diff --git a/app/api/dependencies.py b/app/api/dependencies.py
index abf03d6..29fadb0 100644
--- a/app/api/dependencies.py
+++ b/app/api/dependencies.py
@@ -401,10 +401,108 @@ async def get_current_user_from_clerk(
     )
     user = result.scalar_one_or_none()
     if not user:
-        raise HTTPException(
-            status_code=status.HTTP_401_UNAUTHORIZED,
-            detail="User not found",
-        )
+        # Fetch user data from Clerk API
+        # https://clerk.com/docs/reference/backend-api/tag/users/get/users/%7Buser_id%7D
+        if not CLERK_API_KEY:
+            raise HTTPException(
+                status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
+                detail="Clerk API key not configured",
+            )
+
+        # Call Clerk API to get user info
+        url = f"{CLERK_API_URL}/users/{clerk_user_id}"
+
+        try:
+            async with aiohttp.ClientSession() as session:
+                async with session.get(url, headers={"Authorization": f"Bearer {CLERK_API_KEY}"}) as response:
+                    response.raise_for_status()
+                    user_data = await response.json()
+
+            # Extract email address
+            email = None
+            if user_data.get("primary_email_address_id") and user_data.get(
+                "email_addresses"
+            ):
+                for email_obj in user_data.get("email_addresses", []):
+                    if email_obj["id"] == user_data["primary_email_address_id"]:
+                        email = email_obj.get("email_address")
+                        break
+            if email is None:
+                raise ValueError("No email found in Clerk user data")
+
+            # Use email as username directly
+            username = email
+        except Exception as e:
+            logger.exception(f"Error fetching Clerk user data: {e}")
+            raise HTTPException(
+                status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
+                detail="Failed to fetch user data from Clerk",
+            )
+
+        # Check if user exists with this email
+        result = await db.execute(select(User).filter(User.email == email))
+        existing_user = result.scalar_one_or_none()
+        if existing_user:
+            # Link existing user to Clerk ID
+            try:
+                existing_user.clerk_user_id = clerk_user_id
+                await db.commit()
+                return existing_user
+            except IntegrityError:
+                # Another request might have already linked this user or created a new one
+                await db.rollback()
+                # Retry the query to get the user
+                result = await db.execute(
+                    select(User).filter(User.clerk_user_id == clerk_user_id)
+                )
+                user = result.scalar_one_or_none()
+                if user:
+                    return user
+                # If still no user, continue with creation attempt
+
+        # Create new user
+        try:
+            user = User(
+                email=email,
+                username=username,
+                clerk_user_id=clerk_user_id,
+                is_active=True,
+                hashed_password="",  # Clerk handles authentication
+            )
+            db.add(user)
+            await db.commit()
+            await db.refresh(user)
+
+            # Create default TensorBlock provider for the new user
+            try:
+                await create_default_tensorblock_provider_for_user(user.id, db)
+            except Exception as e:
+                # Log error but don't fail user creation
+                logger.warning(
+                    f"Failed to create default TensorBlock provider for user {user.id}: {e}"
+                )
+
+            return user
+        except IntegrityError as e:
+            # Handle race condition: another request might have created the user
+            await db.rollback()
+            if "users_clerk_user_id_key" in str(e) or "clerk_user_id" in str(e):
+                # Retry the query to get the user that was created by another request
+                result = await db.execute(
+                    select(User).filter(User.clerk_user_id == clerk_user_id)
+                )
+                user = result.scalar_one_or_none()
+                if user:
+                    return user
+                else:
+                    # This shouldn't happen, but handle it gracefully
+                    raise HTTPException(
+                        status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
+                        detail="Failed to create or retrieve user due to database constraint",
+                    )
+            else:
+                # Re-raise other integrity errors
+                raise
 
     return user