Client ID Metadata Documents (CIMD): OAuth Client Identification Using URLs

Summary

Client ID Metadata Documents (CIMD) is a new OAuth approach that allows clients to identify themselves using URLs instead of requiring pre-registration. Clients host a JSON metadata document at an HTTPS URL and use that URL as their client_id, eliminating the need for manual registration with authorization servers. This reduces friction, supports dynamic ecosystems like MCP (Model Context Protocol), and solves interoperability issues in OAuth implementations.