graphql-js

# GraphQL.js

The JavaScript reference implementation for GraphQL, a query language for APIs created by Facebook.

[![npm version](https://badge.fury.io/js/graphql.svg)](https://badge.fury.io/js/graphql)
[![Build Status](https://github.com/graphql/graphql-js/actions/workflows/push.yml/badge.svg?branch=17.x.x)](https://github.com/graphql/graphql-js/actions/workflows/push.yml?query=branch%3A17.x.x)

See more complete documentation at https://graphql.org/ and
https://graphql.org/graphql-js/.

Looking for help? Find resources [from the community](https://graphql.org/community/).

## Getting Started

A general overview of GraphQL is available in the
[README](https://github.com/graphql/graphql-spec/blob/main/README.md) for the
[Specification for GraphQL](https://github.com/graphql/graphql-spec). That overview
describes a simple set of GraphQL examples that exist as [tests](src/__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.

### Using GraphQL.js

Install GraphQL.js from npm

With `npm`:

```sh
npm install --save graphql
```

With `yarn`:

```sh
yarn add graphql
```

With `bun`:

```sh
bun add 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 codebase.

```js
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](src/__tests__) directory.

Then, serve the result of a query against that type schema.

```js
var source = '{ hello }';

graphql({ schema, source }).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.

```js
var source = '{ BoyHowdy }';

graphql({ schema, source }).then((result) => {
  // Prints
  // {
  //   errors: [
  //     { message: 'Cannot query field BoyHowdy on RootQueryType',
  //       locations: [ { line: 1, column: 3 } ] }
  //   ]
  // }
  console.log(result);
});
```

## Want to ride the bleeding edge?

The `npm` branch in this repository is automatically maintained to be the last
commit to `17.x.x` 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-re