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 skills add hamr0/liteagents --skill root-causegit clone --depth 1 https://github.com/hamr0/liteagentsWrote 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/hamr0/liteagents/root-cause)<a href="https://agentmods.dev/skills/hamr0/liteagents/root-cause"><img src="https://agentmods.dev/badge/skills/hamr0/liteagents/root-cause/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/skills/hamr0/liteagents/root-cause"><img src="https://agentmods.dev/badge/skills/hamr0/liteagents/root-cause.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
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 | $0.00056 | $0.02206 |
| Opus 5.5 | $0.00022 | $0.00882 |
| Sonnet 5.5 | $0.00011 | $0.00441 |
| Haiku 4.5 | $0.00006 | $0.00221 |
Grade A, and why
root-cause 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 20d 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:
- root-cause — 100% identical, 0 lines differ
How it starts
The opening of the file, as written. The whole thing — 237 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Root Cause
Find the cause before you change any code.
The Law
NO FIX WITHOUT A CAUSE YOU CAN POINT AT
A fix at the place the error appeared is a symptom fix. It is a failure even when the symptom goes away, because the real cause is still there and will surface somewhere else, later, with less context.
You cannot propose a fix until Phase 1 is done.
When to Use
Any technical issue: a failing test, a production bug, unexpected behaviour, a performance problem, a broken build, an integration that will not talk.
Especially when it feels like overkill:
- Under time pressure — emergencies are exactly when guessing is most tempting and most expensive
- "Just one quick fix" looks obvious
- You have already tried a fix and it did not work
- You do not fully understand the issue
Simple bugs have root causes too, and finding one takes minutes. Guess-and-check takes hours and leaves damage behind.
Phase 1 — Gather Evidence
Do all of this before forming any opinion about the fix.
1. Read the error completely
Do not skim past it. Read the whole message, the whole stack trace, every warning above it. Note line numbers, file paths, error codes. The answer is often written there in full.
2. Reproduce it consistently
Can you trigger it on demand? What are the exact steps? Does it happen every time?
If it is not reproducible, gather more data. Do not start guessing — an intermittent bug you cannot trigger is a bug you cannot prove you fixed.
3. Check what changed
Recent commits, the working diff, new dependencies, config edits, environment differences between the place it works and the place it does not.
Be careful here: the most recent change is the most available suspect, not the most likely one. Recency is a lead to test, never a conclusion.
4. Instrument the boundaries (multi-component systems)
When the path crosses components — CI → build → sign, API → service → database, workflow → script → tool — do not reason about where it breaks. Measure it.
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.
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.
- 20d ago Changed · +16 lines bb7bc5103f5c
- 1mo ago First seen · 221 lines · 56 tokens per session scan A 1413fbc3e619
root-cause is a skill published in the GitHub repository hamr0/liteagents (26 stars, last pushed today), licensed Apache-2.0. It adds 56 tokens to every session and 2,206 once invoked, about $0.0002 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 2026-09-05.
Other skills, from other repositories
windbg-diagnostic-method
Use with every WinDbg plugin investigation to apply evidence-first reasoning, confidence calibration, contrarian review, structured reporting, and deterministic validation. Not a bug-family-specific triage skill.
windbg-kernel-bugcheck-triage
Use when a kernel dump reports a Windows bugcheck; decode parameters and recover exception or trap context before investigating your driver. Not for user-mode process crashes or blaming a module from its name alone.
windbg-kernel-verifier-triage
Use when a kernel dump contains Driver Verifier violations; inspect flags, bugcheck subcodes, and available I/O shadow state. Not for Application Verifier user-mode stops or inferring a violation from enabled flags alone.
windbg-user-exception-triage
Use when a native C/C++ app, service, or user-mode driver host (including UMDF) crashes with a structured exception in a dump or WinDbg session, including native faults inside managed processes. Not for managed .NET exceptions, WinUI/XAML app errors, or kernel bugchecks.
windbg-user-heap-corruption-investigation
Use when an app, service, or user-mode driver host heap fails or Application Verifier detects corruption; inspect history and bounds. Not for kernel pool corruption or ordinary OOM.
windbg-user-ttd-reverse-debugging-triage
Use when an app, service, or user-mode driver host TTD recording is available and earlier calls, writes, or lifetimes matter. Not for kernel replay or history from a normal dump.