It seems like you are working towards a "everyone put their social stuff on their own site" model, which really lines up with the indiewebcamp ideal. I would r

It seems like you are working towards a "everyone put their social stuff on their own site" model, which really lines up with the indiewebcamp ideal. I would recommend looking at https://indiewebcamp.com/webactions https://indiewebcamp.com/webactions, as it's almost exactly what you are looking for, and requires little to no browser support at all, just the ability to register a url as a handler for a protocol. Biggest issue is just getting all the different sites to have support for webactions. The other bit you need is https://indiewebcamp.com/indie-config https://indiewebcamp.com/indie-config