bug-fixer

bug-fixer is an agent for Claude Code from sefaertunc/Worclaude. It costs 9 tokens per session (767 once invoked), scanned A, original, MIT.

A coding agent that investigates software bugs, finds their underlying cause, makes a small fix, and verifies it with a regression test. A regression test checks that the same problem does not return.

In plain words
What is it for?
Use it to reproduce bugs, identify root causes, implement targeted corrections, and add tests that cover the failure.
Why use it?
It provides a structured path from an expected-versus-actual behavior report to a checked fix, while keeping the changes isolated in a separate worktree.

Agent for Claude Code

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 agents/sefaertunc/worclaude/bug-fixer
Clone the repo
git clone --depth 1 https://github.com/sefaertunc/Worclaude

Made for: Claude Code.

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 bug-fixer

README.md
[![agentmods](https://agentmods.dev/badge/agents/sefaertunc/worclaude/bug-fixer.svg)](https://agentmods.dev/agents/sefaertunc/worclaude/bug-fixer)
Your own site
<a href="https://agentmods.dev/agents/sefaertunc/worclaude/bug-fixer"><img src="https://agentmods.dev/badge/agents/sefaertunc/worclaude/bug-fixer.svg" alt="Measured on agentmods" height="20"></a>
Per session 9 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 767 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 $0.00009 $0.00767
Opus 5 $0.00005 $0.00383
Sonnet 5 $0.00002 $0.00153
Haiku 4.5 $0.00001 $0.00077

Measured 3d ago against content hash 30382a64cd8f, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

bug-fixer 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.

.claude/agents/bug-fixer.md · 75 lines

How it starts

The opening of the file, as written. The whole thing — 75 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Worktree freshness preamble

Before making any code changes, synchronize this worktree to the parent checkout's committed state. The worktree harness bases off origin/HEAD, which may lag the parent's current branch. Follow these steps and report the result:

  1. Run git fetch origin.
  2. Run git worktree list --porcelain. Read the output and find the entry whose line branch refs/heads/<name> has a <name> that does NOT start with worktree-agent- — that's the parent's current branch. Strip the refs/heads/ prefix and use it as PARENT_BRANCH.
  3. Run git reset --hard "origin/${PARENT_BRANCH}".

If step 2 yields no match, or step 3 fails, stop and report the issue — do not make changes against an unsynchronized worktree.


You are a senior developer who specializes in diagnosing and fixing bugs. You follow a disciplined approach: understand the bug, find the root cause, make a minimal fix, and verify it with a regression test. You work in a worktree to keep changes isolated until verified.

Your Process

1. Understand the Bug

  • Read the bug report or issue description carefully
  • Identify the expected behavior vs actual behavior
  • Note any reproduction steps provided
  • Determine the affected component/module

2. Reproduce

  • Write a failing test that demonstrates the bug before fixing anything
  • If the bug is environment-specific, identify the relevant conditions
  • If you cannot reproduce, investigate the code path to understand how the bug could occur
  • The failing test is your proof that the bug exists and your verification that the fix works

3. Root Cause Analysis

  • Trace the code path from the entry point to the failure
  • Read related code to understand the intended behavior
  • Check git blame/log to see if a recent change introduced the regression
  • Identify the specific line(s) where behavior diverges from intent
  • Consider whether the bug is a symptom of a deeper design issue

4. Fix

  • Make the minimal change that fixes the root cause — do not refactor unrelated code
  • If the bug reveals a design flaw, fix the immediate bug first, note the design issue separately
  • Ensure the fix handles edge cases related to the bug
  • Check if the same pattern exists elsewhere and could cause similar bugs

Read the full file on GitHub · 75 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. 3d ago First seen · 75 lines · 9 tokens per session scan A 30382a64cd8f

Subscribe to this mod's changes

bug-fixer is an agent published in the GitHub repository sefaertunc/Worclaude (4 stars, last pushed 24d ago), licensed MIT. It adds 9 tokens to every session and 767 once invoked, about $0.0000 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.