resonance-engineering-debugger

A debugging workflow based on reproducing a problem, testing possible causes, and identifying the exact root cause before changing code.

In plain words
What is it for?
Use it to investigate bug reports, error logs, production incidents, flaky tests, and failures in an agent’s work process. It produces a reproduction case, a cause analysis, and a focused fix.
Why use it?
It avoids guesswork and symptom-only fixes, especially when a bug appears only in a particular environment or a test fails unpredictably.

Skill for Claude CodeCodex

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 skills/manusco/resonance/debugger
Any agent
npx skills add manusco/resonance --skill debugger
Clone the repo
git clone --depth 1 https://github.com/manusco/resonance

Made for: Claude Code, Codex.

Per session 57 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,596 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 $0.00057 $0.01596
Opus 5 $0.00028 $0.00798
Sonnet 5 $0.00011 $0.00319
Haiku 4.5 $0.00006 $0.00160

Measured 2d ago against content hash b9c063171913, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

resonance-engineering-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/skills/engineering/debugger/SKILL.md · 93 lines

How it starts

The opening of the file, as written. The whole thing — 93 lines — stays where its author put it; the contents beside it link to each section on GitHub.

/resonance-engineering-debugger: find the truth, not just a patch

Role: investigator of root causes. Invoked as: /debug (to isolate and fix defects). Input: A bug report, error log, or flaky behavior description. Output: A reproduction script, Root Cause Analysis, and a surgical fix. Definition of Done: The reproduction script triggers the bug 100% of the time before the fix. After the fix, the same script passes. The RCA explains the exact logic gap that caused the failure. The fix touches only the lines that caused the bug.

Iron Law: No Fix Without Root Cause.

You do not guess. You hypothesize, test, and prove. Fixing the symptom without understanding the disease is negligence. The next bug like it will be back in 3 months.

Prerequisites (fail fast)

  • You can reproduce the bug at least once. If you cannot reproduce it, step 1 is to build the reproduction case. Nothing else.
  • You know which environment the bug was observed in. Local, staging, and production may have different data shapes.

Algorithm (The 9-Step Protocol)

Copy this checklist and tick items as you go.

  1. Search + Learn: Check 02_memory.md for similar past bugs or "gotchas" in this project. → verify: checked before proceeding.
  2. Reproduce: Write a script or set of steps that triggers the error 100% of the time. → verify: error is deterministic before continuing.
  3. Isolate: Narrow the scope using binary search or git bisect. Comment out half the code. Does it still fail? → verify: the failing surface is minimized.
  4. Hypothesize: Write down your theory about the Smoking Gun in one sentence before running any test. Construct at least one alternative hypothesis that contradicts your primary assumption to defeat Confirmation Bias. → verify: hypothesis is written, not just thought.
  5. Instrument: Add targeted logging or assertions to confirm or refute the hypothesis. → verify: evidence collected from the instrumentation.
  6. Verify Cause: If the hypothesis is wrong, discard and return to step 4. Do not apply blind patches. → verify: the exact line, state, or race condition is confirmed.
  7. Fix: Apply the minimal surgical fix. Match existing style exactly. → verify: run the reproduction script. It must now pass.
    • Harden the class: Before closing, trace the layers the bad value crossed and make the whole bug class structurally impossible where it counts, not just the one line that failed. See Defense in Depth. → verify: the illegal state is now guarded or unrepresentable, and the reproduction script is a permanent regression test.
  8. Self-Improvement: Log the RCA and the Smoking Gun to 02_memory.md to prevent future re-discovery.
  9. Completion: Use the Completion Attestation. Include reproduction evidence, root cause, environment context, and blast radius of the fix.

Read the full file on GitHub · 93 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 · 93 lines · 57 tokens per session scan A b9c063171913

Subscribe to this mod's changes

resonance-engineering-debugger is a skill published in the GitHub repository manusco/resonance (37 stars, last pushed 2d ago), licensed MIT. It adds 57 tokens to every session and 1,596 once invoked, about $0.0003 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.

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