# Cloudflare Workers [[Cloudflare]] Workers is a serverless execution environment that runs JavaScript, TypeScript, Python, Rust, and WebAssembly at the edge of Cloudflare's global network. Code runs inside V8 isolates rather than containers, which keeps cold starts in the low milliseconds and eliminates the per-instance overhead that makes traditional FaaS expensive at scale. The runtime is a subset of the standard Web Platform: `fetch`, `Request`, `Response`, `URL`, `WebSocket`, `Streams`, `Crypto`. Node.js compatibility used to be an opt-in flag; since August 4, 2026 it's on by default for any Worker with a compatibility date of 2026-08-04 or later (`node:crypto`, `node:fs`, `node:http` and friends just work). Workers are designed to be tiny, fast, and stateless ; persistent state lives in companion services like [[Cloudflare Durable Objects]], KV, R2, D1, and Queues. ## Why It Matters The combination of V8 isolates + global anycast deployment + tight integration with the rest of Cloudflare's edge gives Workers a performance and cost profile that is hard to match on AWS Lambda, Vercel, or Fly. Workers Free tier (100k requests/day) is enough to run real production traffic for personal projects, and Workers Paid (\$5/month for 10M requests) is the cheapest serverless platform on the market for most workloads. It is increasingly used as a control plane for AI agent infrastructure: brokers, credential managers, [[Rate Limiting|rate limiters]], webhook routers. [[Crabbox]] uses a Worker (with a Durable Object) as its credential broker for leasing remote test machines. ## Common Use Cases - **API gateways and edge proxies**: rewrite requests, validate auth, fan out to backends - **A/B testing and personalization at the edge**: zero-latency cookie reads - **Webhook routing and transformation**: GitHub → Slack, Stripe → internal queue - **Auth brokers**: hold provider credentials, issue scoped tokens to clients - **AI control planes**: rate limit, meter spend, broker access to GPU/runner pools - **Static asset transformation**: image resizing, HTML rewriting ## Limits Worth Knowing - **CPU time**: 10 ms (free); 30 s by default on paid, configurable up to 5 minutes per request; longer for [[Cloudflare Durable Objects|Durable Object]] alarms and Queues consumers - **Memory**: 128 MB per isolate - **Bundle size**: 64 MiB uncompressed on every plan since September 4, 2026 (the old 3 MB free / 10 MB paid compressed caps are gone) - **No long-lived TCP**: Workers are request/response by design ; for sticky connections use Durable Objects with WebSocket hibernation ## What changed in 2026 - **[[Cloudflare Dynamic Workers|Dynamic Workers]]** (open beta, March 24): a Worker can spin up other Workers at runtime to run untrusted or AI-generated code in milliseconds. It's the engine behind the [[Code Mode MCP Pattern]] and one of the two backends of [[Cloudflare Sandbox SDK|Sandboxes]] - **[[Cloudflare Temporary Accounts|Temporary accounts]]** (June 19): agents can deploy without a Cloudflare account and a human claims the result - **Access on Workers** (August 14): put [[Cloudflare Access and Zero Trust|Cloudflare Access]] in front of one Worker or make every Worker private by default - **Python Workers** run WSGI frameworks such as Django and Flask (September 2) - **Worker Previews** (September 22): an isolated, production-like environment per pull request, with its own URL, config and observability (separate Durable Object and Container namespaces included) - **[[Cloudflare CLI|`cf` CLI]]** (beta, September 28): one CLI for the whole Cloudflare API and for Workers projects, generated by [[Cloudflare Forge]]; `cf migrate` converts a [[Wrangler]] config ## References - Workers home: https://workers.cloudflare.com/ - Documentation: https://developers.cloudflare.com/workers/ - Pricing: https://developers.cloudflare.com/workers/platform/pricing/ - Limits: https://developers.cloudflare.com/workers/platform/limits/ - Changelog, Node.js compatibility on by default (2026-08-04): https://developers.cloudflare.com/changelog/post/2026-08-04-nodejs-compat-default/ - Changelog, 64 MiB Worker size (2026-09-04): https://developers.cloudflare.com/changelog/post/2026-09-04-increased-worker-size-limit/ - Changelog, Dynamic Workers open beta (2026-03-24): https://developers.cloudflare.com/changelog/post/2026-03-24-dynamic-workers-open-beta/ - Changelog, temporary accounts (2026-06-19): https://developers.cloudflare.com/changelog/post/2026-06-19-temporary-accounts-for-agents/ - Changelog, Access on Workers (2026-08-14): https://developers.cloudflare.com/changelog/post/2026-08-14-workers-access/ - Changelog, Python Workers with WSGI frameworks (2026-09-02): https://developers.cloudflare.com/changelog/post/2026-09-02-python-workers-web-framework-support/ - Changelog, Worker Previews (2026-09-22): https://developers.cloudflare.com/changelog/post/2026-09-22-worker-previews/ - Changelog, Cloudflare CLI beta (2026-09-28): https://developers.cloudflare.com/changelog/post/2026-09-28-cloudflare-cli-beta/ ## Related - [[Cloudflare]] - [[Cloudflare Pages]] - [[Cloudflare Durable Objects]] - [[Cloudflare R2]] - [[Cloudflare D1]] - [[Cloudflare KV]] - [[Cloudflare Vectorize]] - [[Cloudflare Hyperdrive]] - [[Cloudflare Workers AI]] - [[Cloudflare Agents SDK]] - [[Cloudflare Sandbox SDK]] - [[Cloudflare Dynamic Workers]] - [[Cloudflare Queues]] - [[Cloudflare Pipelines]] - [[Cloudflare Containers]] - [[Cloudflare Browser Rendering|Cloudflare Browser Run]] - [[KiteSurf]] - [[Cloudflare AI Gateway]] - [[Cloudflare Artifacts]] - [[Cloudflare Email Routing and Sending]] - [[Cloudflare Flagship]] - [[Cloudflare Access and Zero Trust]] - [[Wrangler]] - [[Cloudflare Forge]] - [[Code Mode MCP Pattern]] - [[Crabbox]] - [[OpenClaw]] - [[TypeScript]] - [[Rust]] - [[Cloudflare Temporary Accounts]] — deploy without an account, claim within 60 minutes