fix

fix is a skill for Claude Code from vasuag09/harness-claude. It costs 138 tokens per session (1,745 once invoked), scanned A, original, MIT.

A guided entry point for fixing an existing software bug, such as a failing test, production error, crash, or incorrect result. It reproduces the problem as a failing test, identifies the cause, and prepares a minimal fix plan.

In plain words
What is it for?
Use it for behavioral or logic bugs, regressions, reported defects, and production errors; it is not intended for building a new feature.
Why use it?
It keeps bug work focused on the actual cause and records the failure before code is changed. It then passes the work to the project's existing implementation, review, verification, and release steps.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the harness-claude plugin — 32 skills, 8 agents, 6 hooks, 3 MCP servers shipped together

Good fit Use it for behavioral or logic bugs, regressions, reported defects, and production errors; it is not intended for building a new feature.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/vasuag09/harness-claude/fix
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 vasuag09/harness-claude --skill fix
Clone the repo
git clone --depth 1 https://github.com/vasuag09/harness-claude

Made for: Claude Code.

Or install harness-claude, the plugin that ships this one along with the rest of its 32 skills, 8 agents, 6 hooks, 3 MCP servers.

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 fix

README.md
[![agentmods](https://agentmods.dev/badge/skills/vasuag09/harness-claude/fix.svg)](https://agentmods.dev/skills/vasuag09/harness-claude/fix)
Your own site
<a href="https://agentmods.dev/skills/vasuag09/harness-claude/fix"><img src="https://agentmods.dev/badge/skills/vasuag09/harness-claude/fix.svg" alt="Measured on agentmods" height="20"></a>
Per session 138 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,745 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 $0.00138 $0.01745
Opus 5 $0.00069 $0.00873
Sonnet 5 $0.00028 $0.00349
Haiku 4.5 $0.00014 $0.00175

Measured 8d ago against content hash bcd1b8b3be42, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

fix 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 8d 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/fix/SKILL.md · 93 lines

How it starts

The opening of the file, as written. The whole thing — 93 lines — stays where its author put it; the contents beside it link to each section on GitHub.

/fix — reproduce first, fix minimally, ride the gates

Goal: take something that is already broken and fix it with discipline — capture the bug as a failing test before touching the fix, scope the change to the cause, and let it flow through the harness's existing review/verify/ship gates. The pipeline's front door (/spec → … → /ship) is greenfield-shaped — it assumes you're building. /harness-claude:fix is the parallel entry for bugs: it does the bug-specific work, then hands off rather than re-implementing the gates.

Opt-in. Invoked explicitly; nothing auto-routes a bug here. Git boundary: /harness-claude:fix never commits or pushes — branch creation for non-trivial work is expected (claude/fix-<slug>, see rules/git.md); the fix is committed (if at all) only through /harness-claude:ship when you ask. Reuse, don't rebuild: the regression test goes through harness-claude:tdd-guide; review/verify/ship are the existing skills, not duplicated here.

When /harness-claude:fix, when /harness-claude:build-fix

  • /harness-claude:fix is for behavioral / logic bugs — wrong output, a crash on some input, a regression, a reported defect. It is reproduce-as-a-failing-test-first, then root-cause, then minimal fix.
  • /harness-claude:build-fix is for build / type / compile errors — get the build green with a minimal diff. It is not a competitor: while fixing a behavioral bug you may call /harness-claude:build-fix to keep the build green mid-change. Use /harness-claude:build-fix alone when nothing is behaviorally wrong and you just need the compiler/types happy.

How it works

reproduce (RED test)  →  root cause  →  minimal fix-plan  →  hand off to /implement  →  /verify → /ship

Do this

  1. Branch, then reproduce — capture the bug RED. Apply branch-at-first-write (rules/git.md) before the test file lands: not a git repo → skip silently; already on a non-default branch → stay there; on the default branch with non-trivial work → create claude/fix-<slug> first (never commit or push — that stays gated behind your explicit ask). Then, before writing any fix, produce a failing test that exercises the reported behavior and fails for the right reason. Run it; confirm it's RED. If a reliable automated repro genuinely isn't possible (e.g. needs real hardware, an external outage), say why and record concrete manual repro steps instead — never skip the repro step silently.
  2. Find the root cause, not the symptom. State the actual defect and why it produces the reported behavior. A patch that makes the symptom disappear without naming the cause is not a fix — it's a guess. Use mgrep / the knowledge graph to trace the failing path to its origin.
  3. Write a minimal fix-plan. The smallest change that turns the RED test GREEN, scoped to the cause. No refactor-while-you're-in-there — unrelated cleanup belongs to /harness-claude:refactor-clean, not here. If the only correct fix is a design change, stop and return to /harness-claude:architect or /harness-claude:plan rather than hacking around it.
  4. Add the repro as a durable regression test via harness-claude:tdd-guide. The failing test from step 1 becomes a permanent test (RED → GREEN once the fix lands) so the bug can't silently return. This is the same TDD seam /harness-claude:implement opens each phase with.
  5. Hand off — do not rebuild the gates. Pass the fix-plan + the RED regression test to /harness-claude:implement (it makes the test GREEN with the minimal change), then let the change ride the existing /harness-claude:review + /harness-claude:security-review/harness-claude:verify/harness-claude:ship gates. /harness-claude:fix does not duplicate review, verify, or ship.

Read the full file on GitHub · 93 lines

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. 8d ago First seen · 93 lines · 0 tokens per session scan A bcd1b8b3be42

Subscribe to this mod's changes

fix is a skill published in the GitHub repository vasuag09/harness-claude (2 stars, last pushed 2mo ago), licensed MIT. It adds 138 tokens to every session and 1,745 once invoked, about $0.0007 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.

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