diff --git a/internal/postgres/user.go b/internal/postgres/user.go
new file mode 100644
index 0000000..f24191d
--- /dev/null
+++ b/internal/postgres/user.go
@@ -0,0 +1,61 @@
+package postgres
+
+import (
+	"context"
+	"git.dragse.it/anthrove/otter-space-sdk/pkg/models"
+	"git.dragse.it/anthrove/otter-space-sdk/pkg/models/pgModels"
+	log "github.com/sirupsen/logrus"
+	"gorm.io/gorm"
+)
+
+func CreateUserNodeWithSourceRelation(ctx context.Context, db *gorm.DB, anthroveUserID models.AnthroveUserID, sourceDomain string, userID string, username string) error {
+	user := pgModels.User{
+		BaseModel: pgModels.BaseModel{
+			ID: string(anthroveUserID),
+		},
+	}
+
+	if err := db.WithContext(ctx).FirstOrCreate(&user).Error; err != nil {
+		log.WithFields(log.Fields{
+			"anthrove_user_id": anthroveUserID,
+		}).Error("database: failed to find or create user")
+		return err
+	}
+
+	source := pgModels.Source{
+		Domain: sourceDomain,
+	}
+
+	if err := db.WithContext(ctx).Where(&source).First(&source).Error; err != nil {
+		log.WithFields(log.Fields{
+			"source_domain": sourceDomain,
+		}).Error("database: failed to find source")
+		return err
+	}
+
+	userSource := pgModels.UserSource{
+		UserID:          user.ID,
+		SourceID:        source.ID,
+		AccountUsername: username,
+		AccountID:       userID,
+	}
+
+	if err := db.WithContext(ctx).Create(&userSource).Error; err != nil {
+		log.WithFields(log.Fields{
+			"anthrove_user_id": anthroveUserID,
+			"source_domain":    sourceDomain,
+			"account_username": username,
+			"account_id":       userID,
+		}).Error("database: failed to create user-source relationship")
+		return err
+	}
+
+	log.WithFields(log.Fields{
+		"anthrove_user_id": anthroveUserID,
+		"source_domain":    sourceDomain,
+		"account_username": username,
+		"account_id":       userID,
+	}).Trace("database: created user-source relationship")
+
+	return nil
+}
diff --git a/pkg/database/postgres.go b/pkg/database/postgres.go
index a37c2e0..13fe10d 100644
--- a/pkg/database/postgres.go
+++ b/pkg/database/postgres.go
@@ -54,8 +54,7 @@ func (p *postgresqlConnection) Connect(_ context.Context, endpoint string, usern
 }
 
 func (p *postgresqlConnection) AddUserWithRelationToSource(ctx context.Context, anthroveUserID models.AnthroveUserID, sourceDomain string, userID string, username string) error {
-	//TODO implement me
-	panic("implement me")
+	return postgres.CreateUserNodeWithSourceRelation(ctx, p.db, anthroveUserID, userID, sourceDomain, userID)
 }
 
 func (p *postgresqlConnection) AddSource(ctx context.Context, anthroveSource *graphModels.AnthroveSource) error {