rca

rca is a command for Claude Code from coleam00/Archon. It costs 10 tokens per session (967 once invoked), scanned A, original, MIT.

A command that investigates a GitHub issue and documents its root cause. Root cause means the underlying reason the problem occurs, rather than only the visible symptom.

In plain words
What is it for?
Use it to inspect an issue with the GitHub CLI, trace the affected code across packages, review recent changes, and produce an RCA document.
Why use it?
It gives implementation work an evidence-based explanation of the issue, including reproduction details, relevant code paths, history, and a proposed fix.

Command for Claude Code

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 commands/coleam00/archon/rca
Clone the repo
git clone --depth 1 https://github.com/coleam00/Archon

Made for: Claude Code.

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/commands/coleam00/archon/rca.svg)](https://agentmods.dev/commands/coleam00/archon/rca)
Your own site
<a href="https://agentmods.dev/commands/coleam00/archon/rca"><img src="https://agentmods.dev/badge/commands/coleam00/archon/rca.svg" alt="Measured on agentmods" height="20"></a>
Per session 10 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 967 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 $0.00010 $0.00967
Opus 5 $0.00005 $0.00483
Sonnet 5 $0.00002 $0.00193
Haiku 4.5 $0.00001 $0.00097

Measured 4d ago against content hash d473c556e4ca, 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 4d 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.

.claude/commands/github_bug_fix/rca.md · 153 lines

How it starts

The opening of the file, as written. The whole thing — 153 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Root Cause Analysis: GitHub Issue #$ARGUMENTS

Objective

Investigate GitHub issue #$ARGUMENTS from this repository, identify the root cause, and document findings for implementation.

Prerequisites:

  • Working in a local Git repository with GitHub origin
  • GitHub CLI installed and authenticated (gh auth status)
  • Valid GitHub issue ID from this repository

Investigation Process

1. Fetch GitHub Issue Details

gh issue view $ARGUMENTS

Extract: title, description, labels, status, comments, reproduction steps.

2. Search Codebase

Use subagents for parallel investigation:

Identify relevant code:

  • Search for components, functions, and modules mentioned in issue
  • Trace the code path that would trigger the reported behavior
  • Check related files across package boundaries

Key areas to investigate based on issue type:

  • Platform adapter issues → packages/adapters/
  • Workflow execution → packages/workflows/
  • UI/frontend → packages/web/
  • Session/conversation state → packages/core/src/state/, packages/core/src/db/
  • Git/isolation → packages/isolation/, packages/git/
  • API/server → packages/server/

3. Review Recent History

Check recent changes to affected areas:

git log --oneline -20 -- [relevant-paths]

Look for:

  • Recent modifications that may have introduced the issue
  • Related bug fixes
  • Refactorings that might have changed behavior

4. Investigate Root Cause

Analyze the code to determine:

  • What is the actual bug or issue?
  • Why is it happening? (5 Whys analysis)
  • Is this a logic error, edge case, race condition, or missing validation?
  • Does it cross package boundaries?
  • Are there related issues or symptoms?

Archon-specific considerations:

  • Session state machine transitions — is a transition trigger missing?
  • Mock.module() test isolation — could test pollution mask the issue?
  • SSE streaming — could event ordering or connection drops cause this?
  • ConversationLockManager — could concurrency be involved?
  • Worktree isolation — is the issue environment-specific?

Read the full file on GitHub · 153 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. 4d ago First seen · 153 lines · 10 tokens per session scan A d473c556e4ca

Subscribe to this mod's changes

rca is a command published in the GitHub repository coleam00/Archon (23,366 stars, last pushed today), licensed MIT. It adds 10 tokens to every session and 967 once invoked, about $0.0001 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.