debugger

debugger is a skill for Claude Code, Codex from zhaono1/agent-playbook. It costs 28 tokens per session (1,471 once invoked), scanned A, original, MIT.

A debugging skill for investigating code problems and unexpected behavior in a structured way. Debugging means finding the cause of a problem and correcting it.

In plain words
What is it for?
It is for reproducing bugs, examining errors and logs, tracing likely sources, reducing the problem, and identifying a suitable fix.
Why use it?
It helps narrow a failure from its symptoms to a reproducible cause and the affected part of the code.

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/zhaono1/agent-playbook/debugger
Any agent
npx skills add zhaono1/agent-playbook --skill debugger
Clone the repo
git clone --depth 1 https://github.com/zhaono1/agent-playbook

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 debugger

README.md
[![agentmods](https://agentmods.dev/badge/skills/zhaono1/agent-playbook/debugger.svg)](https://agentmods.dev/skills/zhaono1/agent-playbook/debugger)
Your own site
<a href="https://agentmods.dev/skills/zhaono1/agent-playbook/debugger"><img src="https://agentmods.dev/badge/skills/zhaono1/agent-playbook/debugger.svg" alt="Measured on agentmods" height="20"></a>
Per session 28 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,471 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 $0.00028 $0.01471
Opus 5 $0.00014 $0.00736
Sonnet 5 $0.00006 $0.00294
Haiku 4.5 $0.00003 $0.00147

Measured 4d ago against content hash 22b727ad8187, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

debugger 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.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/debug_report.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

skills/debugger/SKILL.md · 249 lines

How it starts

The opening of the file, as written. The whole thing — 249 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Debugger

An advanced debugging specialist that helps diagnose and resolve code issues systematically.

When This Skill Activates

Activates when you:

  • Report an error or bug
  • Mention "debug this" or "help debug"
  • Describe unexpected behavior
  • Ask why something isn't working

Debugging Process

Phase 1: Understand the Problem

  1. Reproduce the issue

    • What are the exact steps to reproduce?
    • What is the expected behavior?
    • What is the actual behavior?
    • What error messages appear?
  2. Gather context

    # Check recent changes
    git log --oneline -10
    
    # Check error logs
    tail -f logs/error.log
    
    # Check environment
    env | grep -i debug
    

Phase 2: Isolate the Issue

  1. Locate the error source

    • Stack trace analysis
    • Error code lookup
    • Log correlation
  2. Narrow down scope

    • Binary search (comment out half)
    • Minimize reproduction case
    • Identify affected components

Phase 3: Analyze the Root Cause

Common Error Categories
Category Symptoms Investigation Steps
Null/Undefined "Cannot read X of undefined" Trace the variable origin
Type Errors "X is not a function" Check actual vs expected type
Async Issues Race conditions, timing Check promise handling, async/await
State Issues Stale data, wrong state Trace state mutations
Network Timeouts, connection refused Check endpoints, CORS, auth
Environment Works locally, not in prod Compare env vars, versions
Memory Leaks, OOM Profile memory usage
Concurrency Deadlocks, race conditions Check locks, shared state

Phase 4: Form Hypotheses

For each potential cause:

  1. Form a hypothesis
  2. Create a test to validate
  3. Run the test
  4. Confirm or reject

Phase 5: Fix and Verify

  1. Implement the fix
  2. Add logging if needed
  3. Test the fix
  4. Add regression test

Read the full file on GitHub · 249 lines

Files

What ships with it

5 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. 4d ago First seen · 249 lines · 28 tokens per session scan A 22b727ad8187

Subscribe to this mod's changes

debugger is a skill published in the GitHub repository zhaono1/agent-playbook (75 stars, last pushed 9d ago), licensed MIT. It adds 28 tokens to every session and 1,471 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.

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