graphql-sse

What is graphql-sse?

The graphql-sse package provides a way to implement GraphQL over Server-Sent Events (SSE). This allows for real-time updates and subscriptions in a GraphQL API using the SSE protocol, which is a simpler alternative to WebSockets.

What are graphql-sse's main functionalities?

Setting up a GraphQL server with SSE

This code sets up a basic GraphQL server with SSE support. It defines a schema with a query and a subscription, and starts an HTTP server that listens for GraphQL SSE requests.

const { createServer } = require('http');
const { execute, subscribe } = require('graphql');
const { makeExecutableSchema } = require('@graphql-tools/schema');
const { GraphQLSse } = require('graphql-sse');

const typeDefs = `
  type Query {
    hello: String
  }
  type Subscription {
    time: String
  }
`;

const resolvers = {
  Query: {
    hello: () => 'Hello world!',
  },
  Subscription: {
    time: {
      subscribe: async function* () {
        while (true) {
          yield { time: new Date().toISOString() };
          await new Promise(resolve => setTimeout(resolve, 1000));
        }
      },
    },
  },
};

const schema = makeExecutableSchema({ typeDefs, resolvers });
const server = createServer(GraphQLSse({ schema, execute, subscribe }));

server.listen(4000, () => {
  console.log('Server is running on http://localhost:4000/graphql');
});

Client-side subscription using EventSource

This code demonstrates how to subscribe to a GraphQL subscription using the EventSource API on the client side. It listens for messages from the server and logs the data to the console.

const eventSource = new EventSource('http://localhost:4000/graphql?query=subscription{time}');
eventSource.onmessage = function(event) {
  const data = JSON.parse(event.data);
  console.log(data);
};

Other packages similar to graphql-sse

subscriptions-transport-ws

The subscriptions-transport-ws package provides WebSocket support for GraphQL subscriptions. It is more complex than graphql-sse but offers more features and flexibility for real-time communication.

graphql-ws

The graphql-ws package is a lightweight and modern alternative to subscriptions-transport-ws for implementing GraphQL subscriptions over WebSocket. It is designed to be simple and efficient, similar to graphql-sse but using WebSocket instead of SSE.

apollo-server

Apollo Server is a popular GraphQL server implementation that supports subscriptions using WebSocket. It is a comprehensive solution for building GraphQL APIs and includes many features beyond just subscriptions.

README

graphql-sse

Zero-dependency, HTTP/1 safe, simple, GraphQL over Server-Sent Events Protocol server and client.

Use WebSockets instead? Check out graphql-ws!

Get started

Swiftly start with the get started guide on the website.

Recipes

Short and concise code snippets for starting with common use-cases. Available on the website.

Documentation

Auto-generated by TypeDoc and then rendered on the website.

How does it work?

Read about the exact transport intricacies used by the library in the GraphQL over Server-Sent Events 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!

Changelog

2.2.1 (2023-07-31)

Bug Fixes

• handler: Always include the data field in stream messages (#71) (4643c9a)