Skip to main content
It can be the case that the given order remains unfulfilled for a prolonged period of time. The reason for this may be that the order became unprofitable, and no one is willing to fulfill it. In this case, the order must be cancelled to unlock the input amount of funds. Limit orders have a high potential of remaining unfulfilled for prolonged periods of time, until the market conditions are met. One example of such an order is a 0.01 SOL for 20.000 POL limit order which was created for demonstration purposes of this article. The only way to cancel the order is to initiate the cancellation procedure on the chain it was intended to be fulfilled on (the dstChainId parameter from create-tx call payload). During the cancellation process, the order enters a OrderCancelled state, which prevents fulfillment. A cross-chain message is sent through the deBridge cross-chain messaging infrastructure to the DLN contract on the source chain to unlock the given funds. The funds locked on the source chain are returned in full including affiliate and protocol fees. The cancellation procedure can only be initiated by the dstChainOrderAuthorityAddress in a separate transaction on the destination chain. Such transaction can be requested by calling the /v1.0/dln/order/:id/cancel-tx endpoint: 
https://dln.debridge.finance/v1.0/dln/order/0x5aa527db4bb244bb30b05d443db3370e42d29c4a1364601deb54e632f7c70c51/cancel-tx
This gives the response from which the transaction data can be extracted to be signed and broadcasted to the destination chain, described by the following TypeScript type: 
export type CancelTxResponsePayload = {
  cancelBeneficiary: string; // Source chain input funds recipient after cancellation
  chainId: number; // Chain to submit on 
  data: string; // TX data
  from: string; // Allowed tx sender address
  to: string; // TX `to`
  value: string; // TX `value`
}
Detailed runnable script on how to cancel an order is available in the accompanying examples repository. Several considerations:
  • the transaction can be submitted only to the chain where the order has been intended to be fulfilled on, designated with chainId field in the response
  • the transaction call would be accepted only if made by the dstChainOrderAuthorityAddress specified during the given order creation, designated with from field in the response
  • the funds locked on the source chain upon order creation are returned to the srcChainOrderAuthorityAddress specified during the given order creation, designated with the cancelBeneficiary response field
  • the value for the transaction is always positive, needed to cover:
    • the deBridge cross-chain messaging protocol fee (measured in the blockchain native currency where the message is being sent from) to make a cancellation message accepted. Consider looking at the list of supported chains and fees and details on retrieving the deBridge protocol fee;
    • a small amount to cover the gas on the source chain, which gives an incentive to keepers for the successful claim of the cross-chain message on the source chain. In other words, this is a prepayment for potential gas expenses, that will be transferred by the protocol.

​
Further reading