The JavaScript reference implementation for GraphQL, a query language for APIs created by Facebook.
See more complete documentation at https://graphql.org/ and https://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
With yarn:
yarn add graphql
or alternatively using 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); });
Note: Please don't forget to set NODE_ENV=production
if you are running a production server it will disable some checks that can be useful during development but will significantly improve performance.
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 recommended to use builds deployed to 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
GraphQL.js is a general purpose library and can be used both in a Node server and in the browser. As an example, the GraphiQL tool is built with GraphQL.js!
Building a project using GraphQL.js with webpack or rollup should just work and only include the portions of the library you use. This works because GraphQL.js is distributed with both CommonJS (require()
) and ESModule (import
) files. Ensure that any custom build configurations look for .mjs
files!
We actively welcome pull requests, learn how to contribute.
Changes are tracked as GitHub releases.
GraphQL.js is MIT-licensed.
The *.d.ts
files in this project are based on DefinitelyTyped definitions written by: