The idea behind Apps is that they can expand the capabilities of ChatGPT in multiple ways. Text-only MCPs are a type of app that can provide both actions and context in your conversations, but Apps can do much more now that you can bring in custom UI in multiple formats (card, full-screen, etc) as we showed at DevDay in October. Btw UI is proposed for the MCP spec in SEP-1865.
Since then, I’ve seen some very impressive demos and I’m excited to see what developers create on the platform as that’s always the coolest part.
I'm really unexcited about bolting HTML/CSS/JS and the entire webstack into MCP so that a full-featured MCP client has to carry a full web browser, too.
I expect there's a pretty wide divide between what people who write local MCP servers want, versus what people who write cloud webstack MCP webapps want.
Personally, I've been adding local native UI to my MCP servers, but I realize that's probably a losing battle, and if I want to integrate with newer tooling, I'm going to be stuck in web hell.