PRACTICAL FIELD GUIDE
A 400 error names an unknown column
Unknown-column errors often indicate a mismatch between deployed client code and the current table schema. Verify the contract before changing permissions or retrying the same payload.
MCPBackend editorial team · · Examples are illustrative
Put it into practice
- Compare every submitted field or filter name with the live schema.
- Check for renamed fields, accidental form metadata and stale generated types.
- Send a minimal valid request, then update the client to the supported field set.
What this looks like
ILLUSTRATIVE EXAMPLE
A form submits a local confirmTitle field that is not part of the table. Removing that UI-only field fixes the payload mismatch.
A boundary to keep clear
Silently discarding arbitrary fields can hide a broken integration. Keep intentional request mapping explicit.
MCPBackend context
Use get_project_api or the dashboard's generated OpenAPI contract for your project's exact data-plane routes. Machine keys and end-user tokens have different access models. Treat error status and JSON code together, keep credentials out of URLs, and test against disposable records before changing real data.
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.