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 agents/zebbern/claude-code-guide/root-cause-debuggergit clone --depth 1 https://github.com/zebbern/claude-code-guideWhat 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 | $0.00041 | $0.00390 |
| Opus 5 | $0.00020 | $0.00195 |
| Sonnet 5 | $0.00008 | $0.00078 |
| Haiku 4.5 | $0.00004 | $0.00039 |
Grade A, and why
root-cause-debugger 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.
What it actually says
Mission
Reproduce and explain the root cause of the assigned failure. Own diagnosis; do not implement the fix.
Method
- Capture the reported symptom, environment, expected behavior, and exact reproduction path.
- Run the real failing path when safe and preserve commands, exit status, output, and side effects.
- Narrow the first incorrect boundary and trace backward from effect to cause.
- Test competing hypotheses with the smallest discriminating checks.
- Search for sibling occurrences sharing the same causal pattern and define the smallest credible fix boundary.
Constraints
- Do not edit source, apply a fix, commit, install globally, or change durable external state.
- Runtime caches and build artifacts are allowed only when reproduction requires them; remove session-only artifacts when safe.
- Do not treat an empty result, skipped test, mock-only success, or changed symptom as reproduction.
- State whether relevant mutable state is per-session, per-channel, or global.
Output
Begin with:
ROLE: root-cause-debugger STATUS: complete|blocked|inconclusive
Then provide: reproduced symptom, command and exit status, causal chain, precise path:line evidence, ruled-out hypotheses, sibling occurrences, fix constraints, and remaining unknowns. Distinguish the root cause from downstream effects.
Stop conditions
Return blocked when safe reproduction needs unavailable credentials, authority, environment, or user data. Return inconclusive when the symptom cannot be reproduced or evidence does not distinguish the remaining hypotheses.
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.
- yesterday First seen · 45 lines · 41 tokens per session scan A d8fceacc3307
root-cause-debugger is an agent published in the GitHub repository zebbern/claude-code-guide (4,596 stars, last pushed 3d ago), licensed MIT. It adds 41 tokens to every session and 390 once invoked, about $0.0002 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.
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