The Coinecta staking contracts support the requirement of being able to allow users to lock tokens for certain time periods and get a percentage reward for it. Because these locking periods can potentially be long we bind the time lock to a unique CIP-68 NFT (the stake nft) minted during the locking transaction. This allows the user to move to another wallet (for example due to loss of seed phrase of the original wallet) or even sell the stake nft to someone else on a secondary market such as jpg.store.

These are the main requirements the contracts need to fulfil:

• Guarding the assets in the stake pool to only be used as rewards for staking
• Protect the user and ensure the staking reward and time period match their expectation
• Mint unique stake nft to the user
• Rewards are part of the lock from the beginning.

This validator ensures that the assets within the utxo are only spent by a locking transaction or by the owner of the stake pool. Part of it's datum is a list of RewardSettings, each containing a valid locking period in days and the percentage reward that follows with it. The owner can choose to remove the assets from the stake pool or change the reward settings at any time.

Main validations to be done in a locking transaction:

• A new utxo is made with the same datum and validator attached.
• The reward matches the percentage in the chosen reward setting.
• The assets are unchanged other than the reward that is moved to the time lock utxo
• The time lock is locked according to the chosen reward setting.

This validator protects the assets that the user wants to lock. Because the stake_pool is a singleton interacting with it directly could give issues during busy periods. So the user defines their staking order in a stake_proxy utxo after which automated off chain code can ensure the order is fulfilled. If for whatever reason the order is not fulfilled the utxo can be refunded in a transaction signed by the user.

Main validations to be done in a locking transaction:

• The reward is matching user expectation
• The locking period is matching user expectation
• The stake nft is minted to the user using expected policy

This is a fairly simple time lock, making sure it can not be spend before a certain time. Once the time is reached it can be spend as long as the stake nft is burned in the same transaction.

Main validations to be done in unstake transaction:

• The transaction is executed after the unlock time has been reached.
• The stake nft is burned in the transaction.

This minting policy checks which assets are locked and when they unlock. On top of that it ensures the asset name is unique and that a reference nft is minted into the timelock to support CIP 68

The on chain asset name will be the first 28 bytes of a blake2b_256 hash of the output reference of the stake pool input. We store CIP-68 metadata in the time lock to allow for a good representation in wallets etc. The metadata is also checked to ensure it matches what is being locked.

Main validations during a mint:

• Asset name follows the expected template
• Only 1 stake nft and 1 corresponding reference NFT is minted

1 time lock input is shown here, but a user can unstake multiple time locks in 1 transaction assuming they all are passed their unlock time.

Update the build.sh script with the CBOR serialised policy id + asset id of the batcher certificate.

./build.sh

You can write tests in any module using the test keyword. For example:

test foo() {
  1 + 1 == 2
}

To run all tests, simply do:

aiken check

To run only tests matching the string foo, do:

aiken check -m foo

If you're writing a library, you might want to generate an HTML documentation for it.

Use:

aiken docs

Find more on the Aiken's user manual.