Avoiding 409 user_already_exists When Migrating Email/Password Users to OAuth in Appwrite
We’ve migrated all our existing email+password users into Appwrite and now want to switch entirely to OAuth (Google & Apple) for authentication.
Our plan is that with the next app release, users will see a simple login page: Apple Sign-In on iOS, Google Sign-In on Android. We no longer want to prompt them for a password.
Migration setup:
I ran a Node.js script using account.create() to import users like my-apple-account@hotmail.com and my-google-account@gmail.com.
After migration:
**Android & Google: **
await account.createOAuth2Session(provider: OAuthProvider.google);
with my-google-account@gmail.com works perfectly and links to the existing Appwrite user.
**iOS & Apple: **
await account.createOAuth2Session(provider: OAuthProvider.apple);
with my-apple-account@hotmail.com also works and links correctly.
Cross-provider test:
Out of curiosity, on iOS I tried signing in with Google (same my-google-account@gmail.com). The OAuth selector appeared but then redirected to:
https://fra.cloud.appwrite.io/console/auth/oauth2/failure?error={"message":"A+user+with+the+same+id,+email,+or+phone+already+exists+in+this+project.","type":"user_already_exists","code":409}#
Appwrite is attempting to merge the Google identity into the Apple account (because an active session exists for the Apple user) and fails, since my-google-account@gmail.com already has its own Appwrite user.
Questions:
Is there a way to force createOAuth2Session to always link by email to the “correct” existing account, instead of trying to merge into the currently active session?
Would clearing all existing sessions or calling something like account.deleteSessions() before createOAuth2Session(...) prevent this merge attempt?
Are there any recommended migration strategies or Appwrite settings to avoid the 409 user_already_exists conflict when moving from email/password to OAuth?
Any best practices or official guidance would be much appreciated—thank you! 😊
