graphql-http

Simple, pluggable, zero-dependency, GraphQL over HTTP Protocol compliant server and client.

Want a full-featured server? See the servers section!

Need subscriptions? Try graphql-ws or graphql-sse instead!

Getting started

Install

yarn add graphql-http

Create a GraphQL schema

import { GraphQLSchema, GraphQLObjectType, GraphQLString } from 'graphql';

/**
 * Construct a GraphQL schema and define the necessary resolvers.
 *
 * type Query {
 *   hello: String
 * }
 */
const schema = new GraphQLSchema({
  query: new GraphQLObjectType({
    name: 'Query',
    fields: {
      hello: {
        type: GraphQLString,
        resolve: () => 'world',
      },
    },
  }),
});

Start the server

With http

import http from 'http';
import { createHandler } from 'graphql-http/lib/use/node';
import { schema } from './previous-step';

// Create the GraphQL over HTTP Node request handler
const handler = createHandler({ schema });

// Create a HTTP server using the listner on `/graphql`
const server = http.createServer((req, res) => {
  if (req.url.startsWith('/graphql')) {
    handler(req, res);
  } else {
    res.writeHead(404).end();
  }
});

server.listen(4000);
console.log('Listening to port 4000');

With http2

Browsers might complain about self-signed SSL/TLS certificates. Help can be found on StackOverflow.

$ openssl req -x509 -newkey rsa:2048 -nodes -sha256 -subj '/CN=localhost' \
  -keyout localhost-privkey.pem -out localhost-cert.pem

import fs from 'fs';
import http2 from 'http2';
import { createHandler } from 'graphql-http/lib/use/node';
import { schema } from './previous-step';

// Create the GraphQL over HTTP Node request handler
const handler = createHandler({ schema });

// Create a HTTP/2 server using the handler on `/graphql`
const server = http2.createSecureServer(
  {
    key: fs.readFileSync('localhost-privkey.pem'),
    cert: fs.readFileSync('localhost-cert.pem'),
  },
  (req, res) => {
    if (req.url.startsWith('/graphql')) {
      handler(req, res);
    } else {
      res.writeHead(404).end();
    }
  },
);

server.listen(4000);
console.log('Listening to port 4000');

With express

import express from 'express'; // yarn add express
import { createHandler } from 'graphql-http/lib/use/express';
import { schema } from './previous-step';

// Create a express instance serving all methods on `/graphql`
// where the GraphQL over HTTP express request handler is
const app = express();
app.all('/graphql', createHandler({ schema }));

app.listen({ port: 4000 });
console.log('Listening to port 4000');

With fastify

import Fastify from 'fastify'; // yarn add fastify
import { createHandler } from 'graphql-http/lib/use/fastify';
import { schema } from './previous-step';

// Create a fastify instance serving all methods on `/graphql`
// where the GraphQL over HTTP fastify request handler is
const fastify = Fastify();
fastify.all('/graphql', createHandler({ schema }));

fastify.listen({ port: 4000 });
console.log('Listening to port 4000');

With Deno

import { serve } from 'https://deno.land/[email protected]/http/server.ts';
import { createHandler } from 'https://esm.sh/graphql-http/lib/use/fetch';
import { schema } from './previous-step';

// Create the GraphQL over HTTP native fetch handler
const handler = createHandler({ schema });

// Start serving on `/graphql` using the handler
await serve(
  (req: Request) => {
    const [path, _search] = req.url.split('?');
    if (path.endsWith('/graphql')) {
      return handler(req);
    } else {
      return new Response(null, { status: 404 });
    }
  },
  {
    port: 4000, // Listening to port 4000
  },
);

With Bun

import { createHandler } from 'graphql-http/lib/use/fetch'; // bun install graphql-http
import { schema } from './previous-step';

// Create the GraphQL over HTTP native fetch handler
const handler = createHandler({ schema });

// Start serving on `/graphql` using the handler
export default {
  port: 4000, // Listening to port 4000
  fetch(req) {
    const [path, _search] = req.url.split('?');
    if (path.endsWith('/graphql')) {
      return handler(req);
    } else {
      return new Response(null, { status: 404 });
    }
  },
};

Use the client

import { createClient } from 'graphql-http';

const client = createClient({
  url: 'http://localhost:4000/graphql',
});

(async () => {
  let cancel = () => {
    /* abort the request if it is in-flight */
  };

  const result = await new Promise((resolve, reject) => {
    let result;
    cancel = client.subscribe(
      {
        query: '{ hello }',
      },
      {
        next: (data) => (result = data),
        error: reject,
        complete: () => resolve(result),
      },
    );
  });

  expect(result).toEqual({ hello: 'world' });
})();

Recipes

🔗 Client usage with Promise

import { ExecutionResult } from 'graphql';
import { createClient, RequestParams } from 'graphql-http';
import { getSession } from './my-auth';

const client = createClient({
  url: 'http://hey.there:4000/graphql',
  headers: async () => {
    const session = await getSession();
    if (session) {
      return {
        Authorization: `Bearer ${session.token}`,
      };
    }
  },
});

function execute<Data, Extensions>(
  params: RequestParams,
): [request: Promise<ExecutionResult<Data, Extensions>>, cancel: () => void] {
  let cancel!: () => void;
  const request = new Promise<ExecutionResult<Data, Extensions>>(
    (resolve, reject) => {
      let result: ExecutionResult<Data, Extensions>;
      cancel = client.subscribe<Data, Extensions>(params, {
        next: (data) => (result = data),
        error: reject,
        complete: () => resolve(result),
      });
    },
  );
  return [request, cancel];
}

(async () => {
  const [request, cancel] = execute({
    query: '{ hello }',
  });

  // just an example, not a real function
  onUserLeavePage(() => {
    cancel();
  });

  const result = await request;

  expect(result).toBe({ data: { hello: 'world' } });
})();

🔗 Client usage with Observable

import { Observable } from 'relay-runtime';
// or
import { Observable } from '@apollo/client/core';
// or
import { Observable } from 'rxjs';
// or
import Observable from 'zen-observable';
// or any other lib which implements Observables as per the ECMAScript proposal: https://github.com/tc39/proposal-observable
import { createClient } from 'graphql-http';
import { getSession } from './my-auth';

const client = createClient({
  url: 'http://graphql.loves:4000/observables',
  headers: async () => {
    const session = await getSession();
    if (session) {
      return {
        Authorization: `Bearer ${session.token}`,
      };
    }
  },
});

const observable = new Observable((observer) =>
  client.subscribe({ query: '{ hello }' }, observer),
);

const subscription = observable.subscribe({
  next: (result) => {
    expect(result).toBe({ data: { hello: 'world' } });
  },
});

// unsubscribe will cancel the request if it is pending
subscription.unsubscribe();

🔗 Client usage with Relay

import { GraphQLError } from 'graphql';
import {
  Network,
  Observable,
  RequestParameters,
  Variables,
} from 'relay-runtime';
import { createClient } from 'graphql-http';
import { getSession } from './my-auth';

const client = createClient({
  url: 'http://i.love:4000/graphql',
  headers: async () => {
    const session = await getSession();
    if (session) {
      return {
        Authorization: `Bearer ${session.token}`,
      };
    }
  },
});

function fetch(operation: RequestParameters, variables: Variables) {
  return Observable.create((sink) => {
    if (!operation.text) {
      return sink.error(new Error('Operation text cannot be empty'));
    }
    return client.subscribe(
      {
        operationName: operation.name,
        query: operation.text,
        variables,
      },
      sink,
    );
  });
}

export const network = Network.create(fetch);

🔗 Client usage with Apollo

import {
  ApolloLink,
  Operation,
  FetchResult,
  Observable,
} from '@apollo/client/core';
import { print, GraphQLError } from 'graphql';
import { createClient, ClientOptions, Client } from 'graphql-http';
import { getSession } from './my-auth';

class HTTPLink extends ApolloLink {
  private client: Client;

  constructor(options: ClientOptions) {
    super();
    this.client = createClient(options);
  }

  public request(operation: Operation): Observable<FetchResult> {
    return new Observable((sink) => {
      return this.client.subscribe<FetchResult>(
        { ...operation, query: print(operation.query) },
        {
          next: sink.next.bind(sink),
          complete: sink.complete.bind(sink),
          error: sink.error.bind(sink),
        },
      );
    });
  }
}

const link = new HTTPLink({
  url: 'http://where.is:4000/graphql',
  headers: async () => {
    const session = await getSession();
    if (session) {
      return {
        Authorization: `Bearer ${session.token}`,
      };
    }
  },
});

🔗 Client usage with request retries

import { createClient, NetworkError } from 'graphql-http';

const client = createClient({
  url: 'http://unstable.service:4000/graphql',
  shouldRetry: async (err: NetworkError, retries: number) => {
    if (retries > 3) {
      // max 3 retries and then report service down
      return false;
    }

    // try again when service unavailable, could be temporary
    if (err.response?.status === 503) {
      // wait one second (you can alternatively time the promise resolution to your preference)
      await new Promise((resolve) => setTimeout(resolve, 1000));
      return true;
    }

    // otherwise report error immediately
    return false;
  },
});

🔗 Client usage in browser

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8" />
    <title>GraphQL over HTTP</title>
    <script
      type="text/javascript"
      src="https://unpkg.com/graphql-http/umd/graphql-http.min.js"
    ></script>
  </head>
  <body>
    <script type="text/javascript">
      const client = graphqlHttp.createClient({
        url: 'http://umdfor.the:4000/win/graphql',
      });

      // consider other recipes for usage inspiration
    </script>
  </body>
</html>

🔗 Client usage in Node

const fetch = require('node-fetch'); // yarn add node-fetch
const { AbortController } = require('node-abort-controller'); // (node < v15) yarn add node-abort-controller
const { createClient } = require('graphql-http');

const client = createClient({
  url: 'http://no.browser:4000/graphql',
  fetchFn: fetch,
  abortControllerImpl: AbortController, // node < v15
});

// consider other recipes for usage inspiration

🔗 Client usage in Deno

import { createClient } from 'https://esm.sh/graphql-http';

const client = createClient({
  url: 'http://deno.earth:4000/graphql',
});

// consider other recipes for usage inspiration

🔗 Client usage in Bun

import { createClient } from 'graphql-http'; // bun install graphql-http

const client = createClient({
  url: 'http://bun.bread:4000/graphql',
});

// consider other recipes for usage inspiration

🔗 Server handler migration from express-graphql

import express from 'express';
import { schema } from './my-graphql-schema';

-import { graphqlHTTP } from 'express-graphql';
+import { createHandler } from 'graphql-http/lib/use/express';

const app = express();

app.use(
  '/graphql',
-  graphqlHTTP({ schema }),
+  createHandler({ schema }),
);

app.listen(4000);

🔗 Server handler usage with authentication

Authenticate the user within graphql-http during GraphQL execution context assembly. This is a approach is less safe compared to early authentication (see early authentication in Node) because some GraphQL preparations or operations are executed even if the user is not unauthorized.

import { createHandler } from 'graphql-http';
import {
  schema,
  getUserFromCookies,
  getUserFromAuthorizationHeader,
} from './my-graphql';

const handler = createHandler({
  schema,
  context: async (req) => {
    // process token, authenticate user and attach it to your graphql context
    const userId = await getUserFromCookies(req.headers.cookie);
    // or
    const userId = await getUserFromAuthorizationHeader(
      req.headers.authorization,
    );

    // respond with 401 if the user was not authenticated
    if (!userId) {
      return [null, { status: 401, statusText: 'Unauthorized' }];
    }

    // otherwise attach the user to the graphql context
    return { userId };
  },
});

🔗 Server handler usage with custom context value

import { createHandler } from 'graphql-http';
import { schema, getDynamicContext } from './my-graphql';

const handler = createHandler({
  schema,
  context: async (req, args) => {
    return getDynamicContext(req, args);
  },
  // or static context by supplying the value direcly
});

🔗 Server handler usage with custom execution arguments

import { parse } from 'graphql';
import { createHandler } from 'graphql-http';
import { getSchemaForRequest, myValidationRules } from './my-graphql';

const handler = createHandler({
  onSubscribe: async (req, params) => {
    const schema = await getSchemaForRequest(req);

    const args = {
      schema,
      operationName: params.operationName,
      document: parse(params.query),
      variableValues: params.variables,
    };

    return args;
  },
});

🔗 Server handler usage in Node with early authentication (recommended)

Authenticate the user early, before reaching graphql-http. This is the recommended approach because no GraphQL preparations or operations are executed if the user is not authorized.

import { createHandler } from 'graphql-http';
import {
  schema,
  getUserFromCookies,
  getUserFromAuthorizationHeader,
} from './my-graphql';

const handler = createHandler({
  schema,
  context: async (req) => {
    // user is authenticated early (see below), simply attach it to the graphql context
    return { userId: req.raw.userId };
  },
});

const server = http.createServer(async (req, res) => {
  if (!req.url.startsWith('/graphql')) {
    return res.writeHead(404).end();
  }

  try {
    // process token, authenticate user and attach it to the request
    req.userId = await getUserFromCookies(req.headers.cookie);
    // or
    req.userId = await getUserFromAuthorizationHeader(
      req.headers.authorization,
    );

    // respond with 401 if the user was not authenticated
    if (!req.userId) {
      return res.writeHead(401, 'Unauthorized').end();
    }

    const [body, init] = await handler({
      url: req.url,
      method: req.method,
      headers: req.headers,
      body: () =>
        new Promise((resolve) => {
          let body = '';
          req.on('data', (chunk) => (body += chunk));
          req.on('end', () => resolve(body));
        }),
      raw: req,
    });
    res.writeHead(init.status, init.statusText, init.headers).end(body);
  } catch (err) {
    res.writeHead(500).end(err.message);
  }
});

server.listen(4000);
console.log('Listening to port 4000');

🔗 Audit for servers usage in Jest environment

import { fetch } from '@whatwg-node/fetch';
import { serverAudits } from 'graphql-http';

for (const audit of serverAudits({
  url: 'http://localhost:4000/graphql',
  fetchFn: fetch,
})) {
  test(audit.name, async () => {
    const result = await audit.fn();
    if (result.status === 'error') {
      throw result.reason;
    }
    if (result.status === 'warn') {
      console.warn(result.reason); // or throw if you want full compliance (warnings are not requirements)
    }
    // result.status === 'ok'
  });
}

Only GraphQL over HTTP

This is the official GraphQL over HTTP spec reference implementation and as such follows the specification strictly without any additional features (like file uploads, @stream/@defer directives and subscriptions).

Having said this, graphql-http is mostly aimed for library authors and simple server setups, where the requirements are exact to what the aforementioned spec offers.

Servers

If you want a feature-full server with bleeding edge technologies, you're recommended to use one of the following.

Name	Audit
graphql-yoga	✅ Fully compliant
mercurius	✅ Partially compliant
graphql-helix	✅ Partially compliant
apollo-server	⚠️ Not compliant

Documentation

Check the docs folder out for TypeDoc generated documentation.

Audits

Inspect audits of other implementations in the implementations folder. Adding your implementation is very welcome!

Want to help?

File a bug, contribute with code, or improve documentation? Read up on our guidelines below and drive development with yarn test --watch away!

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To initiate the signature process please open a PR against this repo. The EasyCLA bot will block the merge if we still need a membership agreement from you.

You can find detailed information here. If you have issues, please email [email protected].

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