Server Mode Features

Multi-Language Compilation

Server mode auto-detects your project type and compiles using the appropriate toolchain:

Language	Detection	Compiler
Rust	Cargo.toml	cargo build --target wasm32-unknown-unknown via wasmrust plugin
Go	go.mod	TinyGo via wasmgo plugin
C/C++	Makefile with emcc	Emscripten (built-in)
Python	*.py files	waspy plugin
AssemblyScript	asconfig.json	asc via wasmasc plugin

Plugins are installed separately — see Plugins for setup.

Built-in HTTP Server

A lightweight HTTP server (powered by tiny_http) serves:

• The compiled .wasm file with correct application/wasm content type
• JavaScript glue code for wasm-bindgen projects
• An HTML page with module inspection UI
• Static assets from the project directory

wasm-bindgen Support

Server mode automatically detects wasm-bindgen projects:

• Recognizes _bg.wasm files and their JS counterparts
• Serves both the WASM binary and JavaScript glue code
• Handles module imports/exports correctly

# Automatically detected
wasmrun run ./my-wasm-bindgen-project

Live Reload

With --watch, wasmrun monitors your source files and recompiles on changes:

1. File system watcher detects modifications to source, config, and asset files
2. Project is recompiled using the same toolchain
3. Browser refreshes automatically with the new build
4. Build errors are displayed in the terminal without crashing the server

wasmrun run ./my-project --watch

Watched File Types

• Source: *.rs, *.go, *.py, *.c, *.cpp, *.h, *.ts
• Config: Cargo.toml, go.mod, package.json, Makefile
• Assets: *.html, *.css, *.js, *.json

Module Inspection UI

The browser UI provides:

• Module info — exports, imports, memory layout, section sizes
• Plugin info — which plugin compiled the module, its capabilities
• Version info — wasmrun version and build metadata

Available via the /api/module-info and /api/version endpoints.

Smart Project Detection

When given a directory, wasmrun:

1. Checks for installed plugins that match the project
2. Falls back to built-in language detection
3. Compiles using the detected toolchain
4. Serves the output

When given a .wasm file directly, it skips compilation and serves immediately.