Should I use REST or GraphQL?

REST is simpler for CRUD-oriented APIs with broad consumer bases. GraphQL suits complex data graphs where consumers need flexible queries. Most public APIs use REST for its simplicity.

How do I handle API versioning?

URL-path versioning like /v1/resource is the most explicit and cacheable. Header-based versioning is cleaner but harder for consumers to discover. Pick one and document it clearly.

What rate limits should I set?

Start conservative at 100-1000 requests per minute per key depending on your infrastructure. Monitor actual usage patterns and adjust. Always provide a way for consumers to request higher limits.

API Launch Checklist

Ship a production-ready API with proper authentication, rate limiting, versioning, and documentation from day one.

Checklist: API Launch (launch)

Launching a public or partner API requires a different discipline than launching a web app. Consumers will build on your endpoints, so backward compatibility, clear documentation, rate limiting, and predictable error responses are non-negotiable from the start.

Checklist Items

Implement authentication and API key management [critical]: Issue API keys, support OAuth2 where appropriate, and provide a self-serve key rotation flow.
Configure rate limiting and throttling [critical]: Enforce per-key rate limits and return standard 429 responses with Retry-After headers.
Publish comprehensive API documentation [critical]: Provide interactive docs with request/response examples, error codes, and authentication guides.
Implement API versioning strategy [important]: Choose URL-path or header-based versioning and document your deprecation policy.
Standardize error response format [important]: Return consistent JSON error objects with error code, message, and request ID across all endpoints.
Set up request logging and monitoring [important]: Log every API call with latency, status code, and consumer identity for debugging and analytics.
Add request validation and input sanitization [important]: Validate all inputs against schemas and return descriptive 400 errors for malformed requests.
Configure CORS policies [recommended]: Set appropriate CORS headers for browser-based consumers while blocking unauthorized origins.
Create SDKs or code examples [recommended]: Provide client libraries or copy-paste examples in popular languages to reduce integration friction.
Set up a developer portal [recommended]: Build a self-serve portal where developers can register, manage keys, and view usage analytics.

Common Mistakes

No versioning from the start: Add versioning before your first external consumer integrates; retrofitting breaks existing integrations.
Inconsistent error responses: Define a single error schema and enforce it across all endpoints with middleware validation.
Missing rate limiting: One misbehaving consumer can take down your API. Implement rate limiting before any external access.

Frequently Asked Questions

Should I use REST or GraphQL?: REST is simpler for CRUD-oriented APIs with broad consumer bases. GraphQL suits complex data graphs where consumers need flexible queries. Most public APIs use REST for its simplicity.
How do I handle API versioning?: URL-path versioning like /v1/resource is the most explicit and cacheable. Header-based versioning is cleaner but harder for consumers to discover. Pick one and document it clearly.
What rate limits should I set?: Start conservative at 100-1000 requests per minute per key depending on your infrastructure. Monitor actual usage patterns and adjust. Always provide a way for consumers to request higher limits.