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axum-harness: Skill for Claude Code

.agents/skills/harness-diagnose/SKILL.md

harness-diagnose is a skill for Claude Code, Codex from openclosed-org/axum-harness. It costs 56 tokens per session (425 once invoked), scanned A, original, Apache-2.0.

A structured debugging process for finding the cause of bugs, regressions, flaky behaviour, failed checks, and suspicious program behaviour.

In plain words
What is it for?
Use it to investigate failing tests or commands, performance slowdowns, broken rules, intermittent failures, and backend or runtime problems.
Why use it?
It replaces guesswork with a repeatable loop: reproduce the problem, test ranked explanations, make the smallest causal fix, and collect evidence that it stays fixed.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: installed under .agents/ (shared by several agents).

This is openclosed-org/axum-harness's own configuration. It tells Claude Code and Codex how to work on axum-harness itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything axum-harness configures →

not rated 51repo 5mo ago A scan 56 tokens original Apache-2.0
View source ↗ openclosed-org/axum-harness
Reuse

Borrowing it

Nothing to install: this file belongs to openclosed-org/axum-harness. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/openclosed-org/axum-harness/main/.agents/skills/harness-diagnose/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/openclosed-org/axum-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 harness-diagnose

README.md
[![agentmods](https://agentmods.dev/badge/skills/openclosed-org/axum-harness/harness-diagnose/github.svg)](https://agentmods.dev/skills/openclosed-org/axum-harness/harness-diagnose)
Your own site
<a href="https://agentmods.dev/skills/openclosed-org/axum-harness/harness-diagnose"><img src="https://agentmods.dev/badge/skills/openclosed-org/axum-harness/harness-diagnose/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 harness-diagnose

Your own site · 80×15
<a href="https://agentmods.dev/skills/openclosed-org/axum-harness/harness-diagnose"><img src="https://agentmods.dev/badge/skills/openclosed-org/axum-harness/harness-diagnose.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 425 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.
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 $0.00425
Opus 5.5 $0.00022 $0.00170
Sonnet 5.5 $0.00011 $0.00085
Haiku 4.5 $0.00006 $0.00042

Measured 2mo ago against content hash 419b63cb8d55, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

harness-diagnose 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.

.agents/skills/harness-diagnose/SKILL.md · 58 lines

What it actually says

Harness Diagnose

Use this skill for bugs and regressions.

Workflow skills guide process. Ownership skills still decide writable boundaries.

Phases

  1. Build a feedback loop.
  2. Reproduce the exact symptom.
  3. Generate 3-5 ranked falsifiable hypotheses.
  4. Instrument one boundary or variable at a time.
  5. Fix the smallest causal closed loop.
  6. Add regression evidence at the same semantic level.
  7. Run path-scoped gates from agent/manifests/gate-matrix.yml.
  8. Report evidence and residual uncertainty.

Feedback Loop Options

Prefer fast, deterministic, agent-runnable signals:

  1. failing unit, service, integration, replay, or contract test
  2. validator or gate command
  3. CLI invocation with fixture input and expected output
  4. HTTP request against a running server
  5. replayed event, outbox, or projector trace
  6. throwaway harness isolated to one service, server, worker, or repo-tool path
  7. stress loop for flakes or concurrency issues

If no credible loop can be built, stop and state what was tried and what artifact is needed.

Instrumentation Rules

  1. Every probe must test one hypothesis.
  2. Prefer debugger, targeted assertion, or narrow logs over broad logging.
  3. Tag temporary logs with a unique prefix and remove them before completion.
  4. For performance regressions, measure first and fix second.

Completion Report

State:

  1. violated invariant
  2. causal boundary: contract, service, server, worker, platform, tooling, docs, or cross-boundary
  3. repair made
  4. regression evidence added or why no correct seam exists
  5. gates run
  6. gates not run
  7. residual risk or uncertainty
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. 2mo ago First seen · 58 lines · 56 tokens per session scan A 419b63cb8d55

Subscribe to this mod's changes

harness-diagnose is a skill published in the GitHub repository openclosed-org/axum-harness (51 stars, last pushed 5mo ago), licensed Apache-2.0. It adds 56 tokens to every session and 425 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.

Debuggingai-agentsaxum-frameworkdistributed-systemsmicroservicesplatform-engineering
Related

harness-diagnose compared with skills from other repositories

harness-diagnose next to 6 skills from other repositories
ModTypeStarsLast pushLicenceScanTokensWorks with
harness-diagnoseopenclosed-org/axum-harnessSkill515mo agoApache-2.0A56Claude Code, Codex
files-inspectkurtosis-tech/kurtosisSkill5584d agoApache-2.0A51Claude Code, Codex
starlark-devkurtosis-tech/kurtosisSkill5584d agoApache-2.0A50Claude Code, Codex
docker-debugkurtosis-tech/kurtosisSkill5584d agoApache-2.0A45Claude Code, Codex
enclave-inspectkurtosis-tech/kurtosisSkill5584d agoApache-2.0A52Claude Code, Codex
k8s-debug-podskurtosis-tech/kurtosisSkill5584d agoApache-2.0A62Claude Code, Codex
cli-local-buildkurtosis-tech/kurtosisSkill5584d agoApache-2.0A46Claude Code, Codex