durable-objects

durable-objects is Cloudflare’s official skill for building, debugging, and reviewing applications based on Durable Objects. The canonical SKILL.md is published in the official cloudflare/skills repository under skills/durable-objects. According to the provider, Durable Objects help coordinate stateful applications at the edge. The skill is an instruction set for compatible coding agents, not a Cloudflare account, not a replacement for Workers, and not a runtime library. The primary source explicitly directs agents to current official documentation because APIs and configuration can evolve.

Purpose and product boundary

The instructions fit chat rooms, multiplayer applications, collaborative documents, booking and inventory systems, per-tenant state, WebSockets, and scheduled work for individual entities. Their central idea is to model a coordination atom: a Durable Object may represent a room, game, or user instead of forcing every request through one global object. The source also identifies RPC methods, alarms, SQLite storage, bindings, migrations, sharding, and parent-child relationships as areas to review. Stateless HTTP handling, maximum global distribution, and high-fan-out independent requests are better matched to other Cloudflare tools. This boundary prevents the skill from treating every Worker application as a Durable Objects project.

Architecture and operating workflow

According to the provider, an agent should retrieve current documentation first and then inspect the existing project configuration, installed types, and selected storage approach. The source recommends getByName for deterministic routing, while existing IDs or deliberately generated unique IDs serve other justified cases. New classes should configure SQLite migrations correctly, and schema initialization should use blockConcurrencyWhile only in the constructor. Critical data belongs in durable storage first; an in-memory cache must be reconstructible from that storage. RPC methods are preferred for supported compatibility dates, while external I/O inside gates and a single global object should be avoided as throughput hazards. One alarm replaces an existing alarm for the same object, so scheduling, retry, and cancellation behavior need deliberate tests.

Testing and operations

The official reference points new and existing projects to Cloudflare’s Vitest integration for Workers. A useful test checks more than a successful response: one object should retain state across calls, different identities should remain independent, and SQLite data should demonstrate the persistence promised by the design. Alarm tests should use documented test helpers rather than waiting on wall-clock time. Before changing a suite, inspect the installed Vitest, Wrangler, and Cloudflare packages and their configuration. The skill does not replace load testing, monitoring, backup planning, privacy review, or human approval for production changes.

Security and E-E-A-T

This description is grounded in the versioned SKILL.md in Cloudflare’s official repository and official Durable Objects documentation covering concepts, APIs, migrations, storage, best practices, and testing. Cloudflare is, according to the provider, the operator of the described platform; the repository license is identified as Apache-2.0 by the official source. Durable Objects can manage persistent state and connections, so teams must review data modeling, access control, deletion policy, error handling, and location requirements in context. The skill contains no credentials and no dangerous commands. A local agent does not automatically make processing confidential: the selected model provider may process project files and results, while Cloudflare may process requests, logs, and state depending on the service and configuration. Check current limits and provider terms directly with Cloudflare.