performance-profiler

A method for finding where software spends its time or memory and improving the parts that cause slowdowns. Profiling means measuring a running program to identify its busiest code paths.

In plain words
What is it for?
Use it to investigate slow code, web pages, endpoints, database queries, or jobs, including high CPU use, memory use, latency, timeouts, and inefficient algorithms or input/output.
Why use it?
It replaces guesswork with before-and-after measurements, helping locate the real bottleneck and check that a change actually improves performance.

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/jayrha/agentskills/performance-profiler
Any agent
npx skills add JayRHa/AgentSkills --skill performance-profiler
Clone the repo
git clone --depth 1 https://github.com/JayRHa/AgentSkills

Made for: Claude Code, Codex.

Per session 154 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,758 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 $0.00154 $0.01758
Opus 5 $0.00077 $0.00879
Sonnet 5 $0.00031 $0.00352
Haiku 4.5 $0.00015 $0.00176

Measured yesterday against content hash 2c3b8276a7e1, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

performance-profiler 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 1 executable file (scripts/bench.py), 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.

performance-profiler/SKILL.md · 142 lines

How it starts

The opening of the file, as written. The whole thing — 142 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Performance Profiler

Overview

Make slow things fast — correctly and provably. This skill enforces a measure-driven loop: never optimize on a hunch, always profile to find the real hot path, fix the biggest contributor first, then re-measure to confirm the win and guard against regressions.

Keywords: performance, profiling, optimization, bottleneck, latency, throughput, p99, slow, benchmark, flamegraph, CPU profile, memory leak, allocations, N+1 query, caching, big-O, complexity, hot path, regression.

The cardinal rule: measure first. Most "obvious" optimizations target the wrong code. Profilers routinely show that 90% of time sits in a place nobody suspected.

Workflow

Follow this loop. Do not skip steps — especially step 1 and step 6.

  1. Define the goal and a metric. Pick ONE primary metric and a target: wall-clock latency (p50/p95/p99), throughput (req/s, rows/s), CPU time, peak memory (RSS), or allocations. Write down the current value and the target. "Make it faster" is not a goal; "cut p95 from 800ms to under 200ms" is.

  2. Reproduce reliably. Build a repeatable scenario with representative data volume. A bottleneck at 10 rows may vanish at 10M and vice-versa. Disable noise: warm caches, JIT warmup, fixed input, quiet machine, multiple runs.

  3. Measure the baseline. Time/benchmark the whole operation before touching anything. Save the numbers. Use scripts/bench.py for a quick statistically sane wall-clock benchmark of a Python callable or shell command.

  4. Profile to find the hot path. Use a real profiler (not scattered print timers) to attribute cost. Find the function/line/query consuming the most time or memory. See references/profiling-tools.md for the right tool per language and how to read its output.

  5. Diagnose and fix the top contributor. Apply the cheapest effective fix from the optimization hierarchy (see below). Change ONE thing at a time so each change's impact is attributable.

Read the full file on GitHub · 142 lines

Files

What ships with it

4 files 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. yesterday First seen · 142 lines · 154 tokens per session scan A 2c3b8276a7e1

Subscribe to this mod's changes

performance-profiler is a skill published in the GitHub repository JayRHa/AgentSkills (4 stars, last pushed 1mo ago), licensed MIT. It adds 154 tokens to every session and 1,758 once invoked, about $0.0008 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.

Related

Other skills, from other repositories

reverse-engineering-tools

Guide for reverse engineering protected games and anti-cheat components across user mode, kernel mode, and hypervisor-aware environments. Use this skill when analyzing drivers, IOCTL protocols, callback registration, injected-code artifacts, integrity checks, protected binaries, or debugging security-sensitive game…

gmh5225/awesome-game-security · 60 tokens

unity-agent-workflows

Use for AI-assisted Unity work that needs live repo discovery, project-derived routing, runtime-owner proof, runtime-visible output hard stops, runtime numeric proof for repeated visible-output failures, state-step guards, multi-agent scope ownership, modular C#/asmdef safety, UI/scene/visual asset gates, data-first…

hashgraph-online/awesome-codex-plugins · 146 tokens

interpreting-mod-author-instructions

Use when deciding how to correctly download/install a Bethesda mod per the author's instructions — triggers "how do I install", "FOMOD choices", "which file to download", "author说明", "install instructions", "which variant", "按作者说明安装", "这个mod怎么装". NOT for deciding whether to include the mod (use evaluating-bgs-mods)…

hashgraph-online/awesome-codex-plugins · 133 tokens

using-bgs-archive

Use when the user wants to inspect, list, extract, unpack, or repack Bethesda BA2/BSA archives; determine archive format/version/compression; or build archive assets for an MO2 overlay. Triggers - "unpack BA2", "extract BSA", "pack archive", "inspect archive", "bgs-archive".

hashgraph-online/awesome-codex-plugins · 75 tokens

orchestrate

Pipeline orchestration: dispatch the highest-priority ready tasks/work units to agents, manage capacity, and coordinate the Todo to Done flow. Invoked as /agiflow:orchestrate. Uses listtasks, listactivetasksbyorg, listmembers, updatetask, getworkunitprogress.

hashgraph-online/awesome-codex-plugins · 64 tokens

design-director

Используй только внутри активного Codex Project Autopilot-проекта, когда уже выбрана проектная фаза и нужен design direction по плану автопилота.

hashgraph-online/awesome-codex-plugins · 41 tokens