wasm-http-server/docs/tinygo

Compiling with TinyGo

This example demonstrates that go-wasm-http-server can also be compiled with TinyGo, producing significantly smaller WASM blobs, though at the expense of at least one known bug and a reduced standard library.

This example also demonstrates how the same code can be used for both server-side execution, and client-side execution in WASM (providing support for clients that cannot interpret WASM).

Prerequisites

You'll need a version of TinyGo installed. (eg. brew install tinygo-org/tools/tinygo)

You'll need to make sure the first line of sw.js here has the same tinygo version number as your TinyGo version (this was v0.35.0 at time of writing).

Build & run

Compile the WASM blob with TinyGo (this has been done for you for this example):

GOOS=js GOARCH=wasm tinygo build -o api.wasm  .

Run the server (with Go, not TinyGo):

$ go run .
Server starting on http://127.0.0.1:<port>

Important notes

You must use the TinyGo wasm_exec.js, specific to the version of TinyGo used to compile the WASM, in your sw.js. For example, if using the JSDelivr CDN:

importScripts('https://cdn.jsdelivr.net/gh/tinygo-org/tinygo@0.35.0/targets/wasm_exec.js')

Note that the 0.35.0 within the path matches the TinyGo version used:

$ tinygo version
tinygo version 0.35.0 darwin/arm64 (using go version go1.23.4 and LLVM version 18.1.2)
#              ^----^