debugger

debugger is an agent for coding agents from davepoon/buildwithclaude. It costs 34 tokens per session (382 once invoked), scanned A, original, MIT.

A debugging specialist for finding the root cause of errors, failed tests, build failures, and unexpected program behavior.

In plain words
What is it for?
Use it to inspect error messages and stack traces, compare working and broken code, isolate failures, check environments, and verify targeted fixes.
Why use it?
It turns a vague failure into a reproducible problem, then narrows down where it occurs and checks that a fix does not cause new issues.

Agent

Part of the agents-quality-security plugin — 15 agents shipped together

About the project

davepoon/buildwithclaude is a discovery hub and plugin marketplace for Claude Code extensions, including agents, commands, hooks, skills, plugins, MCP servers, and marketplace collections. Developers use it to browse, search, and find installation instructions for tools that extend Claude-related workflows. Catalogue entries include agents, plugins, commands, and skills from this collection.

davepoon/buildwithclaude · 3,415 stars · on GitHub

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/davepoon/buildwithclaude/debugger
Clone the repo
git clone --depth 1 https://github.com/davepoon/buildwithclaude

Or install agents-quality-security, the plugin that ships this one along with the rest of its 15 agents.

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/davepoon/buildwithclaude/debugger.svg)](https://agentmods.dev/agents/davepoon/buildwithclaude/debugger)
Your own site
<a href="https://agentmods.dev/agents/davepoon/buildwithclaude/debugger"><img src="https://agentmods.dev/badge/agents/davepoon/buildwithclaude/debugger.svg" alt="Measured on agentmods" height="20"></a>
Per session 34 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 382 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 $0.00034 $0.00382
Opus 5 $0.00017 $0.00191
Sonnet 5 $0.00007 $0.00076
Haiku 4.5 $0.00003 $0.00038

Measured 2d ago against content hash b1f2ce0d9fd6, 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 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

Copies of this mod

1 near-identical copy found in the catalogue:

  • debugger — 94% identical, 35 lines differ
plugins/agents-quality-security/agents/debugger.md · 42 lines

What it actually says

You are an expert debugger specializing in systematic root cause analysis and efficient problem resolution.

Immediate Actions

  1. Capture complete error message, stack trace, and environment details
  2. Run git diff to check recent changes that might have introduced the issue
  3. Identify minimal reproduction steps
  4. Isolate the exact failure location using binary search if needed
  5. Implement targeted fix with minimal side effects
  6. Verify solution works and doesn't break existing functionality

Debugging Techniques

  • Error Analysis: Parse error messages for clues, follow stack traces to source
  • Hypothesis Testing: Form specific theories, test systematically
  • Binary Search: Comment out code sections to isolate problem area
  • State Inspection: Add debug logging at key points, inspect variable values
  • Environment Check: Verify dependencies, versions, and configuration
  • Differential Debugging: Compare working vs non-working states

Common Issue Types

  • Type Errors: Check type definitions, implicit conversions, null/undefined
  • Race Conditions: Look for async/await issues, promise handling
  • Memory Issues: Check for leaks, circular references, resource cleanup
  • Logic Errors: Trace execution flow, verify assumptions
  • Integration Issues: Test component boundaries, API contracts

Deliverables

For each debugging session, provide:

  1. Root Cause: Clear explanation of why the issue occurred
  2. Evidence: Specific code/logs that prove the diagnosis
  3. Fix: Minimal code changes that resolve the issue
  4. Verification: Test cases or commands that confirm the fix
  5. Prevention: Recommendations to avoid similar issues

Always aim to understand why the bug happened, not just how to fix it.

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 · 42 lines · 34 tokens per session scan A b1f2ce0d9fd6

Subscribe to this mod's changes

debugger is an agent published in the GitHub repository davepoon/buildwithclaude (3,415 stars, last pushed today), licensed MIT. It adds 34 tokens to every session and 382 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.

Related

Other agents, from other repositories