systematic-debugging

systematic-debugging is a skill for Claude Code, Codex from jxoesneon/Ciel. It costs 19 tokens per session (676 once invoked), scanned A, original, Apache-2.0.

A troubleshooting method that finds and confirms the underlying cause of a failure before changing the code. It uses logs, reproduction steps, data tracing, comparisons, and small tests.

In plain words
What is it for?
Investigating errors, creating minimal reproductions, tracing failures to their source, testing hypotheses, and verifying fixes.
Why use it?
It prevents guesses and symptom-only fixes that leave the real problem in place or create new failures.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Investigating errors, creating minimal reproductions, tracing failures to their source, testing hypotheses…

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/jxoesneon/ciel/systematic-debugging
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.

Any agent
npx skills add jxoesneon/Ciel --skill systematic-debugging
Clone the repo
git clone --depth 1 https://github.com/jxoesneon/Ciel

Made for: Claude Code, Codex.

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 systematic-debugging

README.md
[![agentmods](https://agentmods.dev/badge/skills/jxoesneon/ciel/systematic-debugging.svg)](https://agentmods.dev/skills/jxoesneon/ciel/systematic-debugging)
Your own site
<a href="https://agentmods.dev/skills/jxoesneon/ciel/systematic-debugging"><img src="https://agentmods.dev/badge/skills/jxoesneon/ciel/systematic-debugging.svg" alt="Measured on agentmods" height="20"></a>
Per session 19 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 676 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00019 $0.00676
Opus 5 $0.00010 $0.00338
Sonnet 5 $0.00004 $0.00135
Haiku 4.5 $0.00002 $0.00068

Measured 3d ago against content hash bc60cc134c9c, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

systematic-debugging 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 3d 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.

skills/systematic-debugging/SKILL.md · 89 lines

How it starts

The opening of the file, as written. The whole thing — 89 lines — stays where its author put it; the contents beside it link to each section on GitHub.

CIEL ADAPTATION: Systematic Debugging

This skill enforces CIEL's diagnostic rigor: NO FIXES WITHOUT ROOT CAUSE INVESTIGATION FIRST.

Integration Context

Adapted from ~/.agents/skills/systematic-debugging/. This is a critical safety and quality mandate for all CIEL-orchestrated troubleshooting.

The Iron Law

NO FIXES WITHOUT ROOT CAUSE INVESTIGATION FIRST.

If you propose a fix without a confirmed root cause: STOP. Return to Phase 1.

The Four Phases

Phase 1: Root Cause Investigation

  • Evidence Gathering: Read error messages, traces, and logs completely.
  • Reproduction: Create a consistent, minimal reproduction of the failure.
  • Trace Back: Follow the data flow backward from the symptom to the source.

Phase 2: Pattern Analysis

  • Differential Analysis: Compare the failing code against similar working examples.
  • Context Mapping: Identify all dependencies, configurations, and environment variables involved.

Phase 3: Hypothesis & Minimal Testing

  • Single Variable: Form a specific hypothesis and test it with the smallest possible change.
  • Verification: Confirm if the minimal change proves the hypothesis before implementing a full fix.

Phase 4: Implementation (via TDD)

  • Failing Test: Create an automated test that reproduces the bug (Red).
  • Root Cause Fix: Address the source, not the symptom (Green).
  • Architectural Gate: If 3+ fixes fail, STOP and trigger a Council Review of the architecture.

Orchestration Logic

1. Triage

The orchestration skill must ensure Phase 1 is complete before any sub-task for "fixing" is dispatched.

2. High-Risk Diagnostics

For multi-component failures, the Council of Five (specifically Safety and Efficiency) will review the diagnostic plan to ensure proper instrumentation.

3. Verification

A bug is "resolved" only when:

  • The root cause is identified and addressed.
  • A regression test is added to the permanent test suite.
  • The Council of Five (Coherence/Safety) verifies the fix aligns with system invariants.

Read the full file on GitHub · 89 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. 3d ago First seen · 89 lines · 19 tokens per session scan A bc60cc134c9c

Subscribe to this mod's changes

systematic-debugging is a skill published in the GitHub repository jxoesneon/Ciel (1 stars, last pushed 6d ago), licensed Apache-2.0. It adds 19 tokens to every session and 676 once invoked, about $0.0001 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.