Full Swagger vs. one per endpoint

It’s one per endpoint. But you probably only need just one. I’d suggest to start with the Default endpoint and see if that covers all your needs.

You must generate one Swagger file per endpoint — there is no built-in way to get a single combined Swagger file for all endpoints.
 

Each endpoint in Acumatica represents a specific contract/version (e.g., Default/22.200.001, CustomEndpoint/23.100.001)

Endpoints can have:

Different DACs exposed

Different field mappings

Different permissions / structures

Swagger is available
/entity/<EndpointName>/<Version>/$swagger
Example
/entity/Default/22.200.001/$swagger

Thankyou