apollo-server-core

What is apollo-server-core?

The apollo-server-core package is a core library for Apollo Server, which is a community-driven, open-source GraphQL server. It works with various Node.js HTTP server frameworks and provides features necessary to run a GraphQL server, such as schema definition, request processing, and query execution. It's designed to simplify the process of building efficient, scalable GraphQL APIs.

What are apollo-server-core's main functionalities?

Schema Definition

Allows defining a GraphQL schema using the GraphQL schema language. This is the first step in setting up a GraphQL server.

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

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

const server = new ApolloServer({ typeDefs });

Resolvers Implementation

Defines the technique for fetching the types defined in the schema. This code sample shows how to implement a simple resolver.

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

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

Server Setup and Running

Illustrates how to start the Apollo Server and listen on a port. It logs the URL where the server can be accessed.

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

Integrating with Middleware

Shows how to integrate Apollo Server with an Express application using `apollo-server-express`, demonstrating Apollo Server's flexibility with HTTP server frameworks.

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

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

server.applyMiddleware({ app });

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

Other packages similar to apollo-server-core

express-graphql

An Express middleware created by the GraphQL team. It allows the creation of GraphQL servers with Express. Compared to apollo-server-core, it is more tightly coupled with Express and does not offer as extensive a feature set or plugin ecosystem as Apollo Server.

graphql-yoga

A fully-featured GraphQL Server with focus on easy setup, performance & great developer experience. It is built on top of Apollo Server and other libraries, offering a more opinionated setup with sensible defaults.

graphql-helix

A highly flexible and lightweight tool for building GraphQL HTTP servers. Unlike apollo-server-core, GraphQL Helix is not tied to any specific HTTP server framework and focuses on providing a low-level API for handling GraphQL requests.

README

apollo-server-core

This is the core module of the Apollo community GraphQL Server. Read the docs.