Durable Objects

Build stateful, coordinated applications on Cloudflare's edge using Durable Objects.

Important: This guide focuses on SQLite-backed Durable Objects (recommended for all new projects). Configure with new_sqlite_classes in migrations. Legacy KV-backed Durable Objects exist for backwards compatibility but are not covered in detail here to avoid confusion.

When to Use

• Creating new Durable Object classes for stateful coordination
• Implementing RPC methods, alarms, or WebSocket handlers
• Reviewing existing DO code for best practices
• Configuring wrangler.jsonc/toml for DO bindings and migrations
• Writing tests with @cloudflare/vitest-pool-workers
• Designing sharding strategies and parent-child relationships

Reference Documentation