Ante is an Ethereum smart contract testing protocol. Anyone can use Ante to build and run Ante Tests, which are live, on-chain tests that validate the validity of the invariants of a target protocol. By staking on Ante Pools that match to these tests, DeFi protocol programmers and project supporters (such as users or investors) can demonstrate their faith in the stability of the protocol. By challenging the relevant Ante Pools and confirming the Ante Test’s status, security professionals can make money by spotting defective Ante Tests or violated invariants. The money staked in an Ante Pool is distributed pro rata to pool challengers in the event that the Ante Test confirms a failure, plus a bonus to the challenger who started the test.
The overall quantity of staking capital and its relation to challenging capital indicates a protocol’s perceived stability because staked money are vulnerable to loss in the event that tests are unsuccessful. This allows users to evaluate the amount of capital staked behind comparable protocols, providing them with an extra signal about whether DeFi protocols are credible. Users can also confirm whether protocols have ethically developed and implemented live tests, which offer safe smart contract systems an extra layer of security above and beyond standard off-chain static testing. Ante facilitates the process by which DeFi protocol developers can establish credibility and confidence in their protocols.
System design on Ante Protocol
By placing “skin in the game” behind programmatically verified properties of its contract state, or what are known as on-chain invariants, protocols on Ethereum can demonstrate their trust in their code thanks to the Ante Protocol. The remainder of this section is devoted to a full description of the mechanism, which is briefly described below. In order to use Ante for a particular protocol, developers must codify an invariant using the AnteTest interface in a smart contract. This smart contract must have a function that checks on-chain to see if the invariant still holds. Then, using the AntePoolFactory and the IAnteTest interface, they create an Ante Pool instance for that Ante Test.
Any challenger can check on-chain at any moment to see if the Ante Test is still passing. Funds belonging to stakers are frozen and given to challengers and the test validator in the event that such a check is unsuccessful. In the meanwhile, challengers use the Ante Pool to continuously reward stakers for deterioration.
Ante tests and on-chain invariants. On-chain invariants, or boolean statements that can refer to any data in the state of Ethereum at that moment, are tested by ante tests. This statement needs to be implemented by Ante Tests in their interface’s checkTestPasses() function. Ante Tests are allowed to use data from several different smart contracts, even if they are often applied to smart contracts from a single protocol.
Stake, test, and confirm using Ante Pools. Developers can combine an Ante Test with an Ante Pool, a smart contract that enables users to stake, challenge, or validate the test, once it has been launched. We go over each procedure one by one.
Staking: To stake an Ante Test and convey their belief that it will continue to pass, stakers must deposit ETH into the Ante Pool. By dividing decay rewards from challengers proportionately, winners receive block-by-block yield; but, if the Ante Test is not verified, winners forfeit their deposit.
Challenging: In order to challenge an Ante Test and indicate their belief that it will eventually fail, challengers must put Ethereum into the Ante Pool. The challengers will get their deposits back and the stakers’ deposits will be split, less a 5% bounty for the verifier, in the event that the AnteTest’s on-chain verification fails at any point. To cover the stakers’ decay reward, the challengers’ deposit decays by 100 gwei/ETH per block, or about 20% annually.
Verifying: By using the checkTestPasses() method, a challenger who has deposited for a minimum of 12 blocks can confirm that the Ante Test passes for the present on-chain state. Nothing occurs if the function’s value returns true, meaning the test is successful. The verifier receives a bounty of 5% of the stakers’ deposits if the function returns false, meaning the test fails. The remaining staker deposits are distributed pro rata to each challenger.
Implementation details. Now, it will be outlined and clarify a few technical aspects that have an impact on Ante’s exact implementation.
Waiting periods for withdrawals and deposits: Challengers are not eligible for payments until their deposits have been in an Ante Pool for a minimum of 12 blocks, in order to deter them from investing money to frontrun a verification and cause an Ante Test to fail. On Ethereum, this range was selected as the approximate finality threshold.
Stakers are required to wait 6000 blocks, or around one day, before they may withdraw money in reaction to an exploit that is known off-chain but hasn’t yet resulted in the relevant Ante Test failing on chain. This time frame was selected to give verifiers enough time to confirm an Ante Test before fund withdrawals by stakers.
Ante Test Reversions: Failures of the relevant Ante Test are interpreted as reversions of the checkTestPasses() method. Stakeholders must thus make sure that every test they stake on can be carried out properly.
Contracts with upgradeability: Ante Tests are unchangeable. Thus, the checkTestPasses() function is going to return and the Ante Test will always fail if a contract that the Ante Test references is upgraded in an incompatible manner. It is suggested that Ante-using projects either arrange an off-chain migration for all stakeholders in the un-upgraded Ante Test or upgrade in a compatible manner.