lit-happ

What is lit-happ and what is it for?

lit-happ is a software framework for developers who build the web interface of a Holochain app with Lit. It supplies the ViewModel layer that sits between a Holochain app's data and its web components, so screens can be written without handling conductor calls directly.

lit-happ is a developer framework for building the web interface of a Holochain app with Lit, a JavaScript library for web components. Its maintainer describes it as the missing piece between a Holochain app's data and its screen: Holochain DNAs act as the model and Lit elements as the view, and lit-happ supplies the ViewModels that format DNA data for those views, so a view does not need to know how the underlying calls work.

The framework is published as two npm packages. cell-proxy provides classes for talking to a running Holochain conductor and calling zome functions on its cells, and lit-happ builds on that with ViewModel classes and helper elements. A ViewModel presents a Perspective, a deliberately partial slice of the data available, reflecting that no node holds the full picture at once, and binds it to Lit's reactive properties so a screen updates as the data changes.

The repository includes a playground of small example apps under /example, with zomes for a single integer, a single real number and a label, combined into two DNAs. npm run devtest starts a basic happ with two DNAs in three roles, and npm run devtest:clone starts a variant with two clonable roles; both are the quickest way to see the framework in use. Learn more at the repository.

From 3 public sources, checked 23 September 2026.