root-cause-debugging

root-cause-debugging is a skill for Claude Code, Codex from makifbaysal/tasktrooper. It costs 47 tokens per session (1,500 once invoked), scanned A, original, Apache-2.0.

A method for finding the underlying cause of a failing test, build, pipeline, or unexpected behavior before changing code. It starts with a repeatable failing check and uses its complete output to guide investigation.

In plain words
What is it for?
Use it for bugs, failed tests, broken builds, red deployment pipelines, unexpected live behavior, or work returned for revision.
Why use it?
It avoids guess-and-check patches that hide symptoms or create new bugs. A reproducible feedback loop makes it possible to confirm whether a fix actually solves the problem.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it for bugs, failed tests, broken builds, red deployment pipelines, unexpected live behavior, or work returned for revision.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/makifbaysal/tasktrooper/root-cause-debugging
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 makifbaysal/tasktrooper --skill root-cause-debugging
Clone the repo
git clone --depth 1 https://github.com/makifbaysal/tasktrooper

Made for: Claude Code, Codex.

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.

agentmods badge for root-cause-debugging

README.md
[![agentmods](https://agentmods.dev/badge/skills/makifbaysal/tasktrooper/root-cause-debugging/github.svg)](https://agentmods.dev/skills/makifbaysal/tasktrooper/root-cause-debugging)
Your own site
<a href="https://agentmods.dev/skills/makifbaysal/tasktrooper/root-cause-debugging"><img src="https://agentmods.dev/badge/skills/makifbaysal/tasktrooper/root-cause-debugging/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.

agentmods 80×15 button for root-cause-debugging

Your own site · 80×15
<a href="https://agentmods.dev/skills/makifbaysal/tasktrooper/root-cause-debugging"><img src="https://agentmods.dev/badge/skills/makifbaysal/tasktrooper/root-cause-debugging.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 47 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,500 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. 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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00047 $0.01500
Opus 5.5 $0.00019 $0.00600
Sonnet 5.5 $0.00009 $0.00300
Haiku 4.5 $0.00005 $0.00150

Measured 8d ago against content hash 40ee33157312, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

root-cause-debugging scanned grade A with 1 finding 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 8d 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.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

This is the skill: before anything else, name ONE command you have already run that goes red on THIS symptom — a failing test, a `curl` against the running service, a `browser_read_dom` that doesn't find what it should,
catalog/agents/backend-developer/skills/root-cause-debugging/SKILL.md · 99 lines

How it starts

The opening of the file, as written. The whole thing — 99 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Root-Cause Debugging

Overview

Random fixes waste time and create new bugs. Quick patches mask underlying issues.

Core principle: ALWAYS find the root cause before attempting fixes. Symptom fixes are failure.

The Iron Law

NO FIXES WITHOUT ROOT CAUSE INVESTIGATION FIRST

Use this for ANY technical issue: a task returned to need_revision, a failing test, a red pipeline, unexpected behavior. Use it ESPECIALLY under time pressure — systematic is faster than guess-and-check thrashing.

The Four Phases

Complete each phase before the next.

Phase 1 — Build a feedback loop, then investigate

This is the skill: before anything else, name ONE command you have already run that goes red on THIS symptom — a failing test, a curl against the running service, a browser_read_dom that doesn't find what it should, a replayed payload. No loop, no hypothesis. If none exists, write the smallest one that reproduces it (a test is the default; a curl/DOM read is the fallback when the bug is only visible live) before reading another line of code.

  1. Read the feedback completely: the reviewer/QA/pipeline comment on the task, the full error output, stack traces, exact files/lines/messages. They often contain the exact answer.
  2. Reproduce consistently in the task workspace with the loop from above: does it happen every time? Not reproducible → gather more data, don't guess.
  3. Check recent changes: git diff, recent commits on the task branch, config changes.
  4. Stage/prod symptom (a runtime error, not a local failure): before reading code, get_environment for the environment, list_runtime_errors with new: true to see whether the group started with the latest deploy, then query_runtime_logs with text: set to the error message. You hold these tools; use them before guessing from the code alone.
  5. Multi-component systems (API → service → database): add diagnostic logging at each component boundary — what enters, what exits — run once, and locate WHICH layer breaks before touching anything. Tag every line you add with a unique marker, e.g. [DEBUG-a4f2], so cleanup is one grep_code for the tag before you finish — an untagged debug log left behind is a review finding.
  6. Trace the bad value backward from where the error appears to where it originates. Fix at the source, not at the symptom.

Read the full file on GitHub · 99 lines

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.

  1. 8d ago First seen · 99 lines · 47 tokens per session scan A 40ee33157312

Subscribe to this mod's changes

root-cause-debugging is a skill published in the GitHub repository makifbaysal/tasktrooper (113 stars, last pushed yesterday), licensed Apache-2.0. It adds 47 tokens to every session and 1,500 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-10-05.

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