TL;DR: We built Webfuse, a Web Augmentation Platform that lets you modify, automate, and collaborate on any web app — without changing the source code. Think “programmable browser session” where you can inject custom extensions, share sessions, record, automate, and more. It’s built on 10+ years of co-browsing tech from Surfly.

Hi HN,

I’m Nicholas Piël, founder of Surfly — we’ve been building co-browsing solutions since 2012. Over the years, we've developed a technology that allows us to take any web session and convert it into a virtual web session that can be shared and interacted with by multiple participants — all in real-time, and without touching the original app.

This led us to build Webfuse, which we’re now opening up publicly. Webfuse is a Web Augmentation Platform — it lets you modify, automate, and collaborate on any web application, without installing extensions, modifying code, or owning the underlying app.

Why we built it We realized our core tech — real-time rewriting and virtualization of web sessions — was more powerful than just co-browsing. A few of our customers figured this out too, and used our APIs to build completely new tools on top of third-party apps. But until recently, the infrastructure wasn’t mature enough to make this accessible to a broader audience. Now, it is. Webfuse is the product of over a decade of work in this domain.

What’s different Existing solutions like browser extensions, edge code injection, or remote browsers all fall short when it comes to modifying third-party apps securely and scalably. We took a different route: on-the-fly, domain-level rewriting of existing apps inside a secure virtualization layer. This lets us expose a consistent API to developers, while maintaining full compatibility with modern web apps.

You can: Launch virtual sessions that wrap any web app Add custom extensions (browser-extension-like API) Share sessions with multiple users (like multiplayer mode) Inject automation (bots, testing, RPA, etc.) Record sessions, enforce auth, block tracking, etc.

How it works You create a Space — essentially a URL that opens one or more web apps in virtualized form. From there, you can add security, extensions, or UI changes. All of this is configurable through the Webfuse API or UI.

We expose: - REST API - JavaScript session API - Webhooks - Magic Link (JWT-based) API - Extension API (based loosely on browser extension standards)

Why this is interesting If you’ve ever wanted to: Turn a legacy internal tool into a modern frontend, Saasify a browser extension, Inject AI into third-party apps, Or just hack on top of software you don’t own. ...this might give you that ability. Webfuse acts as a programmable overlay on the web.

Site: https://www.webfuse.com Docs: https://docs.surfly.online/category/webfuse-beta

Happy to answer anything here. — Nicholas