The evidence for tracks B and G, in the shape tracks A and E used.
- benchmarks/tasks_v5.py: 18 tasks, DEFAULT_MATRIX = "v5"; v4, v3 and v2 stay
addressable so an earlier report reproduces exactly rather than being only
described. mech_assembly is roadmap criterion 3 - a flange-coupling sheet
built from the part model and the sheet standard, through the code the
tools call (apply_titleblock, draw_part/add_view/dimension_part,
insert_std_part, extract_records -> draw_bom_table, add_balloon), gated on
two numbers that cannot be negotiated: drawing_critique(focus=None) returns
zero issues and the finalize score is at least 90 (it scores 100, 18/18 on
the v5 matrix). The adapter returns the focuses that fired, so a
regression names itself, and a test drops one balloon to prove the gate
fails and names mech_bom_balloon_mismatch.
- Seven correctness checks (32 -> 39). mech_section_hatch_area is the one
that cannot be faked: a sleeve of length 60, outside diameter 40 and bore
20 cuts two faces totalling 1200 mm^2 exactly, read back out of the drawing
through entity_measure. sheet_frame_iso5457_a3 pins the A3 frame (20,10 to
410,287 inside the 420 x 297 trimmed sheet); mech_iso286_on_dimension pins
40 H7 at +0.025/0 through the layout; std_part_iso4014_m12 pins s = 18 and
k = 7.5 by value; mech_thread_unrepresented_is_caught is the seventh: a
quality gate that never fires is not a gate.
- scripts/smoke_mech_com.py executed every new COM path once on AutoCAD 2026
(25.1s): frame, title block, a sectioned shaft with 12 dimensions, an ISO
4014 block with 1 ACADMCP_MECH chunk, a weld symbol, the parts list read off
the drawing, a linked balloon, an xref attached / listed / detached, a
31687-byte .dwg (AC1032) through ActiveX SaveAs, critique 0 issues, exit 0,
every scratch document closed. It retries RPC_E_CALL_REJECTED (measured:
the first call after Documents.Add is refused) and tracks its documents by
the document list, since SaveAs renames them.
- Defects the evidence found, each fixed with a test that fails on the old
code:
* ezdxf dimension_diameter put the text beyond the SECOND chord point;
ActiveX AddDimDiametric puts it beyond the first (measured live: a d50
from (x,170) to (x,220), leader 10, text at (x,160)). Headlessly every
front-view diameter stood on its own chain dimension. ezdxf now follows
ActiveX.
* draw_part's anchor goes on MECH; ActiveX refuses entity.Layer on a
missing layer (measured -0x7ffdfff7 'Key not found'). draw.py ensures
every target layer before the first entity.
* bom.extract_records filtered on INSERT; ActiveX names it BLOCKREFERENCE
(ObjectName AcDbBlockReference) - the live parts list was empty.
* COM _entity_info reported no dimension text_position: ModelSpace.Item
narrows to IAcadEntity, which has no TextPosition (measured
AttributeError); read through _com_unnarrow (TextPosition measured on
AcDbDiametricDimension, WCS). dim_overlap compared bbox centres and a
diameter collided with its own bore.
* pid graph raised KeyError 'start' mid-critique on a LINE whose point read
AutoCAD refused while busy; such a line is left out.
* the validator read "ISO 4014 - M12x60" as fake dimension text.
- The published A/B report is re-run over the grown suite rather than
re-typed (26/39 -> 39/39, 13 fixed, 0 regressed), check_doc_numbers derives
the task count from the v5 matrix, the token table is remeasured with a
TOOL_PACKS=core,mech row (193 tools / 61,673 tokens), and the README's
collected-tests figure is retaken (3990).
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FKFStjEFzpGyLq5bMpWxTd
ruff format was never run repo-wide; CI now enforces 'ruff format --check', so normalize every module once. No behavior changes.
Co-authored-by: Cursor <cursoragent@cursor.com>
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.
