graphql-yoga

Fully-featured GraphQL Server with focus on easy setup, performance & great developer experience

Overview

• Easiest way to run a GraphQL server: Sensible defaults & includes everything you need with minimal setup.
• Includes Subscriptions: Built-in support for GraphQL subscriptions using WebSockets.
• Compatible: Works with all GraphQL clients (Apollo, Relay...) and fits seamless in your GraphQL workflow.

graphql-yoga is based on the following libraries & tools:

• express/apollo-server: Performant, extensible web server framework
• graphql-subscriptions/subscriptions-transport-ws: GraphQL subscriptions server
• graphql.js/graphql-tools: GraphQL engine & schema helpers
• graphql-playground: Interactive GraphQL IDE

Features

• GraphQL spec-compliant
• File upload
• GraphQL Subscriptions
• TypeScript typings
• GraphQL Playground
• Extensible via Express middleware
• Schema directives
• Apollo Tracing
• Accepts both application/json and application/graphql content-types
• Runs everywhere: Can be deployed via now, up, AWS Lambda, Heroku etc.
• Supports middleware out of the box.

Install

yarn add graphql-yoga

Usage

Quickstart (Hosted demo)

import { GraphQLServer } from 'graphql-yoga'
// ... or using `require()`
// const { GraphQLServer } = require('graphql-yoga')

const typeDefs = `
  type Query {
    hello(name: String): String!
  }
`

const resolvers = {
  Query: {
    hello: (_, { name }) => `Hello ${name || 'World'}`,
  },
}

const server = new GraphQLServer({ typeDefs, resolvers })
server.start(() => console.log('Server is running on localhost:4000'))

> To get started with graphql-yoga, follow the instructions in the READMEs of the examples.

API

GraphQLServer

constructor(props: Props): GraphQLServer

The props argument accepts the following fields:

> (*) There are two major ways of providing the schema information to the constructor: > > 1. Provide typeDefs and resolvers and omit the schema, in this case graphql-yoga will construct the GraphQLSchema instance using makeExecutableSchema from graphql-tools. > 2. Provide the schema directly and omit typeDefs and resolvers.

> (**) Notice that the req argument is an object of the shape { request, response, connection } which either carries a request: Request property (when it's a Query/Mutation resolver), response: Response property (when it's a Query/Mutation resolver), or a connection: SubscriptionOptions property (when it's a Subscription resolver). Request is imported from Express.js. Response is imported from Express.js aswell. SubscriptionOptions is from the graphql-subscriptions package. SubscriptionOptions are getting the connectionParams automatically injected under SubscriptionOptions.context.[CONNECTION_PARAMETER_NAME]

Here is example of creating a new server:

const typeDefs = `
  type Query {
    hello(name: String): String!
  }
`

const resolvers = {
  Query: {
    hello: (_, { name }) => `Hello ${name || 'World'}`,
  },
}

const server = new GraphQLServer({ typeDefs, resolvers })

start(options: Options, callback: ((options: Options) => void) = (() => null)): Promise

Once your GraphQLServer is instantiated, you can call the start method on it. It takes two arguments: options, the options object defined above, and callback, a function that's invoked right before the server is started. As an example, the callback can be used to print information that the server has started.

The options object has the following fields:

Additionally, the options object exposes these apollo-server options:

const options = {
  port: 8000,
  endpoint: '/graphql',
  subscriptions: '/subscriptions',
  playground: '/playground',
}

server.start(options, ({ port }) =>
  console.log(
    `Server started, listening on port ${port} for incoming requests.`,
  ),
)

PubSub

See the original documentation in graphql-subscriptions.

mocking

Mocking the schema is straight forward, along wit

import { GraphqlServer, MockList } from 'graphql-yoga'

const typeDefs = `
  type Query {
    hello(name: String): String!
    listOfStrings: [String]
  }
`

const mocks = {
  Query: () => ({
    hello: () => 'Hello World',
    listOfStrings: () => new MockList([2, 6]),
  }),
}

const server = new GraphQLServer({ typeDefs, mocks })

Endpoints

Examples

There are three examples demonstrating how to quickly get started with graphql-yoga:

• hello-world: Basic setup for building a schema and allowing for a hello query.
• subscriptions: Basic setup for using subscriptions with a counter that increments every 2 seconds and triggers a subscription.
• fullstack: Fullstack example based on create-react-app demonstrating how to query data from graphql-yoga with Apollo Client 2.0.

Workflow

Once your graphql-yoga server is running, you can use GraphQL Playground out of the box – typically running on localhost:4000. (Read here for more information.)

Deployment

now

To deploy your graphql-yoga server with now, follow these instructions:

1. Download Now Desktop
2. Navigate to the root directory of your graphql-yoga server
3. Run now in your terminal

Heroku

To deploy your graphql-yoga server with Heroku, follow these instructions:

1. Download and install the Heroku Command Line Interface (previously Heroku Toolbelt)
2. Log in to the Heroku CLI with heroku login
3. Navigate to the root directory of your graphql-yoga server
4. Create the Heroku instance by executing heroku create
5. Deploy your GraphQL server by executing git push heroku master

up (Coming soon 🔜 )

AWS Lambda (Coming soon 🔜 )

FAQ

How does graphql-yoga compare to apollo-server and other tools?

As mentioned above, graphql-yoga is built on top of a variety of other packages, such as graphql.js, express and apollo-server. Each of these provides a certain piece of functionality required for building a GraphQL server.

Using these packages individually incurs overhead in the setup process and requires you to write a lot of boilerplate. graphql-yoga abstracts away the initial complexity and required boilerplate and lets you get started quickly with a set of sensible defaults for your server configuration.

graphql-yoga is like create-react-app for building GraphQL servers.

Can't I just setup my own GraphQL server using express and graphql.js?

graphql-yoga is all about convenience and a great "Getting Started" experience by abstracting away the complexity that comes when you're building your own GraphQL server from scratch. It's a pragmatic approach to bootstrap a GraphQL server, much like how create-react-app removes friction when first starting out with React.

Whenever the defaults of graphql-yoga are too tight a corset for you, you can simply eject from it and use the tooling it's built upon - there's no lock-in or any other kind of magic going on preventing you from doing this.

How to eject from the standard express setup?

The core value of graphql-yoga is that you don't have to write the boilerplate required to configure your express.js application. However, once you need to add more customized behaviour to your server, the default configuration provided by graphql-yoga might not suit your use case any more. For example, it might be the case that you want to add more custom middleware to your server, like for logging or error reporting.

For these cases, GraphQLServer exposes the express.Application directly via its express property:

server.express.use(myMiddleware())

Middleware can also be added specifically to the GraphQL endpoint route, by using:

server.express.post(server.options.endpoint, myMiddleware())

Any middleware you add to that route, will be added right before the apollo-server-express middleware.

Help & Community

Join our Slack community if you run into issues or have questions. We love talking to you!