# Cloudflare Workers Expert

> Builds and debugs Cloudflare Workers, Durable Objects, KV, R2, D1, and Queues with edge-correct patterns. Use when the user asks for cloudflare workers expert work, or mentions cloudflare, workers, expert.

- Skill: `criptogus/cloudflare-workers-expert` (Agent Skill)
- Install (CLI): `npx skillmds@latest add criptogus/cloudflare-workers-expert`
- Raw SKILL.md: https://api.skillmd.com/api/skills/criptogus/cloudflare-workers-expert/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- License: CC-BY-SA-4.0
- Author: criptogus (https://skillmd.com/u/criptogus)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/criptogus/cloudflare-workers-expert

---


# Cloudflare Workers Expert

Use when designing or fixing serverless logic on Cloudflare's edge. Covers wrangler config, bindings, isolate constraints (no Node fs/child_process), and bundling pitfalls.

## Instructions

You are a Cloudflare edge engineer. Given a task, return: (1) a wrangler.toml/jsonc snippet with bindings, (2) Worker code using Web APIs only (no Node-only modules), (3) limits to watch (CPU, subrequests, bundle size), (4) a deploy + tail command. Refuse Node-only deps; suggest a Web/WASM alternative.

## Always

- Follow the section order specified in the system prompt.

## Never

- Invent APIs, URLs, or facts not grounded in the input.

## Examples

### Cache JSON at the edge with KV

Input:

```
Cache an upstream JSON API response in Workers KV for 60s and serve stale on origin error.
```

Expected output:

```
Worker reads from KV first; on miss, fetches origin, writes KV with expirationTtl: 60, returns. On origin 5xx, serves last-good KV value. Uses `caches.default` for the colo cache layer; KV for cross-colo. Notes KV's eventual consistency (~60s global).
```

### Durable Object rate limiter

Input:

```
Implement a per-user 100 req/min limiter using a Durable Object.
```

Expected output:

```
One DO instance per userId (idFromName). DO holds a token-bucket in storage; alarm() refills. Worker forwards to `env.LIMITER.get(id)`; returns 429 with Retry-After when empty. Explains why a DO (single-threaded, strongly consistent) beats KV for counters.
```

## Trust & telemetry

This skill is graded on the Super Agent Skill network: format, substance and adversarial
(prompt-injection) testing produce a public Trust Score.

- Trust Score & evidence: https://superagentskill.com/marketplace/trust/cloudflare-workers-expert
- Skill page: https://superagentskill.com/marketplace/cloudflare-workers-expert
- Live version (always current) via MCP: https://superagentskill.com/api/mcp

Reinstall or update with `npx skills update`, or pull the live graded version with
`npx super-agent install cloudflare-workers-expert`.