backend-api-developmentlisted

# 🔧 Backend API Development Skill > **Philosophy:** APIs are contracts. Build them right the first time. ## When to Use Use this skill when: - Creating a new API endpoint - Building a new service/module - Refactoring existing API code - Adding new functionality to backend - Need to follow RESTful/GraphQL best practices **Do NOT use this skill when:** - Just fixing a small bug (use debugging skill) - Only modifying frontend (use frontend skill) - Database-only changes (use database skill) --- ## Prerequisites Before starting: - [ ] Requirements are clear (what the API should do) - [ ] Understand the existing architecture - [ ] Know the target stack (NestJS, Express, FastAPI, etc.) - [ ] Database schema exists (or will be created) --- ## Process ### Phase 1: DESIGN 📐 **Goal:** Design the API before writing code. **Steps:** 1. **Define the Resource** ```yaml resource: name: User description: Represents a platform user domain: authentication ``` 2. **Design Endpoints (REST)** ```yaml endpoints: - method: GET path: /users description: List all users query_params: [page, limit, search] response: User[] - method: GET path: /users/:id description: Get single user response: User - method: POST path: /users description: Create new user body: CreateUserDto response: User - method: PUT path: /users/:id description: