Use FITD from your own assistant

What it is

The Model Context Protocol (MCP) lets an assistant call tools on your behalf. FITD's MCP server signs in with a personal API key and then does exactly what you would do in the browser: it proposes a spec, waits for you to approve it, builds the part, measures it and hands back the report and the files.

It is not a separate service with its own rules. Every request goes through the same screening, the same account checks and the same credit charge as the website.

1. Create an API key

Sign in, open the account menu and choose Account & API keys. Create a key and copy it — it is shown once. You can hold up to 5 active keys and revoke any of them at any time; revoking one ends every session it opened.

2. Connect your assistant

Claude Code

claude mcp add --transport http fitd https://fitdcad.com/mcp --header "Authorization: Bearer <key>"

Claude Desktop

Add this entry to the app's MCP configuration file, then restart the app.

{
  "mcpServers": {
    "fitd": {
      "command": "npx",
      "args": [
        "-y",
        "mcp-remote",
        "https://fitdcad.com/mcp",
        "--header",
        "Authorization:${FITD_AUTH}"
      ],
      "env": {
        "FITD_AUTH": "Bearer <key>"
      }
    }
  }
}

Replace <key> with your key. Keep it out of anything you share or commit — anyone holding it can spend your credits.

3. The tools

• fitd_propose — Describe a part in plain English and get back a spec card to review — or one clarifying question. Free.
• fitd_answer — Answer the clarifying question, or correct the spec, before anything is built. Free.
• fitd_confirm — Approve the spec and start the build. This is the step that charges credits.
• fitd_status — Where a running build has got to.
• fitd_report — The verification report: every stated dimension, what was measured, and the verdict.
• fitd_download — Links to the STEP and STL files of a finished part.
• fitd_credits — How many credits you have left.

Credits

Proposing and refining a spec is free. fitd_confirm charges credits exactly as the web app does when you approve a spec there — the same price, from the same balance, with the same refunds if a build fails.

What you can and cannot make

Use through the API or MCP is covered by the same Terms and the same prohibited uses as the website. A refused request is refused here too, and counts against your account the same way.