API Development Patterns

REST APIs in Rails use namespaced routes for versioning, strong parameters for validation, and serialization libraries like Blueprinter or JSONAPI::Serializer to format JSON responses. Structure versioned controllers under `app/controllers/api/v1/` with consistent error handling and respond_with patterns across resources.

JWT authentication is a standard pattern for Rails REST APIs. Implement token generation at login, validate tokens in controller filters, and attach user context to requests. Store tokens securely client-side and refresh them before expiration to maintain stateless API sessions.

Yes, Rails APIs can mix serialization libraries—Blueprinter, JSONAPI::Serializer, and Alba each provide different feature sets and performance profiles. Choose based on your response format requirements and complexity; most projects standardize on one library for consistency across endpoints.

Rate limiting uses middleware or gems to throttle requests per user or IP. Pagination applies limit and offset parameters to queries, returning metadata about total records and current position. Both integrate into controller logic and respond_with JSON to enforce production-grade API constraints.

REST APIs return HTTP status codes (400, 401, 404, 500) with standardized JSON error payloads containing message and error code. Use Rails exception handling and custom error classes to map application errors to appropriate responses, ensuring consistent error communication across all endpoints.

Yes, route versioning typically uses API namespace prefixes (`/api/v1/`, `/api/v2/`) with controllers organized by version. This decouples client expectations from internal changes and allows gradual API evolution. Rails routes.rb defines version-specific namespaces mapping to versioned controller paths.