chakra 0.4.0

A WebAssembly Runtime
chakra-0.4.0 is not a library.

Chakra

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Chakra Logo

Chakra is a WebAssembly (WASM) runtime CLI tool.

Features

  • 🚀 Start Chakra Server by pointing to your .wasm file/project and get a ready playground on your browser.
  • 🌐 Instantly opens your default browser with your wasm project and other necessary dependencies pre-loaded.
  • 💻 View execution results and logs on an interactive console.
  • 🔍 Identifies common entry points and runs your wasm project.
  • 📦 Compile your project to wasm using CLI tool directly. (Needs external dependencies.) [WIP]
  • 🧩 Verify and inspect your wasm file weather generated via chakra or any other tool. [WIP]

👋 It's highly experimental, but fast iterating. Welcoming contributors and support to help bring out this project even better!

Installation

From Cargo (Recommended)

cargo install chakra

From Source

git clone https://github.com/anistark/chakra.git
cd chakra
cargo install --path .

Usage

Basic Usage

Run a WebAssembly file directly:

chakra --path ./path/to/your/file.wasm

Custom Port

Specify a custom port (default is 8420):

chakra --path ./path/to/your/file.wasm --port 3000

Verify WASM File

Verify if a WebAssembly file is in the correct format:

chakra verify --path ./path/to/your/file.wasm

For detailed output:

chakra verify --path ./path/to/your/file.wasm --detailed

Stop Server

Stop any running Chakra server:

chakra stop

How It Works

When you run Chakra with a WASM file:

  1. It starts a lightweight HTTP server
  2. Opens your default browser
  3. Serves the WASM file along with a nice UI
  4. Attempts to instantiate and run the WebAssembly module
  5. Shows execution results and console logs

Supported WASM Types

Chakra works best with:

  • Simple C/C++ compiled WASM files
  • Rust WASM files compiled without wasm-bindgen
  • Any WASM that doesn't require extensive JavaScript bindings

For complex WASM modules (like those compiled with wasm-bindgen), Chakra will detect this and provide helpful information, but may not be able to execute them fully.

Examples

Running a simple C-compiled WASM file:

# Compile C to WASM (requires emscripten)
emcc -O2 hello.c -o hello.wasm

# Run with Chakra
chakra --path hello.wasm

Running a simple Rust WASM file:

# Build a WASM file from Rust
cargo build --target wasm32-unknown-unknown --release

# Run with Chakra
chakra --path ./target/wasm32-unknown-unknown/release/yourapp.wasm

Troubleshooting

  • "Port is already in use": Try specifying a different port with --port
  • "No WASM entry point found": Your WASM file might not have standard entry points like main() or _start()
  • "This appears to be a wasm-bindgen module": Try using the original JavaScript loader that came with your WASM file

License

MIT

Credits

Chakra is built with:

  • tiny_http - A lightweight HTTP server
  • clap - Command line argument parsing
  • ❤️ and WebAssembly enthusiasm