# AutoCAD MCP Pro **Production-grade AutoCAD automation for AI agents.** Live through COM on Windows, or headless through ezdxf anywhere — one typed contract, two engines. [![CI](https://github.com/U-C4N/Autocad-MCP/actions/workflows/ci.yml/badge.svg)](https://github.com/U-C4N/Autocad-MCP/actions/workflows/ci.yml) [![PyPI](https://img.shields.io/pypi/v/autocad-mcp-pro?color=1f6feb&label=PyPI&logo=pypi&logoColor=white)](https://pypi.org/project/autocad-mcp-pro/) [![Downloads](https://img.shields.io/pypi/dm/autocad-mcp-pro?color=8957e5&label=downloads)](https://pypi.org/project/autocad-mcp-pro/) [![Python 3.11+](https://img.shields.io/badge/python-3.11%2B-1f6feb?logo=python&logoColor=white)](https://github.com/U-C4N/Autocad-MCP/blob/main/pyproject.toml) [![License: MIT](https://img.shields.io/badge/license-MIT-3fb950)](https://github.com/U-C4N/Autocad-MCP/blob/main/LICENSE) [Install](#install) · [Tools](#what-you-get) · [Engines](#the-two-engines) · [Evidence](#evidence) · [Limits](#what-this-release-is-bad-at) · [Config](#configuration) · [Changelog](https://github.com/U-C4N/Autocad-MCP/blob/main/CHANGELOG.md) ISO A3 sheet: a module-6, 24-tooth spur gear with a keyed bore, its section A-A, ISO 129 dimensions with an H7 bore fit, and an ISO 7200 title block Not a mockup. Every line on this sheet was drawn by the tools this server exposes — ISO layers, involute gear geometry, DIN 6885 keyway, section A-A, ISO 129 dimensions, an ISO 286 H7 bore fit, ISO 7200 title block — then rendered headlessly by view_screenshot. drawing_critique returns 0 issues on it. Rebuild it with python scripts/render_readme_showcase.py. P&ID sheet: a centrifugal pump, a diaphragm-actuated globe control valve, a vertical vessel with two nozzles, a flow controller bubble and an off-page connector, joined by numbered process lines and an electric signal line The same server as a P&ID drafter. pid_from_spec placed five catalogue symbols as real blocks with TAG attributes and named ports, routed four port-to-port lines with ISA-5.1 classes and line numbers in one transaction, then pid_graph read the sheet back: 5 nodes, 4 edges, 0 dangling ends, confidence_min 1.0. Rebuild it with python scripts/render_readme_pid.py. Contact sheet of the 43 P&ID catalogue symbols: valve bodies with actuators, pumps and compressors, heat exchangers, vessels, instrument bubbles, line markers and connectors The catalogue, authored in code. 43 ISO 10628-2 / ISA-5.1 symbols — 11 valve bodies × 6 actuators, 6 rotating machines, 4 heat exchangers, 6 parametric vessels, 7 inline items, the instrument bubble in 4 types × 5 locations, 5 line markers, 3 connectors — every one placed through pid_symbol_insert's own path. Rebuild it with python scripts/render_pid_catalog.py.
> **v1.5 release snapshot:** 241 tools · 8 resources · 5 prompt templates · 4516 collected tests. > 241 is the **registered** count; a default install advertises 236 over `tools/list`, > because `ENABLE_3D` is unset. `system_about` is the runtime authority. ## Why this exists **A big MCP server is expensive to be connected to.** The full catalog costs a client **78,772 tokens** before it has asked for anything. Discovery mode replaces it with two tools and costs **356**. **A drafter searches for `FILLET`, not `entity_fillet`.** Those command names appeared in no tool name or description — `df = 0` against a stock index, not badly ranked but *absent*. The fix was data: an authored corpus of **205 AutoCAD command names and 1318 synonym phrases** covering all 241 tools. A test refuses to let a tool exist without one. | Advertised surface | Tools seen | Idle cost | |---|---:|---:| | `TOOL_PROFILE=full` (default) | 236 | 78,772 tokens | | `TOOL_PACKS=core,settings` (full profile) | 201 | 60,926 tokens | | `TOOL_PACKS=core,mech` (full profile) | 193 | 61,872 tokens | | `TOOL_PACKS=core,arch` (full profile) | 191 | 60,568 tokens | | `TOOL_PACKS=core` (full profile) | 179 | 54,158 tokens | | `TOOL_PROFILE=lean` | 64 | 21,939 tokens | | `DISCOVERY_MODE=search` | 2 | **356 tokens** | > [!NOTE] > Offline ratio estimates, not tokenizer counts, and the *uncached* ratio — prompt caching amortises the idle term. `benchmarks/token_suite.py --tokenizer anthropic` counts for real. ## Install ```bash pip install autocad-mcp-pro # or: uvx autocad-mcp-pro autocad-mcp # stdio MCP server, backend auto-selected ``` ```bash AUTOCAD_MCP_BACKEND=ezdxf autocad-mcp # portable DXF engine, no AutoCAD needed AUTOCAD_MCP_BACKEND=com autocad-mcp # live AutoCAD (needs the [com] extra) ``` | Extra | Pulls in | For | |---|---|---| | *(none)* | `fastmcp`, `ezdxf`, `pydantic` | Headless DXF on any OS — **no rendering** | | `[com]` | `pywin32`, `Pillow` | Live AutoCAD control + window capture | | `[pdf]` | `matplotlib` | PDF export and headless PNG, any platform | | `[full]` | everything above | Development and CI | > [!NOTE] > The bare install **cannot draw pixels** — `ezdxf.addons.drawing` imports Pillow unconditionally, so every render path needs it. Add `[pdf]` for images on Linux or macOS.
Wire it to an MCP client ```json { "mcpServers": { "autocad": { "command": "autocad-mcp", "env": { "AUTOCAD_MCP_BACKEND": "auto", "ALLOWED_PATHS": "C:\\Users\\you\\Documents\\AutoCAD", "TOOL_PROFILE": "full", "DISCOVERY_MODE": "off" } } } } ``` Claude Desktop, Cursor, or any stdio MCP host. For HTTP: `autocad-mcp --transport http --port 8000` — loopback only unless remote HTTP is explicitly enabled **and** a bearer token is set.
## What you get | Area | What it does | |---|---| | Drawing lifecycle | create, open, save, export DXF/PDF, audit *(repairs)*, purge, undo/redo | | Geometry | lines, arcs, polylines, splines, hatches, trim/extend/fillet/chamfer, handle-preserving edits | | Annotation | ISO 129 toleranced dimensions, ISO 286 fits (`fit="H7"`), TABLE, MLEADER, GD&T frames and datums (ISO 1101) | | Engineering generators | involute gears (front + section A-A), DIN 6885 keyed bores, ISO A3 title block | | Mechanical parts | one part model (segments or outline + typed features) and one view engine: front / side / top / section / detail with hidden lines, ISO 128-50 cut faces and ISO 129 dimensions; ISO 4014/4017/4032/7089/4762 fasteners, ISO 15 bearings, DIN 471/472, DIN 509, DIN 332 and ISO 3601-2 as real blocks with attributes; ISO 21920-1 surface texture, ISO 2553 welds, ISO 128-40 section lines | | Sheet & delivery | ISO 5457 frames A4-A0 with zones and trim marks, ISO 7200 title blocks for every size, revision blocks with clouds, ISO 7573 parts lists with ISO 6433 balloons linked by XDATA, CSV/XLSX extraction, xrefs and images on both engines, real `.dwg` on a live seat | | Architecture | one plan model — walls with hosted doors and windows — and one engine: L / T / X junctions resolved, openings cut, poché by material; rooms measured from the faces the walls enclose (never typed) and read back from any plan with a confidence; door / window / room schedules as real TABLEs; a furniture and sanitary catalogue at nominal sizes; structural grid, north arrow, section / level / elevation marks; exterior dimension chains; English or Turkish labels (`lang="tr"`, decimal comma) | | P&ID | catalogue blocks with ports and tags (ISO 10628-2 / ISA-5.1), port-to-port lines with ISA-5.1 classes and line numbers, `pid_graph` reads any P&ID back with confidence, instrument index / line list / equipment list, `pid_from_spec` one-call sheets | | Styles & standards | ISO-25 / ANSI dimension styles, ISOCP / ROMANS text styles, ISO / ANSI leader styles from authored presets; `drawing_apply_standard("iso")` sets all of it plus units and the `mech` layers in one call; `changed` reports only what moved | | Discovery | `search_tools` ranked over an AutoCAD command and synonym corpus — `FILLET`, `BPOLY`, `QSELECT`, `WBLOCK`, `OVERKILL`, `CHSPACE` each rank **#1** of the 236-tool advertised catalog | | Batching | `cad_batch` runs a step list in one round trip; `fields=` projects 11 result-heavy tools | | Paper space | tab lifecycle, viewports, `entity_change_space` (CHSPACE), `page_setup_apply` (ISO 216 / ANSI Y14.1 paper, ctb, scale, device — on both engines), `batch_plot` with every sheet size read back from its PDF's `/MediaBox`, `drawing_export_pdf(layout=…)` | | Page setup & templates | ISO 216 / ANSI Y14.1 sheets, ctb catalog, `batch_plot` verified by the PDF's own `/MediaBox`, five bundled templates built by the server's own tools and pinned reproducible (`drawing_new(template="iso_a3_mech")`, `iso_a1_arch`, `iso_a3_pid`, `ansi_b_mech`, `ansi_d_arch`), save any drawing as a template (`.dwt` on live AutoCAD, `dwt_write` refused headlessly) | | Environment | several open documents headlessly, portable layer states (`ACADMCP_LAYERSTATES` XRECORDs — in the file, not in AutoCAD's Layer States Manager), named views, UCS *(tool coordinates stay WCS)*, a system-variable catalog with ranges, document properties, and on a live seat: launch/attach, preferences, an operator prompt / pick / select — where ESC is `cancelled`, not an error | | Selection | window vs crossing stated back to the caller; a polygon tested against its own shape, not its bounding box | | Boundaries | `boundary_trace` (BOUNDARY/BPOLY) chains loose edges into one closed polyline, arcs kept as bulges *(headless)* | | Measurement | `analysis_measure_entity` measures what is *in* the drawing, by handle | | Hatch depth | gradients, in-place edits, typed edge boundaries *(headless)*, island styles | | Annotation objects | WIPEOUT, REVCLOUD, MTEXT background masks *(headless)*, text find/replace | | 3D solids | `solid_box/cylinder/extrude/revolve/boolean` on live AutoCAD (`ENABLE_3D=true`) | | Quality loop | `drawing_preflight` → `drawing_plan` → `drawing_critique` → `drawing_refine` → `drawing_finalize` (0–100 score) | | Delivery | `drawing_deliver`: DXF/PDF/PNG + SHA-256 manifest + reopen-parity checks | 241 tools in 26 groups; TOOL_PACKS=core hides the nine pid_* tools, the 22 environment tools, the 14 mechanical tools and the 12 architectural tools (TOOL_PACKS=core,mech keeps the mechanical ones, TOOL_PACKS=core,arch the architectural ones) from a client that needs none of them. Plus 8 resources that cost nothing in the tool budget (autocad://drawing/info, layers, blocks, entities/stats, entities/{layer_name}, system/status, pid/symbols, standards/isa51) and 5 prompt templates. **Two rules worth knowing.** Every coordinate in and out of a tool is WCS on both engines — the one exception is TEXT `rotation`, which stays in the entity frame because a mirrored TEXT is mirror-imaged and no scalar angle expresses that. And never read vertices back and shoelace them: that loses **28.2%** of the area on a semicircular edge, silently. `analysis_measure_entity(handle)` reads the real geometry and states its own accuracy. ## The two engines One contract across 19 modules in `backends/contracts/`. `@capability(key, reason=…)` supplies a default that *refuses*, and a test holds both backends' capability key sets equal. There are **27 capability keys**; read `system_capabilities` at runtime rather than trusting the table — five of them depend on how the machine is set up. | Capability | COM (live AutoCAD) | ezdxf (headless) | |---|:---:|:---:| | Live document control | ✅ | — | | Cross-platform, no AutoCAD | — | ✅ | | Transactions and rollback | ✅ | ✅ | | Paper-space layouts + viewports | ✅ | ✅ | | Viewport model-content rendering | ✅ | ✅ ᵐ *(no borders)* | | Selection window / crossing / polygon | ✅ | ✅ | | Entity area by handle | ActiveX `.Area` | Analytic, bulges included | | HATCH filled area (islands subtracted) | AutoCAD's own number | Loops walked, `hatch_style` reported | | REGION / 3DSOLID area | ✅ | — *ACIS is opaque to ezdxf* | | 3D solids | ✅ *with `ENABLE_3D=true`* | — | | DWG write | ✅ | — | | WIPEOUT · MTEXT background colour | — *verified absent, AutoCAD 2026* | ✅ | | REVCLOUD · BPOLY · typed hatch edges | — *no ActiveX member* | ✅ | | CHSPACE | — *unverified on a live seat* | ✅ ᶜ | | Undo history | ✅ | opt-in — `EZDXF_UNDO_DEPTH` | | TABLE and MLEADER | Native | Portable composite | | Screenshots and PDF | Window capture | Matplotlib ᵐ | ᵐ Needs matplotlib ([pdf]/[full]); without it png, pdf, viewport_render and handle_overlay report unsupported headlessly.
ᶜ Headless CHSPACE carries four named restrictions in its capability reason: top-view untwisted viewports only, dimensions refused unless frozen, ACIS/proxy/table refused, viewport clipping reported rather than applied. > [!IMPORTANT] > Every COM path added in v1.5 was executed against a **live AutoCAD 2026**. That run found four defects reading could not — the largest being that `AcadPViewport` has no `ViewCenter` member, so the line setting it had been silently swallowed by a bare `except` since v1.4. ## Evidence Self-measurement, produced by scripts in [`benchmarks/`](https://github.com/U-C4N/Autocad-MCP/blob/main/benchmarks/). ### Correctness — every release re-proves itself 43 deterministic headless checks against the previous tag and the current tree, each in its own subprocess so a hard crash counts as a miss rather than killing the run. | Version | Checks passing | Pass rate | Fixed | Regressed | |---|---:|---:|---:|---:| | v1.5.1 *(baseline)* | 26 / 43 | 60.5 % | — | — | | **v1.6.0-dev** *(this branch)* | **43 / 43** | **100 %** | 17 | **0** | The seventeen fixed rows are new capability (`miss → pass`). Track F adds four: `arch_junction_l_t_x` (an L corner mitres at (4100, −100) / (3900, 100), a T stem stops on the near face at (2950, 100) / (3050, 100), an X cuts all four faces, and the wall areas are 1 400 000, 1 490 000 and 2 360 000 mm² — computed by hand), `arch_room_area_net` (a 4 × 5 m room between 200 mm walls measures 20.00 m² in its label and its record, not the 21.84 m² its axes enclose), `arch_opening_cuts_wall` (both faces are interrupted across a 900 door and two jambs close it) and `arch_rooms_detect_foreign` (a plan of plain lines on a `WALLS` layer yields 20 and 15 m² at confidence 0.6, and nothing is written). Tracks B and G add seven: `mech_part_roundtrip` (a part read back out of its own `ACADMCP_MECH` XDATA equals the part drawn), `mech_section_hatch_area` (a 60 x ⌀40 sleeve with a ⌀20 bore cuts 1200 mm² exactly, measured out of the drawing by `analysis_measure_entity`), `mech_iso286_on_dimension` (40 H7 is +0.025 / 0 and survives the layout), `mech_thread_unrepresented_is_caught` (the ISO 6410 focus fires on a thread drawn as a plain circle — a gate that never fires is not a gate), `std_part_iso4014_m12` (s = 18, k = 7.5, read by value), `sheet_frame_iso5457_a3` (the frame runs 20,10 to 410,287 inside the 420 × 297 sheet) and `bom_balloon_link` (two identical bolts are one row of quantity 2, and its balloon carries the row's item number). The other six are the three P&ID checks of track A and, from track E, `settings_dimstyle_iso25_values` (the ISO-25 preset lands in the DIMSTYLE table with ISO 129-1's numbers), `settings_layer_state_roundtrip` (save → change → restore puts the layer table back, and the state survives save/reopen because it is an XRECORD in the file) and `settings_pdf_mediabox_a3` (the plotted PDF's own `/MediaBox` reads 420 × 297). The 26 checks v1.5.1 was gated on all still pass. Against the older `v1.4.0` baseline the same 26 reported **21 / 26 → 26 / 26, five fixed, zero regressed** — two of those were repaired defects (`fail → pass`), the diameter and radius callouts, which measured the leader as geometry and dimensioned a 40 mm bore as 60 at default settings. ### The task matrix — tasks that can fail An earlier matrix scored this server 10/10, which carried no information: every task in it exercised something the server was built around. Five were added in 1.5 because they *can* fail, and three did while being written; 1.6 adds four more — one the P&ID reader can fail on its own, one where the PDF file, not the setter, is the witness, one where a whole mechanical sheet has to come out clean, and one where a floor plan's rooms are read back off the drawing. | Task | Verified against | |---|---| | `tool_discovery` | six AutoCAD command names, each ranking #1 | | `token_budget` | 78,772 → 356 tokens, against a ceiling fixed in advance | | `hatch_islands` | 300 filled with the island, 400 ignoring it | | `selection_filter` | window 1, crossing 2, bounding box 3, polygon 1 | | `measure_from_handle` | 139.2699 against the 100.0 a vertex shoelace gives | | `pid_roundtrip` | the example sheet drawn by `pid_from_spec`, read back by `pid_graph`, which never sees the spec: 5 nodes, 4 edges, 0 dangling, `confidence_min` 1.0, `FIC-101` wired to `FCV-101` | | `page_setup_truth` | ANSI B then ISO A3 landscape applied to Layout1, each plotted through `batch_plot` and read back from its PDF's `/MediaBox`: 432 × 279 then 420 × 297 mm, not the setter's return value (a fresh layout is already A3, so the B sheet is what a no-op setter cannot fake) | | `mech_assembly` | a flange-coupling A3 sheet — hub with a full section, flange with its bolt-circle end view, two ISO 4014 bolts with ISO 4032 nuts, an ISO 7573 parts list read off the drawing, linked balloons, ISO 5457 frame, ISO 7200 title block — gated on `drawing_critique(focus=None)` returning **zero** issues and a finalize score of at least **90**; a test drops one balloon and watches the gate fail | | `arch_roundtrip` | a two-room plan — an entrance door, an interior door, two windows, a stair — drawn by `arch_plan_from_spec` and read back by `arch_rooms_detect`, which never sees the spec: each room within 0.1 % of its label and of the net floor computed by hand (4825 × 5750 and 3825 × 5750 mm), the door and window schedules listing D1, D2, W1, W2, `drawing_critique(focus=None)` at **zero** and a finalize score of at least **90**; a test removes one room label and watches the gate fail | ### Headless performance Performance across four headless workloads Workloads call the same backend methods the MCP tools call, so server-side overhead is included. Numbers move with hardware; the report records the machine fingerprint. **Read the next section before quoting them** — this release is slower than v1.4.0 at creating entities, on purpose. ## What this release is bad at A page that only lists strengths is a page that has not been measured. **Entity creation is slower than v1.4.0.** Median of three runs on one machine and interpreter: 2,000 lines **1.4× slower**, the 10,000-line roundtrip **2.3× slower**. Attributed — setting `EZDXF_CALL_TIMEOUT=0` returns creation to v1.4.0's numbers. The cost is the per-call `asyncio.wait_for` wrapped around every headless call so one hung call can no longer wedge a server whose document lock is a single `asyncio.Lock`. Deliberate trade, documented knob, on the 1.6 roadmap. The premium quality pass went the other way — **3.7× faster**. **Wave A shipped 13 tools of a planned 39.** Every cut is backed by a measurement. The REGION and 2D-boolean family went because `add_region()` produces a REGION with **zero ACIS bytes**, and the `greiner_hormann` substitute loses **28.2%** of the area on a square with one semicircular edge. **`system_run_command` / `system_run_lisp` are a guardrail, not a security boundary** — the rejection message says so in those words. A 36-verb denylist refuses the obvious cases, but AutoCAD accepts hundreds of commands and `DANGEROUS_COMMANDS_ENABLED=true` switches it off entirely. **Path validation is per-tool, and unscoped until you scope it.** With `ALLOWED_PATHS` empty — the default — the only positive bound is a ten-entry system-directory denylist that does not include `C:/Users`, `/home`, `/root` or `/var`. **Set `ALLOWED_PATHS`.** **Non-AutoCAD ProgIDs are unverified.** `CAD_PROGID` changes which COM application the backend attaches to; nothing beyond the connection has been tested against BricsCAD, ZWCAD or GstarCAD. ### Known limitations of the P&ID track **The router is orthogonal and blind.** `pid_line_draw` picks `auto` from seven orthogonal candidates — straight, one bend, two bends through the midline, or a stub out of each port joined by three bends — by fewest bends then length (or takes `direct`, or the waypoints you pass), and *counts* the lines it crosses — `crossings` comes back in every result and `pid_from_spec` sums it — but it does not route around them. Obstacle-avoiding routing is out of 1.6; move the symbol or pass waypoints. **A foreign drawing is read at the confidence it earns, and no higher.** A block this server did not place classifies by its `TAG`-style attribute or a keyword in its name at 0.6 with inferred ports, or at 0.3 when a line merely touches it — and a 0.3 guess can neither raise nor suppress a critique finding. On the live engine an INSERT turned off a right angle whose members ActiveX cannot measure reports an *approximate* box; `pid_graph` takes the tighter wall of that and the attribute-inclusive box on every side, but a line ending on such a body's true edge can still be reported `dangling` with the nearest port as the hint. Read `stats.confidence_min` first. **Same-file only, DXF headlessly.** Off-page connectors link within one drawing; links across files are not resolved. The headless engine reads DXF; a DWG P&ID is read through the live backend. No DEXPI/Proteus export and no ISA-5.2 binary-logic symbols in this release, recorded in the spec so nobody re-derives the cut. ### Known limitations of the settings track **Layer states are ours.** `layer_state_save` writes a portable snapshot into an `ACADMCP_LAYERSTATES` XRECORD. It survives save/reopen on both engines and travels with the DWG/DXF; it is **not** an AutoCAD `LAYERSTATE` and does not appear in the Layer States Manager. `system_capabilities` reports `layer_states` as `mode: "xrecord"` for that reason. **Six of the 22 environment tools need a live seat.** Preferences, launching, the operator prompts, and the five summary fields of document properties are refused headlessly with `preferences` / `dwgprops` / `live_application` / `interactive_prompt` — a refusal, not a stub. A `.dwt` template is the same case (`dwt_write`): a `.dwt` is a DWG container, so headlessly the template is saved as DXF. `mleaderstyle_create` is *not* such a case — ActiveX has no MLeaderStyle collection, but the `ACAD_MLEADERSTYLE` dictionary holds full `IAcadMLeaderStyle` objects, so both engines create leader styles. **A headless dimension does not re-render.** `dimstyle_modify` reports `dimensions_using_style` and `rerender_required: true` on the ezdxf engine; the DIMENSION keeps its rendered block until it is redrawn. AutoCAD regenerates on the next regen. ## Configuration Nothing loads a `.env` file — export these, or set them in your MCP client's `env` block.
All 17 environment variables | Variable | Default | Purpose | |---|---|---| | `AUTOCAD_MCP_BACKEND` | `auto` | `auto`, `com`, or `ezdxf` | | `CAD_PROGID` | `AutoCAD.Application` | COM ProgID the live backend attaches to | | `TOOL_PROFILE` | `full` | `lean` (64 curated tools, 54 with `TOOL_PACKS=core`) or `full` | | `TOOL_PACKS` | `all` | Vertical packs to advertise: `core,pid,settings` (`core` always on) | | `DISCOVERY_MODE` | `off` | `search` replaces the catalog with `search_tools` + `call_tool` | | `ENABLE_3D` | `false` | Expose the opt-in `solid_*` tools (COM) | | `LOG_LEVEL` | `INFO` | Python logging level | | `ALLOWED_PATHS` | *(empty)* | Comma-separated absolute paths the server may access | | `MAX_UNDO_STACK` | `5` | Maximum retained undo snapshots | | `EZDXF_UNDO_DEPTH` | `0` | Headless undo history depth; `0` disables it | | `MAX_DXF_BYTES` | `536870912` | Reject larger DXF input (512 MB); `0` disables | | `MAX_LIST_LIMIT` | `5000` | Bound list/selection response sizes | | `COM_CALL_TIMEOUT` | `60` | Per-call live AutoCAD timeout (s); `0` disables | | `EZDXF_CALL_TIMEOUT` | `120` | Per-call headless timeout (s); `0` disables | | `DANGEROUS_COMMANDS_ENABLED` | `false` | Allow blocked commands/LISP; reported as unsafe mode | | `ALLOW_REMOTE_HTTP` | `false` | Permit a non-loopback HTTP bind | | `MCP_AUTH_TOKEN` | *(empty)* | Bearer token required for remote HTTP |
## Architecture ```mermaid flowchart LR A[MCP host / AI agent] --> B[FastMCP 3 server] B --> C[Error · audit · timing · logging · capability-refusal middleware] C --> D[Typed contract · 19 modules · 27 capabilities] D --> E[COM backend
single-STA thread] D --> F[ezdxf backend
asyncio.to_thread] E --> G[Live AutoCAD] F --> H[Headless DXF] E --> I[Engineering · critique · scoring · delivery] F --> I ```
The drawing at the top of this page, as tool calls The sequence in [`scripts/render_readme_showcase.py`](https://github.com/U-C4N/Autocad-MCP/blob/main/scripts/render_readme_showcase.py), which produced the hero sheet: ```text drawing_new() ISO linetypes + layers bootstrapped drawing_apply_iso_layers("mech") ISO 128 lineweights per layer drawing_settings({units: "mm", linear_precision: 2}) gear_draw_spur_front_view( involute flanks, not a decorated circle module=6, teeth=24, center=[135, 172], bore_diameter=40, keyway_width=12, keyway_depth=3.3) gear_draw_section_aa(x_offset=300, face_width=46) dimension_linear(...) ISO 129 dimension_diameter(..., fit="H7") deviations from authored ISO 286 tables titleblock_apply_iso_a3(title="SPUR GEAR m6 z24", material="C45E", ...) drawing_critique(focus=None) -> [] must be empty before finalize view_screenshot() -> PNG ``` The full production loop adds `drawing_preflight` and `drawing_plan` at the front, `drawing_refine` after the critique, and `layout_create` + `viewport_create` + `drawing_deliver` at the end.
## Development ```bash uv sync --locked --all-extras uv run pytest uv run ruff check . && uv run ruff format --check . ``` `uv.lock` pins the whole transitive graph, so this reproduces CI exactly. CI runs Linux (3.11 / 3.12), Windows (mocked-COM), plus package, Docker and MCP-registry jobs; the release gate runs the same three test lanes before anything reaches PyPI. Releases are tag-driven: `git tag vX.Y.Z && git push origin vX.Y.Z`. ## Roadmap (1.6) Give back the creation throughput the per-call timeout costs — arm it only for calls that can actually block. ISO 286 interference **shafts** r/s/t/u. HATCH boundary *geometry* in `entity_get` (1.5 measures a hatch's filled area but does not hand back its loops). REGION/3DSOLID area headlessly, which needs a modelling kernel ezdxf does not have. An *allowlist* of permitted AutoLISP heads, replacing the denylist — enumerating dangerous symbols does not terminate. `ezdxf.recover` as a fallback on `drawing_open`. Features ship when their contracts and limitations are testable — not when they make a longer checklist. ## Star History [![Star History Chart](https://api.star-history.com/svg?repos=U-C4N/U-Pool,U-C4N/Autocad-MCP&type=Date&legend=top-left)](https://www.star-history.com/#U-C4N/U-Pool&U-C4N/Autocad-MCP&Date&legend=top-left) ## Author **Umutcan Edizsalan** · Mechanical engineering work at **Anka-Makine** · GitHub [@U-C4N](https://github.com/U-C4N) Built from production drawing work, then made model-agnostic through MCP. ## License [MIT](https://github.com/U-C4N/Autocad-MCP/blob/main/LICENSE) mcp-name: io.github.u-c4n/autocad-mcp