dev-performance-diagnosis

dev-performance-diagnosis is a skill for Claude Code, Codex from BlueSkyXN/Codex-is-all-you-need. It costs 35 tokens per session (354 once invoked), scanned A, original, GPL-3.0.

A guide for finding the causes of slow software, including code, APIs, database queries, memory use, page loading, builds, and scaling limits.

In plain words
What is it for?
Use it to investigate slow requests, growing memory use, slower builds, frontend loading problems, or capacity issues.
Why use it?
It helps identify which part of a system is creating delays or using too many resources.

Skill for Claude CodeCodex

Which agent this was written for is unclear — body not stored (licence); the path alone says nothing.

Good fit Use it to investigate slow requests, growing memory use, slower builds, frontend loading problems, or capacity issues.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/blueskyxn/codex-is-all-you-need/dev-performance-diagnosis
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.

Any agent
npx skills add BlueSkyXN/Codex-is-all-you-need --skill dev-performance-diagnosis
Clone the repo
git clone --depth 1 https://github.com/BlueSkyXN/Codex-is-all-you-need

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 dev-performance-diagnosis

README.md
[![agentmods](https://agentmods.dev/badge/skills/blueskyxn/codex-is-all-you-need/dev-performance-diagnosis/github.svg)](https://agentmods.dev/skills/blueskyxn/codex-is-all-you-need/dev-performance-diagnosis)
Your own site
<a href="https://agentmods.dev/skills/blueskyxn/codex-is-all-you-need/dev-performance-diagnosis"><img src="https://agentmods.dev/badge/skills/blueskyxn/codex-is-all-you-need/dev-performance-diagnosis/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 dev-performance-diagnosis

Your own site · 80×15
<a href="https://agentmods.dev/skills/blueskyxn/codex-is-all-you-need/dev-performance-diagnosis"><img src="https://agentmods.dev/badge/skills/blueskyxn/codex-is-all-you-need/dev-performance-diagnosis.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 35 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 354 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin unknown 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 $0.00035 $0.00354
Opus 5 $0.00017 $0.00177
Sonnet 5 $0.00007 $0.00071
Haiku 4.5 $0.00003 $0.00035

Measured 12d ago against content hash ac0c84a117e4, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

dev-performance-diagnosis 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 12d 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.

examples/catalog/dev/skills/dev-performance-diagnosis/SKILL.md · 63 lines

The source is not reproduced here

Licensed GPL-3.0

The repository is licensed GPL-3.0, which this catalogue does not treat as permission to reproduce the file. Read it at the source.

Read it on GitHub

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. 12d ago First seen · 63 lines · 35 tokens per session scan A ac0c84a117e4

Subscribe to this mod's changes

dev-performance-diagnosis is a skill published in the GitHub repository BlueSkyXN/Codex-is-all-you-need (21 stars, last pushed 27d ago), licensed GPL-3.0. It adds 35 tokens to every session and 354 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 2026-08-30.

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