Get started with PartMode
Open a blank project or template, learn the workspace, and save an editable project.
PartMode MCP · public operating guide
Operate PartMode with an AI agent
Connect your agent securely, make controlled CAD changes against a known revision, and export artifacts with evidence another person can verify.
Learn PartMode
Twelve skills from first sketch to finished artifact
Start with no CAD experience, follow one bounded procedure at a time, and keep an editable model plus evidence you can check. Read a guide yourself or give its Markdown URL to an agent after the PartMode connection below is working.
Sketch and dimension
Create one closed profile with intentional constraints, dimensions, and units.
Extrude a part
Turn a closed profile into an exact solid and verify the intended result.
Cut a part
Remove material for a hole or pocket while preserving the intended body.
Revolve a part
Build a rotational solid from a stable axis, profile, and exact angle.
Use parameters
Drive linked dimensions with named values, equations, and explicit units.
Inspect and measure
Check exact geometry, dimensions, feature history, bodies, and model health.
Assign material and check mass
Set material or density and verify mass, centre of mass, and inertia.
Create configurations
Build named part variants and verify that each resolves independently.
Create a drawing
Generate projected views and verify SVG, DXF, or PDF drawing output.
Import a STEP file
Open, heal, inspect, and preserve an imported exact B-rep model.
Prepare a part for 3D printing
Check the solid, choose 3MF or STL deliberately, and verify the saved mesh.
Start here
Create an account, agent key, and MCP connection
Current production status: Google sign-in is not configured. Use the PartMode account-name and passphrase forms. The CAD editor remains available without an account; the account is required only to create revocable agent keys.
- Create or sign in to the account. Open PartMode Agent access. Create an account with an account name and a passphrase of at least 12 characters, or sign in with an existing account name and passphrase.
- Create the least-powerful suitable key. In the signed-in dashboard, give the key a label and choose Read only or Edit after approval. Leave Allow headless server sessions off for a project that stays in the browser. Enable it only on an edit key when unattended server execution and durable server-side project storage are deliberately required.
- Copy the one-time key. PartMode shows the raw key once.
Store it in OS or client secret
storage exposed as
PARTMODE_AGENT_KEY. Never paste it into a chat, URL, shell command, repository, skill, or tracked configuration file. If it is lost, revoke it and create another. - Add the MCP server. In Codex, run the command below after the secret environment variable is available to the Codex process; other Streamable HTTP MCP clients use the same URL and bearer token.
- Restart and verify. Start a new agent session. The client
must initialize
https://partmode.com/mcp, list PartMode resources and tools, and read the live MCP reference. A skill file by itself is not a connection. - Authorize one CAD session. For a browser-local project, keep the intended project open in a signed-in PartMode tab and approve the visible, bounded request. For headless work, use only a key created with the explicit headless grant. Confirm project identity, permissions, expiry, commit budget, and current revision before any CAD work.
codex mcp add partmode --url https://partmode.com/mcp --bearer-token-env-var PARTMODE_AGENT_KEYIf the agent cannot list PartMode MCP tools, stop at setup. Do not let it simulate the workflow from prose or claim that a CAD operation completed.
Operate with an agent
Three MCP skills cover the operating loop
Connect PartMode to an agent
Configure the hosted MCP server, verify live resources and tools, bind the session to the intended project, and disconnect cleanly.
Edit CAD in PartMode
Inspect exact state, build only live-supported operations, preview the bounded change, commit against one revision, and verify settled evidence.
Export CAD from PartMode
Choose a live-supported format, save to an approved destination, check bytes and SHA-256, parse the artifact, and bind it to its source revision.
Give this to the agent
One prompt to begin
Read https://sphinxstack.com/skills/connect-partmode-to-an-agent.md and follow it.
Then read the learning, edit, or export PartMode skill linked from https://sphinxstack.com/partmode/ that matches my task.
Do not ask me to paste a key. Work only in the project I approve, preview every mutation, and report exact revision-bound evidence.
My task: [describe the CAD change or artifact here]Keep authority bounded
Choose one session model
Browser-approved project recommended
The key authenticates the agent, but it does not grant access to an open CAD project. The person selects the intended PartMode tab and visibly approves the requested permissions, duration, and commit budget.
Server-headless project
Use only when the key was explicitly created with headless access. Open a stable project ID, keep duration and commits bounded, and use the dedicated headless STEP export path when exact STEP output is required.
Finish with proof
What a completed operation reports
- Connection: session path, mode, permissions, expiry, remaining commit budget, project evidence, and disconnect result.
- Edit: source revision, accepted preview identity, committed revision, persistent entities, exact dimensions or topology, and an invariant manifest for unrelated geometry.
- Export: source revision, format, scope, units, byte count, independently computed SHA-256, parse result, and destination.
Screenshots, DOM rows, mesh counts, filenames, and success messages can help explain a result; they are not exact CAD completion evidence by themselves.
Troubleshooting
Common stopping points
- The MCP URL does not look like an app
- That URL is a protocol endpoint. Use the public MCP reference in a browser and configure the endpoint in an MCP client.
- No browser Studio is available
- Open the intended signed-in PartMode project, list Studios again, request a bounded connection, and approve it visibly in that tab.
- The document revision is stale
- Do not retry the old mutation. Inspect the new revision, classify concurrent changes, refresh invariants, and create a new preview.
- An export format is unavailable
- Follow live capabilities. Do not silently substitute a screenshot, mesh, or nearby file type; ask the person to choose an advertised alternative.
Twelve learning skills · PartMode MCP reference · PartMode Help · Connection skill · Editing skill · Export skill