The AsyncLocalStorage API in Node.js is a powerful tool that has since been adopted across multiple runtimes. There is even an effort underway to standardize a variation of the API within JavaScript itself. But what is it? And more importantly, how does it work?

The AsyncLocalStorage API is arguably one of the most important relatively recent additions to Node.js. Today we are seeing implementations being added to other runs such as workerd, deno, and bun. And there is an effort underway in TC-39 to introduce a new AsyncContext API to the language. This talk will introduce async context tracking with AsyncLocalStorage and AsyncContext and discuss how the model is evolving as it is being implemented across multiple platforms.

You can check the slides for James' talk here.