WRT - WebAssembly Runtime

A Rust implementation of a WebAssembly runtime focusing on the Component Model and WASI Preview 2. Designed with safety-critical systems in mind.

Current Status

Early Development - Basic WebAssembly component execution is working:

# Run a Rust-compiled WASI Preview 2 component
./target/debug/wrtd hello_rust.wasm --component
# Output: Hello wasm component world from Rust!

What Works

• WebAssembly Component Model parsing and instantiation
• WASI Preview 2 stdout/stderr output (wasi:cli/stdout, wasi:io/streams)
• Core WebAssembly module execution
• Basic memory management with bounds checking
• no_std compatible foundation (for embedded use cases)

In Progress

• Additional WASI Preview 2 interfaces (filesystem, environment, etc.)
• Cross-component function calls
• Full Component Model linking

Quick Start

# Clone and build
git clone https://github.com/pulseengine/wrt
cd wrt
cargo build --bin wrtd --features "std,wrt-execution"

# Run a WebAssembly component
./target/debug/wrtd your_component.wasm --component

Project Structure

• wrtd/ - Runtime daemon (main executable)
• wrt-runtime/ - Execution engine
• wrt-component/ - Component Model support
• wrt-decoder/ - Binary format parsing
• wrt-foundation/ - Core types and bounded collections
• cargo-wrt/ - Build tooling

Building

# Install build tool (optional but recommended)
cargo install --path cargo-wrt

# Build runtime
cargo build --bin wrtd --features "std,wrt-execution"

# Run tests
cargo test --workspace

Usage

# Basic component execution
wrtd component.wasm --component

# With WASI support
wrtd component.wasm --component --wasi

# Set resource limits
wrtd component.wasm --component --fuel 100000 --memory 1048576

Design Goals

• WASI Preview 2 focus - Targeting the modern component-based WASI
• Safety-critical awareness - Bounded allocations, deterministic behavior
• no_std support - Usable in embedded/constrained environments

License

MIT License - see LICENSE file.