Rivet Actors Overview
Actors are lightweight, stateful functions that maintain persistent state, provide real-time communication, and hibernate when not in use.
Getting Started
Backend Quickstart
Set up actors with Node.js, Bun, and web frameworks
React Quickstart
Build real-time React applications with actors
Key Features
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Long-Lived, Stateful Compute: Each unit of compute is like a tiny server that remembers things between requests – no need to reload data or worry about timeouts. Like AWS Lambda, but with memory and no timeouts.
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Blazing-Fast Reads & Writes: State is stored on the same machine as your compute, so reads and writes are ultra-fast. No database round trips, no latency spikes.
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Realtime, Made Simple: Update state and broadcast changes in realtime with WebSockets or SSE. No external pub/sub systems, no polling – just built-in low-latency events.
Use Cases
Actors are perfect for applications that need persistent state and real-time updates:
AI & Automation
- AI agents: Stateful AI assistants with conversation history
- Workflow automation: Long-running business processes with state persistence
Real-time Communication
- Collaborative documents: Multiple users editing documents simultaneously
- Multiplayer games: Game state management with real-time updates
- Chat rooms: Real-time messaging with message history and user presence
- Live events: Broadcasting updates to many participants
Data & Synchronization
- Local-first sync: Offline-first applications with server synchronization
- Per-user databases: Isolated data stores for each user or tenant
Infrastructure
- Rate limiting: Distributed rate limiting with persistent counters
- Stream processing: Real-time data processing with persistent state
State Management
Actors maintain persistent state that survives restarts, crashes, and deployments. State can be defined as a constant or created dynamically:
Learn more about state management.
Actions
Actions are the primary way to interact with actors. They're type-safe functions that can modify state and communicate with clients:
Actions can be called from your backend, your clients, or other actors:
Learn more about actions and communicating with actors.
Real-time Communication
Actors support real-time bidirectional communication through WebSocket and SSE connections. Clients can establish persistent connections to receive live updates.
For example, to send events to all connected clients:
Clients connect and listen for real-time updates:
Learn more about events and client communication.
Scheduling & Lifecycle
Actors support scheduled tasks and lifecycle management:
Learn more about actor lifecycle.
Type Safety
Rivet provides end-to-end TypeScript safety between clients and actors: