apollo-server/README.md

# GraphQL Server for Express, Connect, Hapi, Koa, and more

Also supports: Restify, Micro, Azure Functions, AWS Lambda and Adonis Framework

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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 for more! Apollo Server works with any GraphQL schema built with [GraphQL.js](https://github.com/graphql/graphql-js), so you can build your schema with that directly or with a convenience library such as [graphql-tools](https://www.apollographql.com/docs/graphql-tools/).

## Documentation

[Read the docs!](https://www.apollographql.com/docs/apollo-server/)

## Principles

Apollo Server is built with the following principles in mind:

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

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

## Getting started

Apollo Server is super easy to set up. Just `npm install apollo-server-<variant>`, write a GraphQL schema, and then use one of the following snippets to get started. For more info, read the [Apollo Server docs](https://www.apollographql.com/docs/apollo-server/). To experiment a live example of Apollo Server, create an [Apollo Launchpad](https://launchpad.graphql.com). Downloading the pad will provide you a local Apollo Server project.

### Installation

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

where `<variant>` is one of the following:

* `express`
* `koa`
* `hapi`
* `restify`
* `lambda`
* `micro`
* `azure-functions`
* `adonis`

### Express

```js
import express from 'express';
import bodyParser from 'body-parser';
import { graphqlExpress, graphiqlExpress } from 'apollo-server-express';

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

const app = express();

// bodyParser is needed just for POST.
app.use('/graphql', bodyParser.json(), graphqlExpress({ schema: myGraphQLSchema }));
app.get('/graphiql', graphiqlExpress({ endpointURL: '/graphql' })); // if you want GraphiQL enabled

app.listen(PORT);
```

### Connect

```js
import connect from 'connect';
import bodyParser from 'body-parser';
import query from 'connect-query';
import { graphqlConnect } from 'apollo-server-express';
import http from 'http';

const PORT = 3000;

const app = connect();

// bodyParser is only needed for POST.
app.use('/graphql', bodyParser.json());
// query is only needed for GET.
app.use('/graphql', query());
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.

The code below requires Hapi 17 or higher.

```js
import Hapi from 'hapi';
import { graphqlHapi } from 'apollo-server-hapi';

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

async function StartServer() {
  const server = new Hapi.server({
    host: HOST,
    port: PORT,
  });

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

  try {
    await server.start();
  } catch (err) {
    console.log(`Error while starting server: ${err.message}`);
  }

  console.log(`Server running at: ${server.info.uri}`);
}

StartServer();
```

### Koa

```js
import koa from 'koa'; // koa@2
import koaRouter from 'koa-router'; // koa-router@next
import koaBody from 'koa-bodyparser'; // koa-bodyparser@next
import { graphqlKoa, graphiqlKoa } from 'apollo-server-koa';

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

// koaBody is needed just for POST.
router.post('/graphql', koaBody(), graphqlKoa({ schema: myGraphQLSchema }));
router.get('/graphql', graphqlKoa({ schema: myGraphQLSchema }));

router.get('/graphiql', graphiqlKoa({ endpointURL: '/graphql' }));

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

### Restify

```js
import restify from 'restify';
import { graphqlRestify, graphiqlRestify } from 'apollo-server-restify';

const PORT = 3000;

const server = restify.createServer({
  title: 'Apollo Server',
});

const graphQLOptions = { schema: myGraphQLSchema };

server.use(restify.plugins.bodyParser());
server.use(restify.plugins.queryParser());

server.post('/graphql', graphqlRestify(graphQLOptions));
server.get('/graphql', graphqlRestify(graphQLOptions));

server.get('/graphiql', graphiqlRestify({ endpointURL: '/graphql' }));

server.listen(PORT, () => console.log(`Listening on ${PORT}`));
```

### AWS Lambda

Lambda function should be run with [Node.js 4.3 or v6.1](https://docs.aws.amazon.com/lambda/latest/dg/nodejs-prog-model-using-old-runtime.html#nodejs-prog-model-runtime-support-policy). Requires an API Gateway with Lambda Proxy Integration.

```js
var server = require('apollo-server-lambda');

exports.handler = server.graphqlLambda({ schema: myGraphQLSchema });
```

### ZEIT Micro

Requires the [Micro](https://github.com/zeit/micro) module

```js
const server = require('apollo-server-micro');

module.exports = server.microGraphql({ schema: myGraphQLSchema });
```

### Adonis Framework

```js
// start/routes.js
const { graphqlAdonis } = require('apollo-server-adonis');

const Route = use('Route');

Route.post('/graphql', graphqlAdonis({ schema: myGraphQLSchema }));
Route.get('/graphql', graphqlAdonis({ schema: myGraphQLSchema }));
```

## Options

Apollo Server can be configured with an options object with 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
* **tracing**: when set to true, collect and expose trace data in the [Apollo Tracing format](https://github.com/apollographql/apollo-tracing)
* **logFunction**: a function called for logging events such as execution times
* **fieldResolver**: a custom default field resolver
* **debug**: a boolean that will print additional debug logging if execution errors occur
* **cacheControl**: when set to true, enable built-in support for Apollo Cache Control

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;
  },
};
```

## Comparison with `express-graphql`

Both Apollo Server and [`express-graphql`](https://github.com/graphql/express-graphql) are GraphQL servers for Node.js, built on top of the [`graphql-js` reference implementation](https://github.com/graphql/graphql-js), but there are a few key differences:

* `express-graphql` works with Express and Connect, Apollo Server supports Express, Connect, Hapi, Koa and Restify.
* Compared to `express-graphql`, Apollo Server has a simpler interface and supports exactly one way of passing queries.
* Apollo Server separates serving [GraphiQL](https://github.com/graphql/graphiql) (an in-browser IDE for exploring GraphQL) from responding to GraphQL requests.
* `express-graphql` contains code for parsing HTTP request bodies, Apollo Server leaves that to standard packages like body-parser.
* Apollo Server includes an `OperationStore` to easily manage whitelisting.
* Apollo Server is built with TypeScript.

### application/graphql requests

`express-graphql` supports the `application/graphql` Content-Type for requests, which is an alternative to `application/json` request with only the query part sent as text. In the same way that we use `bodyParser.json` to parse `application/json` requests for apollo-server, we can use `bodyParser.text` plus one extra step in order to also parse `application/graphql` requests. Here's an example for Express:

```js
import express from 'express';
import bodyParser from 'body-parser';
import { graphqlExpress } from 'apollo-server-express';

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

const helperMiddleware = [
    bodyParser.json(),
    bodyParser.text({ type: 'application/graphql' }),
    (req, res, next) => {
        if (req.is('application/graphql')) {
            req.body = { query: req.body };
        }
        next();
    }
];

express()
    .use('/graphql', ...helperMiddleware, graphqlExpress({ schema: myGraphQLSchema }))
    .listen(3000);
```

## Apollo Server Development

If you want to develop Apollo Server locally you must follow the following instructions:

* Fork this repository

* Install the Apollo Server project in your computer

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

* Install your local Apollo Server in other App

```
cd ~/myApp
npm link apollo-server-<variant>
```