gomode

The problem

Go on WASM is broken in two different ways:

	Binary size	Stdlib	Speed
Standard Go → WASM	3MB+	Full	Slow (heavy runtime)
TinyGo → WASM	~700KB	Incomplete	Fast

Standard Go gives you the full stdlib but a massive binary with a heavy runtime. TinyGo gives you a small fast binary but is missing net/http, crypto, full reflect, and more.

GoMode’s answer

Use TinyGo for the small binary, use Zig to fill every gap — linked into the same WASM binary via wasm-ld. Zero runtime overhead.

Zig (SIMD, allocator, crypto) ──────────→ zig-abi.o
Go handler (TinyGo, CGo, -gc=custom) ──→ wasm-ld → go.wasm (58KB)

JS Worker writes/reads via zerobuf layout (direct DataView on hot path)

Go calls Zig via CGo — compiles to direct WASM call instructions. Same linear memory, no imports, no JS proxy, no serialization.

Quick start

package main

import (
  "gomode"
  "unsafe"
)

//export handle_zerobuf
func handleZerobuf(reqBase uint32) uint32 {
  path := readZBString(uintptr(reqBase) + 1*16)

  switch path {
  case "/":
    return writeResponse(200, "text/plain", "Hello from GoMode!")
  case "/simd":
    data := []float64{1, 2, 3, 4, 5, 6, 7, 8}
    sum := gomode.ZigSimdSumF64(
      uint32(uintptr(unsafe.Pointer(&data[0]))),
      uint32(len(data)),
    )
    return writeResponse(200, "text/plain", formatFloat(sum))
  }
  return writeResponse(404, "text/plain", "not found")
}

func main() {}

8787/simd

npm run build && npm run dev
# → http://localhost:8787