SDK user features
Fern-generated SDKs provide a consistent set of features across all languages to help developers interact with your API. Usage information is auto-generated in your SDK’s README.md, which you can customize.
For a complete example of a generated SDK README, see Intercom’s Python SDK.
Installation and basic usage
Users install SDKs using standard package managers (npm for TypeScript, pip for Python, Maven/Gradle for Java, etc.) from language-specific registries.
Users initialize the client with your API’s base URL and any required authentication, then call methods on the client to interact with your API. Generated SDKs support modern runtimes across languages.
Reference
The README.md file links to an auto-generated reference.md file
(example)
that lists all available API methods organized by resource, including method
signatures with parameter types, usage examples, and request/response structures
for each endpoint.
Error handling
When the API returns a 4xx or 5xx status code, the SDK throws an error that includes the status code, error message, response body, and raw response object.
Webhook signature verification
When you define webhooks in your API spec, Fern automatically generates utilities that allow your users to verify webhook signatures and ensure events originate from your API. For an example, see Square’s Node.js SDK.
Customization options
Your SDK users can configure individual requests using language-specific options:
