Currently in an experimental stage, JSPI should not be used in production applications yet, the developers said. Eventually, it will become a standard, for implementation across major browsers, they said.
Introduced in a V8 blog post on January 19, JSPI bridges synchronous WebAssembly applications and asynchronous web APIs. This is done by suspending the application when it issues a synchronous API call and resuming when the asynchronous I/O operation is concluded. And JSPI does this with very few changes to the application itself.