The JavaScript reference implementation for GraphQL, a query language for APIs created by Facebook.
See more complete documentation at http://graphql.org/ and http://graphql.org/graphql-js/.
Looking for help? Find resources from the community.
An overview of GraphQL in general is available in the README for the Specification for GraphQL. That overview describes a simple set of GraphQL examples that exist as tests in this repository. A good way to get started with this repository is to walk through that README and the corresponding tests in parallel.
Install GraphQL.js from npm
npm install --save graphql
GraphQL.js provides two important capabilities: building a type schema, and serving queries against that type schema.
First, build a GraphQL type schema which maps to your code base.
import {
graphql,
GraphQLSchema,
GraphQLObjectType,
GraphQLString
} from 'graphql';
var schema = new GraphQLSchema({
query: new GraphQLObjectType({
name: 'RootQueryType',
fields: {
hello: {
type: GraphQLString,
resolve() {
return 'world';
}
}
}
})
});
This defines a simple schema with one type and one field, that resolves
to a fixed value. The resolve
function can return a value, a promise,
or an array of promises. A more complex example is included in the top
level tests directory.
Then, serve the result of a query against that type schema.
var query = '{ hello }';
graphql(schema, query).then(result => {
// Prints
// {
// data: { hello: "world" }
// }
console.log(result);
});
This runs a query fetching the one field defined. The graphql
function will
first ensure the query is syntactically and semantically valid before executing
it, reporting errors otherwise.
var query = '{ boyhowdy }';
graphql(schema, query).then(result => {
// Prints
// {
// errors: [
// { message: 'Cannot query field boyhowdy on RootQueryType',
// locations: [ { line: 1, column: 3 } ] }
// ]
// }
console.log(result);
});
The npm
branch in this repository is automatically maintained to be the last
commit to master
to pass all tests, in the same form found on npm. It is
recommend to use builds deployed npm for many reasons, but if you want to use
the latest not-yet-released version of graphql-js, you can do so by depending
directly on this branch:
npm install graphql@git://github.com/graphql/graphql-js.git#npm
We actively welcome pull requests, learn how to contribute.
Changes are tracked as Github releases.
GraphQL is BSD-licensed. We also provide an additional patent grant.