reproduce-bug

reproduce-bug is a command for Claude Code from tajmahal226/compound-engineering-plugin. It costs 20 tokens per session (721 once invoked), scanned A, original, MIT.

A bug-investigation command that examines a GitHub issue, application logs, and browser behavior to reproduce the problem.

In plain words
What is it for?
Use it to investigate Rails console output and AppSignal logs, then reproduce affected pages or user flows in a browser with screenshots.
Why use it?
It helps connect an issue report to useful logs and a repeatable failure, especially when the cause is unclear or involves a web interface.

Command for Claude Code

Written for Claude Code: disable-model-invocation in frontmatter.

Part of the compound-engineering plugin — 20 skills, 17 commands, 1 MCP server shipped together

Good fit Use it to investigate Rails console output and AppSignal logs, then reproduce affected pages or user flows in a browser with screenshots.

Compare 6 commands from other repositories ↓
Install with agentmods
npx agentmods add commands/tajmahal226/compound-engineering-plugin/reproduce-bug
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.

Clone the repo
git clone --depth 1 https://github.com/tajmahal226/compound-engineering-plugin

Made for: Claude Code.

Or install compound-engineering, the plugin that ships this one along with the rest of its 20 skills, 17 commands, 1 MCP server.

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 reproduce-bug

README.md
[![agentmods](https://agentmods.dev/badge/commands/tajmahal226/compound-engineering-plugin/reproduce-bug/github.svg)](https://agentmods.dev/commands/tajmahal226/compound-engineering-plugin/reproduce-bug)
Your own site
<a href="https://agentmods.dev/commands/tajmahal226/compound-engineering-plugin/reproduce-bug"><img src="https://agentmods.dev/badge/commands/tajmahal226/compound-engineering-plugin/reproduce-bug/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 reproduce-bug

Your own site · 80×15
<a href="https://agentmods.dev/commands/tajmahal226/compound-engineering-plugin/reproduce-bug"><img src="https://agentmods.dev/badge/commands/tajmahal226/compound-engineering-plugin/reproduce-bug.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 20 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 721 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 $0.00020 $0.00721
Opus 5 $0.00010 $0.00360
Sonnet 5 $0.00004 $0.00144
Haiku 4.5 $0.00002 $0.00072

Measured 9d ago against content hash 72fedac6edd3, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

reproduce-bug 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 9d 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/compound-engineering/commands/reproduce-bug.md · 101 lines

How it starts

The opening of the file, as written. The whole thing — 101 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Reproduce Bug Command

Look at github issue #$ARGUMENTS and read the issue description and comments.

Phase 1: Log Investigation

Run the following agents in parallel to investigate the bug:

  1. Task rails-console-explorer(issue_description)
  2. Task appsignal-log-investigator(issue_description)

Think about the places it could go wrong looking at the codebase. Look for logging output we can look for.

Run the agents again to find any logs that could help us reproduce the bug.

Keep running these agents until you have a good idea of what is going on.

Phase 2: Visual Reproduction with Playwright

If the bug is UI-related or involves user flows, use Playwright to visually reproduce it:

Step 1: Verify Server is Running

mcp__plugin_compound-engineering_pw__browser_navigate({ url: "http://localhost:3000" })
mcp__plugin_compound-engineering_pw__browser_snapshot({})

If server not running, inform user to start bin/dev.

Step 2: Navigate to Affected Area

Based on the issue description, navigate to the relevant page:

mcp__plugin_compound-engineering_pw__browser_navigate({ url: "http://localhost:3000/[affected_route]" })
mcp__plugin_compound-engineering_pw__browser_snapshot({})

Step 3: Capture Screenshots

Take screenshots at each step of reproducing the bug:

mcp__plugin_compound-engineering_pw__browser_take_screenshot({ filename: "bug-[issue]-step-1.png" })

Step 4: Follow User Flow

Reproduce the exact steps from the issue:

  1. Read the issue's reproduction steps

  2. Execute each step using Playwright:

    • browser_click for clicking elements
    • browser_type for filling forms
    • browser_snapshot to see the current state
    • browser_take_screenshot to capture evidence
  3. Check for console errors:

    mcp__plugin_compound-engineering_pw__browser_console_messages({ level: "error" })
    

Step 5: Capture Bug State

When you reproduce the bug:

  1. Take a screenshot of the bug state
  2. Capture console errors
  3. Document the exact steps that triggered it

Read the full file on GitHub · 101 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. 9d ago First seen · 101 lines · 20 tokens per session scan A 72fedac6edd3

Subscribe to this mod's changes

reproduce-bug is a command published in the GitHub repository tajmahal226/compound-engineering-plugin (4 stars, last pushed 6mo ago), licensed MIT. It adds 20 tokens to every session and 721 once invoked, about $0.0001 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.