Borrowing it
Nothing to install: this file belongs to TheDecipherist/claude-code-mastery-project-starter-kit. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/TheDecipherist/claude-code-mastery-project-starter-kit/main/.claude/skills/debugger/SKILL.mdgit clone --depth 1 https://github.com/TheDecipherist/claude-code-mastery-project-starter-kitWrote 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.
[](https://agentmods.dev/skills/thedecipherist/claude-code-mastery-project-starter-kit/debugger)<a href="https://agentmods.dev/skills/thedecipherist/claude-code-mastery-project-starter-kit/debugger"><img src="https://agentmods.dev/badge/skills/thedecipherist/claude-code-mastery-project-starter-kit/debugger/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/thedecipherist/claude-code-mastery-project-starter-kit/debugger"><img src="https://agentmods.dev/badge/skills/thedecipherist/claude-code-mastery-project-starter-kit/debugger.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00063 | $0.00599 |
| Opus 5.5 | $0.00025 | $0.00240 |
| Sonnet 5.5 | $0.00013 | $0.00120 |
| Haiku 4.5 | $0.00006 | $0.00060 |
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 2mo 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.
How it starts
The opening of the file, as written. The whole thing — 40 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Debugger
You find root causes. You do not patch symptoms, and you do not guess.
Method
Work these in order. Do not skip ahead.
- Reproduce before anything else. Build the smallest script or test that triggers the failure every time. If you cannot reproduce it, stop. The bug is now "why can't I reproduce this," and you investigate that gap instead of writing a fix blind.
- State observed vs expected, precisely. "Under condition X, the system does Y; it should do Z." If you can't fill that in, you don't understand the bug yet.
- Rank two or three hypotheses. Order by likelihood, weighted toward whatever changed most recently. Name each one.
- Falsify the top hypothesis with the cheapest possible probe. One log line, one targeted grep, one assertion. Try to prove yourself wrong before writing any fix. A hypothesis you only confirmed is one you didn't test.
- Fix, and add the regression test in the same change. The test must fail on the old code and pass on the new. Fix without test is not done.
- Record the root cause and one prevention step. What it was, what the falsifying probe showed, and the one change that stops the whole class from recurring.
Production incidents
For anything live, do these three before opening a source file. Most incidents resolve here.
- Change correlation first. What deployed, what flag flipped, what config changed, what traffic shifted in the 30 minutes before the first error.
git log --since, deploy history, flag state. A correlated change usually is the answer. - Trace to the first failing span. Start from the earliest operation that errored or blew its latency budget, not the symptom the user reported. The symptom is downstream.
- Logs, tightly windowed. ±2 minutes around that first error, filtered to the failing service and correlation ID.
grep,jq,awk.
Non-negotiable
- Never ship a fix for a bug you could not reproduce.
- The fix and its regression test land together or not at all.
- Every fix ends with one named prevention measure.
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.
- 2mo ago First seen · 40 lines · 63 tokens per session scan A cfce35ee4be0
debugger is a skill published in the GitHub repository TheDecipherist/claude-code-mastery-project-starter-kit (342 stars, last pushed 4mo ago), licensed MIT. It adds 63 tokens to every session and 599 once invoked, about $0.0003 per session on Opus 5.5. 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.
debugger compared with skills from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| debuggerTheDecipherist/claude-code-mastery-project-starter-kit | Skill | 342 | 4mo ago | MIT | A | 63 | Claude Code |
| systematic-debuggingopen-metadata/OpenMetadata | Skill | 16k | yesterday | Apache-2.0 | A | 37 | Claude Code |
| log-error-digestzebbern/claude-code-guide | Skill | 4.7k | 3d ago | MIT | A | 71 | Claude Code, Codex |
| cwv-optimizeradobe/skills | Skill | 319 | yesterday | Apache-2.0 | A | 112 | Claude Code |
| ci-fixersipyourdrink-ltd/bernstein | Skill | 1.2k | yesterday | Apache-2.0 | A | 15 | Claude Code, Codex |
| incident-response-incident-responsermyndharis/antigravity-skills | Skill | 1.9k | 23d ago | MIT | A | 36 | Claude Code |
| triaging-web-analytics-supportPostHog/posthog | Skill | 41k | yesterday | none | A | 151 | Claude Code, Codex |