To further explain: the standard WASM ABI is essentially just a C ABI, so you can pass integers and pointers around, but you can't do much more; anything more complex needs to be built on top of that, which precludes binding to the DOM API directly.

The existing workarounds for this glue the JS DOM API to the guest language through glue on both sides, but this means that you have to pay the penalty of marshalling through JS for every single call you make.

There's a solution in the works to make direct interaction possible, but it's proven to be quite challenging to finalise: essentially, you need a high-level ABI that can provide a safe and fast interface between the host and whatever guest language, and defining that in a way that makes everyone happy is non-trivial.

For more information, see the Component Model [0] and WIT [1]; the idea is that you will eventually be able to compile your WASM to WASM Components, which can then interface with the host (or other WASM components) through the WIT IDL, including interacting with the browser's DOM.

[0]: https://github.com/WebAssembly/component-model [1]: https://github.com/WebAssembly/component-model/blob/main/des...