systematic-debugging

A step-by-step method for finding a bug's root cause, fixing it, and proving the fix works.

In plain words
What is it for?
Use it to reproduce failures, inspect errors and code paths, test one hypothesis at a time, add regression tests, and verify the full suite.
Why use it?
It prevents guess-and-patch changes that hide symptoms while leaving the real problem in place.

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/new1direction/korgex/systematic-debugging
Any agent
npx skills add New1Direction/korgex --skill systematic-debugging
Clone the repo
git clone --depth 1 https://github.com/New1Direction/korgex

Made for: Claude Code, Codex.

Per session 23 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 272 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 $0.00023 $0.00272
Opus 5 $0.00012 $0.00136
Sonnet 5 $0.00005 $0.00054
Haiku 4.5 $0.00002 $0.00027

Measured 2d ago against content hash 9f41605132dd, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, 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 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.

src/skills_builtin/systematic-debugging/SKILL.md · 23 lines

What it actually says

Resist the urge to guess-and-patch. A bug you can't reproduce isn't fixed.

  1. Reproduce reliably. Find the smallest, deterministic way to trigger it. Capture the exact error/output. If you can't reproduce it, gather more signal before changing anything.
  2. Locate it. Read the actual error and stack. Use Grep/Glob to find the code on the path; read the surrounding code and its callers. Form ONE hypothesis at a time about the root cause.
  3. Test the hypothesis. Add a focused assertion, log, or a failing test that would be true only if your hypothesis holds. Confirm before fixing.
  4. Fix the cause. Change the root cause, not the symptom. Avoid masking it with a catch-all or a retry. Keep the change minimal.
  5. Prove it. Add a regression test that fails before your fix and passes after (see test-driven-development). Re-run the full suite; confirm nothing else broke.
  6. State what the cause was and why the fix addresses it.
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 · 23 lines · 23 tokens per session scan A 9f41605132dd

Subscribe to this mod's changes

systematic-debugging is a skill published in the GitHub repository New1Direction/korgex (5 stars, last pushed 2mo ago), licensed MIT. It adds 23 tokens to every session and 272 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 2026-08-31.