Pretty much all of the features you mention are already in LibreChat (MIT License). If you don't mind self-hosting, then it has branching, convo search, change

Pretty much all of the features you mention are already in LibreChat (MIT License). If you don't mind self-hosting, then it has branching, convo search, change models mid-chat, "presets" (save system prompts), and a whole lot more. I've deployed it in my gov agency for months now, and I've had amazing feedback. https://github.com/danny-avila/LibreChat https://github.com/danny-avila/LibreChat