Open catalogs
A catalog is a list of apps, published as signed public data on Nostr. You choose which catalogs your phone reads, and a ban in one catalog doesn’t reach the others.
What a catalog is
A catalog is a list of apps and their releases, served by a catalog relay and identified by the catalog’s pubkey. Each listing is a signed Nostr event, public data that anyone can read and check, so the same app can appear in more than one catalog. Each catalog sets its own rules for who may publish. Run your own catalog covers what a catalog relay does.
Who publishes the releases
An app in a catalog is a chain of releases, and three kinds of pubkey can add to it:
- The catalog’s own pubkey. A catalog can list apps itself, for example from their public release pages. Zapstore’s default catalog does this with its indexer.
- The developer’s pubkey, once they have claimed the app by proving they hold its Android signing key.
- A delegate pubkey the developer names in their claim, typically for CI. It can publish releases but cannot change who owns the app.
The release with the highest version code is the current one, whoever signed it. An app that only the catalog has ever published is unclaimed. On a claimed app, the catalog can still fill in releases the developer skipped, and they appear under the developer’s listing. Every release, from any of the three, must be signed with the app’s certificate or one linked to it.
Choosing catalogs
Your phone starts with the catalog Zapstore ships with. Settings lists your catalogs in order. You can add a catalog by its pubkey (an npub, a hex key, or an nprofile), reorder the list, and remove a catalog as long as another remains. Each update reads every catalog in the list, one after another, and one that fails does not stop the next.
Your phone
Reads its catalogs in order
1. The catalog it ships with
Unless you replace it
2. A catalog you add
Supplies the apps the first does not have
When two catalogs list the same app, the one higher in the list supplies it.
Bans
Each catalog decides which publishers it accepts. A ban removes a publisher from that catalog only. Another catalog can still list the app, and you choose which catalogs your phone reads.
Default catalog explains how the catalog Zapstore ships with applies a ban.
Zaps
When an app is claimed, a zap goes to the developer’s pubkey. When it isn’t, the zap goes to the catalog that supplied the app, and the app tells you before you send it.
