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Set up and use Proof of Stake (PoS)
This guide goes into detail on how to set up a Proof of Stake network with the Credit Smart Chain, how to stake funds for nodes to become validators and how to unstake funds.
Currently, there is no limit to the number of validators that can stake funds on the Staking Smart Contract.
It holds the necessary testing scripts, ABI files and most importantly the Staking Smart Contract itself.
The only difference between setting up a PoS and PoA cluster is in the genesis generation part.
When generating the genesis file for a PoS cluster, an additional flag is needed
polygon-edge genesis --pos ...
To set the size of an epoch for a cluster (in blocks), when generating the genesis file, an additional flag is specified
polygon-edge genesis --epoch-size 50
This value specified in the genesis file that the epoch size should be
The default value for the size of an epoch (in blocks) is
LOWERING THE EPOCH LENGTH
The default epoch length in blocks (
100000) may be a long time to way for validator set updates. Considering that new blocks are added ~2s, it would take ~55.5h for the validator set to possibly change.
Setting a lower value for the epoch length ensures that the validator set is updated more frequently.
The Staking Smart Contract repo is a Hardhat project, which requires NPM.
To initialize it correctly, in the main directory run:
.envfile with the following parameters in the Smart Contracts repo location:
Where the parameters are:
- JSONRPC_URL - the JSON-RPC endpoint for the running node
- PRIVATE_KEYS - private keys of the staker address
- STAKING_CONTRACT_ADDRESS - the address of the staking smart contract ( default
The Staking Smart Contract is pre-deployed at address
Any kind of interaction with the staking mechanism is done through the Staking Smart Contract at the specified address.
In order to become part of the validator set, an address needs to stake a certain amount of funds above a threshold.
Currently, the default threshold for becoming part of the validator set is
Staking can be initiated by calling the
stakemethod of the Staking Smart Contract, and specifying a value
>= 1 ETH.
npm run stake
stakeHardhat script stakes a default amount of
1 ETH, which can be changed by modifying the
If the funds being staked are
>= 1 ETH, the validator set on the Staking Smart Contract is updated, and the address will be part of the validator set starting from the next epoch.
Addresses that have a stake can only unstake all of their funds at once.
npm run unstake
All addresses that stake funds are saved to the Staking Smart Contract.
.envfile mentioned in the previous section has been set up, and a chain has been started in PoS mode, fetching the list of validators can be done with the following command in the Staking Smart Contract repo:
npm run info