Why exactly typescript? Typescript should be compileable into WebAssembly bytecodes and that's it. If you want it to be transparently compileable, like foo.ts

Why exactly typescript? Typescript should be compileable into WebAssembly bytecodes and that's it. If you want it to be transparently compileable, like foo.ts to be sent as WA bytecodes then something like mod-typescript (on the fly typescript compiler) can be designed that will send (compiled and cached) bytecodes.