OwlCAD’s MCP server gives an AI agent eleven tools for building, checking and exporting print-ready 3D models. Streamable HTTP, bearer-token auth, millimetres and Z-up. Connect Claude Code, Claude Desktop or Cursor.
An MCP endpoint that gives an agent a real CAD kernel: author a parametric tree, evaluate it, render it, check it prints, export it, and save it as a project. Stateless Streamable HTTP — every call is a self-contained POST.
https://mcp.owlcad.com · Pro plan required · No AI credits spent
Any MCP client that speaks HTTP works. Claude Code, Claude Desktop and Cursor are the ones we test against.
In OwlCAD, open Account → Access tokens and create one. Give it only the scopes you need — read alone is the default. Copy it immediately; only a hash is stored.
Add the server to your MCP client’s config, passing the token as a bearer credential.
Restart the client, then have the agent read owlcad://schema/primitives before it builds anything.
{ "mcpServers": { "owlcad": { "url": "https://mcp.owlcad.com", "headers": { "Authorization": "Bearer owlcad_pat_…" } } } }
Stated in the initialize instructions and in owlcad://schema/conventions, because getting them wrong fails silently rather than loudly.
Millimetres for every dimension and coordinate.
Z-up — the build plate is the XY plane.
Rotations in DEGREES, not radians. A tree authored in radians renders as almost no rotation at all.
Exactly one geometry input per call: nodes, scad, or projectId.
Eleven, covering the whole loop from authoring to a print-ready file. Each needs the scope shown; a token that lacks it gets a readable error naming the missing scope.
Runs the real CSG kernel: watertight or not, triangle count, bounding size, printability warning.
PNG images of the model from named views — the tool that lets an agent see its own work.
Overhang area, thinnest wall, and whether it fits a named printer’s build volume.
Evaluates and returns a base64 STL, 3MF or OBJ.
Saves a model as a project on your account and returns its id and editor link.
Replaces an existing project’s geometry, keeping its id and link. Requires the version you read.
Your projects, newest first — how an agent finds an id.
Loads one of your projects and lists its nodes, with the version needed to update it.
Imports an STL, OBJ or 3MF file as a new project, detecting the unit.
Permanently deletes a project and its geometry.
The link that opens a project in the OwlCAD editor — usually the best thing to hand a person.
Read-only, generated at runtime from the same registry the validator enforces — so what an agent reads and what gets applied cannot disagree.
Every shape, modifier and generator, with the valid range of every parameter. Read this first.
Units, axes, rotation units, smoothness tiers and the limits below.
Printer profiles and build volumes, for the printerId argument to print_check.
Bounds, not product quotas — an interactive session is tens of calls. Each is enforced per request.
2,000 (a batch counts once per message)
100
32
45 seconds
8 MB · 200,000 triangles
6 MB
10
Create a token, add the server to your client, and ask for a part. Pro plan required; no AI credits are spent.
An MCP (Model Context Protocol) endpoint at https://mcp.owlcad.com that gives an AI agent eleven tools for building, checking, and exporting print-ready 3D models. Transport is Streamable HTTP and stateless — every call is a self-contained POST authenticated with a personal access token.
Any client that speaks MCP over HTTP — Claude Code, Claude Desktop, and Cursor are the ones we test. Point the client at https://mcp.owlcad.com and pass your token in an Authorization header as a bearer credential.
Millimetres, Z-up, and rotations in DEGREES. These are stated in the initialize instructions and in the owlcad://schema/conventions resource, because getting them wrong is the classic silent error — a rotation authored in radians renders as almost no rotation at all.
Read the owlcad://schema/primitives resource first. It is generated at runtime from the same registry the validator enforces, so the ranges it publishes are the ranges that will actually be applied — an agent never has to guess a parameter name or a bound.
2,000 calls per token per day, 100 projects created per account per day, up to 32 messages in a JSON-RPC batch, and a 45-second budget per request. Tokens are Pro-only and are re-checked on every request, so a lapsed subscription stops one immediately.