Separating Data

Building multi-tenant applications with separate data for each user is a common requirement for many web and mobile apps. With Xano, you can easily implement this functionality without writing any code. In this guide, we'll walk you through the process of separating data so that users can only access and manipulate records that belong to them.

Setting Up User Authentication

The first step is to require user authentication for the API endpoints you want to secure. This ensures that only authenticated users can access and modify data.

1. Open the API endpoint you want to secure.
2. Click on the "Settings" icon and select "User Authentication."
3. This will require an authentication token for anyone trying to access this endpoint.

Filtering Data Based on User ID

Once user authentication is enabled, you can filter data based on the authenticated user's ID. This ensures that each user only sees records that belong to them.

1. In the API endpoint, click on the "Query All Records" function.
2. Go to the "Filter" tab and add a new condition.
3. Set the condition to filter records where the `items.userID` field is equal to `auth.ID`.
4. This will filter the records based on the authenticated user's ID stored in the authentication token.

You can now run the endpoint, and it will only return records that belong to the authenticated user.

Adding Extra Security Layers

Xano provides additional security measures you can implement to further ensure data separation.

1. Add a new function stack item to get the authenticated user's record using `get_record` and `auth.ID`.
2. Add a precondition to check if the user trying to access or modify a record is the owner of that record.
3. Use the `precondition` function and check if the `item.userID` is equal to the `auth.ID`.
4. You can also add a custom error message to display if the precondition fails.

This extra layer of security prevents users from accessing or modifying records that don't belong to them, even if they try to bypass the filter.

Updating and Deleting Records

When updating or deleting records, you can follow a similar approach to ensure users can only modify their own data.

1. Get the record you want to update or delete using the record ID.
2. Add a precondition to check if the `item.userID` matches the `auth.ID`.
3. If the precondition passes, proceed with updating or deleting the record.
4. If the precondition fails, display an error message or prevent the operation.

By following these steps, you can implement robust data separation in your Xano application, ensuring that each user can only access and manipulate their own data.

Role-Based Access Control (RBAC)

In addition to separating data based on user ID, Xano also supports role-based access control (RBAC). This allows you to define different roles for your users (e.g., admin, manager, user) and assign permissions based on those roles. Some users may have access to all records, while others may have limited access. For more information on implementing RBAC in Xano, refer to the documentation.

With Xano's visual interface and powerful functionality, you can easily build secure and scalable backend services without writing a single line of code. Happy building!