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 frameworkgraphql-subscriptions
/subscriptions-transport-ws
: GraphQL subscriptions servergraphql.js
/graphql-tools
: GraphQL engine & schema helpersgraphql-playground
: Interactive GraphQL IDE
Features
- GraphQL spec-compliant
- File upload
- GraphQL Subscriptions
- TypeScript typings
- GraphQL Playground
- Extensible via Express middlewares
- Apollo Tracing
- Accepts both
application/json
andapplication/graphql
content-type - Runs everywhere: Can be deployed via
now
,up
, AWS Lambda, Heroku etc
Install
yarn add graphql-yoga
Usage
Hosted demo)
Quickstart (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:
Key | Type | Default | Note |
---|---|---|---|
typeDefs |
String | null |
Contains GraphQL type definitions in SDL or file path to type definitions (required if schema is not provided *) |
resolvers |
Object | null |
Contains resolvers for the fields specified in typeDefs (required if schema is not provided *) |
schema |
Object | null |
An instance of GraphQLSchema (required if typeDefs and resolvers are not provided *) |
context |
Object or Function | {} |
Contains custom data being passed through your resolver chain. This can be passed in as an object, or as a Function with the signature (req: ContextParameters) => any ** |
(*) There are two major ways of providing the schema information to the
constructor
:
- Provide
typeDefs
andresolvers
and omit theschema
, in this casegraphql-yoga
will construct theGraphQLSchema
instance usingmakeExecutableSchema
fromgraphql-tools
.- Provide the
schema
directly and omittypeDefs
andresolvers
.
(**) Notice that the
req
argument is an object of the shape{ request, connection }
which either carries arequest: Request
property (in case it's aQuery
/Mutation
resolver) or aconnection: SubscriptionOptions
property (in case it's aSubscription
resolver).Request
is imported from Express.js.SubscriptionOptions
is from thegraphql-subscriptions
package.SubscriptionOptions
are getting the connectionParams automatically injected underSubscriptionOptions.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<void>
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 was now started.
The options
object has the following fields:
Key | Type | Default | Note |
---|---|---|---|
cors |
Object | null |
Contains configuration options for cors |
tracing |
Boolean or String | 'http-header' |
Indicates whether Apollo Tracing should be en- or disabled for your server (if a string is provided, accepted values are: 'enabled' , 'disabled' , 'http-header' ) |
port |
Number | 4000 |
Determines the port your server will be listening on (note that you can also specify the port by setting the PORT environment variable) |
endpoint |
String | '/' |
Defines the HTTP endpoint of your server |
subscriptions |
String or false |
'/' |
Defines the subscriptions (websocket) endpoint for your server; setting to false disables subscriptions completely |
playground |
String or false |
'/' |
Defines the endpoint where you can invoke the Playground; setting to false disables the playground endpoint |
uploads |
Object or false |
null |
Provides information about upload limits; the object can have any combination of the following three keys: maxFieldSize , maxFileSize , maxFiles ; each of these have values of type Number; setting to false disables file uploading |
Additionally, the options
object exposes these apollo-server
options:
Key | Type | Note |
---|---|---|
cacheControl |
Boolean | Enable extension that returns Cache Control data in the response |
formatError |
Number | A function to apply to every error before sending the response to clients |
logFunction |
LogFunction | A function called for logging events such as execution times |
rootValue |
any | RootValue passed to GraphQL execution |
validationRules |
Array of functions | DAdditional GraphQL validation rules to be applied to client-specified queries |
fieldResolver |
GraphQLFieldResolver | Provides information about upload limits; the object can have any combination of the following three keys: maxFieldSize , maxFileSize , maxFiles ; each of these have values of type Number; setting to false disables file uploading |
formatParams |
Function | A function applied for each query in a batch to format parameters before execution |
formatResponse |
Function | A function applied to each response after execution |
debug |
boolean | Print additional debug logging if execution errors occur |
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
.
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 subscriptions.
- fullstack: Fullstack example based on
create-react-app
demonstrating how to query data fromgraphql-yoga
with Apollo Client 2.0.
Workflow
Once your graphql-yoga
server is running, you can use GraphQL Playground out of the box โ typically running on localhost:4000
. (Read here for more information.)
Deployment
now
To deploy your graphql-yoga
server with now
, follow these instructions:
- Download Now Desktop
- Navigate to the root directory of your
graphql-yoga
server - Run
now
in your terminal
Heroku
To deploy your graphql-yoga
server with Heroku, follow these instructions:
- Download and install the Heroku Command Line Interface (previously Heroku Toolbelt)
- Log In to the Heroku CLI with
heroku login
- Navigate to the root directory of your
graphql-yoga
server - Create the Heroku instance by executing
heroku create
- Deploy your GraphQL server by executing
git push heroku master
up
(Coming soon ๐ )
๐ )
AWS Lambda (Coming soon FAQ
graphql-yoga
compare to apollo-server
and other tools?
How does 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 provide 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 let's 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.
express
and graphql.js
?
Can't I just setup my own GraphQL server using 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 from scratch. It's a pragmatic approach to bootstrap a GraphQL server, much like create-react-app
removes friction when first starting out with React.
Whenever the defaults of graphql-yoga
are too tight of a corset for you, you can simply eject from it and use the tooling it's build upon - there's no lock-in or any other kind of magic going on preventing you from this.
express
setup?
How to eject from the standard 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())
Middlewares can also be added specifically to the GraphQL endpoint route, by using:
server.express.post(server.options.endpoint, myMiddleware())
Any middlewares you add to that route, will be added right before the apollo-server-express
middleware.
Join our Slack community if you run into issues or have questions. We love talking to you!