refactoring

A Python code review helper that finds duplicate code, overly complex functions, and code that can never run. It uses a command-line scanner called pyscn.

In plain words
What is it for?
Use it to locate complexity hotspots, repeated code, dead code, or a combination of these issues and produce detailed reports.
Why use it?
It shows where a Python codebase is difficult to maintain or contains unnecessary code, so refactoring can be focused on specific findings.

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/ludo-technologies/pyscn/refactoring
Any agent
npx skills add ludo-technologies/pyscn --skill refactoring
Clone the repo
git clone --depth 1 https://github.com/ludo-technologies/pyscn

Made for: Claude Code, Codex.

Per session 52 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 547 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 $0.00052 $0.00547
Opus 5 $0.00026 $0.00273
Sonnet 5 $0.00010 $0.00109
Haiku 4.5 $0.00005 $0.00055

Measured yesterday against content hash c8bf61b74aba, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

refactoring 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.

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.

.claude-plugin/pyscn-mcp/skills/refactoring/SKILL.md · 37 lines

What it actually says

Python Refactoring Analysis with pyscn

Run the pyscn CLI to locate concrete refactoring targets. No install needed: uvx pyscn@latest <command>.

Commands

User Request Command
"Find complex functions" uvx pyscn@latest analyze --select complexity <path>
"Find duplicate code" uvx pyscn@latest analyze --select clones <path>
"Find dead code" uvx pyscn@latest analyze --select deadcode <path>
"What should I refactor first?" uvx pyscn@latest analyze --select complexity,deadcode,clones <path>

Key Flags

  • --min-complexity <n>: minimum complexity to report (default: 5). Risk levels: Low (<10), Medium (10-20), High (>20)
  • --clone-threshold <0.0-1.0>: minimum similarity for clone detection (default: 0.65)
  • --min-severity <critical|warning|info>: dead code severity floor (default: warning). Critical means code after return/break/continue/raise that can never execute.
  • --json: write a detailed report with line-level findings. Report files are NOT written to stdout; they go to .pyscn/reports/ and the path is printed on completion.

Prioritizing Findings

  1. Critical dead code: safe deletions, do these first.
  2. High-complexity functions (>20): extract functions, flatten conditionals.
  3. Clone groups spanning multiple files: extract shared helpers; clones within one file are usually quicker wins.

When suggesting a refactor, cite the specific function names, files, and line ranges from the results, and re-run the same command afterward to confirm the improvement.

MCP Alternative

If the pyscn-mcp MCP server is connected, you can use its tools instead of the CLI: check_complexity (min_complexity), detect_clones (similarity_threshold, min_lines), find_dead_code, or analyze_code with analyses: ["complexity", "clone", "dead_code"] to run several at once. Results are returned inline with no report files.

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 · 37 lines · 52 tokens per session scan A c8bf61b74aba

Subscribe to this mod's changes

refactoring is a skill published in the GitHub repository ludo-technologies/pyscn (1,039 stars, last pushed 3d ago), licensed MIT. It adds 52 tokens to every session and 547 once invoked, about $0.0003 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.