apollo-server

What is apollo-server?

Apollo Server is a community-driven, open-source GraphQL server that works with any GraphQL schema. It is designed to be a self-contained GraphQL server that can be used with any Node.js HTTP server framework, such as Express, Koa, or Hapi.

What are apollo-server's main functionalities?

Creating a Basic GraphQL Server

This code sets up a basic Apollo Server with a single query type 'hello' that returns a string 'Hello world!'.

const { ApolloServer, gql } = require('apollo-server');

const typeDefs = gql`
  type Query {
    hello: String
  }
`;

const resolvers = {
  Query: {
    hello: () => 'Hello world!',
  },
};

const server = new ApolloServer({ typeDefs, resolvers });

server.listen().then(({ url }) => {
  console.log(`🚀  Server ready at ${url}`);
});

Integrating with Express

This code demonstrates how to integrate Apollo Server with an Express application.

const express = require('express');
const { ApolloServer, gql } = require('apollo-server-express');

const typeDefs = gql`
  type Query {
    hello: String
  }
`;

const resolvers = {
  Query: {
    hello: () => 'Hello world!',
  },
};

const server = new ApolloServer({ typeDefs, resolvers });

const app = express();
server.applyMiddleware({ app });

app.listen({ port: 4000 }, () =>
  console.log(`🚀 Server ready at http://localhost:4000${server.graphqlPath}`)
);

Adding Middleware for Authentication

This code adds middleware to the Apollo Server for authentication by checking the authorization header and adding the user to the context.

const { ApolloServer, gql } = require('apollo-server');

const typeDefs = gql`
  type Query {
    hello: String
  }
`;

const resolvers = {
  Query: {
    hello: (parent, args, context) => {
      if (!context.user) throw new Error('Not authenticated');
      return 'Hello world!';
    },
  },
};

const getUser = (token) => {
  // Mock function to get user from token
  return token ? { id: 1, name: 'John Doe' } : null;
};

const server = new ApolloServer({
  typeDefs,
  resolvers,
  context: ({ req }) => {
    const token = req.headers.authorization || '';
    const user = getUser(token);
    return { user };
  },
});

server.listen().then(({ url }) => {
  console.log(`🚀  Server ready at ${url}`);
});

Other packages similar to apollo-server

express-graphql

express-graphql is a middleware for Express that allows you to mount a GraphQL API server. It is simpler and more lightweight compared to Apollo Server, but it lacks some of the advanced features and integrations that Apollo Server offers.

graphql-yoga

graphql-yoga is a fully-featured GraphQL server that is based on Apollo Server and Express. It provides a more opinionated setup with built-in support for features like subscriptions, file uploads, and more. It is easier to get started with but may be less flexible than Apollo Server.

mercurius

mercurius is a GraphQL adapter for Fastify, a fast and low-overhead web framework for Node.js. It offers high performance and integrates well with the Fastify ecosystem, but it may not have as many built-in features as Apollo Server.

README

GraphQL Server for Express, Koa, Hapi, Lambda, and more.

Apollo Server is a community-maintained open-source GraphQL server. It works with pretty much all Node.js HTTP server frameworks, and we're happy to take PRs to add more! Apollo Server works with any GraphQL schema built with GraphQL.js--or define a schema's type definitions using schema definition language (SDL).

Read the documentation for information on getting started and many other use cases and follow the CHANGELOG for updates.

Principles

Apollo Server is built with the following principles in mind:

• By the community, for the community: Its development is driven by the needs of developers.
• Simplicity: By keeping things simple, it is more secure and easier to implement and contribute.
• Performance: It is well-tested and production-ready.

Anyone is welcome to contribute to Apollo Server, just read CONTRIBUTING.md, take a look at the roadmap and make your first PR!

Getting started

To get started with Apollo Server:

• Install with npm install apollo-server-<integration> graphql
• Write a GraphQL schema
• Use one of the following snippets

There are two ways to install Apollo Server:

• Standalone: For applications that do not require an existing web framework, use the apollo-server package.
• Integrations: For applications with a web framework (e.g. express, koa, hapi, etc.), use the appropriate Apollo Server integration package.

For more info, please refer to the Apollo Server docs.

Installation: Standalone

In a new project, install the apollo-server and graphql dependencies using:

npm install apollo-server graphql

Then, create an index.js which defines the schema and its functionality (i.e. resolvers):

const { ApolloServer, gql } = require('apollo-server');

// The GraphQL schema
const typeDefs = gql`
  type Query {
    "A simple type for getting started!"
    hello: String
  }
`;

// A map of functions which return data for the schema.
const resolvers = {
  Query: {
    hello: () => 'world',
  },
};

const server = new ApolloServer({
  typeDefs,
  resolvers,
});

server.listen().then(({ url }) => {
  console.log(`🚀 Server ready at ${url}`);
});

Due to its human-readability, we recommend using schema-definition language (SDL) to define a GraphQL schema--a GraphQLSchema object from graphql-js can also be specified instead of typeDefs and resolvers using the schema property:

const server = new ApolloServer({
  schema: ...
});

Finally, start the server using node index.js and go to the URL returned on the console.

For more details, check out the Apollo Server Getting Started guide and the fullstack tutorial.

For questions, the Apollo community forum is a great place to get help.

Installation: Integrations

While the standalone installation above can be used without making a decision about which web framework to use, the Apollo Server integration packages are paired with specific web frameworks (e.g. Express, Koa, hapi).

The following web frameworks have Apollo Server integrations, and each of these linked integrations has its own installation instructions and examples on its package README.md:

• Express (Most popular)
• Koa
• Hapi
• Fastify
• Amazon Lambda
• Micro
• Azure Functions
• Google Cloud Functions
• Cloudflare (Experimental)

Context

A request context is available for each request. When context is defined as a function, it will be called on each request and will receive an object containing a req property, which represents the request itself.

By returning an object from the context function, it will be available as the third positional parameter of the resolvers:

new ApolloServer({
  typeDefs,
  resolvers: {
    Query: {
      books: (parent, args, context, info) => {
        console.log(context.myProperty); // Will be `true`!
        return books;
      },
    }
  },
  context: async ({ req }) => {
    return {
      myProperty: true
    };
  },
})

Documentation

The Apollo Server documentation contains additional details on how to get started with GraphQL and Apollo Server.

The raw Markdown source of the documentation is available within the docs/ directory of this monorepo--to contribute, please use the Edit on GitHub buttons at the bottom of each page.

Development

If you wish to develop or contribute to Apollo Server, we suggest the following:

• Fork this repository

• Install the Apollo Server project on your computer

git clone https://github.com/[your-user]/apollo-server
cd apollo-server
npm install
cd packages/apollo-server-<integration>/
npm link

• Install your local Apollo Server in the other App

cd ~/myApp
npm link apollo-server-<integration>

Community

Are you stuck? Want to contribute? Come visit us in the Apollo community forum!

Maintainers

• @abernix (Apollo)