debug

debug is a skill for Claude Code, Codex from SienkLogic/plan-build-run. It costs 13 tokens per session (4,728 once invoked), scanned A, original, MIT.

A structured debugging workflow that investigates problems by testing possible causes and saving the findings between sessions.

In plain words
What is it for?
It helps record hypotheses, tests, and results while investigating software issues.
Why use it?
It prevents debugging work and evidence from being lost when the investigation spans multiple conversations.

Skill for Claude CodeCodex

Part of the pbr plugin — 45 skills, 71 commands, 18 agents, 3 hooks 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 skills/sienklogic/plan-build-run/debug
Any agent
npx skills add SienkLogic/plan-build-run --skill debug
Clone the repo
git clone --depth 1 https://github.com/SienkLogic/plan-build-run

Made for: Claude Code, Codex.

Or install pbr, the plugin that ships this one along with the rest of its 45 skills, 71 commands, 18 agents, 3 hooks.

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 debug

README.md
[![agentmods](https://agentmods.dev/badge/skills/sienklogic/plan-build-run/debug.svg)](https://agentmods.dev/skills/sienklogic/plan-build-run/debug)
Your own site
<a href="https://agentmods.dev/skills/sienklogic/plan-build-run/debug"><img src="https://agentmods.dev/badge/skills/sienklogic/plan-build-run/debug.svg" alt="Measured on agentmods" height="20"></a>
Per session 13 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 4,728 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 $0.00013 $0.04728
Opus 5 $0.00006 $0.02364
Sonnet 5 $0.00003 $0.00946
Haiku 4.5 $0.00001 $0.00473

Measured today against content hash 3b17d822e3ee, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

debug 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 today.

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/pbr/skills/debug/SKILL.md · 580 lines

How it starts

The opening of the file, as written. The whole thing — 580 lines — stays where its author put it; the contents beside it link to each section on GitHub.

STOP — DO NOT READ THIS FILE. You are already reading it. This prompt was injected into your context by Claude Code's plugin system. Using the Read tool on this SKILL.md file wastes ~7,600 tokens. Begin executing Step 1 immediately.

Step 0 — Immediate Output

Before ANY tool calls, display this banner:

╔══════════════════════════════════════════════════════════════╗
║  PLAN-BUILD-RUN ► DEBUGGING                                  ║
╚══════════════════════════════════════════════════════════════╝

Then proceed to Step 1.

/pbr:debug — Systematic Debugging

You are running the debug skill. Your job is to run a structured, hypothesis-driven debugging session that persists across conversations. You track every hypothesis, test, and finding in a debug file so work is never lost.

This skill spawns Task(subagent_type: "pbr:debugger") for investigation work.


References

  • references/questioning.md — Investigation questioning patterns: progressive depth, exploratory questions, concrete options (not open-ended)
  • references/ui-brand.md — Status symbols, banners, error boxes for issue reporting

Context Budget

Reference: skills/shared/context-budget.md for the universal orchestrator rules. Reference: skills/shared/agent-type-resolution.md for agent type fallback when spawning Task() subagents.

Additionally for this skill:

  • Never perform investigation work yourself — delegate ALL analysis to the debugger subagent
  • Minimize reading debug file content — read only the latest hypothesis and result section
  • Delegate all code reading, hypothesis testing, and fix attempts to the debugger subagent

Core Principle

Debug systematically, not randomly. Every investigation step must have a hypothesis, a test, and a recorded result. No "let me just try this" — every action has a reason and is documented.


Flow

Step 1: Ensure Debug Directory Exists

CRITICAL (no hook) -- DO NOT SKIP: Create debug directory before any file writes.

Read the full file on GitHub · 580 lines

Files

What ships with it

2 files 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. today First seen · 580 lines · 13 tokens per session scan A 3b17d822e3ee

Subscribe to this mod's changes

debug is a skill published in the GitHub repository SienkLogic/plan-build-run (17 stars, last pushed 5mo ago), licensed MIT. It adds 13 tokens to every session and 4,728 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 2026-09-03.

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