`add_diameter_dim` / `add_radius_dim` measure to the point they are handed;
`leader_length` is a text placement. The ezdxf backend passed
`centre + (radius + leader)` as that point, so the leader became part of the
measurement: a true 40 mm bore was dimensioned 60 at the default
`leader_length=10`, and 108 at 34. Radius callouts were `leader_length` too
large the same way.
This is the worst class of defect for this project -- a wrong number, at
default settings, on the one part of a drawing that exists to carry numbers --
and it shipped in v1.4.0 and earlier. The size now comes from `radius` and
`location` only places the text.
The live COM backend was never affected: ActiveX's AddDimDiametric takes the
two chord points and the leader length as separate arguments. The two engines
had been disagreeing by 2 x leader_length on the same call.
Found while building the drawing for the new README, whose own bore callout was
wrong. Two checks added to correctness_suite.py; both report fail -> pass
against v1.4.0, not miss -> pass, which is what separates a repaired defect
from new capability in that lane. A/B is now 21/26 -> 26/26, five fixed, zero
regressed.
README rewritten from scratch
- Hero is a real ISO A3 sheet the server drew: m6 z24 involute spur gear, DIN
6885 keyed bore, section A-A, ISO 129 dimensions, ISO 286 H7 fit, ISO 7200
title block, 56 entities, drawing_critique clean. New
scripts/render_readme_showcase.py rebuilds it, and the tool-call sequence
that produces it is printed in the page.
- Star history chart, badge row, capability matrix, five evidence lanes, and a
"what this release is bad at" section carrying the 28% throughput regression.
- Every image and repo link is now an absolute URL: README.md is the PyPI long
description, where relative paths 404.
Corrections this work forced, all measured
- The df=0 example was wrong. FILLET is already in entity_fillet's own text;
the commands that genuinely scored zero are WBLOCK, PEDIT, OVERKILL,
LAYTRANS and MATCHPROP.
- 40,305 tokens is the tools/list wire payload; ~25,143 is the part forwarded
to the model. The old wording said "of schema", which is neither.
- `--tokenizer anthropic` needs a package and credentials this repo does not
lock, and refuses rather than falling back. Said so.
- Discovery ranks over the 149-tool advertised catalog, not the 154 registered.
- Five middlewares, not four; the fifth is what makes refusals machine-readable.
- Five of the 27 capability keys are environment-dependent, so the matrix
carries footnotes instead of bare ticks.
- "Every coordinate is WCS" has one deliberate exception: TEXT rotation.
- render_live_chart's axis still said "fixed 10-task matrix" while our bar came
from v3's fifteen. Each bar now carries its own matrix.
- .env.example said MAX_UNDO_STACK=50 (code: 5) and omitted four real
variables, two of them the remote-HTTP controls.
- server.json described an empty ALLOWED_PATHS as blocking access. It disables
the allowlist.
- server.py called the lean profile ~46 tools; it is 47.
- backends/capability.py cited a test file that does not exist.
1249 passed, 1 xfailed.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Tool count 131 -> 154; 474 -> 1242 collected tests.
The release exists for two measured reasons. A 149-tool catalog costs a client
~40,300 tokens before it has asked for anything, and a drafter searching the way
drafters think -- FILLET, BPOLY, QSELECT, WBLOCK -- scored df=0 against the stock
index, because those words were simply not in the data.
Discovery and batching
- DISCOVERY_MODE=search replaces the catalog with search_tools + call_tool,
ranked over an AutoCAD command and synonym corpus (discovery/aliases.py) on
top of fastmcp's BM25 index. Measured: 40,305 -> 356 tokens advertised.
- cad_batch runs a step list in one round trip; fields= projects result-heavy
responses. The `core` profile is gone -- discovery replaced it.
Honesty debt (Tier 0)
- OCS/ECS: `extrusion` appeared nowhere in this codebase, so mirrored and
rotated geometry reported coordinates that were quietly wrong. backends/ocs.py
translates at the backend boundary; every tool coordinate is WCS on both
engines, and a tilted plane refuses rather than answering with a number that
looks fine.
- drawing_save_as(fmt="dwg") wrote DXF bytes to a .dwg path. drawing_audit never
repaired. analysis_measure_area shoelaced points the caller typed in.
- ezdxf calls gained a per-call timeout, so one hung call can no longer wedge a
server whose document lock is a single asyncio.Lock.
Architecture
- The 1854-line backend ABC is 19 contract modules; @capability(key, reason=)
makes optional methods declarative and a gate fails on undeclared holes.
- 8 layout/viewport tools, CHSPACE, CAD_PROGID escape hatch.
- Wave A: selection filters, boundary tracing, hatch depth, annotation objects,
measurement -- 13 tools of a planned 39. The REGION and 2D-boolean family was
cut on evidence: add_region() yields zero ACIS bytes and the greiner_hormann
substitute loses 28.2% of the area on a square with one semicircular edge.
Verified against a live AutoCAD 2026, which found four COM defects no amount of
reading would have caught -- AcadPViewport has no ViewCenter, and the line that
set it had been swallowed by a bare except since v1.4.
Benchmark v3 (15 tasks) and what it caught
- v2 scored this server 10/10, which carried no information: every task in it
exercised something the server was built around. Five tasks were added because
they can fail, and three did while being written -- a hatch could not be
measured though the refusal listed HATCH as measurable, the boundary tools and
the measure tool disagreed about the same shape (139.2177 vs 139.2699), and a
circle stored as two bulged vertices measured 0.0.
- Competitor reports are NOT re-scored. They are pinned v1.4 runs against v2 and
were never asked these five questions; the chart shows those rows `not run`.
- Correctness A/B: 21/24 -> 24/24, zero regressions.
Performance, stated plainly
The published v1.4 perf report was recorded on CPython 3.14 and the new one on
3.11.15, so the apparent 2-6x speedup is the interpreter, not this release.
Re-measured on one interpreter, v1.5.0 is 28% slower creating entities and 22%
slower on the 10k roundtrip. Fully attributed: EZDXF_CALL_TIMEOUT=0 restores
v1.4.0's exact numbers. That is the deadlock fix being paid for, the knob is
documented, and winning it back is on the 1.6 roadmap.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
- TOOL_PROFILE=lean|core|full applied in the lifespan via server-level enable/disable; system_about reports the active profile; opt-in solid_* tools are hidden while ENABLE_3D=false
- layouts: layout_list/create/set_current + viewport_create (scaled model viewports) on both backends; drawing_export_pdf(layout=...); ezdxf uses TILEMODE + active-layout binding, COM switches ActiveLayout and restores it
- ISO 286: engineering/fits.py authored IT4-11 + fundamental-deviation tables (1-500 mm; shafts d..p/h/js, holes D..H/JS) with clear out-of-scope errors; dimension_linear/radius/diameter gained fit= resolved from the measured nominal
- tolerances: DIMTM now signed in deviation/limit modes so double-positive fits (p6 +0.035/+0.022) render correctly; legacy positive-magnitude contract preserved
- solids: solid_box/cylinder/extrude/revolve/boolean native on COM (AddBox/AddCylinder/AddRegion+AddExtrudedSolid/AddRevolvedSolid/Boolean); ezdxf reports the honest solid_3d capability boundary
- capability maps: paper_space native, new viewport_render feature, ENABLE_3D-gated solid_3d
- 60 new tests (profiles, layouts, viewports, layout PDF, fits, gating); version pins in tests now read version.__version__
Co-authored-by: Cursor <cursoragent@cursor.com>
Adds production-grade engineering features and tools: 2D GD&T (feature control frames + datum features) via engineering/gdt.py, ISO‑129 dimension tolerance support (engineering/tolerances.py) and an ezdxf/COM plumbing for toleranced dims, a scalar drawing score + invalidity ratio (engineering/scoring.py) wired into drawing_finalize, in-place entity editors (entity_edit_text/entity_edit_geometry), and a friendly drawing_settings facade. Includes server tool wiring, COM/ezdxf backend implementations, datum-consistency critique, many unit tests, README/CLAUDE/CHANGELOG updates, and a version bump to 1.2.0. Also corrects COM backend capability label (entities_2d).
New COM-only Entity Query tool that reads AutoCAD's implied ("pickfirst")
selection set and returns the selected entity handles + EntityInfo, so the AI
can scope work (e.g. dimension_auto) to exactly what the user picked in the
viewport instead of the whole drawing. Resolves#1 — the layer-juggling
workaround is no longer needed.
- backends/base.py: abstract selection_get() returning a status dict
- backends/com_backend.py: reads ActiveDocument.PickfirstSelectionSet, surfaces
the PICKFIRST sysvar, handles the empty-selection case
- backends/ezdxf_backend.py: headless stub (ok=False, empty handles, same shape)
- server.py: @mcp.tool registration (readOnlyHint), SECTION 5 3 -> 4 tools
- README + CHANGELOG + pyproject: 110 -> 111 tools, v1.1.0 -> v1.1.1
Verified live on AutoCAD 2027 (COM): selection_get correctly returned the
user's grip selection across two distinct picks; 318 tests pass, ruff-clean.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Audit-driven fixes across the dual backend, the premium workflow, and the
engineering layer. 318 tests, ruff-clean.
Quality gate (the moat):
- drawing_finalize now runs the premium ISO-128 critique in addition to the
8-step validator; leftover construction, non-ISO lineweights, untrimmed
corners, duplicates and dim overlap block the gate (strict_critique fails on
warnings too).
- dim_overlap critique no longer a no-op (dim reference point + bbox fallback);
dim/construction layers resolve from the active layer set (iso13567 too).
Stability / correctness:
- view_screenshot & drawing_export_pdf render headless via Agg (no more
worker-thread SIGSEGV).
- gear tooth profile no longer self-overlaps at high tooth counts; section view
no longer duplicates bore lines; validator keyway heuristic fixed.
- ezdxf aligned/angular dim API, full-circle polar array duplicate already
covered by Sprint 1; this bundle adds save-format-from-extension,
entity_offset side selection, ARC length, properties parity (bounding_box /
rotation / char_height), mtext rotation.
COM robustness (mocked-COM tested):
- CoUninitialize on teardown; transaction commit/rollback try/finally + UNDO via
the CMDACTIVE guard; system_run_lisp guard + USERS1 value capture;
set_variable type coercion; HWND via Application.HWND; BlockInfo.description.
Security:
- HTTP remote-bind guard fires on every launch path (incl. `fastmcp run`);
StaticTokenVerifier wired into FastMCP; AutoLISP allowlist bypass-vector tests.
Hygiene: linetype-on-demand in _apply_attrs, honest view_zoom returns, snap-on-arc
sweep handling, point_tangent acos clamp, dynamic tool_groups / tool count,
word-boundary SPUR/HELICAL, undo-stack locking.
Deferred: R22 (undo/transaction stack isolation) lands with the I1 refiner (1.2),
which depends on it.
Before: _validate_http_bind warned about MCP_AUTH_TOKEN being required for
remote HTTP but the token was never passed to the FastMCP constructor, so the
server accepted any request without authentication.
After: a StaticTokenVerifier is built at module load if MCP_AUTH_TOKEN is set
and passed as auth= to FastMCP(). Loopback-only deployments (no token set)
continue to work as anonymous mode.
7 new tests in tests/test_http_auth.py covering: token present/absent, mcp
instance wiring, loopback/remote bind guard, remote-without-token rejection.
233 tests total.
New concrete base methods (backend-agnostic, use entity_get + pure math):
- AutoCADBackend.point_intersection: LINE-LINE, LINE-CIRCLE, CIRCLE-CIRCLE
with ref_x/ref_y disambiguation for multiple candidates.
- AutoCADBackend.point_tangent: external-point-to-circle tangent touch-point
with ref_x/ref_y for side selection; correct perpendicularity formula
(T-F)⊥(T-C) via cos(θ-α)=-r/d.
Registered as MCP tools: point_intersection, point_tangent.
13 new tests in tests/test_meta_tools_geometry.py.
226 tests total.
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.
