In depth: Speakeasy vs Fern

Speakeasy and Fern are two distinct platforms used by API developers to generate SDKs and automate their publication, with each offering unique advantages and features. Fern operates as an SDK generation tool utilizing a domain-specific language to create SDKs in seven languages, while Speakeasy is a comprehensive platform that supports SDK generation in ten languages and includes additional features such as Terraform providers and documentation. Speakeasy is OpenAPI-native, ensuring interoperability with existing API tooling, and offers advanced features like React Hooks and OAuth 2.0 support that are not natively available in Fern. In terms of engineering maturity, Speakeasy has rapidly expanded its language support and offers a more integrated solution for API management with CLI validation and a web interface. While both platforms support runtime data validation, Fern uses a custom serialization library, whereas Speakeasy leverages the popular Zod library. Additionally, Speakeasy provides a streamlined experience with features such as auto-pagination, built-in React Hooks, and a more efficient bundle size, making it more suitable for modern development environments.