Fern
Fern allows developers to instantly transform your OpenAPI into SDKs and Docs. Engineering teams build with Fern to offer a best-in-class developer experience. Stripe, Twilio, and AWS have the resources to invest in internal tooling for developer experience. They provide SDKs (aka client libraries) in multiple languages and developer documentation that stays up-to-date. We are building Fern to productize this process and make it accessible to all software companies.
APIs
Fern
We use Fern to autogenerate our Python and Node API clients from our OpenAPI spec. The clients are high quality, easy to update, and the Fern team moves blazing fast.
Features
Generate production-ready SDKs in TypeScript, Python, Go, Java, C#, PHP, Ruby, Swift, and Rust from OpenAPI specs.
Auto-generate beautiful, branded API documentation with interactive examples and playground.
AI-powered documentation chatbot that answers developer questions using your API docs as context.
Purpose-built API definition language as an alternative to OpenAPI for defining API contracts.
First-class OpenAPI specification support for both SDK generation and documentation.
Built-in API versioning support for documentation and SDK generation across multiple API versions.
Use Cases
Transform OpenAPI specifications into idiomatic client libraries across multiple programming languages.
Generate and host interactive API documentation with custom branding and domain support.
Define APIs using Fern Definition Language and generate server stubs, SDKs, and documentation.
Automatically update and publish SDKs when API specifications change, reducing maintenance burden.
Build comprehensive developer portals with guides, API references, and SDK documentation.
Integrations
CI/CD integration for automatically generating and publishing SDKs on API specification changes.
Automatic publishing of generated TypeScript/JavaScript SDKs to the npm package registry.
Automatic publishing of generated Python SDKs to the Python Package Index.
Automatic publishing of generated Java SDKs to Maven Central repository.
Automatic publishing of generated C# SDKs to the NuGet package registry.