Partykit

PartyKit provides serverless WebSocket rooms on Cloudflare's edge — each 'party' is a room with shared state and broadcast messaging, deployed globally with Durable Objects. For agents: connect to a party room to broadcast real-time updates to all connected clients (live dashboards, notifications, presence indicators), read/write shared room state (persistent across sessions), and build multiplayer features without managing WebSocket servers. TypeScript SDK is clean; deploy a PartyKit server as a simple class. Strong fit for collaborative AI features, shared agent workspaces, and real-time agent coordination channels. Confidence is docs-derived.

Server SDK: define a PartyKit server as a TypeScript class with onConnect(conn), onMessage(msg, conn), onClose(conn) methods. Deploy with npx partykit deploy. REST API: GET https://{project}.{username}.partykit.dev/parties/{party}/{room-id} lists connections. POST /parties/{party}/{room-id} broadcasts a message to all connections in a room (from server or REST). WebSocket client: new PartySocket({host, room}) connects to a party room from the browser or Node.js. Shared state: this.room.storage.put/get for persistent room state. Party → all connections broadcast via this.party.broadcast(msg).

API key auth for deploy: PARTYKIT_TOKEN environment variable (set during partykit login). REST API requests to deployed parties: optionally protected by custom auth logic in the server onConnect/onRequest handlers (developer-implemented). HTTPS enforced. Cloudflare's global network handles DDoS and TLS termination. No built-in per-user auth model — authentication logic is customizable in the server class.

WebSocket connection lifecycle: onConnect → onMessage → onClose with connection object per client. Errors in onMessage are caught and logged; uncaught exceptions cause party restart. Shared state (Durable Objects storage) is durable — survives party restarts. Broadcast: at-most-once delivery to connected clients; clients that disconnect miss messages. Room hibernation: parties hibernate when no connections are active; state is preserved. PartyKit built on Cloudflare Durable Objects — global consistency guarantees. Uptime tied to Cloudflare infrastructure (99.99% SLA).

docs.partykit.io provides getting-started guide, server API reference, client SDK docs, and example applications (collaborative cursors, multiplayer chess, live polls). Getting started: npm install partykit, partykit login, npx partykit dev for local development, npx partykit deploy for production. TypeScript-first. Official starter templates. Active community via PartyKit Discord and GitHub. Free tier available (Cloudflare Workers limits). Part of Cloudflare's ecosystem.