Best 3 Tools for Generating SDK Documentation in 2025

Speakeasy is a complete API toolchain that transforms your OpenAPI specification into ready-to-use developer tools. It creates native SDKs that follow best practices for each programming language, making them feel handwritten rather than machine-generated.

Fern is a platform that automatically generates SDKs and API documentation from your API definition. You provide your OpenAPI, AsyncAPI, or gRPC specification, and Fern creates ready-to-use client libraries in languages like TypeScript, Python, Go, Java, Ruby, C#, PHP, and Swift.

DeveloperHub is a complete documentation tool that combines writing, publishing, and tracking in one place. You can create different types of content including API references, how-to guides, release notes, and knowledge bases all in the same project.