The api.openapi configuration specifies how the MCP server locates and interprets the OpenAPI specification. Correct configuration ensures that the server can load the specification and generate tools accurately.

The following table lists the properties available in the api.openapi subgroup and describes their purpose:
Property Required Purpose Notes
spec_file Yes Path to the OpenAPI specification Can be relative or absolute. Resolved at server startup.
base_url No Default downstream base URL Prefer runtime.http.base_url in new and generated configurations. api.openapi.base_url is still supported for compatibility.
spec_name No Human-readable label Used in logs for only cosmetic purposes.
The following example shows how to configure the api.openapi subgroup in the MCP server configuration file:
{
    "api": {
        "openapi": {
            "spec_file": "openapi.yml"
        }
    },
    "runtime": {
        "http": {
            "base_url": "https://api.example.com"
        }
    }
}