WebCAD for AI assistants
Connect WebCAD to ChatGPT, Codex, Claude or any assistant that supports MCP, and your assistant can design mechanical parts and simple mechanisms in WebCAD for you: it writes the model in ArchScript, WebCAD's text modelling language, builds it in WebCAD, shows you pictures of it, and gives you a STEP file.
Server address: https://mcp.webcad.ca/mcp
What your assistant can do
| Tool | What it does | Credits |
|---|---|---|
| Look up ArchScript capabilities | Finds what ArchScript can do for a topic, with syntax, limits and example names. | Free |
| Get the ArchScript reference | Returns the ArchScript syntax reference. | Free |
| List ArchScript examples / Get an ArchScript example | Lists WebCAD's example scripts and returns one. | Free |
| Check ArchScript syntax | Checks a script and lists the errors to fix. Builds nothing. | Free |
| Build ArchScript in WebCAD | Builds the script and reports PASS, or FAIL with each problem to fix. | Free; in ChatGPT and Codex, 2 for each stress or thermal study it runs |
| Build ArchScript and capture views | Builds the script and returns pictures from the directions you ask for. | Free; in ChatGPT and Codex, 2 for each study it runs with skipFea: false |
| Build ArchScript and export a STEP file | Builds the script and, when the build passes, returns a STEP download link. | Free; in ChatGPT and Codex, 1, plus 2 for each study the build runs |
In ChatGPT and Codex, a STEP file uses 1 WebCAD credit and each stress or thermal study a build runs uses 2 (skipFea: true runs none); everything else is free. In other assistants every tool is free. The credits are your WebCAD account's, the same as in the app.
In assistants that show apps in the conversation (ChatGPT and Claude, for example), a build, a set of pictures or a STEP export also shows the part in 3D: turn it, zoom, see its size, get the STEP file with the Get STEP file button, and keep working on it in the full app with Open in WebCAD, which opens the same part at app.webcad.ca (the part travels in the link itself; nothing is stored). The view uses your assistant's language when the WebCAD app has it, and English otherwise. Loading the view uses no credits.
A PASS means the model builds in WebCAD. Whether a part is right for its purpose (fit, strength, safety, manufacturability) still needs a person's review. Stress results are a first check for a person to review, not an engineering sign-off.
Stress studies in a script run for every account. Thermal studies run for WebCAD Pro accounts only, and CFD studies run only in the WebCAD app, not through assistants; when a build leaves a study out, its result says so.
Connect and sign in
You need a WebCAD account. Sign up free at app.webcad.ca.
- ChatGPT: find WebCAD in the plugin directory and select Connect.
- Codex: add WebCAD from the plugin directory.
- Claude: find WebCAD in the connector directory and select Connect, or add the WebCAD plugin, which brings the connector and a skill for designing parts.
- Other assistants: add a remote MCP server with the address above.
Your assistant opens a WebCAD page where you sign in and choose Allow. The page shows which app is asking and what it will be able to do. The app can build parts for you; it cannot open your projects or change your account.
Disconnect an app
Open WebCAD's Connected apps page, app.webcad.ca/account/connected-apps, and choose Disconnect next to the app. The app loses access at once and must ask again before it can use WebCAD. You can also remove WebCAD in your assistant's settings.
Limits
Looking things up, checking a script, building and pictures use no WebCAD credits. In ChatGPT and Codex, a STEP file uses 1 credit and each stress or thermal study a build runs uses 2; in other assistants these are free too. Every build result says what it used. Builds also have these limits:
| Limit | Value |
|---|---|
| Script size | 256,000 characters |
| Builds | 4 a minute, one at a time, 100 a day per account |
| Lookups and checks | 60 a minute per account |
| Build time | 5 minutes, then the build stops |
| STEP download links | Work for 24 hours |
When a limit is reached, WebCAD says which one and when to try again.
Examples
- "Design a 100 x 60 x 6 mm mounting plate with four M5 holes 8 mm from the edges and give me a STEP file."
- "Make a two-link arm with two hinge joints and show me pictures of it from the front and the side."
- "Design an aluminium wall bracket and check the stress when 200 N hangs from its tip."
Data handling
- What your assistant sends: the ArchScript it writes and the options of each request (for example the views to render).
- What WebCAD keeps: WebCAD does not keep your scripts after a build. So that a STEP file of a script you just built does not build it again, the result of that build (not the script) is held in memory for up to 15 minutes, for your account only. It logs which tool ran, when, for which account and with what outcome, for 30 days. STEP files are kept for 7 days and then deleted. In assistants that show WebCAD's 3D view, the shape of each part you build is kept for 24 hours so that the view can show it, and then deleted.
- What WebCAD returns: build results, pictures and STEP download links go to your assistant, which shows them to you.
- Your account: the app sees your email address so that WebCAD can tell you which account it is using. It cannot read your projects.
- More in the WebCAD privacy policy and terms.
Support
Email info@webcad.ca. Tell us which assistant you used, roughly when, and what you asked for.