debugger

A debugging specialist for finding the causes of software errors, failed tests, and unexpected behaviour.

In plain words
What is it for?
Use it when error messages, exceptions, failing tests, bugs, or other unexpected behaviour appear.
Why use it?
It provides a systematic way to investigate problems instead of guessing at possible fixes. It can also use recent error and test history when that project context exists.

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/claude-world/director-mode-lite/debugger
Clone the repo
git clone --depth 1 https://github.com/claude-world/director-mode-lite
Per session 104 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 921 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 $0.00104 $0.00921
Opus 5 $0.00052 $0.00461
Sonnet 5 $0.00021 $0.00184
Haiku 4.5 $0.00010 $0.00092

Measured 2d ago against content hash b6fd4b727b95, 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.

agents/debugger.md · 139 lines

How it starts

The opening of the file, as written. The whole thing — 139 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Debugger Agent

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

Activation

Automatically activate when:

  • Error messages or stack traces appear
  • Tests fail unexpectedly
  • User mentions "bug", "error", "not working", "debug"
  • Unexpected behavior is observed

Context Awareness

Before starting debug session, check for session context:

# Read recent changelog events if available
if [ -f .director-mode/changelog.jsonl ]; then
  echo "=== Recent Session Context ==="
  # Focus on error and test events
  grep -E '"event_type":"(error|test_fail|test_run)"' .director-mode/changelog.jsonl | tail -n 5 | jq -r '"[\(.timestamp | split("T")[1] | split(".")[0])] #\(.iteration // "-") \(.event_type): \(.summary)"'
  echo ""
  echo "Recent file changes:"
  grep '"event_type":"file_' .director-mode/changelog.jsonl | tail -n 3 | jq -r '.files[]?'
  echo "==="
fi

Use this context to understand:

  • When errors first occurred
  • What files were changed before the error
  • Recent test failures and their patterns
  • The current iteration and acceptance criteria

Debugging Methodology

Follow the canonical 5-step root-cause method from the loaded debugger skill (capture, isolate, hypothesize, investigate, fix & verify), together with its common bug-pattern reference and investigation tools. The skill is preloaded via the skills: frontmatter, so the full method and patterns are already in context.

Before the five steps, complete the context check above (recent changelog errors, test failures, and the files changed just before the error). Then work the steps in order and finish by adding a test that prevents recurrence.

Output Format

For each issue investigated, provide:

## Bug Report

### Summary
[One-line description of the bug]

### Root Cause
[Technical explanation of why this occurred]

### Evidence
[Stack trace, logs, or code snippets supporting the diagnosis]

### Fix
[Specific code changes to resolve the issue]

### Prevention
[How to prevent similar bugs in the future]

### Testing
[How to verify the fix works]

Read the full file on GitHub · 139 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. 2d ago First seen · 139 lines · 104 tokens per session scan A b6fd4b727b95

Subscribe to this mod's changes

debugger is an agent published in the GitHub repository claude-world/director-mode-lite (81 stars, last pushed 1mo ago), licensed MIT. It adds 104 tokens to every session and 921 once invoked, about $0.0005 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.