code-optimizer

code-optimizer is a skill for Claude Code, Codex from ArabelaTso/Skills-4-SE. It costs 76 tokens per session (3,209 once invoked), scanned A, original, Apache-2.0.

A code-review aid for improving Python and Java programs' speed, memory use, and efficiency. It looks for slow patterns and suggests specific changes while keeping behavior intact.

In plain words
What is it for?
Use it to review slow code, reduce memory use, improve database queries, and make file or network operations more efficient. It can show before-and-after examples and discuss trade-offs.
Why use it?
It helps find performance problems that may be difficult to spot by reading code, such as repeated work, excessive memory allocation, slow database access, or blocking input and output.

Skill for Claude CodeCodex

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

Good fit Use it to review slow code, reduce memory use, improve database queries, and make file or network operations more efficient. It can show before-and-after examples and discuss trade-offs.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/arabelatso/skills-4-se/code-optimizer
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 ArabelaTso/Skills-4-SE --skill code-optimizer
Clone the repo
git clone --depth 1 https://github.com/ArabelaTso/Skills-4-SE

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 code-optimizer

README.md
[![agentmods](https://agentmods.dev/badge/skills/arabelatso/skills-4-se/code-optimizer/github.svg)](https://agentmods.dev/skills/arabelatso/skills-4-se/code-optimizer)
Your own site
<a href="https://agentmods.dev/skills/arabelatso/skills-4-se/code-optimizer"><img src="https://agentmods.dev/badge/skills/arabelatso/skills-4-se/code-optimizer/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 code-optimizer

Your own site · 80×15
<a href="https://agentmods.dev/skills/arabelatso/skills-4-se/code-optimizer"><img src="https://agentmods.dev/badge/skills/arabelatso/skills-4-se/code-optimizer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 76 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 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
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 $0.00076 $0.03209
Opus 5.5 $0.00030 $0.01284
Sonnet 5.5 $0.00015 $0.00642
Haiku 4.5 $0.00008 $0.00321

Measured 1mo ago against content hash 34f178e8a592, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

code-optimizer 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 1mo 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.

skills/code-optimizer/SKILL.md · 542 lines

How it starts

The opening of the file, as written. The whole thing — 542 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Code Optimizer

Improve code performance, memory usage, and efficiency through systematic optimization.

Core Capabilities

This skill helps optimize code by:

  1. Analyzing performance bottlenecks - Identifying slow or inefficient code
  2. Suggesting optimizations - Providing concrete improvements with examples
  3. Explaining trade-offs - Describing benefits and potential drawbacks
  4. Measuring impact - Estimating performance gains
  5. Preserving correctness - Ensuring optimizations don't change behavior

Optimization Workflow

Step 1: Identify Optimization Opportunities

Analyze code to find performance bottlenecks.

Look for:

  • Nested loops (O(n²) or worse complexity)
  • Repeated expensive operations
  • Inefficient data structures
  • Unnecessary object creation
  • Database N+1 queries
  • Blocking I/O operations
  • Memory leaks or excessive allocation

Quick Analysis Questions:

  • What is the time complexity? Can it be reduced?
  • Are there repeated calculations that could be cached?
  • Is the right data structure being used?
  • Are there unnecessary copies or allocations?
  • Can operations be batched or parallelized?

Step 2: Categorize the Optimization

Determine the type of optimization needed.

Execution Speed:

  • Algorithm optimization (better complexity)
  • Loop optimization
  • Caching/memoization
  • Lazy evaluation
  • Parallel processing

Memory Usage:

  • Reduce object creation
  • Use generators/streams instead of lists
  • Clear references to enable garbage collection
  • Use appropriate data structures
  • Avoid memory leaks

Database Operations:

  • Query optimization (indexes, joins)
  • Batch operations
  • Connection pooling
  • Caching
  • Reduce round trips

I/O Operations:

  • Buffering
  • Async/non-blocking I/O
  • Batch requests
  • Compression
  • Caching

Step 3: Propose Optimization with Examples

Provide before/after code with clear explanations.

Optimization Template:

## Optimization: [Brief Description]

### Before (Inefficient)
```[language]
[original code]

Issues:

  • Issue 1: [Problem description]
  • Issue 2: [Problem description]

Complexity: O([complexity]) Performance: [estimated time/memory]

After (Optimized)

[optimized code]

Improvements:

  • Improvement 1: [What changed]
  • Improvement 2: [What changed]

Complexity: O([new complexity]) Performance: [estimated time/memory] Gain: [X% faster / Y% less memory]

Why This Works

[Detailed explanation of the optimization]

Trade-offs

Pros:

  • [Benefit 1]
  • [Benefit 2]

Cons:

  • [Drawback 1, if any]
  • [Drawback 2, if any]

When to Use

  • Use when: [scenario]
  • Avoid when: [scenario]

Read the full file on GitHub · 542 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. 1mo ago First seen · 542 lines · 76 tokens per session scan A 34f178e8a592

Subscribe to this mod's changes

code-optimizer is a skill published in the GitHub repository ArabelaTso/Skills-4-SE (259 stars, last pushed 2mo ago), licensed Apache-2.0. It adds 76 tokens to every session and 3,209 once invoked, about $0.0003 per session on Opus 5.5. 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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