@chainlink/cre-sdk-javy-plugin

@chainlink/cre-sdk-javy-plugin

WebAssembly compilation tools for Chainlink CRE SDK workflows using Javy.

This package enables compiling TypeScript/JavaScript workflows to WebAssembly for execution in the Chainlink Runtime Environment. It provides the Javy plugin that exposes CRE host functions to guest workflows.

Installation

bun add @chainlink/cre-sdk-javy-plugin

Quick Start

# One-time setup: download Javy binary and compile plugin
bunx cre-setup

# Compile your workflow to WebAssembly
bunx cre-compile-workflow src/workflow.js dist/workflow.wasm

Usage

Standalone Usage

If using outside the CRE SDK monorepo:

• Install the package

  bun add @chainlink/cre-sdk-javy-plugin
  

• Setup (one-time)

  bunx cre-setup
  

  This downloads the appropriate Javy binary for your OS and compiles the CRE plugin.

• Compile workflows

  bunx cre-compile-workflow <input.js> <output.wasm>
  

Example

# Compile a workflow
bunx cre-compile-workflow src/hello-world.js dist/hello-world.wasm

# The compiled WASM can now be deployed to CRE

Javy Setup & Troubleshooting

macOS

The repo includes pre-compiled Javy binaries. If you encounter Apple security issues:

# Remove quarantine attribute
xattr -d com.apple.quarantine ./bin/javy-arm-macos-v5.0.4

# Make executable
chmod +x ./bin/javy-arm-macos-v5.0.4

# Verify installation
./bin/javy-arm-macos-v5.0.4 --version

Linux

# Make executable
chmod +x ./bin/javy-arm-linux-v5.0.4

# Verify installation
./bin/javy-arm-linux-v5.0.4 --version

Plugin Architecture

The Javy Chainlink SDK plugin exposes host functions to guest workflows:

• Static Linking: Plugin is compiled into the final WASM (current approach)
• Dynamic Loading: Runtime plugin discovery (future enhancement)

Build from Source

Prerequisites

• Rust toolchain with wasm32-wasip1 target
• Bun >= 1.2.21

# Install Rust WASM target
rustup target add wasm32-wasip1

# Install wasm-tools for debugging
cargo install --locked wasm-tools

Building

# Build the plugin
bun run build

# Or manually build the Rust plugin
cd src/javy_chainlink_sdk
cargo build --target wasm32-wasip1 --release

Build Output

After building, you'll find:

• dist/javy_chainlink_sdk.wasm - The compiled plugin
• dist/workflow.wit - WebAssembly Interface Types definitions

Debugging Compiled WASM

Use wasm-tools to inspect compiled workflows:

# Validate a compiled workflow
wasm-tools component targets --world workflow src/workflow.wit dist/workflow.wasm

# Print WASM structure
wasm-tools print dist/workflow.wasm

Configuration

The plugin uses these configuration files:

• src/javy_chainlink_sdk/Cargo.toml - Rust dependencies and build config
• src/workflow.wit - WebAssembly Interface Types for CRE workflows
• bin/compile-workflow.ts - Workflow compilation logic
• bin/setup.ts - One-time setup script

Compatibility

• Javy Version: v5.0.4
• Rust Edition: 2021
• WASM Target: wasm32-wasip1
• Node Runtime: Bun >= 1.2.21

Development

Project Structure

src/
├── javy_chainlink_sdk/     # Rust plugin source
│   ├── src/lib.rs         # Plugin implementation
│   └── Cargo.toml         # Rust dependencies
├── workflow.wit           # WASM interface definitions
bin/
├── setup.ts              # Setup script
└── compile-workflow.ts   # Compilation script

Testing

# Run plugin tests
cd src/javy_chainlink_sdk
cargo test

# Test compilation with example workflow
bunx cre-compile-workflow examples/hello-world.js test-output.wasm

Contributing

• Make changes to the Rust plugin in src/javy_chainlink_sdk/
• Build and test: bun run build
• Test compilation: bunx cre-compile-workflow <test-file> <output>
• Verify WASM output: wasm-tools print <output>

License

See LICENSE in LICENSE.md