Crayon C4 Mcp

Local MCP server for authoring, validating and maintaining a CRAYON-C4 architecture model, so an assistant never writes an invalid model file.

What you can do

• Create and edit C4 model elements, relationships and diagrams through the assistant.
• Validate the architecture model so invalid files are not written.
• Maintain an existing CRAYON-C4 model over time.
• Optionally scan repositories and apply AI enrichment when a license key is supplied.

When to use it

Useful when you keep a CRAYON-C4 architecture model and want an assistant to draft, extend or check it without producing invalid files. The free tier covers the full local authoring loop, so it is worth adding even without a license.

Requirements

Runs as a local stdio process installed from the npm package, so Node.js and a local MCP client are needed. No account or authentication is declared. The optional environment variable CRAYON_C4_LICENSE_KEY unlocks repository scanning and AI enrichment.