wash - wasmCloud Shell

This skill provides expertise in using the wasmCloud Shell (wash) CLI tool for developing and managing WebAssembly components and wasmCloud applications.

Prerequisites

• •wash version 2.0.0 or later (including release candidates like 2.0.0-rc.X)
• •Verify version with: wash --version

Important Notes

Do not use cargo component commands (like cargo component build) when working with wasmCloud projects. Always use wash commands instead:

• •Use wash build or wash dev for building components
• •For plugins, build with wash build --skip-fetch (since wasmcloud:wash interface isn't published)

Core Commands

wash dev

Use wash dev for local development and build loop. This command:

• •Automatically rebuilds your component on file changes
• •Provides a fast iteration cycle during development
• •Watches for changes and recompiles as needed

Example:

wash dev

wash wit update

Use wash wit update when there are mismatched WIT (WebAssembly Interface Types) definitions. This command:

• •Updates WIT dependencies to resolve conflicts
• •Synchronizes WIT definitions across your project
• •Fixes version mismatches in component interfaces

Example:

wash wit update

Common Workflows

Starting a New Project

1. •Initialize your project with wash new https://github.com/cosmonic-labs/<TEMPLATE> --name my-project
2. •cd my-project
3. •Run wash build to build the code
4. •Make changes to your code

Fixing WIT Definition Conflicts

If you encounter errors about mismatched WIT definitions:

1. •Run wash wit update to synchronize definitions
2. •Review the updated WIT files
3. •Continue with wash build

Additional Resources

• •wash is the primary CLI tool for the wasmCloud ecosystem
• •It handles component building, testing, and deployment
• •Supports both local development and production workflows