# Durable Objects

> Stateful coordination on Workers

**Subcategory:** Cloudflare  
**License:** Apache-2.0  
**Source:** https://github.com/cloudflare/skills/blob/main/skills/durable-objects/SKILL.md

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## When it is useful

Create and review Cloudflare Durable Objects. Use when building stateful coordination (chat rooms, multiplayer games, booking systems), implementing RPC methods, SQLite storage, alarms, WebSockets, or reviewing DO code for best practices. Covers Workers integration, wrangler config, and testing with Vitest. Biases towards retrieval from Cloudflare docs over pre-trained knowledge.

## The Catch

Stateful Durable Objects (SQLite, alarms, WebSockets). False-fires on any “stateful agent” that isn’t a DO.