alextnetto / res

# RES: Reverse Engineering SaaS
### Turn a SaaS product into a build kit your team or your coding agent can ship.
**Study a web product through the browser, document how it works, and hand off everything needed to rebuild and launch it, without touching production data.**
Quick start · How RES works · What you get · Examples · Safety model · FAQ · Documentation
 claude plugin marketplace add alextnetto/res 
> [!IMPORTANT]
> RES drives a real browser on accounts you control. Use it only on products you are allowed to study, read the safety model before the first run, and prefer a trial account in a separate browser profile.
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Want to rebuild a product your team relies on, or launch a competitor in your market? Ask your agent to study it with RES. The agent explores the product in a test environment, records every change it makes, and writes what it learns to files: screens and states, business rules with evidence, the data model, API shapes, design tokens, and what could stop the clone from launching, such as integrations that need approval, licenses and certifications.
At the end you get two files. `REPORT.html` is the report you read: one page that starts with the overview and the decisions you need to make, then walks through what the product does, every screen and rule, the data model and design, the build plan, and what to prepare before launch. The zip is for your coding agent: unzip it, give it the folder, and it starts from `BUILD.md`.
RES is one agent skill with plain Markdown templates and a few dependency-free Node.js scripts. It adds about 130 tokens to every session and about 4,600 when it runs (measured with `claude plugin details`).
## Quick start
### Install
In a terminal:
 [code] 
 [code] 
Inside a Claude Code session, the same commands are `/plugin marketplace add alextnetto/res` and `/plugin install res@res`. Start a new session afterwards.
For other agents that read skills from disk, copy the skill folder where your agent reads skills:
 [code] 
You need Node.js 22 or later and an agent that can drive a browser and run JavaScript in the page: Claude in Chrome, Playwright MCP or Chrome DevTools MCP.
### Prepare a safe environment
Create a trial account of the product with an email you own, log in to it in a separate Chrome profile, and connect your agent's browser tool to that profile (how). This is the safest setup: the agent cannot reach your production account even by mistake.
Without a trial account, the agent writes only if you ask it to test or to create a test environment, and then only inside a separate workspace or a sandbox container. Otherwise it only observes.
### Ask your agent
 [code] 
Replace the product, the market and the scope with your own. The agent creates `re- /` in its working directory, works through the phases below, and sends you `REPORT.html` and `re- -handoff- .zip` when it finishes. To continue later, start a session in the same directory and say "Continue the Pipedrive study."
### Use the scripts d