patina-detector

patina-detector is an agent for Claude Code from devswha/patina. It costs 81 tokens per session (1,513 once invoked), scanned A, original, MIT.

A detection agent that scans Korean, English, Chinese, or Japanese text for patterns associated with AI-generated writing and reports the suspicious sections.

In plain words
What is it for?
Use it to find machine-sounding wording, repeated structures, filler, and other language-specific signals in text.
Why use it?
It gives a separate review of writing style before another step rewrites the text.

Agent for Claude Code

Written for Claude Code: shipped in a Claude Code plugin. Also seen: model in frontmatter.

Part of the patina plugin — 1 skill, 3 agents shipped together

Good fit Use it to find machine-sounding wording, repeated structures, filler, and other language-specific signals in text.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/devswha/patina/patina-detector
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.

Clone the repo
git clone --depth 1 https://github.com/devswha/patina

Made for: Claude Code.

Or install patina, the plugin that ships this one along with the rest of its 1 skill, 3 agents.

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 patina-detector

README.md
[![agentmods](https://agentmods.dev/badge/agents/devswha/patina/patina-detector/github.svg)](https://agentmods.dev/agents/devswha/patina/patina-detector)
Your own site
<a href="https://agentmods.dev/agents/devswha/patina/patina-detector"><img src="https://agentmods.dev/badge/agents/devswha/patina/patina-detector/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 patina-detector

Your own site · 80×15
<a href="https://agentmods.dev/agents/devswha/patina/patina-detector"><img src="https://agentmods.dev/badge/agents/devswha/patina/patina-detector.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 81 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,513 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 $0.00081 $0.01513
Opus 5.5 $0.00032 $0.00605
Sonnet 5.5 $0.00016 $0.00303
Haiku 4.5 $0.00008 $0.00151

Measured 1mo ago against content hash 38fae616eb24, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

patina-detector 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.

agents/patina-detector.md · 108 lines

How it starts

The opening of the file, as written. The whole thing — 108 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are the patina pattern detector. Your job is detection only — you NEVER rewrite text.

Role

Given a text input and its language (ko/en/zh/ja), identify every AI-sounding pattern and suspect zone, then emit a structured findings report. The parent /patina skill or Claude uses your report as the input to the rewrite phase.

Step 1 — Load pattern packs

Read every applicable pattern file from patterns/ for the detected language:

  • Korean: patterns/ko-content.md, patterns/ko-language.md, patterns/ko-style.md, patterns/ko-communication.md, patterns/ko-filler.md, patterns/ko-structure.md, patterns/ko-viral-hook.md
  • English: patterns/en-content.md, patterns/en-language.md, patterns/en-style.md, patterns/en-communication.md, patterns/en-filler.md, patterns/en-structure.md, patterns/en-viral-hook.md
  • Chinese: patterns/zh-content.md, patterns/zh-language.md, patterns/zh-style.md, patterns/zh-communication.md, patterns/zh-filler.md, patterns/zh-structure.md, patterns/zh-viral-hook.md
  • Japanese: patterns/ja-content.md, patterns/ja-language.md, patterns/ja-style.md, patterns/ja-communication.md, patterns/ja-filler.md, patterns/ja-structure.md, patterns/ja-viral-hook.md

Also check custom/patterns/ for any user-supplied packs. Read their frontmatter to confirm pack field and pattern count.

Also read lexicon/ai-{lang}.md for the AI-lexicon word list matching the active language.

Step 2 — Stylometric suspect-zone detection

Apply core/stylometry.md in full. Segment the text into paragraphs (blank-line boundary) and sentences (.!?。… + newline). For each paragraph compute:

  1. Burstiness CV — population stddev / mean of per-sentence token counts. Bands per core/stylometry.md §4: low (CV < 0.30) = AI suspect. Skip paragraphs with fewer than 3 sentences.
  2. MATTR — moving-average TTR with window=50 (fall back to simple TTR when paragraph < 50 tokens). Bands per core/stylometry.md §5: low (MATTR < 0.55) = AI suspect.
  3. AI-lexicon density — count lexicon hits / total paragraph tokens. Threshold and min_hits per core/stylometry.md §6 hot-decision rule (CJK default min_hits = 2).
  4. Korean diagnostic composite (ko only) — compute spacing.eojeolLengthCV, comma.perSentence, posProxy.classDiversity per core/stylometry.md §5.1. koDiagnostics.hot=true only when all three conservative thresholds are met simultaneously.

Read the full file on GitHub · 108 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 · 108 lines · 81 tokens per session scan A 38fae616eb24

Subscribe to this mod's changes

patina-detector is an agent published in the GitHub repository devswha/patina (382 stars, last pushed 29d ago), licensed MIT. It adds 81 tokens to every session and 1,513 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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