Web SDK

What is Web SDK and what is it for?

Web SDK is a JavaScript toolkit that let a Holochain app's own web page talk to that app while it runs on a hosting computer, a HoloPort, rather than on the visitor's own machine. It exists because a hosted app's web interface needs more than a plain Holochain connection: it has to work out which hosted identity it is acting as, sign that person in through a protected login window, and then make the app's own calls on their behalf.

Web SDK was the piece Holo Hosting provided for the visible half of a hosted Holochain app. An app running on a HoloPort needs a web interface people can open in a browser, and that interface has to reach the app across the network rather than through a connection on the visitor's own computer. Web SDK packaged that connection as a JavaScript library for building such interfaces; the project's own documentation labels it a prerelease.

The library covers the parts a hosted app's web page cannot do alone. It inserts a small frame into the page that stays hidden until the visitor signs in or signs up, when the frame takes over the screen with a credentials form. Because that form lives in its own frame, the app's web page never sees the visitor's private keys or password. The library also reports which hosted identity is in use and exposes the app's own functions to the page.

A worked example in the repository shows the whole path: open a connection, wait until the client reports the hosted identity is available, ask the visitor to sign in, then call a function on the app and print the result. The project also points to a companion demonstration interface, dummy-ui, in the Chaperone repository, and to a local development server for testing before publishing an app to Holo Hosting. Start with the repository README.

From 4 public sources, checked 23 September 2026.