oracle-debug

oracle-debug is a skill for Claude Code from martinffx/atelier. It costs 56 tokens per session (2,170 once invoked), scanned A, original, MIT.

A step-by-step method for diagnosing software problems by finding the underlying cause before choosing a permanent fix.

In plain words
What is it for?
Use it for bugs, failed tests, build or integration failures, unexpected behavior, intermittent issues, and performance slowdowns.
Why use it?
It reduces repeated trial-and-error patches that can hide the real problem or create new bugs.

Skill for Claude Code

Written for Claude Code: user-invocable in frontmatter. Also seen: mentions subagents.

Part of the atelier plugin — 16 skills shipped together

Good fit Use it for bugs, failed tests, build or integration failures, unexpected behavior, intermittent issues, and performance slowdowns.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/martinffx/atelier/oracle-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 martinffx/atelier --skill oracle-debug
Clone the repo
git clone --depth 1 https://github.com/martinffx/atelier

Made for: Claude Code.

Or install atelier, the plugin that ships this one along with the rest of its 16 skills.

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 oracle-debug

README.md
[![agentmods](https://agentmods.dev/badge/skills/martinffx/atelier/oracle-debug/github.svg)](https://agentmods.dev/skills/martinffx/atelier/oracle-debug)
Your own site
<a href="https://agentmods.dev/skills/martinffx/atelier/oracle-debug"><img src="https://agentmods.dev/badge/skills/martinffx/atelier/oracle-debug/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.

agentmods 80×15 button for oracle-debug

Your own site · 80×15
<a href="https://agentmods.dev/skills/martinffx/atelier/oracle-debug"><img src="https://agentmods.dev/badge/skills/martinffx/atelier/oracle-debug.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 56 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,170 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 $0.00056 $0.02170
Opus 5.5 $0.00022 $0.00868
Sonnet 5.5 $0.00011 $0.00434
Haiku 4.5 $0.00006 $0.00217

Measured 10d ago against content hash eb29077d25d0, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

oracle-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 10d 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/oracle-debug/SKILL.md · 228 lines

How it starts

The opening of the file, as written. The whole thing — 228 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Oracle Debug

Random fixes waste time and create new bugs. Quick patches mask underlying issues.

Core principle: find root cause before a permanent corrective fix. Temporary containment is appropriate when needed to limit security, production, or data-loss impact.

Violating the letter of this process is violating the spirit of debugging.

The Iron Law

NO FIXES WITHOUT ROOT CAUSE INVESTIGATION FIRST

If you haven't completed Phase 1, you cannot propose fixes.

When to Use

Use for any technical issue:

  • Test failures
  • Bugs in production
  • Unexpected behavior
  • Performance regressions
  • Build or integration failures
  • Intermittent failures

Use this especially when:

  • Under time pressure
  • "Just one quick fix" seems obvious
  • You've already tried multiple fixes
  • The previous fix didn't work
  • You don't fully understand the issue

The Four Phases

You must complete each phase before proceeding to the next.


Phase 1 — Root Cause Investigation

Before attempting any fix:

Use the project's domain glossary and ADRs to build a clear mental model of the relevant modules before tracing.

  1. Read error messages carefully. Read the full stack trace, line numbers, file paths, and error codes. Don't skip warnings.

  2. Build a fast feedback loop. If you don't have a fast, deterministic, pass/fail signal for the bug, no amount of code-reading will save you. Spend disproportionate effort here.

    Try these in order:

    • Failing test at the seam that reaches the bug
    • Curl / HTTP script against a running dev server
    • CLI invocation with fixture input
    • Headless browser script (Playwright/Puppeteer)
    • Replay a captured trace (network payload, event log)
    • Throwaway harness (minimal subset of the system)
    • Property/fuzz loop for "sometimes wrong" bugs
    • Bisection harness (e.g., git bisect run)
    • Differential loop (old vs new version)
    • HITL bash script (last resort — structure the human clicks)

    Iterate on the loop: make it faster, sharper, and more deterministic. A 30-second flaky loop is barely better than no loop.

Read the full file on GitHub · 228 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. 10d ago Changed · +2 lines eb29077d25d0
  2. 1mo ago First seen · 226 lines · 56 tokens per session scan A fe3fbe8f6768

Subscribe to this mod's changes

oracle-debug is a skill published in the GitHub repository martinffx/atelier (48 stars, last pushed yesterday), licensed MIT. It adds 56 tokens to every session and 2,170 once invoked, about $0.0002 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.