rivet-dev/actors

What it solves

Rivet Actors provides a primitive for managing stateful, long-running workloads. It eliminates the complexity of manually coordinating compute, in-memory state, and durable persistence, which is typically required for AI agents, collaborative applications, and complex asynchronous workflows.

How it works

It uses a lightweight "actor" model where each actor is a long-lived process with its own co-located in-memory state and automatic persistence (via SQLite or other databases). Actors can be spawned per user, session, or agent, and they hibernate when idle to save costs. The system includes a global edge network for low-latency routing and built-in support for WebSockets, durable message queues, and scheduling (timers/cron).

Who it’s for

Developers building AI agents with persistent memory, real-time collaborative tools (like shared documents), multi-step durable workflows with automatic retries, or per-tenant database architectures.

Highlights

• Ultra-low overhead: Cold starts around 20ms and minimal memory footprint (~0.6KB per instance).
• Integrated State: Co-located state for 0ms read latency.
• Durable Execution: Built-in queues and workflows with automatic retries.
• Global Distribution: Deploys actors close to users via a global edge network.
• Observability Suite: Includes a real-time SQLite viewer, workflow inspector, and REPL for debugging.