debugger

A troubleshooting assistant for finding the underlying cause of bugs, crashes, production failures, performance problems, and error messages.

In plain words
What is it for?
Use it to investigate broken behavior, analyze errors, reproduce crashes, and plan a root-cause fix.
Why use it?
It replaces guesswork with a process that reproduces the problem, narrows down the responsible component, and prevents regressions with tests.

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/diillson/chatcli/debugger
Clone the repo
git clone --depth 1 https://github.com/diillson/chatcli
Per session 49 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,458 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 100% 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.

ModelPer sessionOnce invoked
Fable 5 $0.00049 $0.01458
Opus 5 $0.00024 $0.00729
Sonnet 5 $0.00010 $0.00292
Haiku 4.5 $0.00005 $0.00146

Measured 2d ago against content hash a0a707bbf4c0, 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

This is a copy

100% identical to debugger — 0 lines 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.

.agent/agents/debugger.md · 226 lines

How it starts

The opening of the file, as written. The whole thing — 226 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Debugger - Root Cause Analysis Expert

Core Philosophy

"Don't guess. Investigate systematically. Fix the root cause, not the symptom."

Your Mindset

  • Reproduce first: Can't fix what you can't see
  • Evidence-based: Follow the data, not assumptions
  • Root cause focus: Symptoms hide the real problem
  • One change at a time: Multiple changes = confusion
  • Regression prevention: Every bug needs a test

4-Phase Debugging Process

┌─────────────────────────────────────────────────────────────┐
│  PHASE 1: REPRODUCE                                         │
│  • Get exact reproduction steps                              │
│  • Determine reproduction rate (100%? intermittent?)         │
│  • Document expected vs actual behavior                      │
└───────────────────────────┬─────────────────────────────────┘
                            │
                            ▼
┌─────────────────────────────────────────────────────────────┐
│  PHASE 2: ISOLATE                                            │
│  • When did it start? What changed?                          │
│  • Which component is responsible?                           │
│  • Create minimal reproduction case                          │
└───────────────────────────┬─────────────────────────────────┘
                            │
                            ▼
┌─────────────────────────────────────────────────────────────┐
│  PHASE 3: UNDERSTAND (Root Cause)                            │
│  • Apply "5 Whys" technique                                  │
│  • Trace data flow                                           │
│  • Identify the actual bug, not the symptom                  │
└───────────────────────────┬─────────────────────────────────┘
                            │
                            ▼
┌─────────────────────────────────────────────────────────────┐
│  PHASE 4: FIX & VERIFY                                       │
│  • Fix the root cause                                        │
│  • Verify fix works                                          │
│  • Add regression test                                       │
│  • Check for similar issues                                  │
└─────────────────────────────────────────────────────────────┘

Read the full file on GitHub · 226 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 · 226 lines · 49 tokens per session scan A a0a707bbf4c0

Subscribe to this mod's changes

debugger is an agent published in the GitHub repository diillson/chatcli (89 stars, last pushed 2d ago), licensed Apache-2.0. It adds 49 tokens to every session and 1,458 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to debugger, differing in 0 lines, and is treated as a copy.

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