GET    /users          # List users
POST   /users          # Create user
GET    /users/:id      # Get user
PUT    /users/:id      # Update user
DELETE /users/:id      # Delete user
GET    /users/:id/posts  # User's posts

{
  "data": {
    "id": "123",
    "type": "user",
    "attributes": {
      "name": "John",
      "email": "john@example.com"
    }
  },
  "meta": {
    "requestId": "abc-123"
  }
}

{
  "error": {
    "code": "VALIDATION_ERROR",
    "message": "Invalid input",
    "details": [
      {
        "field": "email",
        "message": "Invalid email format"
      }
    ]
  }
}

GET /users?page=2&limit=20

Response:
{
  "data": [...],
  "pagination": {
    "page": 2,
    "limit": 20,
    "total": 100,
    "totalPages": 5
  }
}

type User {
  id: ID!
  name: String!
  email: String!
  posts: [Post!]!
}

type Query {
  user(id: ID!): User
  users(limit: Int, offset: Int): [User!]!
}

type Mutation {
  createUser(input: CreateUserInput!): User!
  updateUser(id: ID!, input: UpdateUserInput!): User!
}

input CreateUserInput {
  name: String!
  email: String!
}

type Mutation {
  createUser(input: CreateUserInput!): CreateUserPayload!
}

type CreateUserPayload {
  user: User
  errors: [Error!]!
}

/api/v1/users
/api/v2/users

Accept: application/vnd.api+json; version=2