carauction-network

Car Auction Network

This is an interactive, distributed, car auction demo. List assets for sale (setting a reserve price), and watch as assets that have met their reserve price are automatically transferred to the highest bidder at the end of the auction.

This business network defines:

Participants: Member Auctioneer

Assets: Vehicle VehicleListing

Transactions: Offer CloseBidding

The makeOffer function is called when an Offer transaction is submitted. The logic simply checks that the listing for the offer is still for sale, and then adds the offer to the listing, and then updates the offers in the VehicleListing asset registry.

The closeBidding function is called when a CloseBidding transaction is submitted for processing. The logic checks that the listing is still for sale, sorts the offers by bid price, and then if the reserve has been met, transfers the ownership of the vehicle associated with the listing to the highest bidder. Money is transferred from the buyer's account to the seller's account, and then all the modified assets are updated in their respective registries.

To test this Business Network Definition in the Test tab:

In the Auctioneer participant registry, create a new participant.

{
  "$class": "org.acme.vehicle.auction.Auctioneer",
  "email": "[e-mail]",
  "firstName": "Jenny",
  "lastName": "Jones"
}

In the Member participant registry, create two participants.

{
  "$class": "org.acme.vehicle.auction.Member",
  "balance": 5000,
  "email": "[e-mail]",
  "firstName": "Amy",
  "lastName": "Williams"
}

{
  "$class": "org.acme.vehicle.auction.Member",
  "balance": 5000,
  "email": "[e-mail]",
  "firstName": "Billy",
  "lastName": "Thompson"
}

In the Vehicle asset registry, create a new asset of a vehicle owned by [e-mail].

{
  "$class": "org.acme.vehicle.auction.Vehicle",
  "vin": "vin:1234",
  "owner": "resource:org.acme.vehicle.auction.Member#[e-mail]"
}

In the VehicleListing asset registry, create a vehicle listing for car vin:1234.

{
  "$class": "org.acme.vehicle.auction.VehicleListing",
  "listingId": "listingId:ABCD",
  "reservePrice": 3500,
  "description": "Arium Nova",
  "state": "FOR_SALE",
  "vehicle": "resource:org.acme.vehicle.auction.Vehicle#vin:1234"
}

You've just listed an Arium Nova for auction, with a reserve price of 3500!

As soon as a VehicleListing has been created (and is in the FOR_SALE state) participants can submit Offer transactions to bid on a vehicle listing.

Submit an Offer transaction, by submitting a transaction and selecting Offer from the dropdown.

{
  "$class": "org.acme.vehicle.auction.Offer",
  "bidPrice": 2000,
  "listing": "resource:org.acme.vehicle.auction.VehicleListing#listingId:ABCD",
  "member": "resource:org.acme.vehicle.auction.Member#[e-mail]"
}

{
  "$class": "org.acme.vehicle.auction.Offer",
  "bidPrice": 3500,
  "listing": "resource:org.acme.vehicle.auction.VehicleListing#listingId:ABCD",
  "member": "resource:org.acme.vehicle.auction.Member#[e-mail]"
}

To end the auction submit a CloseBidding transaction for the listing.

{
  "$class": "org.acme.vehicle.auction.CloseBidding",
  "listing": "resource:org.acme.vehicle.auction.VehicleListing#listingId:ABCD"
}

This simply indicates that the auction for listingId:ABCD is now closed, triggering the closeBidding function that was described above.

To see the Vehicle was sold you need to click on the Vehicle asset registry to check the owner of the car. The reserve price was met by owner [e-mail] so you should see the owner of the vehicle is now [e-mail].

If you check the state of the VehicleListing with listingId:ABCD is should be SOLD.

If you click on the Member asset registry you can check the balance of each User. You should see that the balance of the buyer [e-mail] has been debited by 3500, whilst the balance of the seller [e-mail] has been credited with 3500.

Congratulations!