cloudflare-workers-performance

cloudflare-workers-performance is a skill for Claude Code, Codex from secondsky/claude-skills. It costs 42 tokens per session (1,451 once invoked), scanned A, original, MIT.

A guide to improving Cloudflare Workers’ speed and resource use by managing CPU time, memory, caching, bundle size, and response streaming. A bundle is the packaged code sent for execution, while streaming processes data in pieces instead of holding it all in memory.

In plain words
What is it for?
Use it to optimize request handling, cache expensive work, reduce package size, stream large responses, and combine storage operations.
Why use it?
It helps prevent slow responses, CPU-limit errors, memory problems, large startup costs, and timeouts.

Skill for Claude CodeCodex

Part of the cloudflare-workers plugin — 10 skills, 5 commands, 3 agents shipped together

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/secondsky/claude-skills/cloudflare-workers-performance
Any agent
npx skills add secondsky/claude-skills --skill cloudflare-workers-performance
Clone the repo
git clone --depth 1 https://github.com/secondsky/claude-skills

Made for: Claude Code, Codex.

Or install cloudflare-workers, the plugin that ships this one along with the rest of its 10 skills, 5 commands, 3 agents.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for cloudflare-workers-performance

README.md
[![agentmods](https://agentmods.dev/badge/skills/secondsky/claude-skills/cloudflare-workers-performance.svg)](https://agentmods.dev/skills/secondsky/claude-skills/cloudflare-workers-performance)
Your own site
<a href="https://agentmods.dev/skills/secondsky/claude-skills/cloudflare-workers-performance"><img src="https://agentmods.dev/badge/skills/secondsky/claude-skills/cloudflare-workers-performance.svg" alt="Measured on agentmods" height="20"></a>
Per session 42 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,451 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 $0.00042 $0.01451
Opus 5 $0.00021 $0.00726
Sonnet 5 $0.00008 $0.00290
Haiku 4.5 $0.00004 $0.00145

Measured yesterday against content hash 4d5886c3c9f5, 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-performance 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 yesterday.

The scan reads SKILL.md. This mod also ships 5 executable files (scripts/benchmark.sh, scripts/profile-worker.sh, templates/caching-layer.ts, …), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

plugins/cloudflare-workers/skills/cloudflare-workers-performance/SKILL.md · 218 lines

How it starts

The opening of the file, as written. The whole thing — 218 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Cloudflare Workers Performance Optimization

Techniques for maximizing Worker performance and minimizing latency.

Quick Wins

// 1. Avoid unnecessary cloning
// ❌ Bad: Clones entire request
const body = await request.clone().json();

// ✅ Good: Parse directly when not re-using body
const body = await request.json();

// 2. Use streaming instead of buffering
// ❌ Bad: Buffers entire response
const text = await response.text();
return new Response(transform(text));

// ✅ Good: Stream transformation
return new Response(response.body.pipeThrough(new TransformStream({
  transform(chunk, controller) {
    controller.enqueue(process(chunk));
  }
})));

// 3. Cache expensive operations
const cache = caches.default;
const cached = await cache.match(request);
if (cached) return cached;

Critical Rules

  1. Stay under CPU limits - 10ms (free), 30ms (paid), 50ms (unbound)
  2. Minimize cold starts - Keep bundles < 1MB, avoid dynamic imports
  3. Use Cache API - Cache responses at the edge
  4. Stream large payloads - Don't buffer entire responses
  5. Batch operations - Combine multiple KV/D1 calls

Top 10 Performance Errors

Error Symptom Fix
CPU limit exceeded Worker terminated Optimize hot paths, use streaming
Cold start latency First request slow Reduce bundle size, avoid top-level await
Memory pressure Slow GC, timeouts Stream data, avoid large arrays
KV latency Slow reads Use Cache API, batch reads
D1 slow queries High latency Add indexes, optimize SQL
Large bundles Slow cold starts Tree-shake, code split
Blocking operations Request timeouts Use Promise.all, streaming
Unnecessary cloning Memory spike Only clone when needed
Missing cache Repeated computation Implement caching layer
Sync operations CPU spikes Use async alternatives

CPU Optimization

Profile Hot Paths

async function profiledHandler(request: Request): Promise<Response> {
  const timing: Record<string, number> = {};

  const time = async <T>(name: string, fn: () => Promise<T>): Promise<T> => {
    const start = Date.now();
    const result = await fn();
    timing[name] = Date.now() - start;
    return result;
  };

  const data = await time('fetch', () => fetchData());
  const processed = await time('process', () => processData(data));
  const response = await time('serialize', () => serialize(processed));

  console.log('Timing:', timing);
  return new Response(response);
}

Read the full file on GitHub · 218 lines

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. yesterday First seen · 218 lines · 42 tokens per session scan A 4d5886c3c9f5

Subscribe to this mod's changes

cloudflare-workers-performance is a skill published in the GitHub repository secondsky/claude-skills (214 stars, last pushed 2d ago), licensed MIT. It adds 42 tokens to every session and 1,451 once invoked, about $0.0002 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 2026-09-03.