Three production-blocking defects + two legal/infra gaps from the recon pass.
R1 (CRITICAL): the 8 premium meta-tools (drawing_plan, drawing_critique,
point_from_snap, construction_xline, construction_clear, drawing_apply_iso_layers,
dimension_auto, entity_select_smart) raised NotImplementedError on the COM
backend — i.e. the entire "non-negotiable" premium workflow crashed on the
DEFAULT Windows backend. Lifted all eight to AutoCADBackend as concrete,
backend-agnostic implementations built on the shared abstract primitives +
the identical EntityInfo.properties contract, so both backends inherit them.
The only backend-specific piece left is the new `_create_xline` primitive
(XLINE has no cross-backend entity_create_* equivalent). Removes ~285 lines of
ezdxf-only duplication; the existing meta-tool test suite now covers shared code.
R2 (CRITICAL): layer_create/layer_modify/entity_set_properties used
int(lineweight), truncating every millimetre lineweight (0.50, 0.25, 0.18, 0.13)
to 0 — silently wiping the whole ISO 128 discipline, because engineering/layers.py
passes mm-floats while the MCP boundary passes hundredths-ints. Added
normalize_lineweight() to reconcile both conventions to ezdxf/COM hundredths and
wired it into all six call sites.
R3 (HIGH): _check_iso128 was a permanent no-op (everything was 0 from R2, so the
`lw <= 0: continue` guard skipped all layers). Fixed by R2; additionally exclude
CONSTRUCTION-class layers (intentionally sub-ISO 0.05mm scratch weight) to avoid
a new false positive, and corrected the misleading "normalises to mm" comment.
Also: add MIT LICENSE (referenced by CLAUDE.md but missing — legal gap) and
restore .github/workflows/ci.yml (lint kept non-blocking until the repo-wide
ruff cleanup; the test job is the real gate).
Verified: 182 passed / 2 xfailed; functional check confirms lineweights now
store as hundredths (GEOMETRY=50) and the ISO critique correctly flags a 0.40mm
layer while passing a clean ISO drawing.
Introduce the autocad-mcp-premium skill with workflow docs, examples, and references (.claude/skills/autocad-mcp-premium/*). Add PlanSpec/critique plumbing and engineering helpers (engineering/plan_spec.py, engineering/critique.py) plus tests and a smoke script. Extend backend API (backends/base.py) with corner operations and premium meta-tools (trim/extend/fillet/chamfer, drawing_plan, drawing_critique, point_from_snap, construction_xline/clear, drawing_apply_iso_layers, dimension_auto, entity_select_smart) and implement COM backend corner ops (backends/com_backend.py) with placeholders for meta-tools. Update CLAUDE.md to document the premium drawing rules and standard workflow. Misc: add examples, references, and tests for premium features, and minor server/backend adjustments.
Introduces an engineering/ package that lets MCP clients produce production-
quality technical drawings without LLM-improvised geometry. Adds 7 new MCP
tools, an 8-step pre-completion validator, and an automatic linetype + layer
bootstrap on drawing_new so CENTER/HIDDEN/PHANTOM and standard mechanical
layers (GEOMETRY, DIM, HATCH, TEXT, TITLEBLOCK, ...) are always available.
- engineering/gear.py: pure-Python involute math, 40+ points/flank, helical
+ spur front views, deterministic section A-A (no helix lines in section).
- engineering/keyway.py: DIN 6885 keyway table + parametric keyed bore /
side-section drawers.
- engineering/titleblock.py: ISO 7200 A3 (420x297 mm) title block; title
text is written verbatim to the title cell.
- engineering/validator.py: DrawingValidator with 8 checks (real DIMENSION
entities, no hidden orphans, linetypes loaded, bore + keyway in both
views when expected, title consistency e.g. forbid 'HELICAL SPUR GEAR'
when helix_angle truthy, saved-to-disk + file-on-disk, screenshot
exported, dwg path returned).
- backends/ezdxf_backend.py: AutoCAD-only linetype fallback (HIDDEN,
BORDER families) so ezdxf doc gets correct patterns when linetype_load
is called for names ezdxf.tools.standards does not ship.
- backends/base.py: concrete helpers set_layer_active / ensure_linetypes.
- server.py: Section 12 with 7 engineering tools, drawing_new(bootstrap=
True), and an ENGINEERING WORKFLOW block in the MCP instructions string.
- 30 new tests covering gear math, DIN6885 lookup, ISO A3 layout, title
verbatim, and every validator check. Tool count 89 -> 96.
Umutcan Edizsalan