Theme editor blocks
App blocks in store themes: what ships today, how a block is framed in a Sneferu theme, and why an outside app cannot register its own block yet.
On this page
An app block puts an app's widget inside a store's theme: a subscribe button on a product page, for example. This page says what exists today. In short: only Hekana's own apps have blocks, and an outside app cannot add one yet.
Status, 2026-10-25. Blocks are built on the storefront side for two first-party apps. The
hk-app-blocktag that places them in a Sneferu theme is not in the published tag reference yet. Do not build a theme that depends on it until it is.
What ships
| App | Block | What it shows |
|---|---|---|
| Subscriptions | subscribe | The plan picker and subscribe form on a product page. |
| Subscriptions | portal | The shopper's own subscription page, opened from a link. |
| AI shopper | icon | The AI shopper icon, in the page flow instead of floating. Its route exists; adding it to the theme editor's insert list is still pending. |
The Subscriptions app itself is open to stores. The blocks are the part that waits on the theme tag.
How a block works
A theme only says where a block goes and passes read-only context such as the product id. The platform renders the block in a frame that belongs to the store's own origin:
- The frame lives at a fixed path under
/hk2/app-block/<app>/<block>. The list of paths is closed: a theme cannot invent one. - The block appears only if the app is installed on the store. If it is not, the frame tells the page and the page removes it.
- The block reports its own height to the page, and it can be framed by the store's own pages only.
- A theme still has no script and no form controls, so the rules in the theme docs are not weakened. The block takes its colours, fonts and radius from the theme's tokens.
What an outside app cannot do
- Register a block. There is no API or manifest field for it. The list of apps and blocks is defined by Hekana.
- Run code in a theme or in checkout. Checkout stays Hekana's page; see checkout extensions for the one thing an app can add there.
- Choose the frame address of an embedded dashboard app (see Authentication).
If your app needs a storefront surface, the supported options today are a checkout extension, discount codes and messages to the customer, all through the Apps API.
For theme developers
You do not need an app to build a theme. For the theme tags and sections, start at Build your first theme.