dsh-sw-cad

dsh-sw-cad

Two MCP servers and two skills that let a DeepSeek Harness or Codex agent drive real CAD software.

They wire up two existing open-source projects — [U-C4N/Autocad-MCP](https://github.com/U-C4N/Autocad-MCP)

and [wzyn20051216/solidworks-automation-skill](https://github.com/wzyn20051216/solidworks-automation-skill) —

so an agent can draw in AutoCAD, model in SolidWorks, and export the results. This repository is the

configuration layer: isolated environments, launch parameters, on-demand loading and client registration.

It does not fork, patch or repackage either server. Both now hide their catalogs behind their own

discovery mode, so this repository no longer ships one: it configures theirs.

English | [中文](README.zh.md)

What it does, and when you want it

A CLI agent that can read a drawing is useful. One that can produce one is a different tool. With this

kit installed, dsh or Codex can take a sentence like "draw an M6 threaded-hole bracket on an ISO A3 sheet

and export PDF" and actually do it — create layers, draw geometry, dimension it, stamp a title block,

run a validator, and hand back a file.

The catch is the same as every COM automation: **the CAD application must be running, and the agent must

run as the same Windows user and integrity level as the CAD app.** This is not a cloud service and there

is no headless substitute for native .dwg / .sldprt output.

Two skills are the entry points. They load lazily — the SKILL.md is read only when a request matches its

description, so an idle session pays nothing for them:

| Skill | How it works |

|---|---|

| solidworks-automation | Script-driven: 66 Python modules (30 sw_*.py COM wrappers plus OCCT/FEA/DFM tooling), with preflight, capability gating and evidence chains |

| autocad-mcp-pro | Authored here (upstream ships no AutoCAD skill). Drives the AutoCAD MCP through its two meta-tools |

Two MCP servers are the muscle, registered in the client config:

| Server | Tools advertised | Idle cost | Mode |

|---|---:|---:|---|

| autocad | 2 | 365 tokens | Upstream DISCOVERY_MODE=search: only search_tools + call_tool; the 242-tool catalog is searched by keyword |

| solidworks | 3 | 474 tokens | Upstream SW_MCP_DISCOVERY=search: sw_search_tools, sw_describe_tool, sw_call_tool; the 66-tool catalog (50 solidworks_ + 14 cadstudio_ + 2 design_*) is searched on demand, and would otherwise cost 23,411 |

*Tool schemas are paid for before the first request. Connected directly the two servers cost 107,143

tokens; through this kit they cost 839, a 99.2% cut. Both sides are measured the same way: the

tools/list bytes on the wire, counted with cl100k_base.*

you speak natural language
   │
   ├─ dsh / Codex lazily loads a skill by its SKILL.md description
   │      ├─ solidworks-automation  → sw_*.py scripts → COM → SolidWorks
   │      └─ autocad-mcp-pro        → search_tools / call_tool → MCP → AutoCAD
   │
   └─ MCP servers (cordis.patch.yml / codex config.toml)
          ├─ autocad    upstream discovery mode, 242 tools on demand
          └─ solidworks upstream discovery, 3 entry tools, 66 tools on demand

What is upstream, what is ours

This matters more than usual here, because the two servers are other people's work. The split is:

| Part | Origin | License |

|---|---|---|

| AutoCAD MCP server (autocad-mcp-pro) | [U-C4N/Autocad-MCP](https://github.com/U-C4N/Autocad-MCP), installed from PyPI | MIT |

| SolidWorks skill + MCP server | [wzyn20051216/solidworks-automation-skill](https://github.com/wzyn20051216/solidworks-automation-skill), cloned at install time | MIT |

| skills/autocad-mcp-pro/SKILL.md | Authored here — upstream has no AutoCAD skill | MIT |

| bin/, lib/ (including probe.py, which checks for the CAD COM servers), package.json, cordis.patch.yml, install.ps1, bootstrap.ps1, codex-config.snippet.toml, assets/, READMEs | Authored here | MIT |

Nothing upstream is vendored. The installer fetches the PyPI package and clones (or zip-downloads) the

SolidWorks repository at install time, so you always get upstream's current code and upstream keeps

ownership of it. The value this repository adds is the part that was missing: verified launch parameters,

the discovery-mode configuration for both servers, the on-demand skill wiring, the junction trick that

keeps gigabytes off C:, and an installer that survives a blocked git

protocol.

One exception, and it is deliberate: patches/ carries two fixes for upstream defects that are

silent — a vertical linear dimension measures 0.0, and every edge's diameter and length come back null.

Both are open as pull requests upstream; until they land, install.ps1 applies the patches to the

installed copies and bootstrap.ps1 reports whether they are in place. See