Designing Language-Agnostic Plugin Systems With Webassembly and Extism

Imagine a world where anyone could write plugins/extensions in any languages that interop with the application, regardless of your stack. Extism makes that real by using WebAssembly. Extism is a flexible framework that removes the lower-level concerns of loading,  executing Wasm code, as well as interoperability with a number of languages like TypeScript. It allows you to integrate WASM code into your servers, the edge, CLIs, IoT, browsers etc. This talk will start with an introduction to Extism and how it helps make great use of one of WebAssembly’s most useful features, portability to enable developers to build truly reusable and extensible systems.

Later the talk will explore the broader plugin ecosystem, discussing why extensibility matters, how it enables long-term sustainability for software projects, and why a language-agnostic approach makes sense in modern systems. Finally, the session deep dives into real-world examples of Extism-powered extensibility, sharing how three very different open-source projects, Helm, Moonrepo, and Reactables make use of Extism based plugin systems. These examples span cloud infrastructure, developer tooling, and state management, demonstrating how Extism enables a consistent, powerful extensibility model across vastly different domains. The talk will finish by covering how anyone can use Extism to build their own plugin ecosystem.