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282 points felarof | 5 comments | | HN request time: 0.697s | source

Hey HN, we're a YC startup building an open-source, privacy-first alternative to Perplexity Comet.

No invite system unlike bunch of others – you can download it today from our website or GitHub: https://github.com/browseros-ai/BrowserOS

--- Why bother building an alternative? We believe browsers will become the new operating systems, where we offload much bunch of our work to AI agents. But these agents will have access to all your sensitive data – emails, docs, on top of your browser history. Open-source, privacy-first alternatives need to exist.

We're not a search or ad company, so no weird incentives. Your data stays on your machine. You can use local LLMs with Ollama. We also support BYOK (bring your own keys), so no $200/month plans.

Another big difference vs Perplexity Comet: our agent runs locally in your browser (not on their server). You can actually watch it click around and do stuff, which is pretty cool! Short demo here: https://bit.ly/browserOS-demo

--- How we built? We patch Chromium's C++ source code with our changes, so we have the same security as Google Chrome. We also have an auto-updater for security patches and regular updates.

Working with Chromium's 15M lines of C++ has been another fun adventure that I'm writing a blog post on. Cursor/VSCode breaks at this scale, so we're back to using grep to find stuff and make changes. Claude code works surprisingly well too.

Building the binary takes ~3 hours on our M4 Max MacBook.

--- Next? We're just 2 people with a lot of work ahead (Firefox started with 3 hackers, history rhymes!). But we strongly believe that a privacy-first browser with local LLM support is more important than ever – since agents will have access to so much sensitive data.

Looking forward to any and all comments!

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layer8 ◴[] No.44524345[source]
I would prefer this as a browser extension, not as its own browser application.
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arjunchint ◴[] No.44527052[source]
We had this exact thought as well, you don't need a whole browser to implement the agentic capabilities, you can implement the whole thing with the limited permissions of a browser extension.

There are plenty of zero day exploit patches that Google immediately rolls out and not to mention all the other features that Google doesn't push to Chromium. I wouldn't trust a random open source project for my day-to-day browser.

Check out rtrvr.ai for a working implementation, we are an AI Web Agent browser extension that meets you where your workflows already are.

replies(2): >>44527600 #>>44529016 #
1. esperent ◴[] No.44529016[source]
> I wouldn't trust a random open source project for my day-to-day browser.

Given that you're working on a direct competitor, this comment reads as fearmongering, designed to drive people over to your product.

replies(2): >>44529489 #>>44530206 #
2. arjunchint ◴[] No.44529489[source]
I personally talked to another agentic browser player, fellou.ai, in the space asking them how they are keeping up with all the Chromium pushes as you need a dedicated team to handle the merges, they flat out told me they are targeting tech enthusiasts that are not interested in the security of their browser as much.

As an ex-Google engineer I know the immense engineering efforts and infrastructure setup to develop Chrome. It is very implausible that two people can handle all the effort to serve a secure browser with 15+ million lines of constantly changing C++ code.

A sandboxxed browser extension is the natural form factor for these agentic capabilities.

replies(1): >>44534388 #
3. Imustaskforhelp ◴[] No.44530206[source]
Conflict of interests at its heart.

I mean, I have no skin in the game but I mean, there are people who are using Dia (browser company) and Dia is closed source so it would be nice to see those people jumping to browser OS atleast.

I personally would prefer it as an extension but there are some limitations as the author of browserOS noted within extensions but I just wish that google/chromium can push those changes upstream I guess.

replies(1): >>44534464 #
4. felarof ◴[] No.44534388[source]
Also, ex-Google engineer here :) Rtrvr looks like great product too!

Definitely understand that keeping up with security patches is important. And this is an engineering challenge and not implausible to do -- Perplexity is 1/1000th the size of Google and they could be build a better product. So, "you can just do things".

We are still on day 1 of launch. We will only get better from here. And we won't be 2 people forever. We plan to hire, expand team and take on the engineering challenges.

5. felarof ◴[] No.44534464[source]
Thank you for your support! Yes, we want to do some cool things that we can't do as extension.

C++ APIs for dom tree, a11y. We eventually want to ship a small fine-tuned LLM and package with browser binary too.

Just getting started!