solidworks-mcp-2

An MCP (Model Context Protocol) connector that drives SOLIDWORKS 2025 and SOLIDWORKS CAM 2025 through COM automation, so an MCP client like Claude can model parts and assemblies, produce drawings, and generate real, posted G-code — with real geometry, real mass properties, and real files on disk, not a simulation of any of those things.

It is a ground-up rebuild of the solidwprks-mcp predecessor concept: one dedicated STA worker thread owns every COM object, clients get opaque session handles instead of raw pointers, every dimensional value has an explicit unit convention, and 13 grouped MCP tools give ~122 modeling/CAM operations their own typed Pydantic schema instead of one giant generic surface. See docs/architecture.md for the full design.

Status

Code-complete for this release: 474 tests passing against a fake-COM layer, ruff/mypy clean, and — unusually for a project at this stage — live-verified against a real, licensed SOLIDWORKS 2025 + SOLIDWORKS CAM 2025 installation. That pass found and fixed 9 real bugs the fake-COM suite alone had not caught, and it honestly documents 2 remaining live-flakiness issues. See "Verified" below and docs/verification/VERIFICATION.md for the full, unedited report.

Install

Requires 64-bit Windows and, to actually connect to SOLIDWORKS, a licensed SOLIDWORKS 2025 (revision 33.x) installation. The package itself installs and its non-live test suite runs on any OS.

git clone https://github.com/rdolan5/solidworks-mcp-2.git
cd solidworks-mcp-2
uv sync

or with plain pip:

python -m venv .venv
.venv\Scripts\pip install -e .

Verify the install (no SOLIDWORKS process launched):

uv run solidworks-mcp --doctor

Configure Claude Desktop

Add to claude_desktop_config.json's mcpServers:

{
  "mcpServers": {
    "solidworks": {
      "command": "C:\\path\\to\\solidworks-mcp-2\\.venv\\Scripts\\solidworks-mcp.exe",
      "args": ["--workspace", "C:\\Users\\you\\Documents\\SOLIDWORKS-MCP"]
    }
  }
}

Configure Claude Code

claude mcp add solidworks -- C:\path\to\solidworks-mcp-2\.venv\Scripts\solidworks-mcp.exe --workspace C:\Users\you\Documents\SOLIDWORKS-MCP

Full step-by-step (both clients, troubleshooting) in docs/configuring-claude.md.

Tool catalog

~40 MCP tools total: 13 grouped tools (each dispatching on a typed operation field to one of ~122 capability-module functions) plus 27 standalone tools for connection, generic COM access, document lifecycle, and CAM connection. Every operation name below is exactly the string you pass as payload.operation; the authoritative, always-current mapping is src/solidworks_mcp/specs.py's TOOL_OPS table.

Standalone tools: solidworks_discover, solidworks_connect, solidworks_api/solidworks_batch/solidworks_array/solidworks_release, solidworks_api_load/solidworks_api_search, solidworks_active_document, solidworks_templates, solidworks_new_document/open_document/save, solidworks_rebuild, solidworks_inspect, solidworks_assembly_tree, solidworks_mass_properties, solidworks_sketch_begin (legacy convenience), solidworks_persistent_reference/resolve_reference, solidworks_modify_feature, solidworks_cam_connect/cam_status/cam_workflow (legacy low-level CAM dispatcher), solidworks_script, solidworks_job/ cancel_job.

Units and selection conventions

Every dimensional field accepts a value plus an optional unit, defaulting to millimetres for length and degrees for angle (SOLIDWORKS' COM API itself is always metres/radians/kilograms internally — this connector converts at the boundary in both directions). Full convention, including handle lifetime and document-targeting rules, in docs/units-and-conventions.md.

Safety model

• Workspace sandboxing: every file-writing tool (solidworks_save, solidworks_exchange's export, CAM's post_process, drawing export) resolves its destination through Runtime.output_path, which rejects any path that resolves outside the configured --workspace directory (default ~/Documents/SOLIDWORKS-MCP). A relative path is resolved inside the workspace; an absolute path elsewhere on disk is refused.

• --allow-scripts: solidworks_script executes arbitrary trusted Python on the COM apartment — full local code execution with the OS user's permissions, not a sandbox. It is only registered when the server is started with --allow-scripts; omit that flag (the default) to disable it entirely.

• Generic API access is still full-trust local automation: solidworks_api/solidworks_batch expose the complete COM surface, including calls that can modify documents, run macros, or touch the local filesystem outside the workspace sandbox via COM's own file APIs (the sandbox is enforced at this connector's boundary, not inside SOLIDWORKS itself). Treat granting an MCP client access to this server as granting it the same trust you'd give a local automation script running as you.

• CAM is never treated as proof of a license or of manufacturing correctness. An installed product, a registered add-in, or a successful API connection does not establish CAM license entitlement — see "CAM notes" below. A void COM return is documented as void, not silently reinterpreted as success.

--doctor

uv run solidworks-mcp --doctor

Prints installed SOLIDWORKS/SOLIDWORKS CAM versions, registered add-ins, and library paths as JSON, discovered from the Windows registry and filesystem — no SOLIDWORKS process is launched. Use it first when solidworks_connect or CAM tools aren't behaving as expected.

CAM notes

SOLIDWORKS CAM access requires the add-in to be installed and registered (discovered from the registry, never guessed) and, separately, a valid license — the connector's own cam.status() deliberately reports license: "unknown" even when the API connection succeeds, because an API connection is not license proof. License checks (solidworks_cam_workflow's license action) require an explicit vendor module name and are recorded per-module, not aggregated into a blanket "licensed" flag. Full detail, including the confirmed add-in identifier/entry point and the CAM operation table, in docs/cam.md.

Verified

docs/verification/VERIFICATION.md is a from-scratch run against a real, licensed SOLIDWORKS 2025 SP5.0 + SOLIDWORKS CAM 2025 installation — every number, error message, and G-code line in it is copied verbatim from an actual run, not fabricated:

That pass also found and fixed 9 real bugs in this codebase (wrong COM member names, ByRef/VARIANT marshalling, treating void-but-successful returns as failures, an unopened-referenced-file assembly-insert bug) — see the report for the full list with exact interfaces and members.

Known issues (not hidden)

• FeatureLinearPattern5/FeatureCircularPattern5 (solidworks_pattern's linear/circular operations) consistently return Nothing against this SOLIDWORKS 2025 install despite a confirmed-correct signature and roughly a dozen parameter/selection variations tried. Open, unresolved blocker.

• AddMate5 (solidworks_assembly's mate operation) is intermittently flaky in this headless COM automation context — selection sometimes reports zero selected objects immediately after component insertion, and the mate call itself sometimes returns an unknown error even with a verified selection. One isolated run did succeed with an identical call, confirming the API itself works; the flakiness wasn't fully root-caused in the time available.

• CAM operation-collection enumeration (solidworks_cam's list_operations) has nothing to enumerate because generate_operation_plan returns None even though the plan demonstrably exists (toolpath generation and posting both succeed and produce real G-code). Only the introspection step is unverified.

See docs/verification/VERIFICATION.md's "Known gaps / confirmed blockers" section for the full detail on all three.

Examples

Worked, documented scripts under examples/ — adapted from the exact sequences run in live verification, not hypothetical code: complex_part_bracket.py, parametric_housing.py, gearbox_assembly.py, drawing_from_part.py, cam_mill_part_to_gcode.py.

Documentation

• docs/architecture.md — STA worker/bridge/gateway/runtime design

• docs/cad-tools.md — geometry/sketch/feature/pattern/body/parametric/material/configuration/analyze

• docs/assemblies.md, docs/drawings.md, docs/cam.md

• docs/units-and-conventions.md

• docs/configuring-claude.md

• docs/verification/VERIFICATION.md

Development

uv sync
uv run pytest -m "not live and not cam"
uv run ruff check
uv run mypy src

See CONTRIBUTING.md for test tiers, code style, and how to add a new operation. CHANGELOG.md covers what changed between the solidwprks-mcp predecessor concept and this release.