apollo-server/README.md

# GraphQL Server for Express, Connect, Hapi and Koa

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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](./CONTRIBUTING.md), take a look at the [roadmap](./ROADMAP.md) 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](http://dev.apollodata.com/tools/graphql-server/index.html).

### 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

```js
import express from 'express';
import { graphqlExpress } from 'graphql-server-express';

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

var app = express();

app.use('/graphql', bodyParser.json(), graphqlExpress({ schema: myGraphQLSchema }));

app.listen(PORT);
```

### Connect
```js
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();

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.

```js
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
```js
import koa from 'koa';
import koaRouter from 'koa-router';
import { graphqlKoa } from 'graphql-server-koa';

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

app.use(koaBody());

router.post('/graphql', graphqlKoa({ schema: myGraphQLSchema }));
app.use(router.routes());
app.use(router.allowedMethods());
app.listen(PORT);
```

## Options

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.

```js
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>
```