Best alternatives to Fern in 2026

A company that offers an API usually needs to hand developers two things: readable documentation, and ready-made code libraries in whatever language those developers use — and hand-writing and maintaining both, in sync, across Python, JavaScript, Go and more, is a job that eats an engineering team's time indefinitely. Fern reads the API's technical specification once and generates both the docs and the code libraries automatically, keeping them in sync as the API changes. Fern is a platform for generating API documentation and SDKs from OpenAPI (and other) specifications, aimed at API-first companies that want a professional developer experience without a dedicated docs team. It auto-generates SDKs in multiple programming languages, supports REST, WebSockets, GraphQL, AsyncAPI and gRPC, includes AI-assisted authoring, an integrated AI chat/search for documentation (llms.txt generation for AI-agent-readable docs), a terminal CLI, MCP server integration, and self-hosting with SAML/OIDC authentication for enterprise needs. The core is Apache-2.0 open source with 3.7k GitHub stars. Pricing runs from a free Hobby tier (250 AI credits) through Team at $150/month (1,000 AI credits, 5 team members, version switching) to custom Enterprise pricing with dedicated support and SSO. Fern reports serving 8,000+ customers and generating 13,392+ SDKs.