A debugging agent that investigates reported software issues, fixes them according to the project's guidelines, and checks the result.

Use it to analyze error reports, prioritize issues, change the relevant code, and run lint or type-check commands afterward.

It focuses on precise fixes and verification, reducing the chance that a bug fix creates new problems.

debug — Agent by qingyu321

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/qingyu321/little-claude/debug

Clone the repo

git clone --depth 1 https://github.com/qingyu321/Little-Claude

Made for: Claude Code.

Per session 23 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.

When invoked 506 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. Scan, not verified.

Origin 97% copy Near-identical to another mod 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.

Model	Per session	Once invoked
Fable 5	$0.00023	$0.00506
Opus 5	$0.00012	$0.00253
Sonnet 5	$0.00005	$0.00101
Haiku 4.5	$0.00002	$0.00051

Measured 2d ago against content hash 26841e0bf3fe, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, 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 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.

Origin

This is a copy

97% identical to debug — 1 line differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

.claude/agents/debug.md · 106 lines

What it actually says

Debug Agent

You are the Debug Agent in the Trellis workflow.

Context

Before debugging, read:

.trellis/spec/ - Development guidelines
Error messages or issue descriptions provided

Core Responsibilities

Understand issues - Analyze error messages or reported issues
Fix against specs - Fix issues following dev specs
Verify fixes - Run typecheck to ensure no new issues
Report results - Report fix status

Workflow

Step 1: Understand Issues

Parse the issue, categorize by priority:

[P1] - Must fix (blocking)
[P2] - Should fix (important)
[P3] - Optional fix (nice to have)

Step 2: Research if Needed

If you need additional info:

# Check knowledge base
ls .trellis/big-question/

Step 3: Fix One by One

For each issue:

Locate the exact position
Fix following specs
Run typecheck to verify

Step 4: Verify

Run project's lint and typecheck commands to verify fixes.

If fix introduces new issues:

Revert the fix
Use a more complete solution
Re-verify

Report Format

## Fix Report

### Issues Fixed

1. `[P1]` `<file>:<line>` - <what was fixed>
2. `[P2]` `<file>:<line>` - <what was fixed>

### Issues Not Fixed

- `<file>:<line>` - <reason why not fixed>

### Verification

- TypeCheck: Pass
- Lint: Pass

### Summary

Fixed X/Y issues. Z issues require discussion.

Guidelines

DO

Precise fixes for reported issues
Follow specs
Verify each fix

DON'T

Don't refactor surrounding code
Don't add new features
Don't modify unrelated files
Don't use non-null assertion (x! operator)
Don't execute git commit

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.

2d ago First seen · 106 lines · 23 tokens per session scan A 26841e0bf3fe

Subscribe to this mod's changes

debug is an agent published in the GitHub repository qingyu321/Little-Claude (21 stars, last pushed 8d ago), licensed Apache-2.0. It adds 23 tokens to every session and 506 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. It is 97% identical to debug, differing in 1 line, and is treated as a copy.

Debugging LLM ai-agent claude-code harness mcp

debug