GraphQL API Development

Modern GraphQL APIs with Apollo Server, schema-first design, efficient data fetching with DataLoader, real-time subscriptions, and query complexity management. Build flexible, type-safe APIs that let clients request exactly what they need.

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NEXT-GENERATION GRAPHQL APIs

GraphQL revolutionizes API development by giving clients the power to request exactly the data they need—nothing more, nothing less. Unlike REST where you might need multiple endpoints or face over-fetching/under-fetching, GraphQL uses a single endpoint with a strongly-typed schema. Our GraphQL API development services include schema design, resolver optimization with DataLoader to solve N+1 query problems, real-time subscriptions for live updates, query complexity analysis to prevent abuse, and comprehensive Apollo Server configurations. Perfect for applications requiring flexible data queries, mobile apps with bandwidth constraints, or complex data relationships.

WHO IT'S FOR

Ideal for modern web applications, mobile apps, dashboard interfaces, content platforms, e-commerce sites with complex product relationships, and teams seeking a unified API layer over multiple data sources.

KEY BENEFITS

/Single endpoint for all data queries
/Clients request only needed fields
/Strongly-typed schema with auto-generated docs
/Real-time updates via WebSocket subscriptions
/DataLoader batching to solve N+1 query problem
/Query complexity limits to prevent abuse
/Built-in GraphQL Playground for testing
/Federation for microservices architecture
/Automatic type validation
/Introspection for schema exploration

GraphQL API Development

WHAT'S INCLUDED

Schema-First Design

GraphQL schema definition with types, queries, mutations, subscriptions, input types, enums, interfaces, unions, and custom scalars (DateTime, JSON, Upload).

Type System

Strong typing with SDL (Schema Definition Language), nullable vs non-nullable fields (!), list types ([User!]!), custom object types, and nested type relationships.

Resolver Implementation

Field-level resolvers, async data fetching, parent-child resolver chains, context injection for authentication, and resolver composition for code reuse.

DataLoader Batching

Batch and cache database queries, solve N+1 query problem, per-request caching, keyed data loading, and optimize performance for nested queries.

Query Complexity Limits

Calculate query depth and breadth, set complexity scores per field, reject overly complex queries, prevent resource exhaustion, and custom cost analysis.

Apollo Server Setup

Apollo Server Express integration, schema stitching, federated gateway, context builders, custom directives, and plugin system for logging/caching.

Authentication & Authorization

JWT token validation in context, directive-based auth (@auth, @hasRole), resolver-level permissions, field-level security, and scope-based access control.

Real-Time Subscriptions

WebSocket-based subscriptions, PubSub implementation with Redis, live data updates, subscription filters, and connection management for scalability.

Error Handling

Structured error responses, custom error classes (ValidationError, AuthenticationError), error extensions with codes, formatted errors for clients, and detailed error logging.

Pagination Strategies

Cursor-based pagination (Relay spec), offset-based pagination, infinite scroll support, connection edges and nodes, pageInfo metadata, and hasNextPage flags.

GraphQL Playground

Interactive schema explorer, query testing interface, auto-complete based on schema, query history, request headers configuration, and documentation panel.

Performance Optimization

Query caching with Apollo Cache, persisted queries for production, Redis caching for resolvers, response compression, and CDN integration for static queries.

HOW WE DO IT

Schema Design

Define GraphQL schema with types, queries, mutations, and subscriptions. Design type relationships, input types, and custom directives for business logic.

Apollo Server Setup

Initialize Apollo Server with Express, configure context for authentication, set up DataLoader instances, and enable GraphQL Playground for development.

Resolver Development

Implement resolvers for each field, integrate DataLoader for batched queries, handle authentication and authorization, and optimize database queries.

Subscriptions & Real-Time

Set up WebSocket transport, implement PubSub with Redis, create subscription resolvers for live updates, and test real-time data synchronization.

Security & Limits

Implement query complexity analysis, add depth limits, configure rate limiting, validate input types, and set up authentication middleware with JWT.

Testing & Deployment

Write integration tests for queries and mutations, test subscriptions, perform load testing, deploy to production with PM2 or Docker, and monitor with Apollo Studio.

TOOLS & TECHNOLOGIES

Apollo Server

GraphQL.js

Node.js

TypeScript

DataLoader

Redis

PostgreSQL

MongoDB

Prisma

TypeORM

JWT

WebSocket

Express

Apollo Studio

GraphQL Playground

Jest

Docker

PM2

Apollo Federation

GraphQL Shield

GraphQL Upload

Sentry

AWS AppSync

Hasura

RELATED SERVICES

READY TO GET STARTED?

Let's discuss your project and see how we can help bring your vision to life.

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CODE EXAMPLES

GRAPHQL SCHEMA

# GraphQL Schema Definition
type User {
  id: ID!
  email: String!
  name: String!
  posts: [Post!]!
  createdAt: DateTime!
}

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

type Comment {
  id: ID!
  content: String!
  author: User!
  post: Post!
  createdAt: DateTime!
}

type AuthPayload {
  token: String!
  user: User!
}

input CreatePostInput {
  title: String!
  content: String!
  published: Boolean
}

input UpdatePostInput {
  title: String
  content: String
  published: Boolean
}

type Query {
  me: User
  user(id: ID!): User
  users(
    page: Int = 1
    limit: Int = 10
    role: String
  ): UserConnection!
  post(id: ID!): Post
  posts(published: Boolean): [Post!]!
}

type Mutation {
  signup(email: String!, password: String!, name: String!): AuthPayload!
  login(email: String!, password: String!): AuthPayload!
  createPost(input: CreatePostInput!): Post!
  updatePost(id: ID!, input: UpdatePostInput!): Post!
  deletePost(id: ID!): Post!
  createComment(postId: ID!, content: String!): Comment!
}

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

type UserConnection {
  edges: [UserEdge!]!
  pageInfo: PageInfo!
  totalCount: Int!
}

type UserEdge {
  node: User!
  cursor: String!
}

type PageInfo {
  hasNextPage: Boolean!
  hasPreviousPage: Boolean!
  startCursor: String
  endCursor: String
}

scalar DateTime

APOLLO SERVER SETUP

// Apollo Server with DataLoader
import { ApolloServer } from 'apollo-server-express';
import DataLoader from 'dataloader';
import jwt from 'jsonwebtoken';
import { typeDefs } from './schema';
import { resolvers } from './resolvers';

// DataLoader for batching
const createLoaders = () => ({
  userLoader: new DataLoader(async (userIds) => {
    const users = await User.findAll({
      where: { id: userIds }
    });
    const userMap = users.reduce((map, user) => {
      map[user.id] = user;
      return map;
    }, {});
    return userIds.map(id => userMap[id]);
  }),

  postsByAuthorLoader: new DataLoader(async (authorIds) => {
    const posts = await Post.findAll({
      where: { authorId: authorIds }
    });
    const postMap = authorIds.reduce((map, id) => {
      map[id] = [];
      return map;
    }, {});
    posts.forEach(post => {
      postMap[post.authorId].push(post);
    });
    return authorIds.map(id => postMap[id] || []);
  })
});

// Context with authentication
const getContext = ({ req }) => {
  const token = req.headers.authorization?.replace('Bearer ', '');
  let user = null;

  if (token) {
    try {
      user = jwt.verify(token, process.env.JWT_SECRET);
    } catch (err) {
      console.error('Invalid token');
    }
  }

  return {
    user,
    loaders: createLoaders()
  };
};

// Apollo Server configuration
const server = new ApolloServer({
  typeDefs,
  resolvers,
  context: getContext,
  playground: process.env.NODE_ENV !== 'production',
  introspection: true,
  formatError: (err) => ({
    message: err.message,
    code: err.extensions?.code || 'INTERNAL_SERVER_ERROR',
    path: err.path
  }),
  plugins: [
    {
      requestDidStart() {
        return {
          didEncounterErrors({ errors }) {
            console.error(errors);
          }
        };
      }
    }
  ]
});

server.applyMiddleware({ app, path: '/graphql' });

RESOLVERS WITH DATALOADER

// GraphQL Resolvers with DataLoader
import { AuthenticationError, UserInputError } from 'apollo-server-express';
import bcrypt from 'bcrypt';
import jwt from 'jsonwebtoken';

export const resolvers = {
  Query: {
    me: (_, __, { user }) => {
      if (!user) throw new AuthenticationError('Not authenticated');
      return User.findByPk(user.id);
    },

    users: async (_, { page = 1, limit = 10, role }, { user }) => {
      if (!user) throw new AuthenticationError('Not authenticated');

      const offset = (page - 1) * limit;
      const where = role ? { role } : {};

      const { rows, count } = await User.findAndCountAll({
        where,
        limit,
        offset,
        order: [['createdAt', 'DESC']]
      });

      return {
        edges: rows.map((node, index) => ({
          node,
          cursor: Buffer.from(`${offset + index}`).toString('base64')
        })),
        pageInfo: {
          hasNextPage: count > offset + limit,
          hasPreviousPage: page > 1,
          startCursor: rows[0] ? Buffer.from(`${offset}`).toString('base64') : null,
          endCursor: rows[rows.length - 1]
            ? Buffer.from(`${offset + rows.length - 1}`).toString('base64')
            : null
        },
        totalCount: count
      };
    }
  },

  Mutation: {
    createPost: async (_, { input }, { user }) => {
      if (!user) throw new AuthenticationError('Not authenticated');

      const post = await Post.create({
        ...input,
        authorId: user.id
      });

      // Publish to subscription
      pubsub.publish('POST_CREATED', { postCreated: post });

      return post;
    }
  },

  User: {
    // Use DataLoader to batch posts query
    posts: (parent, _, { loaders }) => {
      return loaders.postsByAuthorLoader.load(parent.id);
    }
  },

  Post: {
    // Use DataLoader to batch author query
    author: (parent, _, { loaders }) => {
      return loaders.userLoader.load(parent.authorId);
    },

    comments: (parent) => {
      return Comment.findAll({ where: { postId: parent.id } });
    }
  },

  Subscription: {
    postCreated: {
      subscribe: () => pubsub.asyncIterator(['POST_CREATED'])
    }
  }
};

GraphQL API Development

NEXT-GENERATION GRAPHQL APIs

WHO IT'S FOR

KEY BENEFITS

WHAT'S INCLUDED

Schema-First Design

Type System

Resolver Implementation

DataLoader Batching

Query Complexity Limits

Apollo Server Setup

Authentication & Authorization

Real-Time Subscriptions

Error Handling

Pagination Strategies

GraphQL Playground

Performance Optimization

HOW WE DO IT

Schema Design

Apollo Server Setup

Resolver Development

Subscriptions & Real-Time

Security & Limits

Testing & Deployment

TOOLS & TECHNOLOGIES

RELATED SERVICES

RESTful API Development

WebSocket Real-Time APIs

API Gateway Management

Microservices Architecture

Database Optimization

API Integration Services

READY TO GET STARTED?

CODE EXAMPLES

GRAPHQL SCHEMA

APOLLO SERVER SETUP

RESOLVERS WITH DATALOADER