I have tried to promote this for Nostr for a while. Is there a reason this same standard wouldn’t work for you? https://webxdc.org/
Discussion
webxdc can work in Keychat. webxdc is an offline web, while the web apps in the Keychat browser are online web.
“Webxdc app development and deployment is fundamentally easier than developing for and maintaining an application-specific always-online HTTP server. But there are undeniably complications in arranging consistent web app state across user's devices, a typical issue for any Peer-to-Peer (P2P) networking system.”