performance-check

A checklist for reviewing code changes that may affect speed, scale, or resource use. It covers areas such as database queries, API responses, rendering, background jobs, caching, file handling, and algorithms.

In plain words
What is it for?
Use it when changing data access, APIs, interfaces, scheduled work, caching, large data processing, network requests, or recursive code.
Why use it?
It helps identify common performance problems before they affect users, including repeated database queries, oversized responses, missing indexes, and unbounded result lists.

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/zerodeng01/sublinkpro/performance-check
Any agent
npx skills add ZeroDeng01/sublinkPro --skill performance-check
Clone the repo
git clone --depth 1 https://github.com/ZeroDeng01/sublinkPro

Made for: Claude Code, Codex.

Per session 36 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,727 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 $0.00036 $0.01727
Opus 5 $0.00018 $0.00864
Sonnet 5 $0.00007 $0.00345
Haiku 4.5 $0.00004 $0.00173

Measured 3d ago against content hash d0ad520782f9, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

performance-check 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 3d 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.

.agents/skills/performance-check/SKILL.md · 225 lines

How it starts

The opening of the file, as written. The whole thing — 225 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Performance Check Skill

This skill provides a comprehensive performance review checklist for code changes that may impact application performance, scalability, or resource usage.

When to use: When making changes to:

  • Database queries and models
  • API endpoints (especially list/search operations)
  • Frontend rendering logic
  • Background jobs and scheduled tasks
  • Caching mechanisms
  • Large data processing
  • File operations
  • Network requests
  • Recursive algorithms

Performance Check Checklist

🗄️ 1. Database Query Optimization

Check for:

  • N+1 query problem: Are related records loaded efficiently?
  • Missing indexes: Are frequently queried columns indexed?
  • **Select ***: Are only needed columns selected?
  • Unnecessary joins: Are all joins necessary?
  • Query in loop: Are queries executed inside loops?
  • Pagination: Are large result sets paginated?
  • Eager loading: Are associations preloaded when needed?

Detailed guide: references/database-optimization.md (includes code examples)


⚡ 2. API Response Optimization

Check for:

  • Response size: Are responses minimized (exclude unnecessary fields)?
  • Pagination: Are large lists paginated?
  • Filtering: Are list endpoints filterable to reduce data?
  • Compression: Is gzip compression enabled?
  • Caching headers: Are appropriate cache headers set?
  • Partial responses: Can clients request only needed fields?

Detailed guide: references/api-optimization.md (includes load testing example)


🎨 3. Frontend Rendering Optimization

Check for:

  • Unnecessary re-renders: Are components optimized with React.memo/useMemo/useCallback?
  • Large lists: Are large lists virtualized (>100 items)?
  • Heavy computations: Are expensive calculations memoized?
  • Bundle size: Are large dependencies code-split?
  • Image optimization: Are images lazy-loaded and properly sized?
  • Debouncing/Throttling: Are frequent events (scroll, input) debounced?

Read the full file on GitHub · 225 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. 3d ago First seen · 225 lines · 36 tokens per session scan A d0ad520782f9

Subscribe to this mod's changes

performance-check is a skill published in the GitHub repository ZeroDeng01/sublinkPro (1,605 stars, last pushed yesterday), licensed MIT. It adds 36 tokens to every session and 1,727 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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