Authenticate in multifile custom apps
FileMaker Pro files can access one another in a multifile custom app. This can be useful, for example, if you have a centrally accessible file of employee contact information that is used by multiple internal apps.
When you open one file from another (such as for viewing external data or running a script in an external file), FileMaker clients pass to the second file the credentials the user supplied when they signed in to the first file. If the user's account access is the same, FileMaker clients automatically sign in the user to the second file. If there is no corresponding account access entry, the user must sign in to the second file.
If you create the same FileMaker file accounts manually in multiple files, you may make data entry errors. To reduce such errors, use external authentication, OAuth identity provider authentication, or (if files are hosted by FileMaker Cloud) Claris ID authentication. See Set up external authentication, Set up OAuth identity provider authentication, or Set up Claris ID or external IdP authentication.
Review the account access entries and privilege sets in each file of a multifile custom app. If privilege sets do not match across files or an account has additional privileges in a file, users may gain access to data that would normally be restricted to them. See Define privilege sets.
Additionally, make sure that users cannot make references to files in a custom app without the app designer's assistance. Otherwise, they may gain access to restricted data. See Restrict references to a custom app.