It needs to support the reflection service for this to work without supplying proto files. Does it support this?
Yes the reflection service is active and you can use
grpcurl with the ledger api, e.g.
grpcurl -plaintext localhost:6865 com.daml.ledger.api.v1.LedgerIdentityService/GetLedgerIdentity
Keep in mind that as of SDK 1.0.0 we switched the namespace for the services from
com.daml. And while we added “proxy” services to still support the pre 1.0.0 namespace, the reflection service doesn’t properly pick this up, and therefore you
grpcurl only works with the non-deprecated
com.daml namespace of the service names.