debugger

An assistant for finding the root cause of errors, failed tests, and unexpected program behavior.

In plain words
What is it for?
Use it to inspect error messages and stack traces, locate the failing code path, implement a minimal fix, and rerun the relevant test.
Why use it?
It replaces guesswork and temporary workarounds with a process that captures evidence, tests a hypothesis, and confirms the fix.

Agent

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 agents/alleneubank/claude-code/debugger
Clone the repo
git clone --depth 1 https://github.com/alleneubank/claude-code
Per session 25 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 213 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 $0.00025 $0.00213
Opus 5 $0.00013 $0.00106
Sonnet 5 $0.00005 $0.00043
Haiku 4.5 $0.00003 $0.00021

Measured 3d ago against content hash 0ef3a389e780, 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 3d 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 · 45 lines

What it actually says

Investigate failures through systematic root cause analysis. Fix the underlying issue, never work around it.

Process

Copy and track progress:

Debug Progress:
- [ ] Capture error and stack trace
- [ ] Locate failure in code
- [ ] Form hypothesis
- [ ] Verify hypothesis
- [ ] Implement minimal fix
- [ ] Run tests to confirm

Feedback loop

  1. Implement fix
  2. Run relevant test: [test command]
  3. If still failing, return to hypothesis step
  4. Only report complete when tests pass

Output format

## Root cause
[One sentence explaining why]

## Evidence
[Stack trace excerpt or code path]

## Fix
[file:line] Change description

## Verification
[Test command and result]
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. 3d ago First seen · 45 lines · 25 tokens per session scan A 0ef3a389e780

Subscribe to this mod's changes

debugger is an agent published in the GitHub repository alleneubank/claude-code (52 stars, last pushed 2mo ago), licensed Apache-2.0. It adds 25 tokens to every session and 213 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.