Beacon Chain launch hard fork
Mainnet 2020-12-01
The proof-of-stake consensus chain began running separately from mainnet. It merged with mainnet two years later in The Merge.
What changed
- Users
- Nothing changed directly in everyday use. Transfers, fees, and wallet usage all continued on the existing Proof of Work mainnet. There was one new option: depositing 32 ETH into the deposit contract made you a validator. However, at that time there was no way to withdraw deposited ETH, and no date was set for when withdrawals would be possible. Only ETH that could be locked up for a long time should have been deposited.
- Validators
- From this day, the role of validator existed for the first time. By depositing 32 ETH and running a beacon chain node and a validator client, you could take part in proposing and attesting to blocks and earn rewards. Conversely, long periods offline reduced rewards, and breaking the rules made you subject to slashing, which means losing part of your deposit. Rewards only accumulated inside the beacon chain, and withdrawals had to wait for a later upgrade. The beacon chain at this point had no user transactions. Validators were checking whether proof-of-stake consensus actually ran stably.
- Node operators
- There was no immediate change needed for people running mainnet nodes. Mainnet kept running on the existing mainnet clients alone. However, to follow the beacon chain, you had to install a new piece of software separately, called a consensus client. Clients built by several teams, such as Prysm, Lighthouse, Teku, and Nimbus, were available from launch. To run a validator, you had to operate both the existing mainnet client and a consensus client, and this setup continued until The Merge, when the two chains joined.