rca

rca is a skill for Claude Code, Codex from FlorinI/Florians-Claude-Code-Kit. It costs 174 tokens per session (1,177 once invoked), scanned A, original, MIT.

A root-cause analysis guide for finding why software is broken by testing possible explanations before changing code.

In plain words
What is it for?
It helps investigate bugs, regressions, outages, flaky tests, and other unexpected behavior.
Why use it?
It reduces guesses and fixes that only hide the real problem.

Skill for Claude CodeCodex

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.

agentmods
npx agentmods add skills/florini/florians-claude-code-kit/rca
Any agent
npx skills add FlorinI/Florians-Claude-Code-Kit --skill rca
Clone the repo
git clone --depth 1 https://github.com/FlorinI/Florians-Claude-Code-Kit

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 rca

README.md
[![agentmods](https://agentmods.dev/badge/skills/florini/florians-claude-code-kit/rca.svg)](https://agentmods.dev/skills/florini/florians-claude-code-kit/rca)
Your own site
<a href="https://agentmods.dev/skills/florini/florians-claude-code-kit/rca"><img src="https://agentmods.dev/badge/skills/florini/florians-claude-code-kit/rca.svg" alt="Measured on agentmods" height="20"></a>
Per session 174 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,177 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00174 $0.01177
Opus 5 $0.00087 $0.00589
Sonnet 5 $0.00035 $0.00235
Haiku 4.5 $0.00017 $0.00118

Measured 3d ago against content hash d07b3509596e, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

rca 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.

home/skills/rca/SKILL.md · 56 lines

How it starts

The opening of the file, as written. The whole thing — 56 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Root Cause Analysis

When something is broken, the cheap and tempting move is to name the first plausible cause and fix it. That is the single most common way root-cause analysis goes wrong, and it is precisely the failure mode of a fluent model: producing a confident, well-argued, wrong cause. The entire job of this skill is to make one habit automatic on every path — state what would prove the hypothesis wrong, then go check before touching the fix. Everything else is just how much rigor to spend on the writeup.

On invocation: triage the depth, then proceed (do not ask)

The moment this skill triggers, choose a depth from the context you already have. Do not interrogate the user with a stakes questionnaire — that ceremony is exactly what this skill is designed to avoid, and it taxes the common (cheap) case hardest. Infer the stakes, announce your choice in one sentence, and proceed. The user keeps a veto either way.

Default to the light path. Escalate to the heavy path if any of these hold:

  • The fix or finding gates an expensive or hard-to-reverse decision — schema migration, data backfill, system rebuild, pricing or contract change, an irreversible deploy.
  • It touches a high blast-radius surface — auth, payments, money movement, data deletion, security, privacy.
  • It is a recurring or repeat failure, or a whole class of bug, not a one-off.
  • The user asked for a written / full / documented RCA.

Honor explicit overrides in both directions. "Quick diagnosis" or "just fix it" means light even when signals are present — if you think that's genuinely risky, say so in one line and then proceed as asked. "Full RCA" or "write it up" means heavy.

Announce in one line, then go. Don't wait for a reply. For example:

  • "Low-stakes and reversible, so I'll do a quick diagnosis. Say 'go deep' if you want the full RCA."
  • "This gates the migration, so I'll do a full documented RCA."
  • "You asked for the writeup, proceeding heavy."

One more rule that holds on both paths: do not narrate the steps as you work ("now doing Step 4..."). The user should see the observation, the check, and the fix — never the machinery. The steps below are internal scaffolding for you, not a script to read aloud.

Read the full file on GitHub · 56 lines

Files

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.

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. 3d ago First seen · 56 lines · 174 tokens per session scan A d07b3509596e

Subscribe to this mod's changes

rca is a skill published in the GitHub repository FlorinI/Florians-Claude-Code-Kit (5 stars, last pushed 5d ago), licensed MIT. It adds 174 tokens to every session and 1,177 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 2026-08-31.

Related

Other skills, from other repositories

algorithmic-art

Creating algorithmic art using p5.js with seeded randomness and interactive parameter exploration. Use this when users request creating art using code, generative art, algorithmic art, flow fields, or particle systems. Create original algorithmic art rather than copying existing artists' work to avoid copyright…

ThinkInAIXYZ/deepchat · 62 tokens

aptabase-analytics-report

Export and analyze Vibe Aptabase analytics for recent time windows or existing CSV exports, with emphasis on failure rates, affected users, app versions, and OS breakdowns. Use when Codex needs to: (1) export recent analytics with scripts/exportanalytics.py, (2) filter an export to the exact last N hours, (3) restrict…

thewh1teagle/vibe · 0 tokens

deepchat-cli

Use DeepChat's bundled CLI control plane for model inference, image/video/speech generation, transcription, OCR, artifact inspection, public configuration, Skills, and MCP operations. Activate when a user asks to invoke DeepChat capabilities that are not already exposed as a more specific tool, compare models, run a…

ThinkInAIXYZ/deepchat · 80 tokens

git-commit

Generate well-formatted git commit messages following conventional commit standards.

ThinkInAIXYZ/deepchat · 15 tokens

gitnexus-cli

Use when the user needs to run GitNexus CLI commands like analyze/index a repo, check status, clean the index, generate a wiki, or list indexed repos. Examples: "Index this repo", "Reanalyze the codebase", "Generate a wiki".

TabularisDB/tabularis · 59 tokens

gitnexus-impact-analysis

Use when the user wants to know what will break if they change something, or needs safety analysis before editing code. Examples: "Is it safe to change X?", "What depends on this?", "What will break?".

TabularisDB/tabularis · 50 tokens