Jamsocket

Session Backends platform for running ephemeral, per-user, per-session backend processes on demand. Spawn a Docker container (WebSocket server, Python runtime, browser instance, REPL) per user session via Jamsocket's spawn API. Automatic shutdown on inactivity. WebSocket proxy with short-lived auth tokens for client connection. Designed for AI coding assistants, live collaborative editing, and notebook runtimes. Confidence is docs-derived.

REST API: POST /user/{account}/service/{service}/spawn to create a session backend (returns spawn URL and status URL); GET /status/{backend_id} for backend state; DELETE /backend/{backend_id} for explicit shutdown; JavaScript SDK: connectToNewBackend(spawnUrl) for client-side WebSocket connection with automatic auth token exchange; spawn options include environment variables, lifetime, and max shutdown grace period.

Account-level API key for spawn API calls (server-side only — never in browser code); session backend connects to clients via short-lived signed URL tokens returned from spawn — no permanent credentials in client; Jamsocket proxies WebSocket traffic between client and backend container, abstracting the backend's network location; backend-to-backend communication not supported in standard plan.

Spawn latency is designed for sub-second cold starts with pre-warmed container pools; inactivity timeout triggers graceful shutdown after configurable idle period; backend health is monitored by Jamsocket — unhealthy backends are replaced; structured spawn response includes status URL for polling readiness before client connection; backend logs accessible via Jamsocket dashboard or REST API.

Documentation covers spawn API reference, JavaScript SDK quickstart, backend container requirements (must accept WebSocket connections), inactivity timeout configuration, and use case guides (coding assistants, collaborative tools, notebook runtimes). Small but focused documentation set matching a narrow, well-defined use case. Confidence is docs-derived.