Cursor for Userscripts

Hacker News

I’ve been experimenting with embedding an Claude Code/Cursor-style coding agent directly into the browser. At a high level, the agent generates and maintains userscripts and CSS that are re-applied on page load. Rather than just editing DOM via JS in console the agent is treating the page, and the DOM as a file. The models are often trained in RL sandboxes with full access to the filesystem and bash, so they are really good at using it. So to make the agent behave well, I've simulated this environment. The whole state of a page and scripts is implemented as a virtual filesystem hacked on top of browser.local storage. URL is mapped to directories, and the agent starts inside this directory. It has the tools to read/edit files, grep around and a fake bash command that is just used for running scripts and executing JS code. I've tested only with Opus 4.5 so far, and it works pretty reliably. The state of the file system can be synced to the real filesystem, although because Firefox doesn't support Filesystem API, you need to manually import the fs contents first. This agent is really useful for extracting things to CSV, but it's also can be used for fun. Demo: https://x.com/ichebykin/status/2015686974439608607

Visit product View on Hacker NewsJan 28, 2026

Share card

Actual performance

56points

15comments

Made the leaderboard

Launch Intel predictions

Analyze your own launch →

Product HuntOn track for Day 1 leaderboard · Strong signals: agent, cursor, claude · Missing: mac, agents, macos

94%94% predicted probability of success on Product Hunt, based on ML models trained on real launch data.

best fitHighest predicted score across all platforms for this description.

Hacker NewsStrong engagement from HN community · Strong signals: filesystem, ide · Missing: https docs, excited, just released

68%68% predicted probability of success on Hacker News, based on ML models trained on real launch data.

nativeThis product was originally launched on this platform.

Indie HackersFits the IH revenue-focused audience · Missing: supports, reddit linkedin, podcasting

64%64% predicted probability of success on Indie Hackers, based on ML models trained on real launch data.

AppSumoMay struggle as an AppSumo deal · Strong signals: users · Missing: plus, platform, intuitive

33%33% predicted probability of success on AppSumo, based on ML models trained on real launch data.

TrustMRRLess likely to generate early MRR · Strong signals: users · Missing: mobile apps, ios, personal

30%30% predicted probability of success on TrustMRR, based on ML models trained on real launch data.

Acquire.comPre-revenue stage for this audience · Missing: arr, mrr, revenue

17%17% predicted probability of success on Acquire.com, based on ML models trained on real launch data.

BetaListMay not resonate with beta-testers · Missing: web3, chat, crypto

0%0% predicted probability of success on BetaList, based on ML models trained on real launch data.

Correct prediction on native model

Similar products

IPychat – Cursor for IPython43%Launch Intel prediction score: how likely this product is to succeed on its source platform, based on its name, tagline, and description.

IPychat – Cursor for IPython

Hacker News1

Lotas – Cursor for RStudio70%Launch Intel prediction score: how likely this product is to succeed on its source platform, based on its name, tagline, and description.

Lotas – Cursor for RStudio

Hacker News82

WebPilot – "Cursor" for the Browser33%Launch Intel prediction score: how likely this product is to succeed on its source platform, based on its name, tagline, and description.

WebPilot – "Cursor" for the Browser

Hacker News2

wink-cursor87%Launch Intel prediction score: how likely this product is to succeed on its source platform, based on its name, tagline, and description.

A lightweight smiley cursor with "winks" on click

Product Hunt+255Productivity

Cursor for Email52%Launch Intel prediction score: how likely this product is to succeed on its source platform, based on its name, tagline, and description.

Cursor for Email

Hacker News2

Cursor for Your Notes32%Launch Intel prediction score: how likely this product is to succeed on its source platform, based on its name, tagline, and description.

Cursor for Your Notes

Hacker News3

Cursor pagination based on GORM in golang38%Launch Intel prediction score: how likely this product is to succeed on its source platform, based on its name, tagline, and description.

Cursor pagination based on GORM in golang

Hacker News1

Focus Cursor86%Launch Intel prediction score: how likely this product is to succeed on its source platform, based on its name, tagline, and description.

Highlight cursor & markup

Product Hunt+88Productivity

UserPath – Cursor for Analytics43%Launch Intel prediction score: how likely this product is to succeed on its source platform, based on its name, tagline, and description.

UserPath – Cursor for Analytics

Hacker News1

Play Snake or Tetris on Cursor42%Launch Intel prediction score: how likely this product is to succeed on its source platform, based on its name, tagline, and description.

Play Snake or Tetris on Cursor

Hacker News1

Browse all products Analyze your launch