Data Migrations

When you publish changes that alter how an app stores data, the platform automatically prepares the existing data for the new version.

When Migrations Run

Migrations run when you publish a new version of an existing app and the update changes the app's data structure. This can include new fields, renamed fields, new data types, or features that require stored data to be reorganized.

The migration happens during publishing. If a migration is needed, publishing may take longer than a simple update.

What Gets Migrated

Automatic migrations are designed for changes such as:

• Database schema and field definitions.
• Data types and structures.
• Field renames or reorganization.
• New features that need existing data to be updated.

Data Safety

Existing data is preserved while the platform prepares data that works with the new version. Each user still has their own isolated database, so migrations do not mix creator data with user data or one user's data with another's.

Best Practices

Test in preview before publishing. For large structural changes, publish smaller incremental updates so each migration has a clear path.

Stay on the publishing page until the update completes. If a migration fails, review the error, simplify the data change where possible, and try publishing again.