This is very cool, thanks so much for explaining how this works and, of course, for initiating such a cool project!
As far as I can tell, tRPC basically bridges (hides) network communication and allows doing remote procedure calls almost like regular, type-safe function calls on the same machine within the same process.
Now I would give a fortune for having something like that also for cross-language communication and for communicating with other processes (binaries and shell scripts). I've been thinking about this a lot in recent years: In SWE we need to jump through many hoops only because it's so god damn hard to invoke a function or a whole API living somewhere else in a type-safe manner. Intermediate formats like JSON, protobuf, standards like REST, OpenAPI, and GraphQL, and even languages like SQL (and the various ORM libraries it inspired) are all a result of that to some degree: Once data leaves the safe haven of your (hopefully statically typed) programming language where the compiler/interpreter knows exactly what its type is and what the signature of the function is that you're trying to call, you're basically on your own.
I recently read about WASM Interface Types[0] and it seems like a step in the right direction, though unfortunately it will only bridge the – let's call it – type safety gap between processes, not between different machines in a network.
[0]: https://hacks.mozilla.org/2019/08/webassembly-interface-type...