debug

debug is a skill for Claude Code, Codex from ericrisco/rsc-harness. It costs 85 tokens per session (3,177 once invoked), scanned A, original, MIT.

A diagnosis process for finding and proving the root cause of a software failure before changing the code.

In plain words
What is it for?
It helps investigate failing or flaky tests, crashes, incorrect results, and regressions using the appropriate test runners, debuggers, profilers, or race detectors.
Why use it?
It prevents guessed fixes that only hide symptoms or move the problem elsewhere. Reproducing the issue provides evidence that the eventual fix works.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: mentions CLAUDE.md; mentions subagents.

Good fit It helps investigate failing or flaky tests, crashes, incorrect results, and regressions using the appropriate test runners, debuggers, profilers, or race detectors.

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Install with agentmods
npx agentmods add skills/ericrisco/rsc-harness/debug
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 ericrisco/rsc-harness --skill debug
Clone the repo
git clone --depth 1 https://github.com/ericrisco/rsc-harness

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 debug

README.md
[![agentmods](https://agentmods.dev/badge/skills/ericrisco/rsc-harness/debug.svg)](https://agentmods.dev/skills/ericrisco/rsc-harness/debug)
Your own site
<a href="https://agentmods.dev/skills/ericrisco/rsc-harness/debug"><img src="https://agentmods.dev/badge/skills/ericrisco/rsc-harness/debug.svg" alt="Measured on agentmods" height="20"></a>
Per session 85 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,177 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. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
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 $0.00085 $0.03177
Opus 5 $0.00043 $0.01588
Sonnet 5 $0.00017 $0.00635
Haiku 4.5 $0.00009 $0.00318

Measured 4d ago against content hash 43bb3a2a2a22, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

debug 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 4d 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/debug/SKILL.md · 193 lines

How it starts

The opening of the file, as written. The whole thing — 193 lines — stays where its author put it; the contents beside it link to each section on GitHub.

debug — find the cause before you touch the fix

debug is the on-demand diagnosis discipline of the rsc-sdd chain. Something is broken — a test went red, a crash landed, a result is wrong, a regression appeared — and the strongest pull in the room is to change code until the symptom disappears. That pull is the enemy. A symptom that vanishes under a guessed edit usually moved; it rarely died. This skill replaces guess-and-patch with a short, evidence-driven loop that ends only when one confirmed cause has been named, fixed, and proven gone.

The one rule everything else serves: no fix before a reproduced, isolated, confirmed cause. If you cannot make the bug happen on demand, you cannot know you fixed it — you can only know the symptom stopped showing, which is not the same thing.

This is a process skill: it owns the method, never the instruments. The test runner, debugger, race detector and profiler belong to whichever stack the failure lives in — pull them from the delegation table below.

Model tier — heavy (opt-in routing)

This phase's default model tier is heavy — root-cause diagnosis is deep reasoning. Routing is off unless models.enabled: true in 02-DOCS/wiki/sdd/config.yaml. When on: resolve this phase's tier (models.overrides wins over models.phases), map it to a model via models.tiers, and apply per ../sdd/references/model-routing.md — announce the switch per the accompaniment dial when it differs from the session model, and dispatch any Task/parallel subagents on that model. Routing off or no profile → honor the session model silently. Never fake a switch a tool can't make; skip routing on a one-line change.

Read the room first (accompaniment dial)

Before diagnosing, read 02-DOCS/wiki/harness/user-profile.md for the technical + accompaniment level and match it; with no profile yet, assume non-technical — narrate the reasoning plainly and never apply a behavior-changing fix without a quick confirm. The method never changes with the dial — the volume does.

Read the full file on GitHub · 193 lines

Files

What ships with it

2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 4d ago First seen · 193 lines · 85 tokens per session scan A 43bb3a2a2a22

Subscribe to this mod's changes

debug is a skill published in the GitHub repository ericrisco/rsc-harness (70 stars, last pushed today), licensed MIT. It adds 85 tokens to every session and 3,177 once invoked, about $0.0004 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.