GraphQL Server for Express, Connect, Hapi and Koa

GraphQL Server is a community-maintained open-source GraphQL server. It works with all Node.js HTTP server frameworks: Express, Connect, Hapi and Koa.

Principles

GraphQL Server is built with the following principles in mind:

• By the community, for the community: GraphQL Server's development is driven by the needs of developers
• Simplicity: by keeping things simple, GraphQL Server is easier to use, easier to contribute to, and more secure
• Performance: GraphQL Server is well-tested and production-ready - no modifications needed

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

Getting started

GraphQL Server is super easy to set up. Just npm install graphql-server-<variant>, write a GraphQL schema, and then use one of the following snippets to get started. For more info, read the GraphQL Server docs.

Installation

Just run npm install --save graphql-server-<variant> and you're good to go!

where variant is one of the following:

• express
• koa
• hapi

Express

import express from 'express';
import bodyParser from 'body-parser';
import { graphqlExpress } from 'graphql-server-express';

const myGraphQLSchema = // ... define or import your schema here!
const PORT = 3000;

var app = express();

// bodyParser is needed just for POST.
app.use('/graphql', bodyParser.json(), graphqlExpress({ schema: myGraphQLSchema }));

app.listen(PORT);

Connect

import connect from 'connect';
import bodyParser from 'body-parser';
import { graphqlConnect } from 'graphql-server-express';
import http from 'http';

const PORT = 3000;

var app = connect();

// bodyParser is needed just for POST.
app.use('/graphql', bodyParser.json());
app.use('/graphql', graphqlConnect({ schema: myGraphQLSchema }));

http.createServer(app).listen(PORT);

Hapi

Now with the Hapi plugins graphqlHapi and graphiqlHapi you can pass a route object that includes options to be applied to the route. The example below enables CORS on the /graphql route.

import hapi from 'hapi';
import { graphqlHapi } from 'graphql-server-hapi';

const server = new hapi.Server();

const HOST = 'localhost';
const PORT = 3000;

server.connection({
    host: HOST,
    port: PORT,
});

server.register({
    register: graphqlHapi,
    options: {
      path: '/graphql',
      graphqlOptions: {
        schema: myGraphQLSchema,
      },
      route: {
        cors: true
      }
    },
});

server.start((err) => {
    if (err) {
        throw err;
    }
    console.log(`Server running at: ${server.info.uri}`);
});

Koa

import koa from 'koa'; // koa@2
import koaRouter from 'koa-router'; // koa-router@next
import koaBody from 'koa-bodyparser'; // koa-bodyparser@next
import { graphqlKoa } from 'graphql-server-koa';

const app = new koa();
const router = new koaRouter();
const PORT = 3000;

// koaBody is needed just for POST.
app.use(koaBody());

router.post('/graphql', graphqlKoa({ schema: myGraphQLSchema }));
router.get('/graphql', graphqlKoa({ schema: myGraphQLSchema }));

app.use(router.routes());
app.use(router.allowedMethods());
app.listen(PORT);

GraphQL Server can be configured with an options object with the the following fields:

• schema: the GraphQLSchema to be used
• context: the context value passed to resolvers during GraphQL execution
• rootValue: the value passed to the first resolve function
• formatError: a function to apply to every error before sending the response to clients
• validationRules: additional GraphQL validation rules to be applied to client-specified queries
• formatParams: a function applied for each query in a batch to format parameters before execution
• formatResponse: a function applied to each response after execution

All options except for schema are optional.

Whitelisting

The formatParams function can be used in combination with the OperationStore to enable whitelisting.

const store = new OperationStore(Schema);
store.put('query testquery{ testString }');
graphqlOptions = {
    schema: Schema,
    formatParams(params) {
        params['query'] = store.get(params.operationName);
        return params;
    },
};

Differences to express-graphql

GraphQL Server and express-graphql are more or less the same thing (GraphQL middleware for Node.js), but there are a few key differences:

• express-graphql works with Express and Connect, GraphQL Server supports Express, Connect, Hapi and Koa.
• express-graphql's main goal is to be a minimal reference implementation, whereas GraphQL Server's goal is to be a complete production-ready GraphQL server.
• Compared to express-graphql, GraphQL Server has a simpler interface and supports exactly one way of passing queries.
• GraphQL Server separates serving GraphiQL (GraphQL UI) from responding to GraphQL requests.
• express-graphql contains code for parsing HTTP request bodies, GraphQL Server leaves that to standard packages like body-parser.
• Includes an OperationStore to easily manage whitelisting
• Built with TypeScript

Despite express-graphql being a reference implementation, GraphQL Server is actually easier to understand and more modular than express-graphql.

That said, GraphQL Server is heavily inspired by express-graphql (it's the reference implementation after all). Rather than seeing the two as competing alternatives, we think that they both have separate roles in the GraphQL ecosystem: express-graphql is a reference implementation, and GraphQL Server is a GraphQL server to be used in production and evolve quickly with the needs of the community. Over time, express-graphql can adopt those features of GraphQL Server that have proven their worth and become established more widely.

GraphQL Server Development

If you want to develop apollo server locally you must follow the following instructions:

• Fork this repository

• Install the GraphQL Server project in your computer

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

• Install your local GraphQL Server in other App

cd ~/myApp
npm link graphql-server-<variant>