REST (Representational State Transfer) is the standard for web APIs.
Design your API around resources, not actions.
GET /users // Get all users
GET /users/1 // Get user with id 1
POST /users // Create new user
PUT /users/1 // Update user 1
DELETE /users/1 // Delete user 1
Use appropriate HTTP status codes:
Version your API for backward compatibility:
GET /api/v1/users
GET /api/v2/users
Provide clear documentation with examples.
Use consistent naming, proper authentication, and rate limiting.