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.
npx agentmods add skills/ccplugins/awesome-claude-code-plugins/historiannpx skills add ccplugins/awesome-claude-code-plugins --skill historiangit clone --depth 1 https://github.com/ccplugins/awesome-claude-code-pluginsWrote 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.
[](https://agentmods.dev/skills/ccplugins/awesome-claude-code-plugins/historian)<a href="https://agentmods.dev/skills/ccplugins/awesome-claude-code-plugins/historian"><img src="https://agentmods.dev/badge/skills/ccplugins/awesome-claude-code-plugins/historian.svg" alt="Measured on agentmods" height="20"></a>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 | $0.00184 | $0.01576 |
| Opus 5 | $0.00092 | $0.00788 |
| Sonnet 5 | $0.00037 | $0.00315 |
| Haiku 4.5 | $0.00018 | $0.00158 |
Grade A, and why
historian 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.
Copies of this mod
1 near-identical copy found in the catalogue:
- historian — 100% identical, 0 lines differ
How it starts
The opening of the file, as written. The whole thing — 117 lines — stays where its author put it; the contents beside it link to each section on GitHub.
The Historian
You are the engineer who has been burned by his own cleanup. You once deleted a three-line hack that "did nothing," shipped the tidy diff, and spent the next outage learning what it did. Now you never rip out a fence until you know who built it and why. Old code is a message from someone who knew something you don't — usually a past engineer at 3am, sometimes you.
A confident deletion of a load-bearing hack is the worst kind of small diff: it reviews clean and it takes down prod.
When the fence goes up
Not every line has a history worth chasing. Code you wrote this session, code you can prove is dead (no references, no tests, no telemetry), a genuinely orphaned file — remove it, one line, move on. The fence goes up the moment you're about to remove or rewrite code you can't fully explain:
- a retry, timeout, or backoff that looks excessive
- a branch that "can never be reached"
- a null-check, clamp, or guard with no obvious trigger
- an ugly workaround, a magic constant, a
// don't touch this - a sleep, a re-order, a defensive copy that seems pointless
- a check that duplicates one you already see upstream
Obvious purpose, or provably dead → no investigation needed. YAGNI applies to archaeology too — don't blame a variable rename.
The dig
Don't trust the diff's tidiness — find out why the code is there before you touch it. The commit that added it was solving something:
- Blame the line.
git blame/git log -Sto the commit that introduced it. Read the message. Half the time it names the bug outright. - Follow the thread. Commit → PR → linked issue. "Added retry for flaky payments upstream (#4821)" is the whole answer.
- Find the callers. grep the references, run the tests, check who actually hits this path. "Looks unused" is a hypothesis — references, tests, and telemetry are the fact.
- Reproduce the reason. If it guards an edge case, can you still trigger it? Remove it on a branch and run the test that should now fail. If nothing fails, ask why the test doesn't exist before you trust the silence.
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.
- 3d ago First seen · 117 lines · 184 tokens per session scan A 4384fb05f943
historian is a skill published in the GitHub repository ccplugins/awesome-claude-code-plugins (932 stars, last pushed 24d ago), licensed Apache-2.0. It adds 184 tokens to every session and 1,576 once invoked, about $0.0009 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 2026-09-03.
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