Fern OpenAPI

Use this skill when the task is about the API definition Fern reads: making an OpenAPI/AsyncAPI spec produce good SDK method names, groups, types, pagination, errors and docs; adding x-fern-* extensions; deciding between editing the spec, an overlay, or an overrides file; keeping the spec in sync with its source. For generators.yml/publishing use fern-sdks; for CI use fern-workflows; for docs pages use fern-docs.

Fern resources

• OpenAPI docs: https://buildwithfern.com/learn/api-definitions/openapi/overview — append .md to any docs URL for Markdown.
• Extensions index: https://buildwithfern.com/learn/api-definitions/openapi/extensions/overview (pages: method-names, pagination, request-response-examples, availability, audiences, global-headers, global-parameters, sdk-variables, sdk-namespaces, schema-names, parameter-names, property-names, enum-descriptions-and-names, ignoring-elements, retry-behavior, idempotency, api-version, base-path, default-values, server-names-and-url-templating, tag-display-names, discriminator-context, api-explorer-control).
• Endpoint types: https://buildwithfern.com/learn/api-definitions/openapi/endpoints/sse (streaming) · https://buildwithfern.com/learn/api-definitions/openapi/endpoints/webhooks · https://buildwithfern.com/learn/api-definitions/openapi/endpoints/multipart
• Overlays: https://buildwithfern.com/learn/api-definitions/openapi/overlays · Overrides: https://buildwithfern.com/learn/api-definitions/openapi/overrides
• Auth: https://buildwithfern.com/learn/api-definitions/openapi/authentication · Servers: https://buildwithfern.com/learn/api-definitions/openapi/servers
• Sync from a source: https://buildwithfern.com/learn/api-definitions/openapi/sync-your-open-api-specification
• llms.txt: https://buildwithfern.com/learn/llms.txt · MCP: claude mcp add --transport http fern https://buildwithfern.com/learn/_mcp/server

Routing