WebAssembly Compilation

The gh-aw compiler can be built as a WebAssembly (Wasm) module, letting you compile agentic workflows directly in the browser without a server-side Go installation.

Overview

The Wasm build packages the core compilation engine — markdown parsing, frontmatter extraction, import resolution, and YAML generation — into a single .wasm file. You load it with Go’s standard wasm_exec.js runtime, then call a global compileWorkflow() function from JavaScript.

This is useful for:

Interactive playgrounds where users experiment with workflow syntax
Editor integrations that preview compiled YAML in real time
Offline tools that need compilation without a backend

Prerequisites

Go 1.25 or later
make (GNU Make)

Building

Run the following from the repository root:

make build-wasm

This produces two artifacts:

File	Description
`gh-aw.wasm`	The compiled WebAssembly module (~17 MB uncompressed)
`$(go env GOROOT)/misc/wasm/wasm_exec.js`	Go’s Wasm runtime (ships with your Go installation)

Copy both files to your project:

cp gh-aw.wasm your-project/
cp "$(go env GOROOT)/misc/wasm/wasm_exec.js" your-project/

Compression

The raw .wasm binary is ~17 MB. The build pipeline pre-compresses it with brotli at maximum quality (-q 11), producing a gh-aw.wasm.br file of ~5 MB — a ~70% reduction. GitHub Pages serves the .br file automatically when the browser sends Accept-Encoding: br.

# Manual compression (if not using the bundle script)
brotli -k -q 11 gh-aw.wasm    # produces gh-aw.wasm.br (~5 MB)

The docs site bundle script (scripts/bundle-wasm-docs.sh) handles this automatically. If brotli is not installed, it falls back to gzip (-9), which achieves ~6 MB.

JavaScript API

Loading the module

<script src="wasm_exec.js"></script>
<script>
const go = new Go();
WebAssembly.instantiateStreaming(
  fetch("gh-aw.wasm"),
  go.importObject
).then((result) => {
  go.run(result.instance);
  // compileWorkflow is now available globally
});
</script>