Aleph Zero is a PoS (Proof of Stake) blockchain, and as such, it uses staking as a mechanism to keep the platform secure and stable. Unlike in a Proof of Work consensus, where an extensive amount of computational work (mining) is needed to ensure the correctness and integrity of the data on the chain, in Proof of Stake systems the security of the network is guarded by the combined coin collateral coming from nodes producing new blocks (validators) and other coin holders (nominators) who participate by expressing their trust in (nominating) certain validators.
Staking involves temporarily locking (bonding) some AZERO coins and using them as such collateral. As mentioned above, there are two special roles in Aleph Zero which require users to bond their coins:
- Validators are users who run Aleph Zero nodes. They process transactions, validate blocks, and take part in the AlephBFT consensus to finalize blocks, thus making them irreversible. To become a validator, one needs to stake enough AZERO and also have some technical background to run the Aleph Zero node software. If you would like to become a validator, please check out our validator guide for more details about validator staking. Users who contribute to the well-being of the chain as validators are rewarded for their service with AZERO coins.
- Nominators are users who don't run Aleph Zero nodes, but still want to contribute to the network's security and earn staking rewards. They use their stake to nominate some trustworthy validators. As a consequence, a nominator's stake increases the total stake of the chosen validator, who then has proportionally higher vote power in the consensus and earns more rewards. See Staking Rewards for more details on how validators and nominators are rewarded for staking.
Since being a validator requires certain technical expertise and setup, most users contribute by becoming nominators. If you would like to find out how to do that, please visit How to Start Staking section.
The staking process on the Aleph Zero blockchain is organized in periods called eras. Each era lasts approximately 24 hours (strictly speaking: 86400 blocks, which corresponds to 24 hours assuming an average block production time of 1 second) and throughout an era, all staking-related data on the chain (for example, who is a validator, how much is every user staking, who is nominating who and so on) is kept "frozen". Of course that doesn't mean you cannot change your staking choices - you can do it at any moment, but the changes you introduce (for example, adding more stake or changing a validator you nominate) will become effective only at the start of the next era. To be precise, you need to submit your changes at most 15 minutes (900 blocks) before the start of a new era for your changes to have an effect during that era.
The rewards for staking are awarded at the end of each era (exact formulas determining the awarded amounts are explained in Staking Rewards). New rewards are not automatically added to users' accounts at the moment an era ends, they need to be claimed by a special transaction called
payout_stakers. This transaction can be sent by any user and results in rewards for a given era being paid to one chosen validator and all their nominators. So the full rewards payout to all Aleph Zero users requires a separate
payout_stakersto be sent for each validator participating in a given era.
Currently, Aleph Zero Foundation operates an automatic service that sends all the
payout_stakerstransactions right after a new era starts. So there is no need for anyone to perform
Rewards that have been awarded (the era ended), but have not yet been claimed are visible in the Payouts tab. Having this tab empty means that all your rewards have been claimed and are already on your account. To see your past rewards, please inspect your account details on Subscan.