cloudflare-workers

A set of instructions for building applications on Cloudflare Workers, a platform that runs server-side code on Cloudflare’s network near users. It covers request handling, storage, caching, and deployment configuration.

In plain words
What is it for?
Creating API endpoints, handling requests, adding middleware, using key-value storage or object storage, caching responses, and testing with Wrangler.
Why use it?
It explains the platform-specific structure and APIs needed for Workers, reducing guesswork when building serverless functions or edge applications.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/usrrname/cursorrules/cloudflare-workers
Any agent
npx skills add usrrname/cursorrules --skill cloudflare-workers
Clone the repo
git clone --depth 1 https://github.com/usrrname/cursorrules

Made for: Claude Code, Codex.

Per session 10 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 376 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00010 $0.00376
Opus 5 $0.00005 $0.00188
Sonnet 5 $0.00002 $0.00075
Haiku 4.5 $0.00001 $0.00038

Measured 2d ago against content hash 3cf932708971, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

cloudflare-workers scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.claude/skills/cloudflare-workers/SKILL.md · 78 lines

What it actually says

Cloudflare Workers Skill

Build edge functions and applications on Cloudflare's global network.

When to Use

  • Creating serverless edge functions
  • Building API endpoints
  • Handling requests at the edge
  • Implementing middleware

Critical Rules

Worker Structure

  • Export default object with fetch handler
  • Use TypeScript for type safety
  • Handle errors with proper responses
  • Use Request/Response Web APIs

Platform APIs

  • Use KV for key-value storage
  • Use Durable Objects for state
  • Leverage Cache API for caching
  • Use R2 for object storage

Performance

  • Keep cold starts minimal
  • Use streaming for large responses
  • Minimize dependencies
  • Bundle efficiently with wrangler

Development

  • Test locally with wrangler dev
  • Use miniflare for testing
  • Set up proper TypeScript types
  • Configure wrangler.toml correctly

Examples

Good

export interface Env {
  KV_NAMESPACE: KVNamespace;
  DB: D1Database;
}

export default {
  async fetch(
    request: Request,
    env: Env,
    ctx: ExecutionContext
  ): Promise<Response> {
    const url = new URL(request.url);
    
    if (url.pathname === '/api/data') {
      const data = await env.KV_NAMESPACE.get('key');
      return Response.json({ data });
    }
    
    return new Response('Not Found', { status: 404 });
  }
};
  • /cloudflare-hono - Hono framework on Workers
  • /typescript - TypeScript fundamentals
Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 78 lines · 10 tokens per session scan A 3cf932708971

Subscribe to this mod's changes

cloudflare-workers is a skill published in the GitHub repository usrrname/cursorrules (10 stars, last pushed 4mo ago), licensed ISC. It adds 10 tokens to every session and 376 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.