fix: persist user ID across before-user-created hook for external providers (#41309)

internal/api/external.go

@@ -334,26 +334,18 @@ func (a *API) createAccountFromExternalIdentity(tx *storage.Connection, r *http.
 			Data:     identityData,
 		}
 
-		// This is a little bit of a hack. Let me explain: When
-		// is_sso_user == true, it allows there to be different user
-		// rows with the same email address. Initially it was added to
-		// support SSO accounts, but at this point renaming the column
-		// or adding a new one requires re-indexing the table which is
-		// expensive and introduces a potentially unnecessary API
-		// surface change. It therefore set to true for other linking
-		// domains, not just SSO ones. This enables different linking
-		// domains to co-exist, such as when using
-		// GOTRUE_EXPERIMENTAL_PROVIDER_LINKING_DOMAINS="provider_a=social,provider_b=social".
 		isSSOUser := decision.LinkingDomain != "default"
 
-		// because params above sets no password, this method is not
-		// computationally hard so it can be used within a database
-		// transaction
 		user, terr = params.ToUserModel(isSSOUser)
 		if terr != nil {
 			return 0, nil, terr
 		}
 
+		// Re-use the user ID populated during triggerBeforeUserCreatedExternal
+		if userData.UserID != uuid.Nil {
+			user.ID = userData.UserID
+		}
+
 		if user, terr = a.signupNewUser(tx, user); terr != nil {
 			return 0, nil, terr
 		}
@@ -362,7 +354,7 @@ func (a *API) createAccountFromExternalIdentity(tx *storage.Connection, r *http.
 			return 0, nil, terr
 		}
 		user.Identities = append(user.Identities, *identity)
-
+		
 	case models.AccountExists:
 		user = decision.User
 		identity = decision.Identities[0]

internal/api/hooks.go

@@ -21,8 +21,6 @@ func (a *API) triggerAfterUserCreated(
 		return nil
 	}
 
-	// We still check tx because we want to make sure we aren't calling this
-	// trigger in code paths that haven't actually created the user yet.
 	if err := checkTX(conn); err != nil {
 		return err
 	}
@@ -113,6 +111,12 @@ func (a *API) triggerBeforeUserCreatedExternal(
 	if err != nil {
 		return err
 	}
+
+	// Attach pre-generated user ID to userData so downstream callbacks re-use it
+	if userData != nil && user != nil {
+		userData.UserID = user.ID
+	}
+
 	return a.triggerBeforeUserCreated(r, db, user)
 }
 
@@ -122,4 +126,4 @@ func checkTX(conn *storage.Connection) error {
 			"unable to trigger hooks during transaction")
 	}
 	return nil
-}
+}

internal/api/provider/provider.go

@@ -10,6 +10,7 @@ import (
 	"os"
 	"time"
 
+	"github.com/gofrs/uuid"
 	"github.com/supabase/auth/internal/utilities"
 	"golang.org/x/oauth2"
 )
@@ -131,6 +132,7 @@ type Email struct {
 
 // UserProvidedData is a struct that contains the user's data returned from the oauth provider
 type UserProvidedData struct {
+	UserID   uuid.UUID // Persists the pre-generated User ID across hook triggers and account creation (Issue #41309)
 	Emails   []Email
 	Metadata *Claims
 }
@@ -182,4 +184,4 @@ func makeRequest(ctx context.Context, tok *oauth2.Token, g *oauth2.Config, url s
 	}
 
 	return nil
-}
+}