skill CX Codex

bug-fix · undeadlist — Claude Code skill for fixing bugs

Q: How do I install bug-fix in Claude Code?

Run `npx skills add undeadlist/claude-code-agents --skill bug-fix -a claude-code`. The skill file is at `~/.claude/skills/bug-fix/SKILL.md`.

Q: When does bug-fix use browser QA?

For UI bugs, it asks `browser-qa-agent` to replay the reported steps and check related features. API, background-job, build, and test-infrastructure issues skip that stage.

This skill guides an agent through reproducing a bug with a test, applying a focused fix, and checking for regressions. Use it when a bug report needs a verifiable fix.

Install into Claude Code · Skills CLI (Vercel) All methods and platforms ↓

npx skills add undeadlist/claude-code-agents --skill bug-fix -a claude-code

Open on GitHub

What bug-fix does

The workflow starts by asking test-writer to create a failing test from the bug report. Next, code-fixer investigates the cause and changes only what the fix requires. Provide the bug details and reproduction steps.

Then test-runner runs the new test and the existing suite. For UI issues, browser-qa-agent repeats the reported actions and checks related features. Browser QA is skipped for API and background-job bugs, build problems, and test infrastructure issues.

What it helps with

turn a bug report into a failing reproduction test
trace a defect to its cause and make a focused change
check existing tests for regressions
replay a UI bug and verify related features

Example prompts for the agent

Use /bug-fix to investigate a login failure: valid credentials lead to a 500 error. Reproduce it at /login and check that a successful login redirects to the dashboard.
Use /bug-fix for the issue in src/api/auth/login.ts. Write a reproduction test, fix the cause, then run the test suite.
Use /bug-fix to fix this UI issue and verify the original steps in the browser.

How to install bug-fix

1Skills CLI (Vercel)

npx skills add undeadlist/claude-code-agents --skill bug-fix -a claude-code

2Manually: put the files in place

~/.claude/skills/bug-fix/SKILL.md

Copy the whole skill folder; for one project use .claude/skills/bug-fix/

1Skills CLI (Vercel)

npx skills add undeadlist/claude-code-agents --skill bug-fix -a codex

2Manually: put the files in place

.agents/skills/bug-fix/SKILL.md

For all projects use ~/.agents/skills/

1Skills CLI (Vercel)

npx skills add undeadlist/claude-code-agents --skill bug-fix -a cursor

2Manually: put the files in place

.cursor/skills/bug-fix/SKILL.md

Cursor also reads .agents/skills/ and .claude/skills/

1GitHub CLI

gh skill install undeadlist/claude-code-agents bug-fix

2Manually: put the files in place

.github/skills/bug-fix/SKILL.md

1Skills CLI (Vercel)

npx skills add undeadlist/claude-code-agents --skill bug-fix -a gemini-cli

2Platform CLI

gemini skills install https://github.com/undeadlist/claude-code-agents --path skills/bug-fix

Manually: put the files in place

.devin/skills/bug-fix/SKILL.md

The legacy .windsurf/skills/ path still works

Skills CLI (Vercel)

npx skills add undeadlist/claude-code-agents --skill bug-fix -a opencode

Step by step, with commands for each platform: How to install skills in Claude Code: five ways

Questions about bug-fix

How do I install bug-fix in Claude Code?

Run npx skills add undeadlist/claude-code-agents --skill bug-fix -a claude-code. The skill file is at ~/.claude/skills/bug-fix/SKILL.md.

What does bug-fix do?

It guides bug fixing through a reproduction test, a focused code change, and checks of both the new and existing tests.

When does bug-fix use browser QA?

For UI bugs, it asks browser-qa-agent to replay the reported steps and check related features. API, background-job, build, and test-infrastructure issues skip that stage.

Source text

SKILL.md · MIT

---
name: bug-fix
description: Fix bugs with regression prevention using test-first approach
---

# Bug Fix Workflow

Fix bugs with a test-first approach to prevent regressions. Provide the bug description when invoking.

## Execution (Sequential)

### Step 1: Reproduce with Test
Spawn `test-writer` with the bug description:
- Create a test that fails (reproduces the bug)
- Test should pass after the fix is applied

### Step 2: Fix the Bug
Spawn `code-fixer` with the bug description and test file:
- Find root cause
- Implement minimal fix
- Don't refactor unrelated code

### Step 3: Verify
Spawn `test-runner`:
- New test passes (bug is fixed)
- All existing tests pass (no regressions)

### Step 4: Browser QA (if UI bug)
Spawn `browser-qa-agent`:
- Reproduce original steps
- Confirm bug is fixed
- Check related features still work

## Usage

Provide bug details when invoking:
```
/bug-fix

Bug: Login fails with valid credentials
Steps to reproduce:
1. Go to /login
2. Enter valid email/password
3. Click submit
Expected: Redirect to dashboard
Actual: 500 error
Location: src/api/auth/login.ts
```

## Skip browser-qa for
- Non-UI bugs (API, background jobs)
- Build/compilation issues
- Test infrastructure bugs

Similar skills

All skills for Testing and QA →

bug-fix by other authors comes first.

bug-fix bobmatnyc Provides a structured workflow for verifying bug fixes, uncovering root causes, and writing regression tests to prevent recurring defects. CX Codex +1 471installs improve-codebase-architecture Matt Pocock This skill scans a codebase for architectural friction, then builds a visual HTML report with refactoring candidates. Use it before a deeper architecture review. 1,163,035installs design-taste-frontend Leonxlnx This skill directs the design of public pages and work screens, then checks the result in a browser through screenshots. Use it when an interface feels generic or unfinished. CX Codex +1 678,700installs tdd Matt Pocock Guides the red-green TDD loop: ensures tests are written first, keep them at public interfaces, and avoid coupling to implementation details. 1,141,062installs skill-creator official anthropics Creates and refines skills, then tests them with prompts, evaluations, and performance checks. 414,180installs agent-browser vercel-labs A CLI skill for browser control: it opens pages, fills forms, clicks buttons, and tests web apps. Use it when an agent needs to act inside a website. CX Codex +1 1,200,000installs prototype Matt Pocock Creates throwaway prototypes for checking state logic or exploring UI before committing the decision to the main codebase. 986,201installs

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