Hako QuickJS - WebAssembly JavaScript Engine

This is a fork of QuickJS that compiles to WebAssembly using WASI SDK. It provides a C API for embedding JavaScript execution in WebAssembly-based applications with built-in TypeScript type stripping support.

Key Features

• QuickJS JavaScript engine compiled to WebAssembly
• WASI reactor module (~800KB optimized)
• TypeScript type stripping via tree-sitter
• C API wrapper (hako.h/hako.c) for host integration
• Automated binding generation for host languages

Building

Prerequisites:

• WASI SDK (version 27 or later)
• wasm-opt (from Binaryen)
• Bun (for code generation)
• wasm-objdump (from WABT, for bindings)

Build steps:

1. Set WASI_SDK_PATH environment variable: export WASI_SDK_PATH=/path/to/wasi-sdk

2. Build hako.wasm: ./release-hako.sh

This runs make, compiles all sources, and optimizes the output with wasm-opt.

Code Generation

The codegen.ts tool generates language bindings from the compiled WASM module.

1. Parse WASM and generate bindings metadata: bun run codegen.ts parse hako.wasm hako.h bindings.json

   This extracts:

   • WASM type signatures and exports from hako.wasm
   • C function signatures and documentation from hako.h
   • Combines into bindings.json with complete metadata

2. Generate host language bindings: bun run codegen.ts generate csharp bindings.json HakoRegistry.cs

   Currently supports C# binding generation. The generated code includes:

   • Typed wrapper methods
   • Parameter marshalling
   • Documentation comments

Project Structure

hako.h - Public C API with function exports and documentation hako.c - Implementation wrapping QuickJS and TypeScript stripper ts_strip/ - TypeScript type stripping using tree-sitter release-hako.sh - Build script with wasm-opt optimization Makefile - WASI build configuration codegen.ts - Binding generator tool

Documentation

For detailed QuickJS documentation, see doc/quickjs.pdf or doc/quickjs.html. For Hako-specific usage, see the host implementations in the main repository.