WebSockets

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Install

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Where it runs

{
  "error": "WebSocket endpoints need a server that can upgrade connections. Run this service with the Baseline CLI or createEmulator; a plain fetch handler serves HTTP only.",
  "documentation_url": "https://docs.deploybaseline.com/websockets"
}

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The kit

• webSocketRoute(app, path, { authorize, onConnection }) checks the handshake (return metadata, or an HTTP status such as 401 to refuse it), accepts it, tracks the connection, pings it, and closes it when the service stops.
• ConnectionRegistry lists open connections with message counts, broadcasts to a filtered set, reports changes, and closes everything with closeAll().
• startHeartbeat(socket, { intervalMs, maxMissed }) pings on an interval and drops a client that stops answering.
• ResumeBuffer keeps the last events of a session, numbered from 1, so a client that reconnects with the last number it saw can get what it missed.

import { connectWs } from "@deploybaseline/testing";

const client = await connectWs("ws://localhost:4003/link/?ticket=...");
const hello = await client.next(); // the next message, JSON parsed
const event = await client.nextMatching((message) => message.type === "events_api");
client.send({ envelope_id: event.envelope_id });
await client.close();

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Other transports