@faia/graphql-ws
v5.3.0
Published
Coherent, zero-dependency, lazy, simple, GraphQL over WebSocket Protocol compliant server and client
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Readme
Getting started
Install
$ yarn add graphql-ws
Create a GraphQL schema
import { buildSchema } from 'graphql';
// Construct a schema, using GraphQL schema language
const schema = buildSchema(`
type Query {
hello: String
}
type Subscription {
greetings: String
}
`);
// The roots provide resolvers for each GraphQL operation
const roots = {
query: {
hello: () => 'Hello World!',
},
subscription: {
greetings: async function* sayHiIn5Languages() {
for (const hi of ['Hi', 'Bonjour', 'Hola', 'Ciao', 'Zdravo']) {
yield { greetings: hi };
}
},
},
};
Start the server
With ws
import ws from 'ws'; // yarn add ws
import { useServer } from 'graphql-ws/lib/use/ws';
const server = new ws.Server({
port: 4000,
path: '/graphql',
});
useServer(
// from the previous step
{ schema, roots },
server,
);
console.log('Listening to port 4000');
With uWebSockets.js
import uWS from 'uWebSockets.js'; // yarn add uWebSockets.js@uNetworking/uWebSockets.js#<tag>
import { makeBehavior } from 'graphql-ws/lib/use/uWebSockets';
uWS
.App()
.ws(
'/graphql',
makeBehavior(
// from the previous step
{ schema, roots },
),
)
.listen(4000, (listenSocket) => {
if (listenSocket) {
console.log('Listening to port 4000');
}
});
With fastify-websocket
import Fastify from 'fastify'; // yarn add fastify
import fastifyWebsocket from 'fastify-websocket'; // yarn add fastify-websocket
import { makeHandler } from 'graphql-ws/lib/use/fastify-websocket';
const fastify = Fastify();
fastify.register(fastifyWebsocket);
fastify.get(
'/graphql',
{ websocket: true },
makeHandler(
// from the previous step
{ schema, roots },
),
);
fastify.listen(4000, (err) => {
if (err) {
fastify.log.error(err);
return process.exit(1);
}
console.log('Listening to port 4000');
});
Use the client
import { createClient } from 'graphql-ws';
const client = createClient({
url: 'ws://welcomer.com:4000/graphql',
});
// query
(async () => {
const result = await new Promise((resolve, reject) => {
let result;
client.subscribe(
{
query: '{ hello }',
},
{
next: (data) => (result = data),
error: reject,
complete: () => resolve(result),
},
);
});
expect(result).toEqual({ hello: 'Hello World!' });
})();
// subscription
(async () => {
const onNext = () => {
/* handle incoming values */
};
let unsubscribe = () => {
/* complete the subscription */
};
await new Promise((resolve, reject) => {
unsubscribe = client.subscribe(
{
query: 'subscription { greetings }',
},
{
next: onNext,
error: reject,
complete: resolve,
},
);
});
expect(onNext).toBeCalledTimes(5); // we say "Hi" in 5 languages
})();
Recipes
import { createClient, SubscribePayload } from 'graphql-ws';
const client = createClient({
url: 'ws://hey.there:4000/graphql',
});
async function execute<T>(payload: SubscribePayload) {
return new Promise<T>((resolve, reject) => {
let result: T;
client.subscribe<T>(payload, {
next: (data) => (result = data),
error: reject,
complete: () => resolve(result),
});
});
}
// use
(async () => {
try {
const result = await execute({
query: '{ hello }',
});
// complete
// next = result = { data: { hello: 'Hello World!' } }
} catch (err) {
// error
}
})();
import { createClient, SubscribePayload } from 'graphql-ws';
const client = createClient({
url: 'ws://iterators.ftw:4000/graphql',
});
function subscribe<T>(payload: SubscribePayload): AsyncIterableIterator<T> {
let deferred: {
resolve: (done: boolean) => void;
reject: (err: unknown) => void;
} | null = null;
const pending: T[] = [];
let throwMe: unknown = null,
done = false;
const dispose = client.subscribe<T>(payload, {
next: (data) => {
pending.push(data);
deferred?.resolve(false);
},
error: (err) => {
throwMe = err;
deferred?.reject(throwMe);
},
complete: () => {
done = true;
deferred?.resolve(true);
},
});
return {
[Symbol.asyncIterator]() {
return this;
},
async next() {
if (done) return { done: true, value: undefined };
if (throwMe) throw throwMe;
if (pending.length) return { value: pending.shift()! };
return (await new Promise<boolean>(
(resolve, reject) => (deferred = { resolve, reject }),
))
? { done: true, value: undefined }
: { value: pending.shift()! };
},
async return() {
dispose();
return { done: true, value: undefined };
},
};
}
(async () => {
const subscription = subscribe({
query: 'subscription { greetings }',
});
// subscription.return() to dispose
for await (const result of subscription) {
// next = result = { data: { greetings: 5x } }
}
// complete
})();
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
const client = createClient({
url: 'ws://graphql.loves:4000/observables',
});
function toObservable(operation) {
return new Observable((observer) =>
client.subscribe(operation, {
next: (data) => observer.next(data),
error: (err) => observer.error(err),
complete: () => observer.complete(),
}),
);
}
const observable = toObservable({ query: `subscription { ping }` });
const subscription = observable.subscribe({
next: (data) => {
expect(data).toBe({ data: { ping: 'pong' } });
},
});
// ⏱
subscription.unsubscribe();
import { GraphQLError } from 'graphql';
import {
Network,
Observable,
RequestParameters,
Variables,
} from 'relay-runtime';
import { createClient } from 'graphql-ws';
const subscriptionsClient = createClient({
url: 'ws://i.love:4000/graphql',
connectionParams: () => {
const session = getSession();
if (!session) {
return {};
}
return {
Authorization: `Bearer ${session.token}`,
};
},
});
// yes, both fetch AND subscribe handled in one implementation
function fetchOrSubscribe(operation: RequestParameters, variables: Variables) {
return Observable.create((sink) => {
if (!operation.text) {
return sink.error(new Error('Operation text cannot be empty'));
}
return subscriptionsClient.subscribe(
{
operationName: operation.name,
query: operation.text,
variables,
},
{
...sink,
error: (err) => {
if (err instanceof Error) {
return sink.error(err);
}
if (err instanceof CloseEvent) {
return sink.error(
// reason will be available on clean closes
new Error(
`Socket closed with event ${err.code} ${err.reason || ''}`,
),
);
}
return sink.error(
new Error(
(err as GraphQLError[]).map(({ message }) => message).join(', '),
),
);
},
},
);
});
}
export const network = Network.create(fetchOrSubscribe, fetchOrSubscribe);
import { createClient, defaultExchanges, subscriptionExchange } from 'urql';
import { createClient as createWSClient } from 'graphql-ws';
const wsClient = createWSClient({
url: 'ws://its.urql:4000/graphql',
});
const client = createClient({
url: '/graphql',
exchanges: [
...defaultExchanges,
subscriptionExchange({
forwardSubscription(operation) {
return {
subscribe: (sink) => {
const dispose = wsClient.subscribe(operation, sink);
return {
unsubscribe: dispose,
};
},
};
},
}),
],
});
import {
ApolloLink,
Operation,
FetchResult,
Observable,
} from '@apollo/client/core';
import { print, GraphQLError } from 'graphql';
import { createClient, ClientOptions, Client } from 'graphql-ws';
class WebSocketLink 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: (err) => {
if (err instanceof Error) {
return sink.error(err);
}
if (err instanceof CloseEvent) {
return sink.error(
// reason will be available on clean closes
new Error(
`Socket closed with event ${err.code} ${err.reason || ''}`,
),
);
}
return sink.error(
new Error(
(err as GraphQLError[])
.map(({ message }) => message)
.join(', '),
),
);
},
},
);
});
}
}
const link = new WebSocketLink({
url: 'ws://where.is:4000/graphql',
connectionParams: () => {
const session = getSession();
if (!session) {
return {};
}
return {
Authorization: `Bearer ${session.token}`,
};
},
});
import { createClient } from 'graphql-ws';
import { waitForHealthy } from './my-servers';
const url = 'ws://i.want.retry:4000/control/graphql';
const client = createClient({
url,
retryWait: async function waitForServerHealthyBeforeRetry() {
// if you have a server healthcheck, you can wait for it to become
// healthy before retrying after an abrupt disconnect (most commonly a restart)
await waitForHealthy(url);
// after the server becomes ready, wait for a second + random 1-4s timeout
// (avoid DDoSing yourself) and try connecting again
await new Promise((resolve) =>
setTimeout(resolve, 1000 + Math.random() * 3000),
);
},
});
import { createClient, Client, ClientOptions } from 'graphql-ws';
import { giveMeAFreshToken } from './token-giver';
interface RestartableClient extends Client {
restart(): void;
}
function createRestartableClient(options: ClientOptions): RestartableClient {
let restartRequested = false;
let restart = () => {
restartRequested = true;
};
const client = createClient({
...options,
on: {
...options.on,
opened: (socket) => {
options.on?.opened?.(socket);
restart = () => {
if (socket.readyState === WebSocket.OPEN) {
// if the socket is still open for the restart, do the restart
socket.close(4205, 'Client Restart');
} else {
// otherwise the socket might've closed, indicate that you want
// a restart on the next opened event
restartRequested = true;
}
};
// just in case you were eager to restart
if (restartRequested) {
restartRequested = false;
restart();
}
},
},
});
return {
...client,
restart: () => restart(),
};
}
const client = createRestartableClient({
url: 'ws://graceful.restart:4000/is/a/non-fatal/close-code',
connectionParams: async () => {
const token = await giveMeAFreshToken();
return { token };
},
});
// all subscriptions from `client.subscribe` will resubscribe after `client.restart`
import { createClient } from 'graphql-ws';
let activeSocket,
timedOut,
pingSentAt = 0,
latency = 0;
createClient({
url: 'ws://i.time.out:4000/and-measure/latency',
keepAlive: 10_000, // ping server every 10 seconds
on: {
opened: (socket) => (activeSocket = socket),
ping: (received) => {
if (!received /* sent */) {
pingSentAt = Date.now();
timedOut = setTimeout(() => {
if (activeSocket.readyState === WebSocket.OPEN)
activeSocket.close(4408, 'Request Timeout');
}, 5_000); // wait 5 seconds for the pong and then close the connection
}
},
pong: (received) => {
if (received) {
latency = Date.now() - pingSentAt;
clearTimeout(timedOut); // pong is received, clear connection close timeout
}
},
},
});
import {
createClient,
Client,
ClientOptions,
stringifyMessage,
PingMessage,
PongMessage,
MessageType,
} from 'graphql-ws';
interface PingerClient extends Client {
ping(payload?: PingMessage['payload']): void;
pong(payload?: PongMessage['payload']): void;
}
function createPingerClient(options: ClientOptions): PingerClient {
let activeSocket: WebSocket;
const client = createClient({
disablePong: true,
...options,
on: {
opened: (socket) => {
options.on?.opened?.(socket);
activeSocket = socket;
},
},
});
return {
...client,
ping: (payload) => {
if (activeSocket.readyState === WebSocket.OPEN)
activeSocket.send(
stringifyMessage({
type: MessageType.Ping,
payload,
}),
);
},
pong: (payload) => {
if (activeSocket.readyState === WebSocket.OPEN)
activeSocket.send(
stringifyMessage({
type: MessageType.Pong,
payload,
}),
);
},
};
}
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>GraphQL over WebSocket</title>
<script
type="text/javascript"
src="https://unpkg.com/graphql-ws/umd/graphql-ws.min.js"
></script>
</head>
<body>
<script type="text/javascript">
const client = graphqlWs.createClient({
url: 'ws://umdfor.the:4000/win/graphql',
});
// consider other recipes for usage inspiration
</script>
</body>
</html>
const ws = require('ws'); // yarn add ws
const Crypto = require('crypto');
const { createClient } = require('graphql-ws');
const client = createClient({
url: 'ws://no.browser:4000/graphql',
webSocketImpl: ws,
/**
* Generates a v4 UUID to be used as the ID.
* Reference: https://gist.github.com/jed/982883
*/
generateID: () =>
([1e7] + -1e3 + -4e3 + -8e3 + -1e11).replace(/[018]/g, (c) =>
(c ^ (Crypto.randomBytes(1)[0] & (15 >> (c / 4)))).toString(16),
),
});
// consider other recipes for usage inspiration
// minimal version of `import { useServer } from 'graphql-ws/lib/use/ws';`
import ws from 'ws'; // yarn add ws
import { makeServer } from 'graphql-ws';
import { schema } from './my-graphql-schema';
// make
const server = makeServer({ schema });
// create websocket server
const wsServer = new ws.Server({
port: 4000,
path: '/graphql',
});
// implement
wsServer.on('connection', (socket, request) => {
// a new socket opened, let graphql-ws take over
const closed = server.opened(
{
protocol: socket.protocol, // will be validated
send: (data) =>
new Promise((resolve, reject) => {
socket.send(data, (err) => (err ? reject(err) : resolve()));
}), // control your data flow by timing the promise resolve
close: (code, reason) => socket.close(code, reason), // there are protocol standard closures
onMessage: (cb) =>
socket.on('message', async (event) => {
try {
// wait for the the operation to complete
// - if init message, waits for connect
// - if query/mutation, waits for result
// - if subscription, waits for complete
await cb(event.toString());
} catch (err) {
// all errors that could be thrown during the
// execution of operations will be caught here
socket.close(1011, err.message);
}
}),
},
// pass values to the `extra` field in the context
{ socket, request },
);
// notify server that the socket closed
socket.once('close', (code, reason) => closed(code, reason));
});
// check extended implementation at `{ useServer } from 'graphql-ws/lib/use/ws'`
import http from 'http';
import ws from 'ws'; // yarn add ws
import { makeServer } from 'graphql-ws';
import { schema } from './my-graphql-schema';
import { validate } from './my-auth';
// extra in the context
interface Extra {
readonly request: http.IncomingMessage;
}
// your custom auth
class Forbidden extends Error {}
function handleAuth(request: http.IncomingMessage) {
// do your auth on every subscription connect
const good = validate(request.headers['authorization']);
// or const { iDontApprove } = session(request.cookies);
if (!good) {
// throw a custom error to be handled
throw new Forbidden(':(');
}
}
// make graphql server
const gqlServer = makeServer<Extra>({
schema,
onConnect: async (ctx) => {
// do your auth on every connect
await handleAuth(ctx.extra.request);
},
onSubscribe: async (ctx) => {
// or maybe on every subscribe
await handleAuth(ctx.extra.request);
},
onNext: async (ctx) => {
// haha why not on every result emission?
await handleAuth(ctx.extra.request);
},
});
// create websocket server
const wsServer = new ws.Server({
port: 4000,
path: '/graphql',
});
// implement
wsServer.on('connection', (socket, request) => {
// you may even reject the connection without ever reaching the lib
// return socket.close(4403, 'Forbidden');
// pass the connection to graphql-ws
const closed = gqlServer.opened(
{
protocol: socket.protocol, // will be validated
send: (data) =>
new Promise((resolve, reject) => {
// control your data flow by timing the promise resolve
socket.send(data, (err) => (err ? reject(err) : resolve()));
}),
close: (code, reason) => socket.close(code, reason), // for standard closures
onMessage: (cb) => {
socket.on('message', async (event) => {
try {
// wait for the the operation to complete
// - if init message, waits for connect
// - if query/mutation, waits for result
// - if subscription, waits for complete
await cb(event.toString());
} catch (err) {
// all errors that could be thrown during the
// execution of operations will be caught here
if (err instanceof Forbidden) {
// your magic
} else {
socket.close(1011, err.message);
}
}
});
},
},
// pass request to the extra
{ request },
);
// notify server that the socket closed
socket.once('close', (code, reason) => closed(code, reason));
});
import ws from 'ws'; // yarn add ws
import { makeServer, stringifyMessage, MessageType } from 'graphql-ws';
import { schema } from './my-graphql-schema';
// make
const server = makeServer({ schema });
// create websocket server
const wsServer = new ws.Server({
port: 4000,
path: '/graphql',
});
// implement
wsServer.on('connection', (socket, request) => {
// subprotocol pinger because WS level ping/pongs might not be available
let pinger, pongWait;
function ping() {
if (socket.readyState === socket.OPEN) {
// send the subprotocol level ping message
socket.send(stringifyMessage({ type: MessageType.Ping }));
// wait for the pong for 6 seconds and then terminate
pongWait = setTimeout(() => {
clearInterval(pinger);
socket.close();
}, 6_000);
}
}
// ping the client on an interval every 12 seconds
pinger = setInterval(() => ping(), 12_000);
// a new socket opened, let graphql-ws take over
const closed = server.opened(
{
protocol: socket.protocol, // will be validated
send: (data) => socket.send(data),
close: (code, reason) => socket.close(code, reason),
onMessage: (cb) =>
socket.on('message', async (event) => {
try {
// wait for the the operation to complete
// - if init message, waits for connect
// - if query/mutation, waits for result
// - if subscription, waits for complete
await cb(event.toString());
} catch (err) {
// all errors that could be thrown during the
// execution of operations will be caught here
socket.close(1011, err.message);
}
}),
// pong received, clear termination timeout
onPong: () => clearTimeout(pongWait),
},
// pass values to the `extra` field in the context
{ socket, request },
);
// notify server that the socket closed and stop the pinger
socket.once('close', (code, reason) => {
clearTimeout(pongWait);
clearInterval(pinger);
closed(code, reason);
});
});
Please check the worker-graphql-ws-template
repo out.
import ws from 'ws'; // yarn add ws
import express from 'express';
import { graphqlHTTP } from 'express-graphql';
import { useServer } from 'graphql-ws/lib/use/ws';
import { schema } from './my-graphql-schema';
// create express and middleware
const app = express();
app.use('/graphql', graphqlHTTP({ schema }));
const server = app.listen(4000, () => {
// create and use the websocket server
const wsServer = new ws.Server({
server,
path: '/graphql',
});
useServer({ schema }, wsServer);
});
import express from 'express';
import { ApolloServer } from 'apollo-server-express';
import ws from 'ws'; // yarn add ws
import { useServer } from 'graphql-ws/lib/use/ws';
import { schema } from './my-graphql-schema';
// create express
const app = express();
// create apollo server
const apolloServer = new ApolloServer({ schema });
// apply middleware
apolloServer.applyMiddleware({ app });
const server = app.listen(4000, () => {
// create and use the websocket server
const wsServer = new ws.Server({
server,
path: '/graphql',
});
useServer({ schema }, wsServer);
});
import http from 'http';
import ws from 'ws'; // yarn add ws
import { execute, subscribe } from 'graphql';
import { GRAPHQL_TRANSPORT_WS_PROTOCOL } from 'graphql-ws';
import { useServer } from 'graphql-ws/lib/use/ws';
import { SubscriptionServer, GRAPHQL_WS } from 'subscriptions-transport-ws';
import { schema } from './my-graphql-schema';
// graphql-ws
const graphqlWs = new ws.Server({ noServer: true });
useServer({ schema }, graphqlWs);
// subscriptions-transport-ws
const subTransWs = new ws.Server({ noServer: true });
SubscriptionServer.create(
{
schema,
execute,
subscribe,
},
subTransWs,
);
// create http server
const server = http.createServer(function weServeSocketsOnly(_, res) {
res.writeHead(404);
res.end();
});
// listen for upgrades and delegate requests according to the WS subprotocol
server.on('upgrade', (req, socket, head) => {
// extract websocket subprotocol from header
const protocol = req.headers['sec-websocket-protocol'];
const protocols = Array.isArray(protocol)
? protocol
: protocol?.split(',').map((p) => p.trim());
// decide which websocket server to use
const wss =
protocols?.includes(GRAPHQL_WS) && // subscriptions-transport-ws subprotocol
!protocols.includes(GRAPHQL_TRANSPORT_WS_PROTOCOL) // graphql-ws subprotocol
? subTransWs
: // graphql-ws will welcome its own subprotocol and
// gracefully reject invalid ones. if the client supports
// both transports, graphql-ws will prevail
graphqlWs;
wss.handleUpgrade(req, socket, head, (ws) => {
wss.emit('connection', ws, req);
});
});
server.listen(4000);
import ws from 'ws'; // yarn add ws
import { useServer } from 'graphql-ws/lib/use/ws';
import { schema } from './my-graphql-schema';
const wsServer = new ws.Server({
port: 4000,
path: '/graphql',
});
useServer(
{
schema,
onConnect: (ctx) => {
console.log('Connect', ctx);
},
onSubscribe: (ctx, msg) => {
console.log('Subscribe', { ctx, msg });
},
onNext: (ctx, msg, args, result) => {
console.debug('Next', { ctx, msg, args, result });
},
onError: (ctx, msg, errors) => {
console.error('Error', { ctx, msg, errors });
},
onComplete: (ctx, msg) => {
console.log('Complete', { ctx, msg });
},
},
wsServer,
);
import http from 'http';
import ws from 'ws'; // yarn add ws
import url from 'url';
import { useServer } from 'graphql-ws/lib/use/ws';
import { schema } from './my-graphql-schema';
const server = http.createServer(function weServeSocketsOnly(_, res) {
res.writeHead(404);
res.end();
});
/**
* Two websocket servers on different paths:
* - `/wave` sends out waves
* - `/graphql` serves graphql
*/
const waveWS = new ws.Server({ noServer: true });
const graphqlWS = new ws.Server({ noServer: true });
// delegate upgrade requests to relevant destinations
server.on('upgrade', (request, socket, head) => {
const pathname = url.parse(request.url).pathname;
if (pathname === '/wave') {
return waveWS.handleUpgrade(request, socket, head, (client) => {
waveWS.emit('connection', client, request);
});
}
if (pathname === '/graphql') {
return graphqlWS.handleUpgrade(request, socket, head, (client) => {
graphqlWS.emit('connection', client, request);
});
}
return socket.destroy();
});
// wave on connect
waveWS.on('connection', (socket) => {
socket.send('🌊');
});
// serve graphql
useServer({ schema }, graphqlWS);
server.listen(4000);
import ws from 'ws'; // yarn add ws
import { useServer } from 'graphql-ws/lib/use/ws';
import { schema, roots, getDynamicContext } from './my-graphql';
const wsServer = new ws.Server({
port: 4000,
path: '/graphql',
});
useServer(
{
context: (ctx, msg, args) => {
return getDynamicContext(ctx, msg, args);
}, // or static context by supplying the value direcly
schema,
roots,
},
wsServer,
);
import ws from 'ws'; // yarn add ws
import { useServer } from 'graphql-ws/lib/use/ws';
import { schema, checkIsAdmin, getDebugSchema } from './my-graphql';
const wsServer = new ws.Server({
port: 4000,
path: '/graphql',
});
useServer(
{
schema: async (ctx, msg, executionArgsWithoutSchema) => {
// will be called on every subscribe request
// allowing you to dynamically supply the schema
// using the depending on the provided arguments.
// throwing an error here closes the socket with
// the `Error` message in the close event reason
const isAdmin = await checkIsAdmin(ctx.request);
if (isAdmin) return getDebugSchema(ctx, msg, executionArgsWithoutSchema);
return schema;
},
},
wsServer,
);
import ws from 'ws'; // yarn add ws
import { useServer } from 'graphql-ws/lib/use/ws';
import { validate } from 'graphql';
import { schema, myValidationRules } from './my-graphql';
const wsServer = new ws.Server({
port: 4000,
path: '/graphql',
});
useServer(
{
validate: (schema, document) =>
validate(schema, document, myValidationRules),
},
wsServer,
);
import { parse, validate } from 'graphql';
import ws from 'ws'; // yarn add ws
import { useServer } from 'graphql-ws/lib/use/ws';
import { schema, myValidationRules } from './my-graphql';
const wsServer = new ws.Server({
port: 4000,
path: '/graphql',
});
useServer(
{
onSubscribe: (ctx, msg) => {
const args = {
schema,
operationName: msg.payload.operationName,
document: parse(msg.payload.query),
variableValues: msg.payload.variables,
};
// dont forget to validate when returning custom execution args!
const errors = validate(args.schema, args.document, myValidationRules);
if (errors.length > 0) {
return errors; // return `GraphQLError[]` to send `ErrorMessage` and stop subscription
}
return args;
},
},
wsServer,
);
import { parse, validate, getOperationAST, GraphQLError } from 'graphql';
import ws from 'ws'; // yarn add ws
import { useServer } from 'graphql-ws/lib/use/ws';
import { schema } from './my-graphql';
const wsServer = new ws.Server({
port: 4000,
path: '/graphql',
});
useServer(
{
onSubscribe: (_ctx, msg) => {
// construct the execution arguments
const args = {
schema,
operationName: msg.payload.operationName,
document: parse(msg.payload.query),
variableValues: msg.payload.variables,
};
const operationAST = getOperationAST(args.document, args.operationName);
if (!operationAST) {
// returning `GraphQLError[]` sends an `ErrorMessage` and stops the subscription
return [new GraphQLError('Unable to identify operation')];
}
// handle mutation and query requests
if (operationAST.operation !== 'subscription') {
// returning `GraphQLError[]` sends an `ErrorMessage` and stops the subscription
return [new GraphQLError('Only subscription operations are supported')];
// or if you want to be strict and terminate the connection on illegal operations
throw new Error('Only subscription operations are supported');
}
// dont forget to validate
const errors = validate(args.schema, args.document);
if (errors.length > 0) {
// returning `GraphQLError[]` sends an `ErrorMessage` and stops the subscription
return errors;
}
// ready execution arguments
return args;
},
},
wsServer,
);
// 🛸 server
import { parse, ExecutionArgs } from 'graphql';
import ws from 'ws'; // yarn add ws
import { useServer } from 'graphql-ws/lib/use/ws';
import { schema } from './my-graphql-schema';
// a unique GraphQL execution ID used for representing
// a query in the persisted queries store. when subscribing
// you should use the `SubscriptionPayload.query` to transmit the id
type QueryID = string;
const queriesStore: Record<QueryID, ExecutionArgs> = {
iWantTheGreetings: {
schema, // you may even provide different schemas in the queries store
document: parse('subscription Greetings { greetings }'),
},
};
const wsServer = new ws.Server({
port: 4000,
path: '/graphql',
});
useServer(
{
onSubscribe: (_ctx, msg) => {
const persistedQuery =
queriesStore[msg.payload.extensions?.persistedQuery];
if (persistedQuery) {
return {
...persistedQuery,
variableValues: msg.payload.variables, // use the variables from the client
};
}
// for extra security you only allow the queries from the store.
// if you want to support both, simply remove the throw below and
// graphql-ws will handle the query for you
throw new Error('404: Query Not Found');
},
},
wsServer,
);
// 📺 client
import { createClient } from 'graphql-ws';
const client = createClient({
url: 'ws://persisted.graphql:4000/queries',
});
(async () => {
const onNext = () => {
/**/
};
await new Promise((resolve, reject) => {
client.subscribe(
{
query: '', // query field is required, but you can leave it empty for persisted queries
extensions: {
persistedQuery: 'iWantTheGreetings',
},
},
{
next: onNext,
error: reject,
complete: resolve,
},
);
});
expect(onNext).toBeCalledTimes(5); // greetings in 5 languages
})();
// 🛸 server
import ws from 'ws'; // yarn add ws
import { useServer } from 'graphql-ws/lib/use/ws';
import { schema } from './my-graphql-schema';
import { isTokenValid } from './my-auth';
const wsServer = new WebSocket.Server({
port: 4000,
path: '/graphql',
});
useServer(
{
schema,
onConnect: async (ctx) => {
// do your auth check on every connect
if (!(await isTokenValid(ctx.connectionParams?.token)))
// returning false from the onConnect callback will close with `4403: Forbidden`;
// therefore, being synonymous to ctx.extra.socket.close(4403, 'Forbidden');
return false;
},
onSubscribe: async (ctx) => {
// or maybe on every subscribe
if (!(await isTokenValid(ctx.connectionParams?.token)))
return ctx.extra.socket.close(4403, 'Forbidden');
},
onNext: async (ctx) => {
// why not on every result emission? lol
if (!(await isTokenValid(ctx.connectionParams?.token)))
return ctx.extra.socket.close(4403, 'Forbidden');
},
},
wsServer,
);
// 📺 client
import { createClient } from 'graphql-ws';
import {
getCurrentToken,
getCurrentTokenExpiresIn,
refreshCurrentToken,
} from './my-auth';
// non-fatal WebSocket connection close events will cause the
// client to automatically reconnect. the retries are silent, meaning
// that the client will not error out unless the retry attempts have been
// exceeded or the close event was fatal (read more about the fatal
// close events in the documentation). additionally, all active subscriptions
// will automatically resubscribe upon successful reconnect. this behaviour
// can be leveraged to implement a secure and sound way of authentication;
// handling server-side validation, expiry indication and timely token refreshes
// indicates that the server closed the connection because of
// an auth problem. it indicates that the token should refresh
let shouldRefreshToken = false,
// the socket close timeout due to token expiry
tokenExpiryTimeout = null;
const client = createClient({
url: 'ws://server-validates.auth:4000/graphql',
connectionParams: async () => {
if (shouldRefreshToken) {
// refresh the token because it is no longer valid
await refreshCurrentToken();
// and reset the flag to avoid refreshing too many times
shouldRefreshToken = false;
}
return { token: getCurrentToken() };
},
on: {
connected: (socket) => {
// clear timeout on every connect for debouncing the expiry
clearTimeout(tokenExpiryTimeout);
// set a token expiry timeout for closing the socket
// with an `4403: Forbidden` close event indicating
// that the token expired. the `closed` event listner below
// will set the token refresh flag to true
tokenExpiryTimeout = setTimeout(() => {
if (socket.readyState === WebSocket.OPEN)
socket.close(4403, 'Unauthorized');
}, getCurrentTokenExpiresIn());
},
closed: (event) => {
// if closed with the `4403: Forbidden` close event
// the client or the server is communicating that the token
// is no longer valid and should be therefore refreshed
if (event.code === 4403) shouldRefreshToken = true;
},
},
});
Documentation
Check the docs folder out for TypeDoc generated documentation.
How does it work?
Read about the exact transport intricacies used by the library in the GraphQL over WebSocket Protocol document.
Want to help?
File a bug, contribute with code, or improve documentation? Read up on our guidelines for contributing and drive development with yarn test --watch
away!
Disclaimer
This library and the GraphQL over WebSocket Protocol are not cross-compatible with the legacy subscriptions-transport-ws
and its accompanying Protocol.
You must use graphql-ws
coherently and implement the GraphQL over WebSocket Protocol on both sides, server and the client.