OP here. I built this because I was tired of emailing PSBT files back and forth or pasting hex data into chat apps.

It is a stateless WebSocket server running on Cloudflare Durable Objects. The 'room' exists only in memory and nukes itself after 20 minutes (or when all users leave).

Privacy: Client-side encryption (keys are in the URL fragment, never sent to server).

Architecture: No database. Just ephemeral state.

Stack: Angular + Hono + LNBits (for optional paid upgrades).

It is open source (AGPLv3).

Code: https://github.com/scarlin90/signingroom

I'd love feedback on the Durable Objects implementation or the UX flow.