Go back to an earlier app version

See every version of your app with who built and published it, and put Live on an earlier or later version at once, knowing first what might stop working.

Every version of an app is kept. When a new version does something wrong on Live, you can put Live back on a version it served before: everyone opening the app gets that version at once. Once the newer version works again, you can put Live forward on it the same way. Only Builders and Administrators do this.

See the versions

Open the app’s page from Apps in the sidebar.
Under Versions, choose All versions. The number after it is how many the app has.

The list shows the newest version first, a page at a time:

Version: its number, with Live or Preview on the version each one serves.
Built: who built it and when.
Data model: the version of your data model on Live that has everything it was built on, as the publish panel’s Details number them, or that it waits for changes still in Preview.
On Live: when Live first served it and who published it, or Never.

Put Live on another version

On the version you want, choose Go back to this version (an older one than Live’s) or Go forward to this version (a newer one). Only versions Live served before have it.
Read the question. It says which way Live moves, for example Live goes back to version 3 (published 12 October). Version 5 stays in the history., and what might stop working (see below).
Choose Put this version on Live, or Cancel.

Live serves that version within a few seconds, on your real records. Preview keeps the newest version, so you can fix it with the assistant, build again and publish it as usual with Publish. The move is live at once: it says Saved, live now. The move shows in the event log as App version put on Live, with who did it.

You can also ask the assistant to put an app on another version. It asks you first on a card with the same words, and does nothing until you say yes.

What might stop working

Your data model may have changed since the version you pick was built. When a version is built, kvyk records which entities and fields its code reads and writes. The question then lists only the changes that version uses, each with what stops working:

Adding orders will fail: Orders now requires Delivery date, which this version doesn’t fill in.
The Coupons screen won’t load: Coupons was removed.
Price may show wrongly: Price of Products changed from text to number.

When nothing it uses changed, it says Nothing this version uses has changed since it was published. Changes the version doesn’t use, such as a field you added to another entity, are not mentioned.

Sometimes kvyk can’t tell everything a version uses: it was built before kvyk recorded this, or its code reaches your data in a way the build couldn’t follow. The question then says so and lists every change to your data model since that version was built, as changes that may affect it.

The warnings don’t stop you: you decide. To fix what they name, build a new version instead, or restore what was deleted from Recently deleted (Restore deleted data) and publish it first.