A checker for places where a repository's comments, documentation, automation, versions, or dependencies no longer match the code. It verifies claims against the repository before correcting or removing them.

Use it to clean up README files, CLAUDE.md, changelogs, workflow comments, TODOs, dependency versions, publish settings, and references to removed or renamed code.

It helps prevent stale instructions and misleading comments from sending developers in the wrong direction. It also identifies outdated automation and mismatched version information.

derot — Skill for Claude Code by ANcpLua/ancplua-claude-plugins

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 ANcpLua/ancplua-claude-plugins --skill derot

Clone the repo

git clone --depth 1 https://github.com/ANcpLua/ancplua-claude-plugins

Made for: Claude Code.

Or install derot, the plugin that ships this one along with the rest of its 1 skill, 2 commands, 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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/ancplua/ancplua-claude-plugins/derot/github.svg)](https://agentmods.dev/skills/ancplua/ancplua-claude-plugins/derot)

Your own site

<a href="https://agentmods.dev/skills/ancplua/ancplua-claude-plugins/derot"><img src="https://agentmods.dev/badge/skills/ancplua/ancplua-claude-plugins/derot/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/ancplua/ancplua-claude-plugins/derot"><img src="https://agentmods.dev/badge/skills/ancplua/ancplua-claude-plugins/derot.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 133 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 1,158 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.

Model	Per session	Once invoked
Fable 5.1	$0.00133	$0.01158
Opus 5.5	$0.00053	$0.00463
Sonnet 5.5	$0.00027	$0.00232
Haiku 4.5	$0.00013	$0.00116

Measured 2mo ago against content hash ec2b5160c1d2, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

derot 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 2mo 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.

plugins/derot/skills/derot/SKILL.md · 44 lines

How it starts

The opening of the file, as written. The whole thing — 44 lines — stays where its author put it; the contents beside it link to each section on GitHub.

derot — truth-drift auditor

Rot = any place a repo's stated intent has drifted from what the code/build actually is. derot finds it, verifies it against ground truth, and fixes it — correcting where the knowledge is still useful, deleting only what is purely obsolete.

The five rot dimensions

Comment rot — comments that lie about the code beneath them: stale version numbers, references to renamed/removed symbols/methods/files/diagnostic-IDs, resolved TODO/FIXME/HACK/"temporary"/"workaround for X", descriptions of old behavior, copy-paste comments describing a different member, dead-code comments.
Doc rot — CLAUDE.md / README / CHANGELOG / workflow tables whose dependency versions, file lists, command names, or workflow names don't match reality. (Shipped past CHANGELOG entries are history, not rot — never flag them.)
Infra rot — workflow comments that lie; unpinned actions (@v1 → SHA-pin with a # vN comment); hardcoded publish accounts → dynamic secrets; expired/long-lived API keys → OIDC trusted publishing.
Version sync — pins/claims out of sync across Version.props / Directory.Packages.props / global.json / docs; published-vs-pinned drift; a property referenced but defined only by an injected SDK (annotate, don't "fix").
Dependency rationalization — a narrow sub-package used where a parent/meta suffices; a superseded package still used after its successor shipped; redundant direct references already present transitively. This dimension needs external knowledge, not just the repo — see references/dependency-rationalization.md.

Discipline — non-negotiable

Correct beats delete. If a comment explains a genuinely non-obvious why (a workaround's reason, an invariant), fix the wrong details and KEEP the explanation. Delete only when purely obsolete.
Verify root + every transitive use. Before changing anything a comment/doc describes, read the code it refers to and everything that depends on it. Never "fix" a comment to match a wrong assumption — fix whichever of {comment, code} is actually wrong, and chase the change through every caller.
Never invent. Can't confirm it's stale? Leave it; report it as unverified. Do not guess.
Terse + behavioral corrections. Say what/why; don't restate the code.
No drive-by behavior changes. Comments/docs + the named CI modernizations only — unless fixing rot exposes a real bug, in which case say so and fix the root cause.

Read the full file on GitHub · 44 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

references/dependency-rationalization.md 2.7 KB

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.

2mo ago First seen · 44 lines · 133 tokens per session scan A ec2b5160c1d2

Subscribe to this mod's changes

derot is a skill published in the GitHub repository ANcpLua/ancplua-claude-plugins (6 stars, last pushed 2d ago), licensed MIT. It adds 133 tokens to every session and 1,158 once invoked, about $0.0005 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 2026-08-31.

Debugging ancplua-fleet

derot next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
derotANcpLua/ancplua-claude-plugins	Skill	6	2d ago	MIT	A	133	Claude Code
systematic-debuggingopen-metadata/OpenMetadata	Skill	16k	yesterday	Apache-2.0	A	37	Claude Code
log-error-digestzebbern/claude-code-guide	Skill	4.7k	today	MIT	A	71	Claude Code, Codex
incident-response-incident-responsermyndharis/antigravity-skills	Skill	2.0k	4d ago	MIT	A	36	Claude Code, Codex
cwv-optimizeradobe/skills	Skill	324	yesterday	Apache-2.0	A	112	Claude Code
ci-fixersipyourdrink-ltd/bernstein	Skill	1.2k	yesterday	Apache-2.0	A	15	Claude Code, Codex
diagnosing-missing-recordingsPostHog/posthog	Skill	41k	today	none	A	76	Claude Code, Codex