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Using the MgvCleaner contract to clean failing offers

Mangrove provides a cleaner contract called MgvCleaner to ease cleaning. This contract provides a collect method that calls Mangrove.snipes (forwarding the parameters unchanged) but will revert if any offer in the targets array succeed. Thus, cleaning via the cleaner contract guards you from offers unexpectedly succeeding when you try to snipe them to collect a bounty.

The prerequisites and steps needed to use the MgvCleaner.collect function are:


  • msg.sender must have approved Mangrove for spending inbound_tkn on the offer list you want to clean.


  1. Call MgvCleaner.collect(..) specifying the offer list and an array of offers to clean. Refer to the documentation for sniping for details on the parameters.
  2. The collected bounties (in native token) will be transferred to msg.sender.

If at least one offer succeeds, the call will revert. The revert reason depends on whether MgvCleaner has sufficient allowance to trade all succeeding offers on behalf of msg.sender on that offer list:

Revert reasonDescription
"mgvCleaner/anOfferDidNotFail"MgvCleaner has sufficient allowance.
"mgv/lowAllowance"MgvCleaner does not have sufficient allowance.


Assume you have a cleaning bot that has 900 DAI and has approved Mangrove for spending its DAI.

Your bot detects that offer #708 on the WETH/DAI offer list will fail. The offer wants 800 DAI and gives 0.6584 WETH,

To clean the offer, your cleaning bot triggers the following steps:

  1. The bot calls MgvCleaner.collect with targets set to [[708,type(uint96).max,0,type(uint).max]] and fillWants set to false.
  2. Mangrove will use the bot's DAI to execute offer #708 and revert the offer execution after noticing that the offer fails.
  3. Because the offer failed, Mangrove transfers a bounty to MgvCleaner.
  4. MgvCleaner transfers the bounty to the bot account.

Further reading