performance-profiler

performance-profiler is a skill for Claude Code, Codex from seaworld008/Commonly-used-high-value-skills. It costs 36 tokens per session (3,209 once invoked), scanned A, original, MIT.

A profiling guide for Node.js, Python, and Go programs that measures CPU, memory, input/output, bundle size, database queries, and load behavior.

In plain words
What is it for?
Creating flamegraphs, finding memory leaks, analyzing bundles, checking slow queries, detecting repeated database queries, and running load tests.
Why use it?
It helps identify the actual bottleneck behind slow responses, growing memory use, large frontend bundles, or database delays.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Needs its repository: it runs a file that does not travel with it, so clone the repository first. The line is clinic flame -- node dist/server.js.

Good fit Creating flamegraphs, finding memory leaks, analyzing bundles, checking slow queries, detecting repeated database queries, and running load tests.

Compare 6 skills from other repositories ↓
Install

Getting it into your agent

It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.

Clone the repo
git clone --depth 1 https://github.com/seaworld008/Commonly-used-high-value-skills
agentmods
npx agentmods add skills/seaworld008/commonly-used-high-value-skills/performance-profiler

Made for: Claude Code, Codex.

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 performance-profiler

README.md
[![agentmods](https://agentmods.dev/badge/skills/seaworld008/commonly-used-high-value-skills/performance-profiler/github.svg)](https://agentmods.dev/skills/seaworld008/commonly-used-high-value-skills/performance-profiler)
Your own site
<a href="https://agentmods.dev/skills/seaworld008/commonly-used-high-value-skills/performance-profiler"><img src="https://agentmods.dev/badge/skills/seaworld008/commonly-used-high-value-skills/performance-profiler/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for performance-profiler

Your own site · 80×15
<a href="https://agentmods.dev/skills/seaworld008/commonly-used-high-value-skills/performance-profiler"><img src="https://agentmods.dev/badge/skills/seaworld008/commonly-used-high-value-skills/performance-profiler.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 36 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,209 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 3 findings, up to medium

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • medium Data Exfiltration · line 114
    Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.
    Fix: Verify the destination URL is trusted and necessary. Remove or replace with documented APIs. Ensure no secrets, tokens, or PII are transmitted.
  • medium MCP Rug Pull · line 317
    npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.
    Fix: Pin the version: npx @scope/[email protected]
  • medium Excessive Agency · line 591
    Skill allows unbounded resource consumption (API calls, storage, compute). Without rate limits or quotas, a compromised or misbehaving agent can cause denial-of-service or cost overruns.
    Fix: Set explicit rate limits, timeouts, and resource quotas for API calls, file operations, and compute. Implement circuit breakers for runaway loops.
How audits are shown
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 5.1 $0.00036 $0.03209
Opus 5 $0.00018 $0.01605
Sonnet 5 $0.00007 $0.00642
Haiku 4.5 $0.00004 $0.00321

Measured 5d ago against content hash 239b4f895515, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

performance-profiler scanned grade A with 1 finding 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 5d 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.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

curl -X POST http://localhost:3000/debug/heap-snapshot
openclaw-skills/performance-profiler/SKILL.md · 469 lines

How it starts

The opening of the file, as written. The whole thing — 469 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Performance Profiler

Tier: POWERFUL
Category: Engineering
Domain: Performance Engineering


Overview

Systematic performance profiling for Node.js, Python, and Go applications. Identifies CPU, memory, and I/O bottlenecks; generates flamegraphs; analyzes bundle sizes; optimizes database queries; detects memory leaks; and runs load tests with k6 and Artillery. Always measures before and after.

Core Capabilities

  • CPU profiling — flamegraphs for Node.js, py-spy for Python, pprof for Go
  • Memory profiling — heap snapshots, leak detection, GC pressure
  • Bundle analysis — webpack-bundle-analyzer, Next.js bundle analyzer
  • Database optimization — EXPLAIN ANALYZE, slow query log, N+1 detection
  • Load testing — k6 scripts, Artillery scenarios, ramp-up patterns
  • Before/after measurement — establish baseline, profile, optimize, verify

When to Use

  • App is slow and you don't know where the bottleneck is
  • P99 latency exceeds SLA before a release
  • Memory usage grows over time (suspected leak)
  • Bundle size increased after adding dependencies
  • Preparing for a traffic spike (load test before launch)
  • Database queries taking >100ms

Golden Rule: Measure First

# Establish baseline BEFORE any optimization
# Record: P50, P95, P99 latency | RPS | error rate | memory usage

# Wrong: "I think the N+1 query is slow, let me fix it"
# Right: Profile → confirm bottleneck → fix → measure again → verify improvement

Node.js Profiling

CPU Flamegraph

# Method 1: clinic.js (best for development)
npm install -g clinic

# CPU flamegraph
clinic flame -- node dist/server.js

# Heap profiler
clinic heapprofiler -- node dist/server.js

# Bubble chart (event loop blocking)
clinic bubbles -- node dist/server.js

# Load with autocannon while profiling
autocannon -c 50 -d 30 http://localhost:3000/api/tasks &
clinic flame -- node dist/server.js
# Method 2: Node.js built-in profiler
node --prof dist/server.js
# After running some load:
node --prof-process isolate-*.log | head -100

Read the full file on GitHub · 469 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 5d ago Changed · -168 lines · -29 tokens per session 239b4f895515
  2. 9d ago First seen · 637 lines · 65 tokens per session scan A efbfd0c28a68

Subscribe to this mod's changes

performance-profiler is a skill published in the GitHub repository seaworld008/Commonly-used-high-value-skills (70 stars, last pushed 5d ago), licensed MIT. It adds 36 tokens to every session and 3,209 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.

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