatTooltipModule,
     MatSortModule,
+    FilamentFilterComponent,
   ],
   templateUrl: './filament-table.component.html',
   styleUrl: './filament-table.component.scss',
   changeDetection: ChangeDetectionStrategy.OnPush,
 })
-export class FilamentTableComponent {
-  /** Filament data input — reactive signal for live updates */
-  readonly filaments = signal<Filament[]>([]);
+export class FilamentTableComponent implements OnInit {
+  private readonly filamentService = inject(FilamentService);
+
+  /** Filament data — reactive signal driven by FilamentService */
+  readonly filaments = this.filamentService.filaments;
 
   /** Columns to display — defaults to all columns */
   @Input()
@@ -63,6 +72,8 @@ export class FilamentTableComponent {
     'brand',
     'serial',
     'remaining',
+    'cost',
+    'usage',
     'stockLevel',
     'status',
   ]);
@@ -70,9 +81,24 @@ export class FilamentTableComponent {
   /** Default columns for template binding */
   readonly columns = this._displayedColumns;
 
+  /** Current filter state */
+  readonly filterState = signal<FilamentFilterState>({
+    materialBaseNames: [],
+    colorSearch: '',
+    lowStockOnly: false,
+    activeOnly: false,
+  });
+
   /** Sorted filament data */
   readonly sortedFilaments = signal<Filament[]>([]);
 
+  /** Computed: filtered + sorted filament data for display */
+  readonly filteredFilaments = computed(() => {
+    const data = this.sortedFilaments();
+    const filters = this.filterState();
+    return data.filter((f) => this.matchesFilter(f, filters));
+  });
+
   /** Computed: count of low/critical spools */
   readonly lowStockCount = computed(() =>
     this.filaments().filter(
@@ -85,132 +111,20 @@ export class FilamentTableComponent {
     this.filaments().filter((f) => classifyStockLevel(f) === 'critical').length
   );
 
-  constructor() {
-    // Initialize sorted data from filaments
-    // (MatSort handles sorting via sortChange; we start unsorted)
-
-    // Development: seed with sample data for visual testing
-    // TODO: Replace with service data from FilamentService / SignalR
-    this.updateFilaments([
-      {
-        id: '1',
-        materialBaseId: 'm1',
-        materialBaseName: 'PLA',
-        materialFinishId: 'f1',
-        materialFinishName: 'Basic',
-        materialModifierId: null,
-        materialModifierName: null,
-        brand: 'Bambu Lab',
-        colorName: 'White',
-        colorHex: '#F5F5F5',
-        weightTotalGrams: 1000,
-        weightRemainingGrams: 850,
-        filamentDiameterMm: 1.75,
-        spoolSerial: 'SN-001',
-        purchasePrice: 25.00,
-        purchaseDate: '2026-01-15T00:00:00Z',
-        isActive: true,
-        createdAt: '2026-01-15T00:00:00Z',
-        updatedAt: '2026-04-20T00:00:00Z',
-        qrCodeUrl: '',
-      },
-      {
-        id: '2',
-        materialBaseId: 'm2',
-        materialBaseName: 'PETG',
-        materialFinishId: 'f2',
-        materialFinishName: 'Matte',
-        materialModifierId: 'mod1',
-        materialModifierName: 'Carbon Fiber',
-        brand: 'Polymaker',
-        colorName: 'Fire Engine Red',
-        colorHex: '#FF0000',
-        weightTotalGrams: 1000,
-        weightRemainingGrams: 80,
-        filamentDiameterMm: 1.75,
-        spoolSerial: 'SN-002',
-        purchasePrice: 35.00,
-        purchaseDate: '2026-02-01T00:00:00Z',
-        isActive: true,
-        createdAt: '2026-02-01T00:00:00Z',
-        updatedAt: '2026-04-25T00:00:00Z',
-        qrCodeUrl: '',
-      },
-      {
-        id: '3',
-        materialBaseId: 'm1',
-        materialBaseName: 'PLA',
-        materialFinishId: 'f1',
-        materialFinishName: 'Basic',
-        materialModifierId: null,
-        materialModifierName: null,
-        brand: 'eSun',
-        colorName: 'Sky Blue',
-        colorHex: '#87CEEB',
-        weightTotalGrams: 1000,
-        weightRemainingGrams: 200,
-        filamentDiameterMm: 1.75,
-        spoolSerial: 'SN-003',
-        purchasePrice: 20.00,
-        purchaseDate: '2026-03-10T00:00:00Z',
-        isActive: true,
-        createdAt: '2026-03-10T00:00:00Z',
-        updatedAt: '2026-04-26T00:00:00Z',
-        qrCodeUrl: '',
-      },
-      {
-        id: '4',
-        materialBaseId: 'm3',
-        materialBaseName: 'ABS',
-        materialFinishId: 'f1',
-        materialFinishName: 'Basic',
-        materialModifierId: null,
-        materialModifierName: null,
-        brand: 'Hatchbox',
-        colorName: 'Black',
-        colorHex: '#1A1A1A',
-        weightTotalGrams: 1000,
-        weightRemainingGrams: 450,
-        filamentDiameterMm: 1.75,
-        spoolSerial: 'SN-004',
-        purchasePrice: 22.00,
-        purchaseDate: null,
-        isActive: true,
-        createdAt: '2026-01-20T00:00:00Z',
-        updatedAt: '2026-04-18T00:00:00Z',
-        qrCodeUrl: '',
-      },
-      {
-        id: '5',
-        materialBaseId: 'm1',
-        materialBaseName: 'PLA',
-        materialFinishId: 'f3',
-        materialFinishName: 'Silk',
-        materialModifierId: null,
-        materialModifierName: null,
-        brand: 'Overturn',
-        colorName: 'Gold',
-        colorHex: '#FFD700',
-        weightTotalGrams: 500,
-        weightRemainingGrams: 15,
-        filamentDiameterMm: 1.75,
-        spoolSerial: 'SN-005',
-        purchasePrice: 28.00,
-        purchaseDate: null,
-        isActive: false,
-        createdAt: '2025-12-01T00:00:00Z',
-        updatedAt: '2026-04-01T00:00:00Z',
-        qrCodeUrl: '',
-      },
-    ]);
+  ngOnInit(): void {
+    // Initialize sorted data from FilamentService
+    this.sortedFilaments.set([...this.filaments()]);
   }
 
-  /** Update filament data — called by parent or service */
+  /** Update filament data — called externally or from a SignalR handler */
   updateFilaments(data: Filament[]): void {
-    this.filaments.set(data);
+    this.filamentService.setFilaments(data);
     this.sortedFilaments.set([...data]);
   }
 
+  /** All filament data — for the filter component to derive material options */
+  readonly allFilaments = this.filaments;
+
   /** Handle sort changes from MatSort */
   sortData(sort: Sort): void {
     const data = [...this.filaments()];
@@ -233,6 +147,18 @@ export class FilamentTableComponent {
             getRemainingPercent(b),
             isAsc
           );
+        case 'cost':
+          return compare(
+            a.purchasePrice ?? 0,
+            b.purchasePrice ?? 0,
+            isAsc
+          );
+        case 'usage':
+          return compare(
+            a.weightTotalGrams - a.weightRemainingGrams,
+            b.weightTotalGrams - b.weightRemainingGrams,
+            isAsc
+          );
         case 'stockLevel':
           return compare(
             stockLevelOrder(classifyStockLevel(a)),
@@ -252,6 +178,46 @@ export class FilamentTableComponent {
     this.sortedFilaments.set(sorted);
   }
 
+  /** Handle filter changes from FilamentFilterComponent */
+  onFilterChange(state: FilamentFilterState): void {
+    this.filterState.set(state);
+  }
+
+  /** Check if a filament matches the current filter state */
+  private matchesFilter(filament: Filament, filters: FilamentFilterState): boolean {
+    // Material filter — empty means all
+    if (
+      filters.materialBaseNames.length > 0 &&
+      !filters.materialBaseNames.includes(filament.materialBaseName)
+    ) {
+      return false;
+    }
+
+    // Color search — empty means all
+    if (
+      filters.colorSearch &&
+      !filament.colorName.toLowerCase().includes(filters.colorSearch) &&
+      !filament.colorHex.toLowerCase().includes(filters.colorSearch)
+    ) {
+      return false;
+    }
+
+    // Low stock filter — show only critical/low
+    if (filters.lowStockOnly) {
+      const level = classifyStockLevel(filament);
+      if (level !== 'critical' && level !== 'low') {
+        return false;
+      }
+    }
+
+    // Active only filter
+    if (filters.activeOnly && !filament.isActive) {
+      return false;
+    }
+
+    return true;
+  }
+
   /** Template helper: get remaining percent */
   getRemainingPercent = getRemainingPercent;
 
@@ -293,6 +259,29 @@ export class FilamentTableComponent {
     }
     return `${Math.round(grams)}g`;
   }
+
+  /** Template helper: format currency */
+  formatCurrency(value: number): string {
+    return new Intl.NumberFormat('en-US', {
+      style: 'currency',
+      currency: 'USD',
+      minimumFractionDigits: 2,
+      maximumFractionDigits: 2,
+    }).format(value);
+  }
+
+  /** Template helper: compute cost per gram for a filament */
+  getCostPerGram(filament: Filament): number | null {
+    if (filament.purchasePrice === null || filament.purchasePrice === 0 || filament.weightTotalGrams <= 0) {
+      return null;
+    }
+    return filament.purchasePrice / filament.weightTotalGrams;
+  }
+
+  /** Template helper: compute grams used for a filament */
+  getGramsUsed(filament: Filament): number {
+    return filament.weightTotalGrams - filament.weightRemainingGrams;
+  }
 }
 
 /** Compare helper for sorting */

frontend/src/app/components/inventory-summary/inventory-summary.component.html

@@ -0,0 +1,145 @@
+<!-- Inventory Dashboard Summary — filament metrics at a glance -->
+<section class="inventory-summary" role="region" aria-label="Inventory summary">
+
+  <!-- Loading State -->
+  @if (loading()) {
+    <div class="summary-loading" role="status" aria-live="polite">
+      <mat-icon aria-hidden="true" class="spin">sync</mat-icon>
+      <span>Loading inventory...</span>
+    </div>
+  }
+
+  <!-- Error State -->
+  @else if (error()) {
+    <div class="summary-error" role="alert" aria-live="assertive">
+      <mat-icon aria-hidden="true">error_outline</mat-icon>
+      <span>{{ error() }}</span>
+      <button class="retry-btn" (click)="refresh()" aria-label="Retry loading inventory">
+        <mat-icon aria-hidden="true">refresh</mat-icon>
+        Retry
+      </button>
+    </div>
+  }
+
+  <!-- Loaded State -->
+  @else {
+    <!-- Health Status Indicator -->
+    <div class="summary-item health-status"
+         [class]="healthClass()"
+         [matTooltip]="healthLabel()"
+         matTooltipPosition="below">
+      <mat-icon aria-hidden="true">
+        @switch (healthClass()) {
+          @case ('critical') { error }
+          @case ('low') { warning }
+          @default { check_circle }
+        }
+      </mat-icon>
+      <span class="health-text">{{ healthLabel() }}</span>
+    </div>
+
+    <!-- Total Spool Count -->
+    <div class="summary-item metric-card"
+         matTooltip="Total filament spools in inventory"
+         matTooltipPosition="below">
+      <mat-icon aria-hidden="true" class="metric-icon">inventory_2</mat-icon>
+      <div class="metric-content">
+        <span class="metric-value">{{ totalCount() }}</span>
+        <span class="metric-label">Total Spools</span>
+      </div>
+      @if (activeCount() < totalCount()) {
+        <span class="metric-detail">{{ activeCount() }} active</span>
+      }
+    </div>
+
+    <!-- Low Stock Count -->
+    <div class="summary-item metric-card"
+         [class.has-alert]="hasLowStock()"
+         [class.has-critical]="hasCritical()"
+         [matTooltip]="hasCritical()
+           ? criticalCount() + ' critical, ' + (lowStockCount() - criticalCount()) + ' low'
+           : hasLowStock()
+             ? lowStockCount() + ' spools at or below 25% remaining'
+             : 'All spools above 25% remaining'"
+         matTooltipPosition="below">
+      <mat-icon aria-hidden="true" class="metric-icon">
+        @if (hasCritical()) { error }
+        @else if (hasLowStock()) { warning }
+        @else { check_circle }
+      </mat-icon>
+      <div class="metric-content">
+        <span class="metric-value">{{ lowStockCount() }}</span>
+        <span class="metric-label">Low Stock</span>
+      </div>
+      @if (hasCritical()) {
+        <span class="metric-detail critical-detail">{{ criticalCount() }} critical</span>
+      }
+    </div>
+
+    <!-- Estimated Total Value -->
+    <div class="summary-item metric-card"
+         matTooltip="Estimated total value of active spools"
+         matTooltipPosition="below">
+      <mat-icon aria-hidden="true" class="metric-icon">payments</mat-icon>
+      <div class="metric-content">
+        <span class="metric-value">{{ formatCurrency(totalValue()) }}</span>
+        <span class="metric-label">Est. Value</span>
+      </div>
+    </div>
+
+    <!-- Average Cost per Gram -->
+    @if (avgCostPerGram() !== null) {
+      <div class="summary-item metric-card"
+           matTooltip="Average cost per gram across priced, active spools"
+           matTooltipPosition="below">
+        <mat-icon aria-hidden="true" class="metric-icon">scale</mat-icon>
+        <div class="metric-content">
+          <span class="metric-value">${{ avgCostPerGram()!.toFixed(2) }}/g</span>
+          <span class="metric-label">Avg Cost/g</span>
+        </div>
+      </div>
+    }
+
+    <!-- Total Usage -->
+    <div class="summary-item metric-card"
+         matTooltip="Total filament used across all spools"
+         matTooltipPosition="below">
+      <mat-icon aria-hidden="true" class="metric-icon">trending_down</mat-icon>
+      <div class="metric-content">
+        <span class="metric-value">{{ formatWeight(totalGramsUsed()) }}</span>
+        <span class="metric-label">Total Used</span>
+      </div>
+    </div>
+
+    <!-- Estimated Used Value -->
+    @if (estimatedUsedValue() !== null) {
+      <div class="summary-item metric-card"
+           matTooltip="Estimated value of filament consumed"
+           matTooltipPosition="below">
+        <mat-icon aria-hidden="true" class="metric-icon">receipt_long</mat-icon>
+        <div class="metric-content">
+          <span class="metric-value">{{ formatCurrency(estimatedUsedValue()!) }}</span>
+          <span class="metric-label">Used Value</span>
+        </div>
+      </div>
+    }
+
+    <!-- Overall Remaining Stock Bar -->
+    <div class="summary-item metric-card stock-bar-card"
+         matTooltip="{{ formatWeight(totalRemainingGrams()) }} of {{ formatWeight(totalCapacityGrams()) }} remaining"
+         matTooltipPosition="below">
+      <mat-icon aria-hidden="true" class="metric-icon">line_weight</mat-icon>
+      <div class="metric-content stock-bar-content">
+        <div class="stock-bar-header">
+          <span class="metric-value">{{ overallRemainingPercent() }}%</span>
+          <span class="metric-label">Remaining</span>
+        </div>
+        <mat-progress-bar
+          mode="determinate"
+          [value]="overallRemainingPercent()"
+          [ngClass]="healthClass()">
+        </mat-progress-bar>
+      </div>
+    </div>
+  }
+</section>

frontend/src/app/components/inventory-summary/inventory-summary.component.scss

@@ -0,0 +1,257 @@
+/**
+ * Inventory Summary Component Styles
+ * Touch-optimized for kiosk (Raspberry Pi 5) and mobile PWA
+ * Matches the existing dark theme from app.scss
+ */
+
+// Touch-optimized sizing
+$touch-target-min: 48px;
+$kiosk-font-primary: 24px;
+$mobile-font-primary: 18px;
+$spacing-unit: 8px;
+
+// Status colors — high contrast for workshop/bright environments
+$color-healthy: #4ade70;    // Green
+$color-low: #fbbf24;        // Amber/Yellow
+$color-critical: #f87171;   // Red
+$color-bg: #1a1a2e;         // Matches app.scss
+$color-text: #e0e0e0;
+$color-text-muted: rgba(255, 255, 255, 0.7);
+$color-card-bg: rgba(255, 255, 255, 0.05);
+$color-card-border: rgba(255, 255, 255, 0.1);
+
+.inventory-summary {
+  display: flex;
+  align-items: stretch;
+  gap: $spacing-unit * 2;
+  padding: $spacing-unit * 2;
+  overflow-x: auto;
+  -webkit-overflow-scrolling: touch;
+  scrollbar-width: thin;
+
+  @media (max-width: 600px) {
+    flex-wrap: wrap;
+    padding: $spacing-unit;
+    gap: $spacing-unit;
+  }
+}
+
+// Health status indicator
+.health-status {
+  display: flex;
+  align-items: center;
+  gap: $spacing-unit;
+  padding: $spacing-unit $spacing-unit * 2;
+  border-radius: 24px;
+  min-height: $touch-target-min;
+  white-space: nowrap;
+  transition: background-color 0.3s ease;
+
+  &.healthy {
+    background-color: rgba($color-healthy, 0.15);
+    color: $color-healthy;
+  }
+
+  &.low {
+    background-color: rgba($color-low, 0.15);
+    color: $color-low;
+  }
+
+  &.critical {
+    background-color: rgba($color-critical, 0.15);
+    color: $color-critical;
+  }
+
+  .health-text {
+    font-size: 14px;
+    font-weight: 600;
+    letter-spacing: 0.02em;
+
+    @media (max-width: 480px) {
+      font-size: 12px;
+    }
+  }
+
+  mat-icon {
+    font-size: 20px !important;
+    width: 20px !important;
+    height: 20px !important;
+  }
+}
+
+// Metric card
+.metric-card {
+  display: flex;
+  align-items: center;
+  gap: $spacing-unit;
+  padding: $spacing-unit $spacing-unit * 2;
+  background-color: $color-card-bg;
+  border: 1px solid $color-card-border;
+  border-radius: 12px;
+  min-height: $touch-target-min;
+  white-space: nowrap;
+  transition: border-color 0.2s ease, background-color 0.2s ease;
+
+  &:hover {
+    border-color: rgba(255, 255, 255, 0.2);
+    background-color: rgba(255, 255, 255, 0.08);
+  }
+
+  @media (max-width: 480px) {
+    padding: $spacing-unit;
+  }
+
+  &.has-alert {
+    border-color: rgba($color-low, 0.4);
+  }
+
+  &.has-critical {
+    border-color: rgba($color-critical, 0.5);
+    background-color: rgba($color-critical, 0.08);
+  }
+}
+
+.metric-icon {
+  color: $color-text-muted;
+  font-size: 22px !important;
+  width: 22px !important;
+  height: 22px !important;
+
+  .has-alert & {
+    color: $color-low;
+  }
+
+  .has-critical & {
+    color: $color-critical;
+  }
+}
+
+.metric-content {
+  display: flex;
+  flex-direction: column;
+  gap: 2px;
+}
+
+.metric-value {
+  font-size: $kiosk-font-primary;
+  font-weight: 700;
+  line-height: 1.2;
+  color: $color-text;
+
+  @media (max-width: 480px) {
+    font-size: $mobile-font-primary;
+  }
+}
+
+.metric-label {
+  font-size: 11px;
+  color: $color-text-muted;
+  text-transform: uppercase;
+  letter-spacing: 0.08em;
+}
+
+.metric-detail {
+  font-size: 11px;
+  color: $color-text-muted;
+  margin-left: $spacing-unit;
+
+  &.critical-detail {
+    color: $color-critical;
+    font-weight: 600;
+  }
+}
+
+// Stock bar card
+.stock-bar-card {
+  flex: 1 1 200px;
+  min-width: 180px;
+}
+
+.stock-bar-content {
+  flex: 1;
+  min-width: 0;
+}
+
+.stock-bar-header {
+  display: flex;
+  align-items: baseline;
+  gap: $spacing-unit;
+  margin-bottom: 4px;
+}
+
+// Progress bar color classes
+::ng-deep .mat-mdc-progress-bar {
+  &.healthy .mdc-linear-progress__bar-inner {
+    background-color: $color-healthy !important;
+  }
+
+  &.low .mdc-linear-progress__bar-inner {
+    background-color: $color-low !important;
+  }
+
+  &.critical .mdc-linear-progress__bar-inner {
+    background-color: $color-critical !important;
+  }
+}
+
+// Loading state
+.summary-loading {
+  display: flex;
+  align-items: center;
+  gap: $spacing-unit;
+  padding: $spacing-unit * 2;
+  color: $color-text-muted;
+  font-size: 14px;
+
+  .spin {
+    animation: spin 1s linear infinite;
+  }
+}
+
+@keyframes spin {
+  0% { transform: rotate(0deg); }
+  100% { transform: rotate(360deg); }
+}
+
+// Error state
+.summary-error {
+  display: flex;
+  align-items: center;
+  gap: $spacing-unit;
+  padding: $spacing-unit * 2;
+  background-color: rgba($color-critical, 0.1);
+  border: 1px solid rgba($color-critical, 0.3);
+  border-radius: 12px;
+  color: $color-critical;
+  font-size: 14px;
+
+  .retry-btn {
+    display: flex;
+    align-items: center;
+    gap: 4px;
+    background: transparent;
+    border: 1px solid rgba($color-critical, 0.4);
+    color: $color-critical;
+    padding: 4px 12px;
+    border-radius: 8px;
+    cursor: pointer;
+    font-size: 13px;
+    min-height: $touch-target-min - 8px;
+    transition: background-color 0.2s ease;
+
+    &:hover {
+      background-color: rgba($color-critical, 0.15);
+    }
+
+    mat-icon {
+      font-size: 16px !important;
+      width: 16px !important;
+      height: 16px !important;
+    }
+  }
+}
+
+// Summary item base
+.summary-item {
+  flex-shrink: 0;
+}

frontend/src/app/components/inventory-summary/inventory-summary.component.ts

@@ -0,0 +1,207 @@
+import {
+  ChangeDetectionStrategy,
+  Component,
+  OnDestroy,
+  OnInit,
+  computed,
+  inject,
+  signal,
+} from '@angular/core';
+import { CommonModule } from '@angular/common';
+import { MatIconModule } from '@angular/material/icon';
+import { MatChipsModule } from '@angular/material/chips';
+import { MatTooltipModule } from '@angular/material/tooltip';
+import { MatProgressBarModule } from '@angular/material/progress-bar';
+import { FilamentService } from '../../services/filament.service';
+import {
+  classifyStockLevel,
+} from '../../models/filament.model';
+import { Subscription } from 'rxjs';
+
+/**
+ * Inventory Dashboard Summary — shows filament inventory at a glance.
+ *
+ * Displays:
+ * - Total filament spool count
+ * - Low stock count (spools ≤25% remaining, i.e. "low" or "critical")
+ * - Estimated total filament value (sum of purchase prices for active spools)
+ *
+ * Data is sourced from the shared FilamentService signal,
+ * which is loaded on init and can be refreshed via refresh().
+ */
+@Component({
+  selector: 'app-inventory-summary',
+  standalone: true,
+  imports: [
+    CommonModule,
+    MatIconModule,
+    MatChipsModule,
+    MatTooltipModule,
+    MatProgressBarModule,
+  ],
+  templateUrl: './inventory-summary.component.html',
+  styleUrls: ['./inventory-summary.component.scss'],
+  changeDetection: ChangeDetectionStrategy.OnPush,
+})
+export class InventorySummaryComponent implements OnInit, OnDestroy {
+  private readonly filamentService = inject(FilamentService);
+  private subscription: Subscription | null = null;
+
+  /** All filament data — reactive signal from shared service */
+  readonly filaments = this.filamentService.filaments;
+
+  /** Loading state */
+  readonly loading = signal<boolean>(true);
+
+  /** Error state */
+  readonly error = signal<string | null>(null);
+
+  /** Computed: total number of filament spools */
+  readonly totalCount = computed(() => this.filaments().length);
+
+  /** Computed: count of active spools */
+  readonly activeCount = computed(
+    () => this.filaments().filter((f) => f.isActive).length
+  );
+
+  /** Computed: count of low/critical stock spools (≤25% remaining) */
+  readonly lowStockCount = computed(
+    () =>
+      this.filaments().filter(
+        (f) =>
+          classifyStockLevel(f) === 'low' ||
+          classifyStockLevel(f) === 'critical'
+      ).length
+  );
+
+  /** Computed: count of critically low spools (≤10% remaining) */
+  readonly criticalCount = computed(
+    () =>
+      this.filaments().filter((f) => classifyStockLevel(f) === 'critical')
+        .length
+  );
+
+  /** Computed: estimated total value of active spools */
+  readonly totalValue = computed(() =>
+    this.filaments()
+      .filter((f) => f.isActive && f.purchasePrice !== null)
+      .reduce((sum, f) => sum + (f.purchasePrice ?? 0), 0)
+  );
+
+  /** Computed: average cost per gram across active spools with a price */
+  readonly avgCostPerGram = computed(() => {
+    const priced = this.filaments().filter(
+      (f) => f.isActive && f.purchasePrice !== null && f.purchasePrice! > 0 && f.weightTotalGrams > 0
+    );
+    if (priced.length === 0) return null;
+    const totalCost = priced.reduce((sum, f) => sum + f.purchasePrice!, 0);
+    const totalWeight = priced.reduce((sum, f) => sum + f.weightTotalGrams, 0);
+    return totalWeight > 0 ? totalCost / totalWeight : null;
+  });
+
+  /** Computed: total grams used across all spools */
+  readonly totalGramsUsed = computed(() =>
+    this.filaments().reduce(
+      (sum, f) => sum + (f.weightTotalGrams - f.weightRemainingGrams),
+      0
+    )
+  );
+
+  /** Computed: total estimated value of used filament */
+  readonly estimatedUsedValue = computed(() => {
+    const priced = this.filaments().filter(
+      (f) => f.isActive && f.purchasePrice !== null && f.purchasePrice! > 0 && f.weightTotalGrams > 0
+    );
+    if (priced.length === 0) return null;
+    return priced.reduce((sum, f) => {
+      const usedFraction = (f.weightTotalGrams - f.weightRemainingGrams) / f.weightTotalGrams;
+      return sum + f.purchasePrice! * usedFraction;
+    }, 0);
+  });
+
+  /** Computed: total remaining weight across all spools in grams */
+  readonly totalRemainingGrams = computed(() =>
+    this.filaments().reduce((sum, f) => sum + f.weightRemainingGrams, 0)
+  );
+
+  /** Computed: total capacity weight across all spools in grams */
+  readonly totalCapacityGrams = computed(() =>
+    this.filaments().reduce((sum, f) => sum + f.weightTotalGrams, 0)
+  );
+
+  /** Computed: overall remaining percentage */
+  readonly overallRemainingPercent = computed(() => {
+    const capacity = this.totalCapacityGrams();
+    if (capacity <= 0) return 0;
+    return Math.round(
+      (this.totalRemainingGrams() / capacity) * 100
+    );
+  });
+
+  /** Computed: whether to show a low-stock alert */
+  readonly hasLowStock = computed(() => this.lowStockCount() > 0);
+
+  /** Computed: whether to show a critical-stock alert */
+  readonly hasCritical = computed(() => this.criticalCount() > 0);
+
+  /** Computed: status label for the inventory health */
+  readonly healthLabel = computed(() => {
+    if (this.hasCritical()) return 'Critical Stock';
+    if (this.hasLowStock()) return 'Low Stock Alert';
+    return 'Stock Healthy';
+  });
+
+  /** Computed: health status color class */
+  readonly healthClass = computed(() => {
+    if (this.hasCritical()) return 'critical';
+    if (this.hasLowStock()) return 'low';
+    return 'healthy';
+  });
+
+  ngOnInit(): void {
+    this.loadFilaments();
+  }
+
+  ngOnDestroy(): void {
+    this.subscription?.unsubscribe();
+  }
+
+  /** Load filament data from the API via FilamentService */
+  loadFilaments(): void {
+    this.loading.set(true);
+    this.error.set(null);
+    this.subscription = this.filamentService.getFilaments().subscribe({
+      next: () => {
+        this.loading.set(false);
+      },
+      error: (err) => {
+        console.error('Failed to load filaments:', err);
+        this.error.set('Failed to load inventory data');
+        this.loading.set(false);
+      },
+    });
+  }
+
+  /** Refresh data — called externally when data changes (e.g., SignalR notification) */
+  refresh(): void {
+    this.loadFilaments();
+  }
+
+  /** Format weight for display */
+  formatWeight(grams: number): string {
+    if (grams >= 1000) {
+      return `${(grams / 1000).toFixed(1)}kg`;
+    }
+    return `${Math.round(grams)}g`;
+  }
+
+  /** Format currency for display */
+  formatCurrency(value: number): string {
+    return new Intl.NumberFormat('en-US', {
+      style: 'currency',
+      currency: 'USD',
+      minimumFractionDigits: 2,
+      maximumFractionDigits: 2,
+    }).format(value);
+  }
+}

frontend/src/app/models/material.model.ts

@@ -0,0 +1,50 @@
+/**
+ * Material lookup models matching the Extrudex backend Material DTOs.
+ * Used for populating dropdowns in the filament add/edit form.
+ */
+
+/** Material base (e.g., PLA, PETG, ABS). */
+export interface MaterialBase {
+  /** Unique identifier. */
+  id: string;
+  /** Human-readable name (e.g., "PLA", "PETG"). */
+  name: string;
+  /** Density in g/cm³. */
+  densityGperCm3: number;
+  /** Created timestamp (UTC). */
+  createdAt: string;
+  /** Updated timestamp (UTC). */
+  updatedAt: string;
+}
+
+/** Material finish (e.g., Basic, Matte, Silk). */
+export interface MaterialFinish {
+  /** Unique identifier. */
+  id: string;
+  /** Human-readable name (e.g., "Basic", "Matte"). */
+  name: string;
+  /** Foreign key to the parent material base. */
+  materialBaseId: string;
+  /** Name of the parent material base (for display). */
+  materialBaseName: string;
+  /** Created timestamp (UTC). */
+  createdAt: string;
+  /** Updated timestamp (UTC). */
+  updatedAt: string;
+}
+
+/** Material modifier (e.g., Carbon Fiber, Wood Fill). Optional. */
+export interface MaterialModifier {
+  /** Unique identifier. */
+  id: string;
+  /** Human-readable name (e.g., "Carbon Fiber"). */
+  name: string;
+  /** Foreign key to the parent material base. */
+  materialBaseId: string;
+  /** Name of the parent material base (for display). */
+  materialBaseName: string;
+  /** Created timestamp (UTC). */
+  createdAt: string;
+  /** Updated timestamp (UTC). */
+  updatedAt: string;
+}

frontend/src/app/models/paged-response.model.ts

@@ -0,0 +1,13 @@
+/**
+ * Generic paged response wrapper matching the Extrudex backend PagedResponse<T>.
+ */
+export interface PagedResponse<T> {
+  /** The items in this page. */
+  items: T[];
+  /** Total number of items across all pages. */
+  totalCount: number;
+  /** The current page number (1-based). */
+  pageNumber: number;
+  /** The number of items per page. */
+  pageSize: number;
+}

frontend/src/app/services/filament.service.ts

@@ -0,0 +1,52 @@
+import { Injectable, inject } from '@angular/core';
+import { HttpClient } from '@angular/common/http';
+import { Observable, Subscription } from 'rxjs';
+import { signal } from '@angular/core';
+import { Filament } from '../models/filament.model';
+
+/**
+ * API base URL — matches the Extrudex backend.
+ * TODO: Move to environment config when environments are set up.
+ */
+const API_BASE_URL = '/api/filaments';
+
+/**
+ * Service for managing filament inventory data.
+ *
+ * Provides:
+ * - A reactive `filaments` signal for components to bind to
+ * - REST methods for GET, POST, DELETE endpoints
+ * - Real-time updates via SignalR should be layered on top when the hub is ready
+ */
+@Injectable({ providedIn: 'root' })
+export class FilamentService {
+  private readonly http = inject(HttpClient);
+
+  /** Reactive filament data — components read from this signal */
+  readonly filaments = signal<Filament[]>([]);
+
+  /** Fetch all filament spools and update the signal */
+  getFilaments(): Observable<Filament[]> {
+    const req = this.http.get<Filament[]>(API_BASE_URL);
+    req.subscribe({
+      next: (data) => this.filaments.set(data),
+      error: (err) => console.error('Failed to load filaments:', err),
+    });
+    return req;
+  }
+
+  /** Fetch a single filament by ID */
+  getFilament(id: string): Observable<Filament> {
+    return this.http.get<Filament>(`${API_BASE_URL}/${id}`);
+  }
+
+  /** Set filament data directly — used by components or SignalR handlers */
+  setFilaments(data: Filament[]): void {
+    this.filaments.set(data);
+  }
+
+  /** Delete a filament spool by ID */
+  deleteFilament(id: string): Observable<void> {
+    return this.http.delete<void>(`${API_BASE_URL}/${id}`);
+  }
+}

frontend/src/environments/environment.prod.ts

@@ -0,0 +1,8 @@
+/**
+ * Environment configuration for the Extrudex frontend (production).
+ * Override API URL for deployed environments.
+ */
+export const environment = {
+  production: true,
+  apiBaseUrl: '/api',
+};

frontend/src/environments/environment.ts

@@ -0,0 +1,8 @@
+/**
+ * Environment configuration for the Extrudex frontend.
+ * Replace API URL with the actual backend endpoint in production.
+ */
+export const environment = {
+  production: false,
+  apiBaseUrl: 'http://localhost:5000',
+};