cloudflare-durable-objects

SKILL.md

Stateful Durable Objects for real-time apps, coordination, and persistent state management.

SQLite-backed storage with 10GB capacity, SQL queries, and atomic transactions; KV backend available for simpler key-value use cases

WebSocket hibernation API supports thousands of concurrent connections with automatic wake-up; message size limit increased to 32 MiB (Oct 2025)

Alarms API for scheduling future tasks, batching, and cleanup without relying on setTimeout/setInterval

RPC method calls for type-safe direct invocation, or HTTP fetch handler for complex routing and WebSocket upgrades; three ID strategies (name-based, unique, string-based)

Prevents 20 documented issues including class export errors, migration misconfiguration, hibernation state loss, boolean binding in SQLite, and outgoing WebSocket connection pitfalls

Cloudflare Durable Objects

Status: Production Ready ✅
Last Updated: 2026-01-21
Dependencies: cloudflare-worker-base (recommended)
Latest Versions: wrangler@4.58.0, @cloudflare/workers-types@4.20260109.0
Official Docs: https://developers.cloudflare.com/durable-objects/

Recent Updates (2025):

Oct 2025: WebSocket message size 1 MiB → 32 MiB, Data Studio UI for SQLite DOs (view/edit storage in dashboard)

Aug 2025: getByName() API shortcut for named DOs

June 2025: @cloudflare/actors library (beta) - recommended SDK with migrations, alarms, Actor class pattern. Note: Beta stability - see active issues before production use (RPC serialization, vitest integration, memory management)

May 2025: Python Workers support for Durable Objects

April 2025: SQLite GA with 10GB storage (beta → GA, 1GB → 10GB), Free tier access

Feb 2025: PRAGMA optimize support, improved error diagnostics with reference IDs

Quick Start