The x-mcp OpenAPI extension is a custom extension used to document and configure Model Context Protocol (MCP) servers within an OpenAPI specification. MCP is an open protocol enabling AI models to interact with external systems and APIs in a standardized way.
Mintlify - https://www.mintlify.com/docs/api-playground/openapi-setup#mcp
Redocly - https://redocly.com/docs/realm/content/api-docs/openapi-extensions/x-mcp
speakeasy - https://www.speakeasy.com/mcp/tool-design/optimizing-openapi
openapi-mcp-generator - https://github.com/harsha-iiiv/openapi-mcp-generator
Christian Posta - https://blog.christianposta.com/semantics-matter-exposing-openapi-as-mcp-tools/