ZChains Whitepaper
  • Overview
  • Tokenomics
    • Glossary
    • Tokenomics
  • Get started
    • Installation
    • Local Setup
    • Cloud Setup
    • CLI Command
  • Additional Features
    • Explorer
    • Network stress testing
  • Architecture
    • Architecture Overview
    • Modules
      • Blockchain
      • Consensus
      • JSON RPC
      • Minimal
      • Networking
      • Other modules
      • Protocol
      • Sealer
      • State
      • Storage
      • TxPool
      • Types
  • Community
    • Propose a new feature
    • Report an issue
  • Concepts
    • State in Ethereum
  • Configuration
    • Manage private keys
    • Server configuration file
    • Secret Managers
      • Set up AWS SSM (Systems Manager)
      • Set up GCP Secrets Manager
      • Set up Hashicorp Vault
  • Consensus
    • Proof of Stake
    • Set up and use Proof of Stake (PoS)
  • Working with node
    • Backup/restore node instance
    • Query JSON RPC endpoints
    • Query operator information
  • Development Roadmap
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  • Overview
  • Staking Smart Contract
  • Setting up an N node cluster
  • Setting the length of an epoch
  • Using the Staking Smart Contract scripts
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  1. Consensus

Set up and use Proof of Stake (PoS)

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Last updated 10 months ago

Overview

This guide goes into detail on how to set up a Proof of Stake network with the ZChains, how to stake funds for nodes to become validators and how to unstake funds.

It is highly encouraged to read and go through the / sections, before going along with this PoS guide. These sections outline the steps needed to start a Proof of Stake (PoS) cluster with the ZChains.

Currently, there is no limit to the number of validators that can stake funds on the Staking Smart Contract.

Staking Smart Contract

The repo for the Staking Smart Contract is located .

It holds the necessary testing scripts, ABI files and most importantly the Staking Smart Contract itself.

Setting up an N node cluster

Setting up a network with the ZChains is covered in the / sections.

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 --pos:

polygon-edge genesis --pos ...

Setting the length of an epoch

Epochs are covered in detail in the section.

To set the size of an epoch for a cluster (in blocks), when generating the genesis file, an additional flag is specified --epoch-size:

polygon-edge genesis --epoch-size 50

This value specified in the genesis file that the epoch size should be 50 blocks.

The default value for the size of an epoch (in blocks) is 100000.

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. :::

Using the Staking Smart Contract scripts

Prerequisites

The Staking Smart Contract repo is a Hardhat project, which requires NPM.

To initialize it correctly, in the main directory run:

npm install

Setting up the provided helper scripts

Create an .env file with the following parameters in the Smart Contracts repo location:

JSONRPC_URL=http://localhost:10002
PRIVATE_KEYS=0x0454f3ec51e7d6971fc345998bb2ba483a8d9d30d46ad890434e6f88ecb97544
STAKING_CONTRACT_ADDRESS=0x0000000000000000000000000000000000001001

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 0x0000000000000000000000000000000000001001)

Staking funds

:::info Staking address The Staking Smart Contract is pre-deployed at address 0x0000000000000000000000000000000000001001.

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 1 ETH.

Staking can be initiated by calling the stake method of the Staking Smart Contract, and specifying a value >= 1 ETH.

npm run stake

The stake Hardhat script stakes a default amount of 1 ETH, which can be changed by modifying the scripts/stake.ts file.

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.

Unstaking funds

Addresses that have a stake can only unstake all of their funds at once.

npm run unstake

Fetching the list of stakers

All addresses that stake funds are saved to the Staking Smart Contract.

npm run info

:::info Lowering the epoch length As outlined in the section, epoch blocks are used to update the validator sets for nodes.

Scripts for interacting with the deployed Staking Smart Contract are located on the .

To learn more about the Staking Smart Contract, please visit the section. :::

After the .env file mentioned in the has been set up, and a chain has been started in PoS mode, staking can be done with the following command in the Staking Smart Contract repo:

After the .env file mentioned in the has been set up, and a chain has been started in PoS mode, unstaking can be done with the following command in the Staking Smart Contract repo:

After the .env file mentioned in the 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:

Local Setup
Cloud Setup
here
Local Setup
Cloud Setup
Epoch Blocks
Epoch Blocks
Staking Smart Contract repo
Staking Smart Contract
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