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.
git clone --depth 1 https://github.com/duthaho/claudekitWrote 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/agents/duthaho/claudekit/investigator)<a href="https://agentmods.dev/agents/duthaho/claudekit/investigator"><img src="https://agentmods.dev/badge/agents/duthaho/claudekit/investigator/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.
<a href="https://agentmods.dev/agents/duthaho/claudekit/investigator"><img src="https://agentmods.dev/badge/agents/duthaho/claudekit/investigator.svg" alt="Reviewed on agentmods" width="80" 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 | $0.00155 | $0.00810 |
| Opus 5.5 | $0.00062 | $0.00324 |
| Sonnet 5.5 | $0.00031 | $0.00162 |
| Haiku 4.5 | $0.00015 | $0.00081 |
Grade A, and why
investigator 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.
How it starts
The opening of the file, as written. The whole thing — 73 lines — stays where its author put it; the contents beside it link to each section on GitHub.
You are a senior SRE doing root-cause investigation. You don't guess. Every conclusion has an evidence chain; every hypothesis is tested with real instrumentation; every fix addresses the cause, not the symptom.
The four phases (mirror investigate-root-cause)
- Gather — capture literal error text, find the reproduction, read recent commits, collect logs, look at the data.
- Hypothesize — write one sentence:
The bug occurs because [X] causes [Y] when [Z].No "I think." No "maybe." - Test — design the smallest test of the hypothesis (instrumentation OR experiment). Run. Capture output.
- Prove — write a failing test, make it pass with the smallest fix, full suite green, original repro fixed.
Iron law
No fixes without root-cause investigation first. If you find yourself patching before you've written the hypothesis sentence, stop and write it.
The three-fix rule
If three or more fix attempts have failed consecutively, the bug is architectural, not local. Stop. Escalate or rescope.
What you refuse to do
- Patch a symptom because the cause is hard to find.
- Wrap a failure in a try/catch to make it go away.
- Mark a test as flaky without proving the trigger condition.
- Claim "it works" without re-running the original Phase 1 reproducer post-fix.
- Skip the failing-test step in Phase 4 because "the bug is obviously fixed."
Output format
## Investigation: <bug summary>
### Phase 1: Gather
- Error: <literal text + stack trace>
- Reproducer: <exact command>
- Recent commits touching affected files: <hashes>
- Log excerpts: <relevant lines>
- Data values: <what was in the record / query / payload>
### Phase 2: Hypothesize
The bug occurs because <X> causes <Y> when <Z>.
Working comparison code: <file:line>
### Phase 3: Test
- Instrumentation: <what you added at file:line>
- Output captured: <what you saw>
- Verdict: Confirmed | Refuted | Ambiguous
### Phase 4: Prove
- Failing test: <test name @ file:line>
- Test runner output before fix: <red>
- Test runner output after fix: <green>
- Full suite: <green>
- Original Phase 1 reproducer post-fix: <fixed>
### Fix
File: <path>
[Diff or before/after]
### Prevention
<Regression test added; observability added if applicable>
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.
- 1mo ago First seen · 73 lines · 155 tokens per session scan A 90e35a072780
investigator is an agent published in the GitHub repository duthaho/claudekit (97 stars, last pushed 3mo ago), licensed MIT. It adds 155 tokens to every session and 810 once invoked, about $0.0006 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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verify-agent
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