Client ID Metadata Document (CIMD)

Client ID Metadata Document (CIMD): A JSON file on the client's domain whose HTTPS URL is used as the OAuth client_id, the recommended MCP registration method. Example: Vercel MCP accepts CIMD clients without review since 2 Nov 2026. Also in the glossary is agents.json: An OpenAPI-based file at /.well-known/agents.json describing flows of API calls for agents.

Definition

A JSON file on the client's domain whose HTTPS URL is used as the OAuth client_id, the recommended MCP registration method.

Example, with source

Vercel MCP accepts CIMD clients without review since 2 Nov 2026. (vercel.com, read 4 November 2026)

Where it appears on this site

• MCP
• OAuth for MCP

Neighbouring terms

• AI gateway: A proxy in front of model APIs that adds caching, rate limits, logs and billing across providers.
• Code Mode: A Cloudflare approach where the agent writes code against a typed API instead of calling many tools one by one, set by portal policy.
• Confused deputy: An attack where a proxy with its own credentials is tricked into acting for someone else; MCP security guidance addresses it for OAuth proxies.