tinywasm/client

Build-only WebAssembly compilation manager for TinyWASM.

As of v2, client has a single responsibility: compile the WASM binary and serve it at /client.wasm. All JavaScript composition has moved to tinywasm/js.

Responsibilities

✅ Owns	❌ No longer owns
WASM compilation (Go stdlib / TinyGo)	wasm_exec.js embedding
Serving /client.wasm via HTTP	Javascript struct / GetSSRClientInitJS
3-mode compiler selection (L/M/S)	Generating script.js content
File watcher for web/main.wasm.go	WasmExecGoSignatures / WasmExecTinyGoSignatures
VS Code GOOS/GOARCH config	ClearJavaScriptCache
Project scaffolding (CreateDefaultWasmFileClientIfNotExist)

CLI Tool

go install github.com/tinywasm/client/cmd/wasmbuild@latest
wasmbuild        # Go stdlib mode (L)  → writes web/public/client.wasm + script.js
wasmbuild -tinygo # TinyGo mode (S)

script.js is now generated via tinywasm/js.PageBootstrap() — the embedded wasm_exec.js lives in js/assets/ (single source of truth).

See cmd/wasmbuild for details.

🛠 Basic Usage

cfg := client.NewConfig()
cfg.SourceDir = func() string { return "web" }
cfg.OutputDir = func() string { return "web/public" }

twc := client.New(cfg)
twc.SetAppRootDir("/path/to/project")
twc.SetMainInputFile("app.go") // default: "client.go"
twc.SetOutputName("app")       // default: "client"

Mode switching

twc.Change("S") // "L" = Go, "M" = TinyGo debug, "S" = TinyGo prod

HTTP serving

twc.RegisterRoutes(mux) // registers /client.wasm (or /prefix/client.wasm)

ArgumentsForServer

// Returns []string{"-wasmsize_mode=L"} (for subprocess injection)
args := twc.ArgumentsForServer()

Storage modes

Mode	Use case
In-Memory (default)	Fast dev — compiles to buffer, served directly
Disk	Static integration — compiles to OutputDir, served via http.ServeFile

twc.UseDiskStorage()   // switch to disk
twc.UseMemoryStorage() // switch back to memory

Project Initialization

// Generates web/client.go + .vscode/settings.json if missing
twc.CreateDefaultWasmFileClientIfNotExist(false)

⚙️ Configuration

• Config struct: shared deps (Store, Logger), directory functions (SourceDir, OutputDir). See config.go.
• Setters: reactive — re-initialize internal state automatically.

📋 Requirements

• Go 1.21+
• TinyGo (optional — needed for M/S modes only)

JavaScript composition

All JS is now the responsibility of tinywasm/js:

import "github.com/tinywasm/js"

// In tinywasm/app boot:
js.SetRuntime(js.RuntimeGo) // or RuntimeTinyGo
scripts := []any{js.PageBootstrap()} // registers with assetmin

See tinywasm/js for the full typed API including ServiceWorker and WebWorker.