WebSocket Link
Execute subscriptions (or other operations) over WebSocket with the subscriptions-transport-ws library
⚠️ We no longer recommend using WebSocketLink or the subscriptions-transport-ws library, because the library is not actively maintained. To execute subscriptions, We instead recommend using the newer graphql-ws library with the accompanying GraphQLWsLink.
Whichever library you use, make sure you use the same library in your server and any clients you support. For more information, see Choosing a subscription library.
The WebSocketLink is a terminating link that's used most commonly with GraphQL subscriptions (which usually communicate over WebSocket), although you can send queries and mutations over WebSocket as well.
WebSocketLink requires the subscriptions-transport-ws library. Install it in your project like so:
npm install subscriptions-transport-ws
Constructor
import { WebSocketLink } from "@apollo/client/link/ws";import { SubscriptionClient } from "subscriptions-transport-ws";const link = new WebSocketLink(new SubscriptionClient("ws://localhost:4000/graphql", {reconnect: true}));
Options
The WebSocketLink constructor takes either a SubscriptionClient object or an options object with the following fields. (These options are passed directly to the SubscriptionClient constructor.)
| Name / Type | Description |
|---|---|
| Required. The URL of the WebSocket endpoint to connect to (e.g., |
| Options for configuring the WebSocket connection. |
| A W3C-compliant WebSocket implementation to use. Provide this if your environment does not provide native WebSocket support (for example, in Node.js). |
Usage
See Subscriptions.