<![CDATA[Is the user/registration endpoint safe for concurrent calls?]]>I need to register a user across multiple applications (8 in my case) using the /api/user/registration endpoint. To improve performance, I'd like to make these calls in parallel rather than sequentially.

Question: Is it safe to call the user/registration endpoint concurrently for the same user across different applications? Could this cause:

  • Race conditions with the database
  • Duplicate records
  • Conflicting updates to the user object

Or should I stick with sequential calls to avoid potential issues?

]]>https://fusionauth.io/community/forum/topic/3273/is-the-user-registration-endpoint-safe-for-concurrent-callsRSS for NodeTue, 27 Oct 2026 16:07:19 GMTTue, 20 Oct 2026 21:05:43 GMT60<![CDATA[Reply to Is the user/registration endpoint safe for concurrent calls? on Mon, 26 Oct 2026 22:51:53 GMT]]>The /api/user/registration endpoint can be problematic when called concurrently for the same user. FusionAuth recommends using sequential calls.

Recommendation: Make your registration calls sequentially, one after another, even though it may take slightly longer. This ensures data consistency and avoids potential conflicts or failures during the registration process.

There is currently no single API call to atomically register a user to multiple applications. Each registration to an application requires a separate API call, and sequential execution is the safest approach.

Related Documentation

]]>https://fusionauth.io/community/forum/post/8885https://fusionauth.io/community/forum/post/8885Mon, 26 Oct 2026 22:51:53 GMT