Base44 Lets You Test Backend Functions on a Branch
Base44Base44 now runs the branch's own version of a changed backend function when users use Test Function and Logs in the Code tab. Each branch gets its own copy of the functions it changes, so changes can be tested before merging to main. Merging then deploys the changed functions to main.
Key Takeaways
- Test Function and Logs now run the branch's version of any function changed on a branch, so backend edits can be verified before merging.
- Each branch gets its own copy of every changed function plus the shared code those functions use.
- Merging deploys the changed functions to main, but the live app only changes after publishing.
- In the preview, owners and signed-in editors see the branch's version, while signed-out visitors and app users still get the last published version.
- On a branch the button reads Save instead of Save & Redeploy, since redeploying happens on main.
- The first backend function is created on main, and GitHub-imported apps always make backend changes on main.
Backend Functions Get Branch-Aware Testing
On November 1, 2026, Base44 made the Code tab's Test Function and Logs tools work against a branch. On a branch, they run that branch's version of any function changed there. Functions that were not changed on the branch run main's version. Backend changes can therefore be tried and inspected before they touch main.
How Functions Are Handled on a Branch
Users can add and change backend functions on a branch. The branch gets its own copy of each function it changes, along with any shared code those functions use. When the branch is merged, the changed functions are deployed to main.
Which Version Runs in the Preview
Who sees the branch's version depends on who is using the preview. The app owner or an editor signed in to the app sees the branch's version. Everyone else, such as signed-out visitors and app users, gets the version from the last publish. A flow that relies on one of those functions for non-editor users cannot use the branch's changes until the work is merged and published.
Saving and Redeploying
On a branch, the button reads Save rather than Save & Redeploy, because redeploying happens on main. Redeploying updates the preview and editor tests, but the live app keeps its last published version until publish, and publishing sends all main changes live at once. Automations and workflows that call a function use the latest version without a publish, according to the Base44 docs.
Limits to Know
An app's first backend function is created on main. In apps imported from GitHub, backend changes always happen on main.