debugging-toolkit-debugger — Claude Code subagent
This subagent investigates errors, failed tests, and odd behavior by tracing failures to their cause and checking a focused fix.
/plugin marketplace add wshobson/agents
/plugin install debugging-toolkit@claude-code-workflowsWhat debugging-toolkit-debugger does
debugging-toolkit-debugger works through an issue from the first error message to a verified solution. It captures the stack trace, identifies how to reproduce the problem, narrows down where the failure occurs, and proposes the smallest suitable code change. The goal is to address the underlying cause rather than cover up the symptom.
Its process includes reading logs, reviewing recent code changes, testing hypotheses, adding targeted debug output, and inspecting variable state. Each investigation can include a cause explanation, supporting evidence, a concrete fix, a test plan, and prevention advice. The configuration sets the model to sonnet.
The subagent is available for Claude Code, Codex, and Cursor. Claude Code needs .claude/agents/debugger.md; without that file, the agent will not be connected. Codex uses .codex/agents/debugger.toml, while Cursor uses .cursor/agents/debugger.md.
What it helps with
- trace an error from its stack trace and logs
- diagnose a failing test
- pinpoint where a failure starts
- test a hypothesis against recent code changes
- prepare and verify a minimal fix
Example prompts for the agent
- Investigate this error, use the stack trace, and identify the root cause.
- Find out why the test started failing after the latest code changes.
- Locate the failure, suggest the smallest fix, and describe how to verify it.
How to install debugging-toolkit-debugger
1Plugin marketplace
/plugin marketplace add wshobson/agents/plugin install debugging-toolkit@claude-code-workflows2Manually: put the files in place
.claude/agents/debugger.mdFor all projects use ~/.claude/agents/. Claude delegates by the description field or an @-mention
Manually: put the files in place
.codex/agents/debugger.tomlCodex defines subagents in TOML: name, description, developer_instructions. Move the Markdown text into developer_instructions by hand. For all projects use ~/.codex/agents/
Manually: put the files in place
.cursor/agents/debugger.mdCursor also reads .claude/agents/
Step by step, with commands for each platform: Claude Code subagents: how to create one, call it and keep context clean
Questions about debugging-toolkit-debugger
How do I install debugging-toolkit-debugger in Claude Code?
Add the marketplace with /plugin marketplace add wshobson/agents, install it with /plugin install debugging-toolkit@claude-code-workflows, then connect .claude/agents/debugger.md.
What does debugging-toolkit-debugger do?
It examines errors, logs, and test failures to locate the underlying cause. The subagent returns evidence, a focused code fix, a verification plan, and prevention advice.
Which platforms support debugging-toolkit-debugger?
It is set up for Claude Code, Codex, and Cursor. The corresponding agent files are .claude/agents/debugger.md, .codex/agents/debugger.toml, and .cursor/agents/debugger.md.
Source text
debugger.md · MIT
--- name: debugging-toolkit-debugger description: Debugging specialist for errors, test failures, and unexpected behavior. Use proactively when encountering any issues. model: sonnet --- You are an expert debugger specializing in root cause analysis. When invoked: 1. Capture error message and stack trace 2. Identify reproduction steps 3. Isolate the failure location 4. Implement minimal fix 5. Verify solution works Debugging process: - Analyze error messages and logs - Check recent code changes - Form and test hypotheses - Add strategic debug logging - Inspect variable states For each issue, provide: - Root cause explanation - Evidence supporting the diagnosis - Specific code fix - Testing approach - Prevention recommendations Focus on fixing the underlying issue, not just symptoms.
© Seth Hobson · MIT · wshobson/agents
