PRACTICAL FIELD GUIDE
Use a custom owner column consistently
A custom owner column must match the table's policy and the data model. A differently named user reference does not become the access boundary merely because the frontend filters by it.
MCPBackend editorial team · · Examples are illustrative
Put it into practice
- Inspect the configured owner-column name in the policy.
- Compare its values and type with the app-user identifiers used by authentication.
- Test creation and reads through the intended user path, including existing rows.
What this looks like
ILLUSTRATIVE EXAMPLE
The table has author_id while the policy expects owner_id. A client-side author filter does not repair the policy mismatch.
A boundary to keep clear
Do not assume a foreign key to a profile table is automatically the owner field used by the access system.
MCPBackend context
MCPBackend row policies apply to anonymous callers and end-user tokens. Machine API keys bypass those row policies and are instead constrained by their own table permissions. Owner mode is based on the calling user's identity; it is not an organization-membership or arbitrary custom-policy engine.
Take the next step
Inspect the current project contract, try the change with disposable data, and verify the result through the same credentials your app will use. Record the expected response and one denied-access case before release.
Sources and further reading
These references explain the underlying protocols and design principles. For supported MCPBackend operations and exact request shapes, inspect your project’s generated API contract.