Installing and integrating the Extism JS SDK

What is Extism?

Extism is the cross-language framework for building with WebAssembly, designed to be a universal plug-in system to call end-user supplied code from within your application.

This is a multi-platform JavaScript SDK for Extism. It works in all the major JavaScript runtimes:

• Browsers (Firefox, Chrome, WebKit)
• Node
• Deno
• Bun
• Cloudflare Workers

Instead of using FFI and the libextism shared object, this library uses whatever Wasm runtime is already available with the JavaScript runtime.

Requirements

You must be working in a codebase that is written in, or targets JavaScript, and running in one of the runtimes above. Be sure that you can find a package.json and know where the primary root of the project is - if not, confirm with your user.