five-whys

five-whys is a command for coding agents from NikiforovAll/claude-code-rules. It costs 16 tokens per session (341 once invoked), scanned A, original, Apache-2.0.

A command for investigating the root cause of a problem by repeatedly asking why it happened. The Five Whys is a problem-solving method that traces a symptom back through five causes.

In plain words
What is it for?
Defining a problem, asking five successive why questions, checking the reasoning, and developing preventive solutions.
Why use it?
It helps separate the underlying cause from the visible symptom so proposed fixes address the source of the problem.

Command

Part of the handbook-extras plugin — 7 commands, 4 agents shipped together

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/nikiforovall/claude-code-rules/five-whys
Clone the repo
git clone --depth 1 https://github.com/NikiforovAll/claude-code-rules

Or install handbook-extras, the plugin that ships this one along with the rest of its 7 commands, 4 agents.

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 five-whys

README.md
[![agentmods](https://agentmods.dev/badge/commands/nikiforovall/claude-code-rules/five-whys.svg)](https://agentmods.dev/commands/nikiforovall/claude-code-rules/five-whys)
Your own site
<a href="https://agentmods.dev/commands/nikiforovall/claude-code-rules/five-whys"><img src="https://agentmods.dev/badge/commands/nikiforovall/claude-code-rules/five-whys.svg" alt="Measured on agentmods" height="20"></a>
Per session 16 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 341 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 $0.00016 $0.00341
Opus 5 $0.00008 $0.00170
Sonnet 5 $0.00003 $0.00068
Haiku 4.5 $0.00002 $0.00034

Measured 3d ago against content hash c2e0e5e72790, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

five-whys 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.

plugins/handbook-extras/commands/five-whys.md · 48 lines

What it actually says

Five Whys Analysis

Use the "Five Whys" root cause analysis technique to deeply understand problems.

Process:

1. Define the Problem

Clearly state the issue or symptom

2. Ask "Why?" Five Times

  • Why did this problem occur? → Answer 1
  • Why did Answer 1 happen? → Answer 2
  • Why did Answer 2 happen? → Answer 3
  • Why did Answer 3 happen? → Answer 4
  • Why did Answer 4 happen? → Answer 5 (Root Cause)

3. Validate Root Cause

  • Verify the logical chain
  • Check if addressing root cause prevents recurrence
  • Consider multiple root causes if applicable

4. Develop Solutions

  • Address the root cause, not just symptoms
  • Create preventive measures
  • Consider systemic improvements

Example:

Problem: Application crashes when processing large files

  1. Why? → The application runs out of memory
  2. Why? → It loads entire file into memory at once
  3. Why? → The file parser wasn't designed for streaming
  4. Why? → Initial requirements only specified small files
  5. Why? → Requirements gathering didn't consider future growth

Root Cause: Incomplete requirements gathering process Solution: Implement streaming parser and improve requirements process

Best Practices:

  • Focus on process, not people
  • Look for systemic issues
  • Document the analysis
  • Involve relevant stakeholders
  • Test solutions address root cause
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 · 48 lines · 16 tokens per session scan A c2e0e5e72790

Subscribe to this mod's changes

five-whys is a command published in the GitHub repository NikiforovAll/claude-code-rules (141 stars, last pushed 5d ago), licensed Apache-2.0. It adds 16 tokens to every session and 341 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.