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Dutch auction contract

This page outlines the Dutch Auction Contract, designed for conducting Dutch auctions on a blockchain platform. It details the contract's functionality, structure, and application.


  • Auction Management: Set up and manage dutch auctions with start and end dates, starting and reserve prices.
  • Initial High Price: Begins with a high asking price, set above the expected market value.
  • Price Reduction: Gradual reduction of the price over a predetermined period.
  • First Bid Wins: The auction concludes with the first bid at the current price.
  • Auction Finalization: Details the process for ending the auction and awarding the item to the bidder.

Technical specifications

The following sections provide reference information for writing a smart contract to conduct a dutch auction using Marmalade on the Kadena network.


You can define the following capabilities to manage permissions in conventional auctions:

  • GOVERNANCE: Defines governance for the contract and is controlled by the keyset defined under the ADMIN-KS constant.
  • AUCTION_CREATED: Specifies the event emitted after the auction is created by the seller.
  • PRICE_ACCEPTED: Specifies the event emitted after the buyer successfully executes the function in a sales contract.
  • DUMMY: Acts as a placeholder capability for the buyer-guard field.


  • auctions-schema: Describes auction information including token-id, start-date, end-date, start-price, reserve-price, sell-price, price-interval-seconds, buyer, and buyer-guard.


  • auctions: Stores auction information.


  • enforce-quote-update: Enforces a quote update when required for sale contracts. This function is called by the policy-manager.enforce-buy function to validate that the buyer has transferred the fungible amount equal to current-price set by the dutch auction. The function updates the auctions table with the winner information.
  • enforce-withdrawal: Enforces a withdrawal when required for sale contracts. This function is called by the policy-manager.enforce-withdraw function to validate that the auction has expired, or that the bid has already been placed.
  • validate-auction: Validates that the auction information adheres to contract logic in the create-auction and update-auction functions.
  • create-auction: Allows sellers to create the dutch auction for their token after providing auction information.
  • update-auction: Allows sellers to update auction information before the auction start time.
  • retrieve-auction: Retrieves auction information from the auctions table.
  • get-current-price: Calculates the current auction price by starting with the start-price and gradually reducing the price per price-interval-seconds, always ending with the last time interval at the reserve-price.


  • ADMIN-KS: Sets the marmalade-sale.marmalade-contract-admin for the GOVERNANCE capability.

  • DUMMY_GUARD: Acts as a placeholder guard constant for the buyer-guard field.