corda / / TwoPartyTradeFlow


object TwoPartyTradeFlow

This asset trading flow implements a "delivery vs payment" type swap. It has two parties (B and S for buyer and seller) and the following steps:

  1. S sends the StateAndRef pointing to what they want to sell to B, along with info about the price they require B to pay. For example this has probably been agreed on an exchange.
  2. B sends to S a SignedTransaction that includes the state as input, B's cash as input, the state with the new owner key as output, and any change cash as output. It contains a single signature from B but isn't valid because it lacks a signature from S authorising movement of the asset.
  3. S signs it and commits it to the ledger, notarising it and distributing the final signed transaction back to B.

Assuming no malicious termination, they both end the flow being in possession of a valid, signed transaction that represents an atomic asset swap.

Note that it's the seller who initiates contact with the buyer, not vice-versa as you might imagine.



class Buyer : FlowLogic<SignedTransaction>


class Seller : FlowLogic<SignedTransaction>


This object is serialised to the network and is the first flow message the seller sends to the buyer.

data class SellerTradeInfo



class AssetMismatchException : FlowException


class UnacceptablePriceException : FlowException