debug

debug is a skill for Claude Code, Codex from OutlineDriven/odin-codex-plugin. It costs 61 tokens per session (1,130 once invoked), scanned A, original, Apache-2.0.

A method for finding the exact cause of a software defect through a reproducible example and one testable explanation at a time. It uses failures, logs, traces, and targeted inspection as evidence.

In plain words
What is it for?
Investigating crashes, exceptions, failing or intermittent tests, incorrect results, and regressions whose cause is not immediately clear.
Why use it?
It avoids guessing or changing many things at once, which can hide the real cause. The goal is to identify the assumption and code line responsible for the failure.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Investigating crashes, exceptions, failing or intermittent tests, incorrect results, and regressions whose cause is not immediately clear.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/outlinedriven/odin-codex-plugin/debug
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.

Any agent
npx skills add OutlineDriven/odin-codex-plugin --skill debug
Clone the repo
git clone --depth 1 https://github.com/OutlineDriven/odin-codex-plugin

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 debug

README.md
[![agentmods](https://agentmods.dev/badge/skills/outlinedriven/odin-codex-plugin/debug/github.svg)](https://agentmods.dev/skills/outlinedriven/odin-codex-plugin/debug)
Your own site
<a href="https://agentmods.dev/skills/outlinedriven/odin-codex-plugin/debug"><img src="https://agentmods.dev/badge/skills/outlinedriven/odin-codex-plugin/debug/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for debug

Your own site · 80×15
<a href="https://agentmods.dev/skills/outlinedriven/odin-codex-plugin/debug"><img src="https://agentmods.dev/badge/skills/outlinedriven/odin-codex-plugin/debug.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 61 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,130 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 $0.00061 $0.01130
Opus 5.5 $0.00024 $0.00452
Sonnet 5.5 $0.00012 $0.00226
Haiku 4.5 $0.00006 $0.00113

Measured 1mo ago against content hash 877cce404c4e, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, 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 1mo 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.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

  • debug — 100% identical, 0 lines differ
skills/debug/SKILL.md · 74 lines

How it starts

The opening of the file, as written. The whole thing — 74 lines — stays where its author put it; the contents beside it link to each section on GitHub.

A bug is a falsified assumption. Find the assumption, falsify it deliberately, observe the divergence, narrow until one line owns the lie. No speculation, no shotgun edits, no "fix and rerun" guessing.

When to Apply / NOT

Apply: test fails and cause unclear; production stack trace; intermittent / flaky behavior; wrong output without crash; regression after known commit window; heisenbug.

NOT apply: performance regression with correct outputs; security defect; symptom obvious from one-line read; architectural confusion.

Anti-patterns

  • Shotgun debugging: editing several files hoping one fixes it.
  • Print-and-rerun: adding logs without a target observation.
  • Premature fix: patching symptom before isolating root cause.
  • Ignoring the trace: stack frames are evidence.
  • Changing two variables at once: defeats falsification.
  • Deleting the failing test: capturing the bug is the asset.

Hypothesis Loop (language-neutral)

  1. Observe — Reproduce the failure deterministically.
  2. Trace — Read the failure artifact (stack, log, core dump).
  3. Hypothesize — One falsifiable claim. Rank hypotheses by likelihood.
  4. Instrument — Insert minimum probe (breakpoint, structured log, assertion).
  5. Run — Execute the minimal repro.
  6. Confirm or refute — If refuted, demote and pick next hypothesis.
  7. Narrow — Binary-search the suspect range. Use git bisect for regressions.
  8. Confirm root cause — Inverse test: removing/altering the cause must restore correctness.
  9. Hand off — Forward to TDD: minimal repro becomes permanent failing test.

Stack-Trace Reading

  • Top frame is innermost: the failure point.
  • Cause vs context: An exception's caused by chain encodes why; the stack encodes where.
  • Async traces: virtual stacks drop frames between awaits — capture causal context.
  • Symbol fidelity: Strip-mode binaries lose frame names. Build with debug info.
  • Inlined / optimized frames: <inlined> markers signal source-line-to-instruction map is approximate.

Read the full file on GitHub · 74 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. 1mo ago First seen · 74 lines · 61 tokens per session scan A 877cce404c4e

Subscribe to this mod's changes

debug is a skill published in the GitHub repository OutlineDriven/odin-codex-plugin (14 stars, last pushed 3mo ago), licensed Apache-2.0. It adds 61 tokens to every session and 1,130 once invoked, about $0.0002 per session on Opus 5.5. 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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