dev-debug

dev-debug is a skill for Claude Code, Codex from christopherlouet/claude-base. It costs 33 tokens per session (1,839 once invoked), scanned A, original, MIT.

A methodical guide to finding and fixing software problems. It starts with reproducing the symptom and collecting logs before testing possible causes.

In plain words
What is it for?
Use it to investigate bugs, capture useful evidence, rank possible causes, and verify the fix.
Why use it?
It reduces guesswork when code has an error, behaves unexpectedly, or fails only in certain conditions.

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/christopherlouet/claude-base/dev-debug
Any agent
npx skills add christopherlouet/claude-base --skill dev-debug
Clone the repo
git clone --depth 1 https://github.com/christopherlouet/claude-base

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 dev-debug

README.md
[![agentmods](https://agentmods.dev/badge/skills/christopherlouet/claude-base/dev-debug.svg)](https://agentmods.dev/skills/christopherlouet/claude-base/dev-debug)
Your own site
<a href="https://agentmods.dev/skills/christopherlouet/claude-base/dev-debug"><img src="https://agentmods.dev/badge/skills/christopherlouet/claude-base/dev-debug.svg" alt="Measured on agentmods" height="20"></a>
Per session 33 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,839 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 5.1 $0.00033 $0.01839
Opus 5 $0.00016 $0.00920
Sonnet 5 $0.00007 $0.00368
Haiku 4.5 $0.00003 $0.00184

Measured 2d ago against content hash 86c10fef1fef, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-05, from the pricing page.

Security

Grade A, and why

dev-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 2d 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/skills/dev-debug/SKILL.md · 252 lines

How it starts

The opening of the file, as written. The whole thing — 252 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Debug a Problem

Goal

Identify the root cause of a bug methodically via a systematic 4-phase approach.

Systematic Methodology (4 Phases)

┌──────────────────────────────────────────────────────────────────┐
│                   SYSTEMATIC DEBUGGING                            │
├──────────────────────────────────────────────────────────────────┤
│                                                                   │
│  PHASE 1: OBSERVATION          Collect without interpreting       │
│  ═══════════════════                                              │
│  - Reproduce the exact symptom                                    │
│  - Document the environment                                       │
│  - Capture logs, stack traces, states                             │
│  - DO NOT jump to conclusions                                     │
│                                                                   │
│  PHASE 2: HYPOTHESES           Reason systematically              │
│  ════════════════════                                             │
│  - List ALL possible causes                                       │
│  - Rank by probability (high/medium/low)                          │
│  - Define a validation test for each hypothesis                   │
│  - Use the 5 Whys technique                                       │
│                                                                   │
│  PHASE 3: INVESTIGATION        Prove, do not assume               │
│  ══════════════════════                                           │
│  - Test ONE hypothesis at a time                                  │
│  - Use strategic tracing and logging                              │
│  - Isolate with binary search (code or git bisect)                │
│  - Document each tested hypothesis (confirmed/refuted)            │
│                                                                   │
│  PHASE 4: VERIFICATION         Confirm the fix is real            │
│  ════════════════════                                             │
│  - Reproduce the original bug (must fail without the fix)         │
│  - Apply the minimal fix                                          │
│  - Prove the bug is fixed                                         │
│  - Verify the absence of side effects                             │
│  - Add a non-regression test                                      │
│  - Defense in depth: assertions on invariants                     │
│                                                                   │
└──────────────────────────────────────────────────────────────────┘

Read the full file on GitHub · 252 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. 2d ago First seen · 252 lines · 33 tokens per session scan A 86c10fef1fef

Subscribe to this mod's changes

dev-debug is a skill published in the GitHub repository christopherlouet/claude-base (5 stars, last pushed yesterday), licensed MIT. It adds 33 tokens to every session and 1,839 once invoked, about $0.0002 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.