What's the best way to get a Canton participant's fingerprint/namespace?

Questions
1

When you allocate a party in Canton, it returns as partyName::fingerprint. As an actor outside of the participant, I’d like to figure out the participant’s fingerprint so I can know, prior to allocation, what my party’s name will be. Is that possible?

2

The best option I’m aware of is to query the participant id and use the namespace from that, e.g., see this grpcurl session:

moritz@right-adjunct ~/foobar> grpcurl -plaintext localhost:6865 com.daml.ledger.api.v1.admin.PartyManagementService/GetParticipantId
{
  "participant_id": "sandbox::1220ac922ccc5e275ccc65d61b37e4f31897f7504b7bf9a0d204956dc6798a682889"
}
moritz@right-adjunct ~/foobar [1]> grpcurl -plaintext -d '{"party_id_hint": "alice"}' localhost:6865 com.daml.ledger.api.v1.admin.PartyManagementService/AllocateParty
{
  "party_details": {
    "party": "alice::1220ac922ccc5e275ccc65d61b37e4f31897f7504b7bf9a0d204956dc6798a682889",
    "is_local": true
  }
}
3

You can guess this if you like, but the ledger API doesn’t permit you to make this assumption; the produced party ID “is implementation-specific”.

I don’t know whether Canton provides stricter guarantees, if you intend for your allocator to only work with Canton.

1 Like
4

+1 to this!

Regardless, Canton could decide to change this between versions, so only Ledger API guarantees should be taken as such. I think the way to think of party IDs is as opaque handles, which is what they are as per Ledger API.