Generate complete API documentation
AI writes full 20-page public API documentation from your endpoints.
Generate complete API documentation
River's API Documentation Writer creates complete, professional API documentation from your endpoint list. You provide endpoints, methods, parameters, and notes, and the AI writes full documentation including introduction, authentication, endpoints, request/response examples, error codes, rate limiting, and best practices. Whether you're documenting REST APIs, GraphQL, or webhooks, you get comprehensive documentation that developers can actually use.
Unlike bare endpoint lists, we create complete developer experiences. The AI understands API documentation standards (clear descriptions, realistic examples, error handling, authentication flows, versioning), writes in developer-friendly language, and structures information for quick reference and deep understanding. You get documentation that reduces support requests and accelerates integration.
This tool is perfect for software engineers documenting APIs, backend developers launching public APIs, product teams improving developer experience, and startups creating their first API docs. If you have endpoints but no documentation, or if your docs need serious improvement, this tool helps. Use it when launching APIs or improving existing documentation to make integration easier for developers.
What Makes API Documentation Effective
API documentation succeeds when developers can integrate quickly without contacting support. Effective documentation means clear endpoint descriptions (what it does, when to use it), complete request/response examples (real JSON, not placeholders), proper authentication guidance (step-by-step setup), comprehensive error documentation (every possible error with solutions), rate limiting explanations, and working code samples in multiple languages. Weak documentation lists endpoints without context. Strong documentation anticipates questions and provides answers before developers ask.
The best API docs understand developer workflows. Start with quickstart guide (get developers to first successful call in 5 minutes). Follow with authentication (make it copy-pasteable). Then core endpoints (most commonly used first). Include realistic examples (actual use cases, not toy data). Document every parameter (type, required/optional, validation rules, examples). Show complete request/response cycles. Explain errors thoroughly (what caused it, how to fix it). Provide SDKs or code samples. Update when API changes. Good docs are living documents, not one-time writeups.
To improve API documentation, test it with new developers (can they integrate without help?). Include working curl commands (developers copy-paste to verify). Show realistic data (not foo and bar). Document edge cases and errors (especially common mistakes). Explain rate limits clearly (requests per time unit, headers to check). Version your API and docs together. Provide changelog showing what changed. Include troubleshooting section for common issues. Make examples copy-pasteable (working code, not pseudocode). Remember: every support question is documentation failure. Document so thoroughly that developers succeed independently. Great documentation is great developer experience.
What You Get
Complete 20-page API documentation
Introduction, authentication, and getting started sections
Full endpoint documentation with examples
Request/response specifications and error codes
Rate limiting, versioning, and best practices
Professional developer-ready documentation
How It Works
- 1Paste endpoint informationProvide endpoints, methods, parameters, and any existing notes
- 2AI writes complete documentationOur AI creates full API docs in 5 to 7 minutes
- 3Review and customizeRead through documentation, add specific examples and details
- 4Publish for developersHost on your docs site, share with developers, reduce support load
Frequently Asked Questions
Can this document GraphQL APIs or just REST?
Primarily optimized for REST APIs, but adapts to GraphQL if you provide schema and query examples. For REST, provide endpoints and methods. For GraphQL, provide schema types and example queries. The AI structures documentation appropriately for the API type. Specify your API type in the input for best results.
Will the examples work or are they placeholders?
The AI generates realistic examples based on your endpoint descriptions. You should review and update with actual data, authentication tokens, and real responses from your API. Think of generated examples as templates. Replace placeholder data with actual values from your system. Test all examples before publishing.
How do I handle authentication documentation?
Describe your auth method in the input (API key, OAuth, JWT, etc.). The AI writes appropriate authentication section. Review carefully and add specific details like where to get API keys, exact header formats, token refresh flows, and troubleshooting steps. Authentication is critical. Make it copy-pasteable and test it.
Should I include internal endpoints or just public API?
For public API documentation, include only public endpoints. Internal endpoints need separate internal docs with different security considerations. Public docs should assume external developers with limited knowledge of your system. Internal docs can assume more context. Keep them separate for security and clarity.
How often should API documentation be updated?
Update immediately when API changes. Breaking changes need advance notice (deprecation warnings, migration guides). New endpoints need documentation before release. Changed behavior needs updated examples. Maintain changelog showing all changes with dates. Stale documentation destroys developer trust. Keep docs synchronized with actual API behavior always.
What is River?
River is an AI-powered document editor that helps you write better, faster. With intelligent writing assistance, real-time collaboration, and powerful AI tools, River transforms how professionals create content.
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Get intelligent suggestions and assistance as you write.
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