Rotunda
A browser built for agents with simulated typing
Details
- External ID
- 48121824
- Source
- HN
- Company
- —
- Product
- Rotunda
- Website domain
- github.com
- Launched
- May 13, 2026
- Cohort
- —
- Upvotes
- 13
- Upvotes percentile
- 0.654281098546042
- Tags
- —
- Fetched at
- Sept. 7, 2026, 9:26 p.m.
- Updated at
- Sept. 7, 2026, 9:26 p.m.
Description
Hi HN! Pierce here.Rotunda is a firefox fork primarily intended for agent use, which I’ve been hacking on nights/weekends.There was a [lengthy](https://news.ycombinator.com/item?id=48024859) discussion last week on how expensive computer use models are. The cost is going to drop eventually, but I think on some level it's still usually the wrong primitive. The web gives us access to beautiful structured formats, plaintext, etc... why throw that away if we don't have to?I realized at some point that for 99% of automations I just want agents to be able to control my Chrome instance. But that’s easier said that done: CDP (the Chrome automation protocol) leaks a ton of state about being programmatically controlled, either by toggling window attributes or by running `page.evaluate()` commands right in the page context. Plus if you look at an automation running it's pretty obvious what happens: the mouse jumps around, fields are filled instantly, etc.Rotunda tries to fix this. Its standout features:- Realistic simulation of mouse movements and keyboard commands, powered by a trained RNN on my own timing patterns from the last week. (still feel weird about opting-in to a key logger but whatever)- Doesn’t lie about its host specs, only fibs about some client side details. Stealth browsers are too easy to flag statistically when you’re adding noise to canvas pixels or audio pipelines.- It runs on your local device with a CLI or Playwright API accessible to Claude, Codex, or whatever your harness-de-jure today looks like.- Patches modern Firefox (150) with an agentic harness to keep this updated over timeMPL-2.0 on GitHub: https://github.com/monkeysee-ai/rotundaLonger writeup on the design choices: https://pierce.dev/notes/a-browser-for-agentsAlso check out the demo on the site! https://www.rotunda.sh/Pretty excited by how this turned out but we’re still super early. Give it a try and please flag any issues!
Enrichment
- Theme
- browser automation and scraping for AI
- Vertical
- Horizontal
- Function
- Agent / copilot
- Audience
- Developer
- AI stance
- AI-native
- Project type
- Commercial product
- Normalized one-liner
- browser for agents with simulated typing
- Manually corrected
- False
Could you build this?
No Forking and modifying the Gecko/Firefox engine to simulate human-like OS-level or DOM-level input events for agent automation requires deep C++ browser engine expertise.
What it would actually take: Building a custom Firefox fork requires navigating Mozilla's extensive C++ codebase (Gecko/SpiderMonkey) and build system (Mach). The developer must modify event dispatching in the window manager and DOM event pipelines to ensure synthetic keyboard and mouse events pass anti-bot fingerprinting and synthetic-event detection (e.g., `isTrusted` flags, hardware timing jitter, and canvas/WebRTC fingerprint spoofing). This requires deep browser internals knowledge and anti-bot evasion expertise.
Discussion
5 comments analyzed.
Concerns raised: Mouse movement fingerprints may not be unique enough for reliable identity verification, Risk that captchas will eventually detect trained timing patterns and lock out users, Uncertainty whether bezier classification actually works for human detection
Feature requests: Browser viewport width should respond to window resizing in headed mode, Biased decoding model to input randomized personality vectors affecting RNN generation, Granular permissions system for agent use of browser
Competitors
Other products that read as similar to this one — 134 launches clear the similarity bar, closest 8 shown.
Attention rank: #62 of 135 (itself plus its competitors, highest first — normalized so YC and Product Hunt are compared fairly).
Launched 190 days after the earliest competitor.
- Browser4 · hn · 2025-12-13 · 7 upvotes · similarity 0.48
- PageAgent, A GUI agent that lives inside your web app · hn · 2026-03-05 · 147 upvotes · similarity 0.44
- I made a browser TUI with its own layout engine · hn · 2026-07-07 · 6 upvotes · similarity 0.43
- Libretto · hn · 2026-04-15 · 134 upvotes · similarity 0.43
- Toad. A unified terminal UI for coding agents · hn · 2025-12-18 · 14 upvotes · similarity 0.42
- You Are an Agent · hn · 2026-02-01 · 14 upvotes · similarity 0.41
- SubjectiveZero, an open-source agentic node editor for creative coding · hn · 2026-07-10 · 25 upvotes · similarity 0.41
- Persona.js · hn · 2026-06-20 · 27 upvotes · similarity 0.41
Other launches for this product
- No other launches for this product.
Same idea, different domain
Nobody's really built a agent / copilot tool for Agriculture yet.