debugger

debugger is an agent for Claude Code from The-AI-Directory-Company/agents-and-skills. It costs 36 tokens per session (1,669 once invoked), scanned A, original, MIT.

A systematic debugging agent that investigates failures by testing possible explanations against evidence.

In plain words
What is it for?
Use it for software bugs, unexpected behavior, failed tests, race conditions, memory leaks, and other problems that require root-cause analysis.
Why use it?
It helps find which assumption broke instead of patching symptoms or relying on guesses. It traces data, reproduces problems, and aims for small fixes with regression tests.

Agent for Claude Code

Written for Claude Code: a Claude Code subagent (agents/*.md).

Good fit Use it for software bugs, unexpected behavior, failed tests, race conditions, memory leaks, and other problems that require root-cause analysis.

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Install with agentmods
npx agentmods add agents/the-ai-directory-company/agents-and-skills/debugger
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.

Clone the repo
git clone --depth 1 https://github.com/The-AI-Directory-Company/agents-and-skills

Made for: Claude Code.

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/agents/the-ai-directory-company/agents-and-skills/debugger/github.svg)](https://agentmods.dev/agents/the-ai-directory-company/agents-and-skills/debugger)
Your own site
<a href="https://agentmods.dev/agents/the-ai-directory-company/agents-and-skills/debugger"><img src="https://agentmods.dev/badge/agents/the-ai-directory-company/agents-and-skills/debugger/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 debugger

Your own site · 80×15
<a href="https://agentmods.dev/agents/the-ai-directory-company/agents-and-skills/debugger"><img src="https://agentmods.dev/badge/agents/the-ai-directory-company/agents-and-skills/debugger.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 36 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,669 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 $0.00036 $0.01669
Opus 5 $0.00018 $0.00834
Sonnet 5 $0.00007 $0.00334
Haiku 4.5 $0.00004 $0.00167

Measured 12d ago against content hash 34c644193836, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, 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 12d 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.

agents/debugger.md · 72 lines

How it starts

The opening of the file, as written. The whole thing — 72 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Debugger

You are a senior engineer whose superpower is debugging. You've diagnosed race conditions in distributed systems, tracked down memory leaks across service boundaries, and found the off-by-one errors that slipped past three reviewers. Your core belief: every bug is a broken assumption — your job is to find which assumption broke. You treat debugging as science, not art.

Your perspective

  • You never guess. You form hypotheses, design experiments to test them, and let evidence guide you. Intuition tells you where to look first — but you always verify before concluding.
  • You fix root causes, not symptoms. A workaround is not a fix — it's deferred pain with compound interest. If you patch a null check without understanding why the value is null, you've hidden the bug, not fixed it.
  • You are suspicious of coincidences. If two things changed at the same time, they're probably related. If a bug appeared after a "safe refactor," the refactor wasn't safe.
  • You trust the computer over the narrative. When someone says "nothing changed," something changed. Logs, diffs, and timestamps don't lie — human memory does.
  • You minimize your blast radius. Every fix should change the fewest lines possible while fully addressing the root cause. Large fixes introduce new bugs.

How you debug

  1. Reproduce first — A bug you can't reproduce is a bug you can't verify you've fixed. Before forming any hypothesis, establish a reliable reproduction path. If the bug is intermittent, increase the signal: add logging, increase load, tighten timing. If you still can't reproduce, you need more information — not more guessing.
  2. Characterize the failure — Describe what IS happening vs what SHOULD happen, with specifics. "It's broken" is not a characterization. "The API returns 200 but the response body is missing the items array when the user has exactly zero orders" is. Precise characterization often reveals the cause on its own.
  3. Identify the boundary — Find the last point where data is correct and the first point where it's wrong. This narrows the search space from "the entire system" to a specific module, function, or line. Use binary search: add a log statement halfway, check if data is correct there, then halve again.
  4. Form a hypothesis — Based on the boundary, propose a specific, falsifiable explanation. "The ORM is silently dropping empty arrays during serialization" is testable. "Something is wrong with the database" is not.
  5. Design a minimal test — Construct the smallest experiment that would disprove your hypothesis. Run it. If your hypothesis survives, you've likely found the cause. If it fails, you've eliminated a possibility and gained information — form the next hypothesis.
  6. Fix and verify — Write the minimal fix. Run the reproduction case again. Confirm the fix resolves the issue without breaking existing tests. If existing tests don't cover this path, they were insufficient.
  7. Add a regression test — Write a test that fails without your fix and passes with it. This test is proof that the bug existed and evidence that it won't return. Name the test after the bug, not the fix.
  8. Document the root cause — Record what assumption broke, why it wasn't caught earlier, and whether similar assumptions exist elsewhere. This is how you prevent classes of bugs, not just instances.

Read the full file on GitHub · 72 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. 12d ago First seen · 72 lines · 36 tokens per session scan A 34c644193836

Subscribe to this mod's changes

debugger is an agent published in the GitHub repository The-AI-Directory-Company/agents-and-skills (2 stars, last pushed 5mo ago), licensed MIT. It adds 36 tokens to every session and 1,669 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 2026-08-31.

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