Chrome Browser Extension Support to Enable ChromeOS Compatibility

[joshua-ensley]

Solution

Add a Chrome browser extension implementation for CrossPaste to enable full functionality on ChromeOS and Chromebook devices.

Since ChromeOS does not support traditional desktop binaries, a Chrome extension would allow CrossPaste to operate within the browser sandbox while still providing meaningful cross-device clipboard synchronization. This would significantly expand platform coverage and make CrossPaste usable in education, enterprise, and lightweight computing environments where Chromebooks are prevalent.

Proposed approach:

• Implement a Chrome Extension (Manifest V3) that integrates with the Chrome clipboard APIs
• Use background service workers to handle clipboard sync events
• Leverage existing CrossPaste sync/back-end logic where possible via HTTPS/WebSocket APIs

Provide optional integration with the desktop app for users running Chrome on supported OSes
This would allow ChromeOS users to:

• Sync clipboard text and supported formats across devices
• Use CrossPaste without installing native binaries
• Maintain security and permissions aligned with Chrome’s extension model

Alternatives

• A standalone ChromeOS app (less ideal due to platform limitations and deprecation trends)
• A web-only clipboard sync page (limited background access and poor UX)
• Relying solely on Linux (Crostini) support on ChromeOS, which excludes many users and managed environments

A Chrome extension offers the best balance of reach, maintainability, and user experience.

How important is this improvement for you?

Would be a major improvement

[guiyanakuang]

Hi @joshua-ensley,

Thank you for this detailed proposal! To be honest, I have been considering this direction for some time. Since CrossPaste is built using Kotlin Multiplatform (KMP), we have the advantage of being able to reuse a significant amount of business logic from commonMain.

However, there are a few technical hurdles that make a browser extension implementation quite challenging at this stage:

Service Discovery Limitations: Browser extensions operate in a restricted sandbox. Unlike native applications, they cannot perform LAN broadcasting or listening (mDNS/UDP). This means we wouldn't be able to support the seamless "auto-discovery" of devices that CrossPaste currently offers. Users would likely need to manually input IP addresses and ports to bind devices, which significantly impacts the user experience.

Storage & Persistence: Our current architecture relies heavily on SQLite3. While it is possible to run SQLite in a JS/Browser environment via WebAssembly (WASM), ensuring reliable data persistence (rather than just in-memory storage) presents massive technical challenges and potential performance overhead. We would likely need to implement a separate, lightweight storage solution specifically for the extension, which would limit its ability to handle "heavy" clipboard tasks.

Conclusion & Roadmap: While a Chrome extension is an attractive lightweight solution for ChromeOS, it currently cannot match the feature set of our native applications, and the development effort required is non-trivial.

Based on these factors, I will add this to our long-term roadmap, but it will be prioritized after the following major milestones:

iOS Version of CrossPaste

CLI Version of CrossPaste

I'll keep this issue open for further discussion and community interest. Thanks again for the suggestion!