graphql

GraphQL API Design

Instructions

1. Assess the API need: Flexible queries, real-time data, or complex relationships.
2. Follow GraphQL conventions:
   • Schema-first or code-first approach
   • Proper type definitions
   • N+1 query prevention with DataLoader
   • Input validation
3. Provide complete examples: Include schema, resolvers, and client queries.
4. Guide on best practices: Pagination, error handling, authentication.

Schema Design

Basic Types

type User {
  id: ID!
  email: String!
  name: String!
  avatar: String
  role: Role!
  posts: [Post!]!
  createdAt: DateTime!
  updatedAt: DateTime!
}

type Post {
  id: ID!
  title: String!
  content: String!
  published: Boolean!
  author: User!
  comments: [Comment!]!
  tags: [Tag!]!
  createdAt: DateTime!
}

enum Role {
  USER
  ADMIN
  MODERATOR
}

scalar DateTime

Input Types

input CreateUserInput {
  email: String!
  name: String!
  password: String!
  role: Role = USER
}

input UpdateUserInput {
  email: String
  name: String
  avatar: String
}

input PostFilters {
  published: Boolean
  authorId: ID
  tags: [String!]
  search: String
}

Queries and Mutations

type Query {
  # Single resource
  user(id: ID!): User
  post(id: ID!): Post

  # Collections with pagination
  users(
    first: Int
    after: String
    filter: UserFilter
  ): UserConnection!

  posts(
    first: Int
    after: String
    filter: PostFilters
    orderBy: PostOrderBy
  ): PostConnection!

  # Current user
  me: User
}

type Mutation {
  # User mutations
  createUser(input: CreateUserInput!): CreateUserPayload!
  updateUser(id: ID!, input: UpdateUserInput!): UpdateUserPayload!
  deleteUser(id: ID!): DeleteUserPayload!

  # Auth mutations
  login(email: String!, password: String!): AuthPayload!
  logout: Boolean!

  # Post mutations
  createPost(input: CreatePostInput!): Post!
  updatePost(id: ID!, input: UpdatePostInput!): Post!
  publishPost(id: ID!): Post!
  deletePost(id: ID!): Boolean!
}

type Subscription {
  postCreated: Post!
  commentAdded(postId: ID!): Comment!
}