posecode-mcp

A Model Context Protocol server for Posecode. It lets a model in an MCP client learn the .posecode language, validate a movement against configured range-of-motion limits, and return a link that animates the movement as a 3D figure.

This closes the loop the playground left open: no copy-pasting a system prompt or shuttling text between a chat window and the editor.

Tools

| Tool | What it does | | --- | --- | | posecode_authoring_guide | Returns the Posecode authoring guide (grammar, joints, actions, example) so a capable model can draft raw .posecode for validation. | | validate_posecode | Parses a .posecode document and returns errors plus any range-of-motion clamps (angles outside the configured rig bounds). | | render_posecode | Validates, then returns a permalink that renders the movement in the Posecode playground. Hand it to the user to watch. |

validate_posecode / render_posecode flag invalid documents as MCP error results so the model knows to fix and retry.

Use from an MCP client

Run the latest published server directly from npm:

npx -y posecode-mcp@latest

For an MCP client that accepts JSON server configuration:

{
  "mcpServers": {
    "posecode": {
      "command": "npx",
      "args": ["-y", "posecode-mcp@latest"],
      "env": { "POSECODE_BASE_URL": "https://posecode.org" }
    }
  }
}

POSECODE_BASE_URL is optional: it sets the playground that render permalinks point at (defaults to the hosted playground).

Local development

From the Posecode monorepo, run the TypeScript source with the workspace script:

npm start -w posecode-mcp

That development command uses tsx src/stdio.ts; MCP consumers do not need a repository checkout, an absolute source path, or a separate tsx install.

How it fits

render_posecode builds its links with posecode-share, the same permalink primitive the playground uses, and validates with posecode-parser. The server does not render the movement itself; 3D math runs in the user's browser when the link is opened.

License

AGPL-3.0-only. A separate commercial license is available for closed-source product use.