PUT /conversations/{id} now returns 400 on duplicate custom attribute names
BreakingBreaking change
This is a breaking change — integrations that rely on the affected behaviour will need updates before the change rolls out.
What changed
The PUT /conversations/{id} endpoint now returns a 400 INVALID_PARAMETER error when the request body includes custom_attributes and the workspace has multiple non-archived conversation custom attributes sharing the same name. Previously, the request would silently succeed by applying the update to a non-deterministic attribute. Clients that rely on the old silent-success behaviour will now receive an error and must resolve duplicate attribute names in workspace settings before retrying.