Fern
Generate SDKs, API Reference, and Postman Collections from your API.
Overview
Fern is an open-source toolchain that helps developers generate client-side SDKs in various languages (like TypeScript, Python, Java, Go) and beautiful API documentation from a single, simple API definition. It focuses on improving the developer experience for API consumers by providing type-safe, idiomatic SDKs and clear documentation, all generated from one source of truth.
✨ Key Features
- Automatic SDK Generation (TypeScript, Python, Java, Go)
- API Reference Documentation Generation
- Postman Collection Generation
- Simple, YAML-based API definition format
- Open-source and self-hostable
- Hosted documentation option
🎯 Key Differentiators
- Primary focus on high-quality, idiomatic SDK generation
- Documentation is generated as a byproduct of the SDK definition
- Simpler, more developer-friendly API definition format than OpenAPI
Unique Value: Automates the creation of the entire developer toolkit for an API—SDKs, documentation, and Postman collections—from a single source of truth, ensuring consistency and saving significant development time.
🎯 Use Cases (3)
✅ Best For
- API-first companies that want to provide a first-class developer experience with robust SDKs
- Teams looking to automate the creation and maintenance of their API's developer ecosystem
💡 Check With Vendor
Verify these considerations match your specific requirements:
- Teams that only need API documentation and have no need for SDK generation
🏆 Alternatives
While other tools can generate code, Fern focuses on producing high-quality, human-readable, and idiomatic SDKs that feel handwritten, which is a significant differentiator.
💻 Platforms
✅ Offline Mode Available
🔌 Integrations
🛟 Support Options
- ✓ Email Support
- ✓ Live Chat
- ✓ Dedicated Support (Enterprise tier)
🔒 Compliance & Security
💰 Pricing
Free tier: The open-source CLI is free. Hosted services have a free tier for public projects.
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