Chakra

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

Chakra supports both flag-based arguments using --path and direct positional arguments for a more intuitive command line experience.

Basic Usage

Run on current directory:

chakra

Run a WebAssembly file directly:

chakra myfile.wasm

# Using --path flag
chakra --path ./path/to/your/file.wasm

# With --wasm flag explicitly
chakra --wasm myfile.wasm

Run a project directory:

chakra ./my-wasm-project

# Using --path flag
chakra --path ./my-wasm-project

Custom Port

Specify a custom port (default is 8420):

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

Watch Mode

Enable watch mode for live reloading:

chakra --path ./path/to/your/project --watch
# Or
chakra ./my-wasm-project --watch

Verify WASM File

Verify if a WebAssembly file is in the correct format:

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

# Using --path flag
chakra verify --path ./path/to/your/file.wasm

For detailed output:

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

Inspect WASM File

Get detailed information about a WASM file:

chakra inspect ./path/to/your/file.wasm
# Or
chakra inspect --path ./path/to/your/file.wasm

Compile a Project to WASM

Compile a project directory to WebAssembly:

chakra compile ./my-project
# Or
chakra compile --path ./my-project

With a custom output directory:

chakra compile ./my-project --output ./build

Run with Specific Language

Specify a language for compilation:

chakra run ./my-project --language rust

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 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 ./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