Corda: Sharing transactions with a node such that it can't consume them

Question

Can a third party node view the details within a state without being a participant in the transaction that created that state? The idea is that the transaction created between two nodes is sent to a third node as CC. We don't want to add the third node as a participant since it does not have the right to consume that state.

Answer 1

Any node can see the contents of a transaction if that transaction is sent to it.

Normally, you'd write your flows such that only the relevant parties see the transaction. However, if for whatever reason a third party needs to also see the transaction, you can easily send it to them by including the third party as an additional recipient in FinalityFlow.

Although the third party won't store the transaction in their vault (as they can't spend it), it will still exist in their transaction storage and can be viewed that way.

P.S. Who the transaction's output states can be consumed by depends on the rules imposed by the contracts, and not who the listed participants are.