Summary
kerf-engine is 33% complete across 3 milestones. $15.14 spent. Currently executing M002/S01.
1/3Milestones
3/9Slices
planningPhase
$15.14Cost
17.34MTokens
51m 18sDuration
384Tool calls
15Units
6Remaining
16.0/hrRate
$5.05Cost/slice
45.2kTokens/tool
100.0%Cache hit
M001Scope
33%
Executing M002/S01 — Import & Convert UI (View 1)
ETA: ~22m 31s remaining (6 slices at 16.0/hr)
Blockers
No blockers or high-risk items found.
Progress
M001 Kerf Engine — Raster-to-Vector Pipeline & API 3/3
S01 Core Pipeline — Preprocessing + Vectorization high — dependency installation, OpenCV+Potrace+VTracer integration critical
untested
S02 Post-Processing + Output Formats (SVG, DXF, JSON) high — DXF generation quality is hard to validate programmatically S01 critical
provides: postprocess_svg() function for RDP simplification + island detection + node countingprovides: Output generators: generate_dxf(), generate_json(), generate_svg()provides: /engine/simplify endpoint for SVG-to-SVG/DXF/JSON simplificationprovides: output_format routing on /engine/trace (svg, dxf, json)provides: _format_response() pattern for consistent multi-format responsesrequires: Core pipeline: preprocessing + potrace_trace() + vtracer_trace() producing raw SVG output
passed
Decisions
- DXF output as raw bytes with application/dxf content-type and metadata in X-Kerf-Metadata header
- postprocess_svg() replaces regex metadata extraction — full XML path parsing for structured PathInfo objects
- _format_response() shared helper for consistent response shaping across endpoints
- Islands placed on separate ISLANDS layer in DXF for downstream CAM tool compatibility
- Bezier curves linearized during post-processing for RDP simplification and DXF polyline generation
Patterns
- PostProcessResult as the universal intermediate representation consumed by all output generators
- Output generators are pure functions: PostProcessResult → bytes/string, no side effects
- _format_response() pattern for consistent multi-format API responses with metadata
S03 Preset System + Engine Docker Packaging low — presets are config files; Docker packaging is well-understood S02 critical
provides: Preset system with 5 tuned configs and merge-based param resolutionprovides: GET /engine/presets endpointprovides: Docker image kerf-engine:dev with healthcheckprovides: GET /engine/health endpointrequires: Post-processing pipeline and output format generators (SVG, DXF, JSON) consumed by preset-driven trace flow
passed
Decisions
- Preset default is 'sign' — covers the most common use case
- Presets use flat JSON with three sections (preprocessing, vectorization, postprocessing)
- resolve_params merges preset → user_params with user taking precedence
- Custom preset has empty param sections so pipeline defaults apply unless user provides overrides
- Multi-stage Docker build separates build deps from runtime (smaller image, no compiler tools)
- Engine image contains only engine source — enforces Engine/App separation (D001)
- Health endpoint at /engine/health for namespace consistency with other /engine/* routes
Patterns
- Preset-driven pipeline configuration: presets define defaults, user params override
- Multi-stage Docker build pattern for Python+C extension packages (pypotrace)
- Dual health endpoints: /health (root) for simple checks, /engine/health (namespaced) for Docker/orchestration
M002 M002 0/3 critical path
S01 Import & Convert UI (View 1) medium — debounced preview updates, Engine API integration from browser critical
untested
S02 Design Canvas Core (View 2) medium — Konva.js setup, selection handles, undo/redo state management S01 critical
provides: postprocess_svg() function for RDP simplification + island detection + node countingprovides: Output generators: generate_dxf(), generate_json(), generate_svg()provides: /engine/simplify endpoint for SVG-to-SVG/DXF/JSON simplificationprovides: output_format routing on /engine/trace (svg, dxf, json)provides: _format_response() pattern for consistent multi-format responsesrequires: Core pipeline: preprocessing + potrace_trace() + vtracer_trace() producing raw SVG output
passed
Decisions
- DXF output as raw bytes with application/dxf content-type and metadata in X-Kerf-Metadata header
- postprocess_svg() replaces regex metadata extraction — full XML path parsing for structured PathInfo objects
- _format_response() shared helper for consistent response shaping across endpoints
- Islands placed on separate ISLANDS layer in DXF for downstream CAM tool compatibility
- Bezier curves linearized during post-processing for RDP simplification and DXF polyline generation
Patterns
- PostProcessResult as the universal intermediate representation consumed by all output generators
- Output generators are pure functions: PostProcessResult → bytes/string, no side effects
- _format_response() pattern for consistent multi-format API responses with metadata
S03 Text System + Font Loading medium — opentype.js integration, font loading from volume, path extraction accuracy S02 critical
provides: Preset system with 5 tuned configs and merge-based param resolutionprovides: GET /engine/presets endpointprovides: Docker image kerf-engine:dev with healthcheckprovides: GET /engine/health endpointrequires: Post-processing pipeline and output format generators (SVG, DXF, JSON) consumed by preset-driven trace flow
passed
Decisions
- Preset default is 'sign' — covers the most common use case
- Presets use flat JSON with three sections (preprocessing, vectorization, postprocessing)
- resolve_params merges preset → user_params with user taking precedence
- Custom preset has empty param sections so pipeline defaults apply unless user provides overrides
- Multi-stage Docker build separates build deps from runtime (smaller image, no compiler tools)
- Engine image contains only engine source — enforces Engine/App separation (D001)
- Health endpoint at /engine/health for namespace consistency with other /engine/* routes
Patterns
- Preset-driven pipeline configuration: presets define defaults, user params override
- Multi-stage Docker build pattern for Python+C extension packages (pypotrace)
- Dual health endpoints: /health (root) for simple checks, /engine/health (namespaced) for Docker/orchestration
M003 M003 0/3
S01 Export Flow (View 3) + DXF Generation high — DXF scale accuracy and geometry quality critical
untested
S02 Docker Packaging + README low — Docker packaging is well-understood pattern S01 critical
provides: postprocess_svg() function for RDP simplification + island detection + node countingprovides: Output generators: generate_dxf(), generate_json(), generate_svg()provides: /engine/simplify endpoint for SVG-to-SVG/DXF/JSON simplificationprovides: output_format routing on /engine/trace (svg, dxf, json)provides: _format_response() pattern for consistent multi-format responsesrequires: Core pipeline: preprocessing + potrace_trace() + vtracer_trace() producing raw SVG output
passed
Decisions
- DXF output as raw bytes with application/dxf content-type and metadata in X-Kerf-Metadata header
- postprocess_svg() replaces regex metadata extraction — full XML path parsing for structured PathInfo objects
- _format_response() shared helper for consistent response shaping across endpoints
- Islands placed on separate ISLANDS layer in DXF for downstream CAM tool compatibility
- Bezier curves linearized during post-processing for RDP simplification and DXF polyline generation
Patterns
- PostProcessResult as the universal intermediate representation consumed by all output generators
- Output generators are pure functions: PostProcessResult → bytes/string, no side effects
- _format_response() pattern for consistent multi-format API responses with metadata
S03 Embed Mode medium — Shadow DOM + Konva.js + font loading interactions S02 critical
provides: Preset system with 5 tuned configs and merge-based param resolutionprovides: GET /engine/presets endpointprovides: Docker image kerf-engine:dev with healthcheckprovides: GET /engine/health endpointrequires: Post-processing pipeline and output format generators (SVG, DXF, JSON) consumed by preset-driven trace flow
passed
Decisions
- Preset default is 'sign' — covers the most common use case
- Presets use flat JSON with three sections (preprocessing, vectorization, postprocessing)
- resolve_params merges preset → user_params with user taking precedence
- Custom preset has empty param sections so pipeline defaults apply unless user provides overrides
- Multi-stage Docker build separates build deps from runtime (smaller image, no compiler tools)
- Engine image contains only engine source — enforces Engine/App separation (D001)
- Health endpoint at /engine/health for namespace consistency with other /engine/* routes
Patterns
- Preset-driven pipeline configuration: presets define defaults, user params override
- Multi-stage Docker build pattern for Python+C extension packages (pypotrace)
- Dual health endpoints: /health (root) for simple checks, /engine/health (namespaced) for Docker/orchestration
Timeline
| # | Type | ID | Model | Started | Duration | Cost | Tokens | Tools | Tier | Routed | Trunc | CHF |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | execute-task | M001/S01/T01 | opus-4-6 | Mar 26, 2026, 04:00 AM | 6m 19s | $1.14 | 1.31M | 39 | ||||
| 2 | execute-task | M001/S01/T02 | opus-4-6 | Mar 26, 2026, 04:07 AM | 3m 41s | $0.976 | 1.03M | 30 | ||||
| 3 | execute-task | M001/S01/T03 | opus-4-6 | Mar 26, 2026, 04:11 AM | 3m 59s | $1.12 | 1.29M | 34 | ||||
| 4 | execute-task | M001/S01/T04 | opus-4-6 | Mar 26, 2026, 04:15 AM | 3m 29s | $0.0000 | 0 | 0 | ||||
| 5 | execute-task | M001/S01/T05 | opus-4-6 | Mar 26, 2026, 04:18 AM | 4m 8s | $1.37 | 1.35M | 40 | ||||
| 6 | complete-slice | M001/S01 | opus-4-6 | Mar 26, 2026, 04:22 AM | 3m 19s | $0.734 | 655.6k | 21 | ||||
| 7 | complete-slice | M001/S01 | opus-4-6 | Mar 26, 2026, 04:25 AM | 2m 4s | $0.796 | 881.5k | 30 | ||||
| 8 | execute-task | M001/S02/T01 | opus-4-6 | Mar 26, 2026, 04:28 AM | 4m 27s | $1.42 | 1.43M | 29 | ||||
| 9 | execute-task | M001/S02/T03 | opus-4-6 | Mar 26, 2026, 04:37 AM | 2m 33s | $1.12 | 833.4k | 20 | ||||
| 10 | complete-slice | M001/S02 | opus-4-6 | Mar 26, 2026, 04:39 AM | 2m 8s | $0.572 | 626.3k | 17 | ||||
| 11 | execute-task | M001/S03/T01 | opus-4-6 | Mar 26, 2026, 04:42 AM | 3m 51s | $1.44 | 1.64M | 31 | ||||
| 12 | execute-task | M001/S03/T02 | opus-4-6 | Mar 26, 2026, 04:45 AM | 3m 45s | $1.52 | 2.14M | 35 | ||||
| 13 | complete-slice | M001/S03 | opus-4-6 | Mar 26, 2026, 04:49 AM | 2m 25s | $0.682 | 870.9k | 20 | ||||
| 14 | validate-milestone | M001 | opus-4-6 | Mar 26, 2026, 04:52 AM | 2m 30s | $1.29 | 1.96M | 16 | ||||
| 15 | complete-milestone | M001 | opus-4-6 | Mar 26, 2026, 04:54 AM | 2m 33s | $0.946 | 1.33M | 22 |
Dependencies
M001: Kerf Engine — Raster-to-Vector Pipeline & API
done
active
pending
parked
M002: M002
done
active
pending
parked
M003: M003
done
active
pending
parked
Metrics
$15.14Total cost
17.34MTotal tokens
1.2kInput
118.9kOutput
16.60MCache read
616.8kCache write
51m 18sDuration
15Units
384Tool calls
0Truncations
Token breakdown
Input: 1.2k (0.0%)Output: 118.9k (0.7%)Cache read: 16.60M (95.8%)Cache write: 616.8k (3.6%)
Cost over time
Cost by phase
Tokens by phase
Cost by slice
Cost by model
Duration by slice
Slice timeline
Health
| Token profile | standard |
| Truncation rate | 0.0% per unit (0 total) |
| Continue-here rate | 0.0% per unit (0 total) |
| Tool calls | 384 |
| Messages | 145 assistant / 3 user |
Tier breakdown
| Tier | Units | Cost | Tokens |
|---|---|---|---|
| unknown | 15 | $15.14 | 17.34M |
Changelog 3
M001/S03
Preset System + Engine Docker Packaging
Mar 26, 2026, 04:52 AM
Shipped 5 pipeline presets (sign, patch, stencil, detailed, custom) with merge-based param resolution, GET /engine/presets endpoint, and a multi-stage Docker image with healthcheck that runs the engine standalone.
Decisions
- Preset default is 'sign' — covers the most common use case
- Presets use flat JSON with three sections (preprocessing, vectorization, postprocessing)
- resolve_params merges preset → user_params with user taking precedence
- Custom preset has empty param sections so pipeline defaults apply unless user provides overrides
- Multi-stage Docker build separates build deps from runtime (smaller image, no compiler tools)
- Engine image contains only engine source — enforces Engine/App separation (D001)
- Health endpoint at /engine/health for namespace consistency with other /engine/* routes
10 files modified
engine/presets/sign.json— Sign preset — aggressive simplification for signage vectorizationengine/presets/patch.json— Patch preset — smooth curves with auto-close for embroideryengine/presets/stencil.json— Stencil preset — heavy simplification with fixed thresholdengine/presets/detailed.json— Detailed preset — max fidelity for illustrationsengine/presets/custom.json— Custom preset — empty defaults, user controls everythingengine/presets/loader.py— Preset loader with caching, listing, and param merge resolutionengine/api/routes.py— Added GET /engine/presets, GET /engine/health, wired preset into /engine/traceengine/tests/test_presets.py— 28 tests covering loader, resolution, endpoint, integration, cross-preset differentiationdocker/Dockerfile.engine— Multi-stage Dockerfile: builder compiles pypotrace, runtime uses slim image with engine source only.dockerignore— Excludes .git, .venv, __pycache__, .gsd, node_modules from Docker build context
M001/S02
Post-Processing + Output Formats (SVG, DXF, JSON)
Mar 26, 2026, 04:41 AM
Full post-processing pipeline (RDP simplification, island detection, open path repair) with three output format generators (SVG, DXF, JSON) and /engine/simplify endpoint — 169 tests passing.
Decisions
- DXF output as raw bytes with application/dxf content-type and metadata in X-Kerf-Metadata header
- postprocess_svg() replaces regex metadata extraction — full XML path parsing for structured PathInfo objects
- _format_response() shared helper for consistent response shaping across endpoints
- Islands placed on separate ISLANDS layer in DXF for downstream CAM tool compatibility
- Bezier curves linearized during post-processing for RDP simplification and DXF polyline generation
9 files modified
engine/pipeline/postprocess.py— New: Post-processing module with RDP simplification, island detection, open path repair, SVG path parsing (414 lines)engine/output/__init__.py— New: Package init exporting generate_dxf, generate_json, generate_svgengine/output/dxf.py— New: AC1015 DXF generator using ezdxf — LWPOLYLINE entities with island layer separation (66 lines)engine/output/json_output.py— New: JSON output generator with path commands and properties (76 lines)engine/output/svg.py— New: SVG output generator returning simplified SVG from PostProcessResult (22 lines)engine/api/routes.py— Rewritten: integrated postprocess_svg(), output_format routing, /engine/simplify endpoint, _format_response() helper (175 lines)engine/tests/test_postprocess.py— New: Tests for RDP, island detection, open paths, SVG parsing, node counting (375 lines)engine/tests/test_output.py— New: Tests for DXF structure, JSON structure, SVG output, round-trip consistency (274 lines)engine/tests/test_api.py— Rewritten: 35 integration tests for /engine/trace and /engine/simplify across all format combinations (515 lines)
M001/S01
Core Pipeline — Preprocessing + Vectorization
Mar 26, 2026, 04:30 AM
Knowledge 16
Rules 1
| ID | Scope | Rule |
|---|---|---|
| # | Scope | Rule |
Patterns 6
| ID | Pattern |
|---|---|
| # | Pattern |
| P001 | Test images generated programmatically via numpy |
| P002 | Tests must use .venv/bin/python -m pytest |
| P003 | PostProcessResult is the universal intermediate representation |
| P004 | _format_response() for consistent multi-format API responses |
| P005 | Preset-driven pipeline: resolve_params() merges preset → user |
Lessons 9
| ID | Lesson |
|---|---|
| # | What Happened |
| L001 | pypotrace fails to build from pip |
| L002 | VTracer Python bindings work directly — no subprocess needed |
| L003 | pypotrace Bitmap requires uint32 data |
| L004 | ezdxf emits pyparsing deprecation warnings in tests |
| L005 | DXF output format needs binary response, not JSON envelope |
| L006 | postprocess_svg() fully parses SVG paths into coordinates |
| L007 | Docker build context must be project root, not engine/ |
| L008 | Engine container has dual health endpoints |
Captures
No captures recorded.
Artifacts
Missing changelogs 6
| Milestone | Slice | Title |
|---|---|---|
| M002 | S01 | Import & Convert UI (View 1) |
| M002 | S02 | Design Canvas Core (View 2) |
| M002 | S03 | Text System + Font Loading |
| M003 | S01 | Export Flow (View 3) + DXF Generation |
| M003 | S02 | Docker Packaging + README |
| and 1 more | ||
Recently completed 3
| Milestone | Slice | Title | Completed |
|---|---|---|---|
| M001 | S03 | Preset System + Engine Docker Packaging | Mar 26, 2026, 04:52 AM |
| M001 | S02 | Post-Processing + Output Formats (SVG, DXF, JSON) | Mar 26, 2026, 04:41 AM |
| M001 | S01 | Core Pipeline — Preprocessing + Vectorization | Mar 26, 2026, 04:30 AM |
Planning
| ID | Milestone | State | Context | Draft | Updated |
|---|---|---|---|---|---|
| M001 | Kerf Engine — Raster-to-Vector Pipeline & API | undiscussed | |||
| M002 | M002 | undiscussed | |||
| M003 | M003 | undiscussed |