durable-objects

Durable Objects provide per-entity durable SQLite storage and concurrency controls on the Cloudflare edge, enabling stateful application logic without centralized databases or ad-hoc in-memory state. You design one Durable Object per logical atom like a room or user session.

You configure wrangler durable object bindings and SQLite migrations in your wrangler configuration file to ensure strong consistency storage. This setup allows atomic writes and proper schema management for your edge application's stateful data.

Yes, you can test Cloudflare Durable Objects using @cloudflare/vitest-pool-workers. This approach validates patterns for deterministic stub routing, RPC methods, alarms, and WebSocket handlers to ensure operational correctness.

The best way to route requests is by using deterministic stub routing via getByName to target a specific Durable Object. This ensures stateful coordination is handled by the correct per-entity instance without bottlenecks.

Implementing RPC methods instead of fetch handlers in Durable Objects provides structured operational correctness for stateful coordination. This pattern integrates cleanly with alarms and WebSocket handling while maintaining strong consistency storage rules.

You should avoid Durable Objects if your stateful edge application requires cross-entity queries or complex relational joins, as Durable Objects provide per-entity SQLite storage designed for isolated coordination atoms rather than global querying.