Capabilities
Fern SDKs are built to have every feature you need.
Move fast and break nothing with type safety
Fine-tune SDK resources and method names
Fail fast if payloads diverge from your schema
Fern SDKs include support for discriminated unions
SDKs that handle multipart form data
SDKs that are fault-tolerant as your API evolves
Fern will automatically publish your SDKs to registries like npm, PyPI, and Maven
Paginate through API responses easily with offset, cursor, and link-based pagination.
Learn more
Fern supports OAuth as a first class citizen
Automatically retry failed requests with exponential backoff
Verify the signature of incoming webhook requests
Built-in protection against duplicate submissions
Learn more
Stream JSON data from your server to your client (i.e. chat completions)
Test your SDK against a mock server
No longer depend on manually written code snippets
Extend the generated SDK to provide additional functionality
Learn more
Multiple API Definitions. One SDK.
Learn more
Send and receive messages over WebSockets
Learn how to use the Model Context Protocol (MCP) to integrate AI capabilities with your Fern documentation
Learn more
