Fern - SDKs for your API ⚡
Auto-generate your client libraries, API reference, and server code
TLDR: Fern generates useful artifacts for your API, like SDKs, docs, and server code. Star us on GitHub! ⭐

Steve Yazicioglu, Head of Engineering at Candid Health (Series A)
Problem
When building APIs, we spent a lot of our time doing things like:
- Writing types & networking logic on the backend
- Communicating details of the API endpoints over Slack
- Re-writing the same types & networking logic on the frontend
- Re-writing the same types & networking logic in each SDK or client library
- Re-writing the same information in our docs & Postman Collection
Inevitably, these multiple sources of truth get out of sync, causing runtime bugs, wasted hours of debugging, and frustration.
Solution
Fern productizes schema-first API design. You define the schema of your API (or give us an OpenAPI spec) and we generate:
- SDKs in popular programming languages. Our SDKs feel handwritten. They can be used externally for customers or internally for your frontend/microservices.
- API docs that sync to your provider of choice.
- Postman Collection complete with examples of successful and unsuccessful requests
- Server-side validation to make sure that you serve the API you promised.
Fern also registers all versions of your API in a registry — no need to ping a coworker over Slack to understand how to consume an API.
With love 💌,
Team Fern 🌿 (Deep, and Danny)
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