A well-designed REST API is one of the most valuable things you can build for a client. Done right, it powers mobile apps, third-party integrations, and future features you haven't planned yet.
Sanctum vs Passport
For most projects, Laravel Sanctum is the right choice. It's lightweight, easy to configure, and handles SPA authentication and mobile token authentication cleanly. Passport is overkill unless you're building an OAuth2 server that issues tokens to third parties.
API Versioning From Day One
Always version your API: /api/v1/users. It costs nothing upfront and saves enormous pain when you need to make breaking changes later. Use route groups with version prefixes.
Use API Resources
Never return Eloquent models directly from API controllers. Use Laravel's API Resource classes to transform your data. This gives you a consistent response format and prevents accidentally leaking sensitive fields like passwords or internal IDs.
Standardize Error Responses
Every error response should have the same structure: { "message": "...", "errors": {...}, "code": 422 }. Handle this in a base controller or middleware so every error follows the contract.
Rate Limiting
Apply throttle middleware to all API routes. Laravel's built-in rate limiter supports per-user limits, which is far more useful than global IP-based limits for authenticated APIs.
Document Everything
Use Laravel Scribe or write a Postman collection. An undocumented API is an unusable API for any developer who joins the project later — including yourself six months from now.