Export key attribute uniquename for component CustomAPI must start with a valid customization prefix exception while creating Custom Action in Dynamics 365

We might get below error while creating a custom action from the maker portal without specifying the prefix.

Unhandled exception:

Exception type: System.ServiceModel.FaultException`1[Microsoft.Xrm.Sdk.OrganizationServiceFault]

Message: Export key attribute uniquename for component CustomAPI must start with a valid customization prefix

As the message suggests, we need to add prefix to the Unique Name of the custom API.

Check the prefix of the solution publisher and specify the same.

Adding the prefix allows us to save and create the Custom action record.

Microsoft docs suggest that is should match the prefix specified for the solution publisher

but it seems we can specify any prefix there and it allows us to save the record.

More on Custom API –

Create Custom API Message –
https://nishantrana.me/2021/01/13/use-custom-api-to-create-custom-messages-in-dynamics-365/

Execute Privilege Name Property –

https://nishantrana.me/2021/01/14/execute-privilege-name-executeprivilegename-property-of-custom-api-in-dynamics-365-microsoft-dataverse/

Allowed Custom Processing Step Type Property –

https://nishantrana.me/2021/01/20/allowed-custom-processing-step-type-allowedcustomprocessingsteptype-property-of-custom-api-in-dynamics-365-microsoft-dataverse/

Hope it helps..