Sale Contracts
With Sale Contracts, Marmalade V2 introduces a new way to manage the sale of a token. WHen offering a token up for sale in the ledger, it is now possible to also provide a reference to a sale contract. This sale contract can then be used to manage the sale of the token which allows for maximum flexibility and creativity in the sale of a token.
Security is an important aspect of selling a token, especially when it comes to guaranteeing royalty. Therefore the sale contracts are required to be registered within the Policy Manager. This ensures that the sale contract is known to the Policy Manager and that the Policy Manager can enforce the sale contract. Before registering the sale contract will undergo a review process to ensure that it is safe to use.
Where Sale Contracts are aimed at general purpose sales, Marmalade token creators still have complete flexibility to implement any custom sale logic within a policy and attach it to the token itself. This allows for a wide range of sale options and flexibility.
Sale Contract Interface
The sale contract interface is a light interface which needs to be implemented by any sale contract. It is used by the Policy Manager to enforce the sale contract. The interface is defined as follows:
(defun enforce-quote-update:bool (sale-id:string price:decimal) @doc "Read-only Function that is enforced to update quote price at enforce-buy")(defun enforce-quote-update:bool (sale-id:string price:decimal) @doc "Read-only Function that is enforced to update quote price at enforce-buy")The function enforce-quote-update is called in from the buy step in the
ledger and takes two parameters:
- sale-id (type: string): This parameter represents the identifier of the sale, which is basicaly the pact-id that is created when the token is offered up for sale in the ledger.
- price (type: decimal): This parameter represents the finale price associated with the sale.
Available Sale Contracts
The available sale contracts are listed below. More sale contracts will follow
but in the meantime, you can also create your own sale contract. The sale
contracts can be found in the
Marmalade Github repository
under pact/sale-contracts. Just create a pull request and we will review your
sale contract and take care of deployment and whitelisting it in the Policy
Manager.
Conventional Auction
A conventional auction is a sale contract that allows for the sale of a token
through a conventional auction. The seller can set a reserve price which will
ensure that the token is not sold below a certain price. The auction will run
for a set amount of time and the highest bidder will win the auction. If the
reserve price is not met, the seller can choose to cancel the auction and the
token will be returned to the seller. The contract is deployed at
marmalade-sale.conventional-auction.
Using a Sale Contract
The sale contract can be used by providing the sale contract's module name as
part of the quote specification when calling the offer function in the ledger.
Here's an example of the quote specification with the sale contract's module
name mentioned under the key sale-type.
"quote" : { "fungible": coin ,"sale-price": 0.0 ,"seller-fungible-account": { "account": "k:seller" ,"guard": {"keys": ["seller"], "pred": "keys-all"} } ,"sale-type": "marmalade-sale.conventional-auction"}"quote" : { "fungible": coin ,"sale-price": 0.0 ,"seller-fungible-account": { "account": "k:seller" ,"guard": {"keys": ["seller"], "pred": "keys-all"} } ,"sale-type": "marmalade-sale.conventional-auction"}Note: When using a sale contract the sale-price during offer must
always be 0.0, since the sale contract will be responsible for updating the
price during the buy step.