What is the WebAssembly Component Model?

It is a proposal that builds upon Wasm to allow different Wasm modules (components) to communicate using high-level types, enabling language interoperability and modular application design.

How does this skill handle WASI Preview 1 to Preview 2 migration?

The skill provides specific guidance on target changes (wasm32-wasip2), networking API differences, and using WASI adapters to bridge gaps between versions.

Does WebAssembly support threading?

Currently, wasm32-wasip2 does not natively support standard threading; this skill provides workarounds and best practices for using single-threaded or async patterns.

How do I fix 'unknown import' errors in runtimes like Wasmtime?

The skill offers a diagnostic workflow to check WIT definitions, verify runtime version support (e.g., Wasmtime 18+ for full WASI 0.2), and align interface versions.

Can I compose components written in different languages?

Yes, this skill provides patterns for cross-language composition, such as using a Python ML library from a Rust component using WIT definitions.

WebAssembly Component Development

Name: WebAssembly Component Development
Author: cosmonic-labs

bycosmonic-labs

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API Development

Develops, composes, and troubleshoots modular WebAssembly applications using the Component Model and WASI standards.

About

This skill empowers developers to master the WebAssembly Component Model by providing expert guidance on WASI Preview 2 fundamentals, language interoperability, and cross-language composition. It streamlines the process of building modular Wasm applications, offering practical implementation patterns for Rust, Python, and JavaScript while addressing critical runtime compatibility issues and troubleshooting common pitfalls like threading limitations, string encoding errors, and unknown import mismatches across runtimes like Wasmtime and wasmCloud.

Key Features

12 GitHub stars
Cross-language composition patterns using WebAssembly Interface Types (WIT)
Advanced testing strategies including mock components and lightweight host harnesses
Comprehensive WASI Preview 2 guidance for networking, filesystem, and CLI interactions
Best practices for designing modular component boundaries and facade patterns
Automated troubleshooting for runtime compatibility and version alignment errors

Use Cases

Migrating existing WebAssembly modules from WASI Preview 1 to the modern Preview 2 standard
Developing high-performance, sandboxed plugin systems for cloud-native or edge environments
Building modular microservice architectures that combine components written in Rust, Python, and JavaScript

About

Key Features

12 GitHub stars
Cross-language composition patterns using WebAssembly Interface Types (WIT)
Advanced testing strategies including mock components and lightweight host harnesses
Comprehensive WASI Preview 2 guidance for networking, filesystem, and CLI interactions
Best practices for designing modular component boundaries and facade patterns
Automated troubleshooting for runtime compatibility and version alignment errors

Use Cases

Migrating existing WebAssembly modules from WASI Preview 1 to the modern Preview 2 standard
Developing high-performance, sandboxed plugin systems for cloud-native or edge environments
Building modular microservice architectures that combine components written in Rust, Python, and JavaScript