Using WASI

TinyGo is very useful for compiling programs for use on servers and other edge devices (WASI).

TinyGo programs can run in Extism, Fastly Compute@Edge, Fermyon Spin, tau, wazero and many other WebAssembly runtimes.

Both WASI Preview 1 (wasip1) and WASI Preview 2 (wasip2) are currently supported.

Here is a small TinyGo program for use within a WASI host application:

package main

//go:wasmimport yourmodulename add
func add(x, y uint32) uint32

// main is required for the `wasip1` target, even if it isn't used.
func main() {}

//go:wasmimport may only appear on function declarations without a body (the implementation is provided by the host).

To compile the above TinyGo program for use on any WASI runtime:

GOOS=wasip1 GOARCH=wasm tinygo build -o main.wasm main.go