Participants in participants.json

In the participants.json file specified for describing roles and their access tokens for Daml Script, there is a default_participant specified. Under what cases is this user used within a script? What are good defaults for this user?

There are two cases where the default participant will be used:

1. You perform a per-party operation (e.g., submit, query, …) and there is no party → participant mapping in participant config for this party.
2. You perform a per-participant operation and you did not specify a participant (allocateParty) or you specified a participant (allocatePartyOn) but you did not specify that participant name in your participant config.

There is also a third option here combining the two: you perform a per-party operation and there is a party → participant mapping but the participant name you’re mapping to is not in your participant config.

Now all of that might sound a bit convoluted so let me try to summarize it: The default participant as a fallback whenever no other participant has been specified directly or indirectly (via a party → participant mapping).