hypothesis-debug

hypothesis-debug is a skill for Claude Code, Codex from JeonJe/claude-plugins. It costs 107 tokens per session (861 once invoked), scanned A, original, MIT.

A structured method for debugging failures by comparing multiple possible causes and testing which ones the evidence rules out. It examines code, the environment, data, and measurement errors.

In plain words
What is it for?
Use it to investigate incidents, bugs, and unclear failures, then document evidence and add a regression check to prevent recurrence.
Why use it?
It reduces guesswork and helps distinguish the real root cause from a fix that only hides the symptom.

Skill for Claude CodeCodex

Part of the verification plugin — 3 skills shipped together

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/jeonje/claude-plugins/hypothesis-debug
Any agent
npx skills add JeonJe/claude-plugins --skill hypothesis-debug
Clone the repo
git clone --depth 1 https://github.com/JeonJe/claude-plugins

Made for: Claude Code, Codex.

Or install verification, the plugin that ships this one along with the rest of its 3 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 hypothesis-debug

README.md
[![agentmods](https://agentmods.dev/badge/skills/jeonje/claude-plugins/hypothesis-debug.svg)](https://agentmods.dev/skills/jeonje/claude-plugins/hypothesis-debug)
Your own site
<a href="https://agentmods.dev/skills/jeonje/claude-plugins/hypothesis-debug"><img src="https://agentmods.dev/badge/skills/jeonje/claude-plugins/hypothesis-debug.svg" alt="Measured on agentmods" height="20"></a>
Per session 107 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 861 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 $0.00107 $0.00861
Opus 5 $0.00053 $0.00430
Sonnet 5 $0.00021 $0.00172
Haiku 4.5 $0.00011 $0.00086

Measured 3d ago against content hash f34166a606f9, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

hypothesis-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 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.

plugins/verification/skills/hypothesis-debug/SKILL.md · 56 lines

How it starts

The opening of the file, as written. The whole thing — 56 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Hypothesis-driven debugging

Force a systematic path from symptom to root cause: facts-only intake → parallel evidence collection → competing hypotheses (≥2) with mandatory falsification → discriminating probe → report with regression prevention. Never "just try a fix" on a guess.

References index

File When to read
references/hypothesis-lanes.md Phase 3 — building the competing-hypothesis set; Phase 4+ — 5-why vertical descent
references/troubleshoot-report-template.md Phase 5 — report skeleton

Phases

1. Intake — facts only

Record: symptom in one line; when it started; affected scope (users/requests/time window); what changed recently (deploys, config, data); and explicitly, what is NOT yet known. No hypotheses at this phase — an early guess anchors the whole investigation.

2. Parallel evidence collection

Collect from every available source in parallel, read-only: application/error logs, DB state (read-only queries), metrics/APM, reproduction attempt in a safe environment. Label each finding with its source and timestamp. Time-zone discipline: convert all timestamps to one zone before correlating — mixed-zone timelines fabricate causality.

3. Localize + hypothesize (competing, ≥2)

Read hypothesis-lanes.md. Draw at least one hypothesis from each of the three lanes — code logic / environment & data / measurement error — so a single fixation cannot capture the investigation. For each hypothesis maintain:

Hypothesis Evidence for Evidence against Discriminating probe Status

Mandatory falsification: for the leading hypothesis, actively look for evidence that would disprove it before promoting it. A hypothesis you never tried to kill is not confirmed.

4. Probe loop

Design the cheapest probe that discriminates between the top hypotheses (a log line, a targeted query, a minimal reproduction). Run it, then promote or falsify. Repeat until one hypothesis survives with direct evidence. If the same probe fails twice, stop gathering more of the same logs — restate hypothesis/observation/next-probe in three lines and pick a different check.

Read the full file on GitHub · 56 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. 3d ago First seen · 56 lines · 107 tokens per session scan A f34166a606f9

Subscribe to this mod's changes

hypothesis-debug is a skill published in the GitHub repository JeonJe/claude-plugins (3 stars, last pushed 29d ago), licensed MIT. It adds 107 tokens to every session and 861 once invoked, about $0.0005 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.

Related

Other skills, from other repositories

api-testing

HTTP API testing with Supertest (TS) and httpx/pytest (Python). Use when the user mentions API testing, Supertest, httpx, REST/GraphQL validation, or HTTP response errors.

laurigates/claude-plugins · 45 tokens

researching-code

Use this skill when the user asks an architectural or semantic question about a codebase — phrases like "how does X work?", "what's the architecture?", "help me understand this codebase", "find all components that use Y", "trace the data flow from A to B", "where is feature Z handled", "I'm new to this code, where do…

shopwareLabs/ai-coding-tools · 121 tokens

dev-environment-bootstrapping

Use this skill when the user asks to bootstrap, set up, create, or initialize a Shopware development environment from scratch — phrases like "set up a Shopware dev environment", "clone and install Shopware", "initialize a Shopware plugin project", "bootstrap Shopware and a new plugin called X", "get a fresh Shopware…

shopwareLabs/ai-coding-tools · 144 tokens

phpunit-integration-to-unit-migrating

Use this skill ONLY when the user explicitly requests an audit, migration, or evaluation of whether a Shopware integration test belongs in the unit suite — trigger phrases like "audit integration tests", "migrate integration tests to unit", "is this an integration test or a unit test", "evaluate integration tests for…

shopwareLabs/ai-coding-tools · 152 tokens

cross-browser-typography-qa

Use this skill when web text looks clipped, flattened, wrapped incorrectly, misaligned, or materially different between Chromium and WebKit/Safari. Treat text rendering as both a geometry problem and a visual paint problem: passing DOM bounds does not prove that every glyph is intact.

AtlasOmnia/hermes-custom-pack · 56 tokens

ryk

Use when Pi tool calls are protected by ryk runtime guardrails or when a secret was captured from a Pi prompt.

christopherkarani/ryk · 26 tokens