performance-analysis

performance-analysis is a skill for Claude Code, Codex from event4u-app/agent-config. It costs 31 tokens per session (1,148 once invoked), scanned A, original, MIT.

A performance-audit procedure for finding bottlenecks in application code, database queries, endpoints, jobs, and data-heavy workflows. It focuses on analysis before writing optimization code.

In plain words
What is it for?
Use it to audit a codebase, investigate a slow endpoint or job, or inspect code handling large datasets and external calls.
Why use it?
It helps reveal where time is actually being spent, including repeated database queries and slow hot paths, before changes are made.

Skill for Claude CodeCodex

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

Good fit Use it to audit a codebase, investigate a slow endpoint or job, or inspect code handling large datasets and external calls.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/event4u-app/agent-config/performance-analysis
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 event4u-app/agent-config --skill performance-analysis
Clone the repo
git clone --depth 1 https://github.com/event4u-app/agent-config

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-analysis

README.md
[![agentmods](https://agentmods.dev/badge/skills/event4u-app/agent-config/performance-analysis/github.svg)](https://agentmods.dev/skills/event4u-app/agent-config/performance-analysis)
Your own site
<a href="https://agentmods.dev/skills/event4u-app/agent-config/performance-analysis"><img src="https://agentmods.dev/badge/skills/event4u-app/agent-config/performance-analysis/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-analysis

Your own site · 80×15
<a href="https://agentmods.dev/skills/event4u-app/agent-config/performance-analysis"><img src="https://agentmods.dev/badge/skills/event4u-app/agent-config/performance-analysis.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 31 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,148 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 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 $0.00031 $0.01148
Opus 5 $0.00015 $0.00574
Sonnet 5 $0.00006 $0.00230
Haiku 4.5 $0.00003 $0.00115

Measured 8d ago against content hash f40a4d028454, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

performance-analysis 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 8d 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.

src/skills/performance-analysis/SKILL.md · 130 lines

How it starts

The opening of the file, as written. The whole thing — 130 lines — stays where its author put it; the contents beside it link to each section on GitHub.

performance-analysis

Mission

Find performance bottlenecks before they affect users. This skill is proactive — it analyzes code for performance issues, not just responds to "it's slow" reports.

For writing performant code patterns (caching, eager loading, Redis), use the performance skill. For test suite performance, use test-performance.

When to use

Use this skill when:

  • Auditing a codebase or flow for performance bottlenecks
  • analysis-autonomous-mode routes here after detecting slow patterns
  • Reviewing code that handles large datasets, loops, or external calls
  • Investigating why a specific endpoint or job is slow

Do NOT use when:

  • Writing new caching/optimization code → use performance
  • Optimizing test suite speed → use test-performance
  • Hunting for functional bugs → use bug-analyzer (proactive mode)

Procedure: Performance analysis

1. Identify hotspots

Focus on code paths with high execution frequency or large data volumes:

  • API endpoints called frequently (list endpoints, dashboards)
  • Queue jobs processing batches
  • Scheduled commands running on large datasets
  • Import/export operations
  • Report generation

2. Database query analysis

Pattern What to look for
N+1 queries ->load() or relationship access in loops, missing ->with()
Missing indexes WHERE clauses on unindexed columns, slow ORDER BY
Full table scans SELECT * without WHERE, LIKE '%term%'
Unnecessary queries Same query executed multiple times in one request
Large result sets Loading thousands of models when only counts or IDs are needed
Missing pagination ->get() on unbounded queries
Suboptimal joins Multiple queries that should be a single JOIN
Transaction scope Transactions holding locks longer than necessary

3. Application-level bottlenecks

Pattern What to look for
Synchronous I/O HTTP calls, file operations, or API calls in the request cycle
Memory bloat Loading entire collections when chunking would work
Redundant computation Same calculation repeated without caching
Missing cache Data that rarely changes but is queried on every request
Stale cache Cache that is never invalidated or has wrong TTL
Serialization overhead Large models serialized to JSON unnecessarily
Loop inefficiency O(n²) patterns with nested loops or repeated array searches

Read the full file on GitHub · 130 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. 8d ago First seen · 130 lines · 31 tokens per session scan A f40a4d028454

Subscribe to this mod's changes

performance-analysis is a skill published in the GitHub repository event4u-app/agent-config (10 stars, last pushed today), licensed MIT. It adds 31 tokens to every session and 1,148 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 2026-09-04.

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