Do we have an (entitlement / any) API to get list of identities who have access to an entitlement ?
You can get that from either search in UI or the v3/search endpoint.
Query via UI would look something like this:
@access(id:{entitlement_id})
Or via POST v3/search
{
"query": {
"query": "@access(id:{entitlement_id})"
},
"indices": [
"identities"
],
"includeNested": false,
"sort": [
"displayName"
]
}