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How to validate


This tutorial works with current Alexander testnet and has been updated for PoC-4.

To be a good validator, you should

  • Have DOTs to stake (Basic Requirement)
  • Keep your node up to the latest version
  • Have enough knowledge of network security to create a robust network
  • Use HSM (Hardware Security Module) to protect your key (Highly Recommended)

You should NOT run a validator if you have DOTs, but you do not have enough technical knowledge to set up a validator. It is recommended to delegate/nominate your DOTs to someone you trust for helping you to do this kind of work.

As a nominator, you can still get the rewards by nominating multiple validators. If you want to know more about nominator, please see here.

For this tutorial, we use Ubuntu 18.04 and will be running on PoC-4 Alexander testnet. No matter what operating system you are using, setup should not be too much difference. There is a lot of VPS choice out there, feel free to pick the one you like.


Please make sure that you do NOT use this setup & configuration on mainnet. This guide simply walks you through step-by-step how to set up & run a validator node. If you would like to run a validator seriously when mainnet is live, you have to be REALLY careful on some areas like key management, DDOS protection and high availability.

Install rust

curl -sSf | sh
sudo apt install make clang pkg-config libssl-dev

This command will fetch the latest version of Rust and install it, then execute the second command to install the required software before installing Polkadot.

rustup update

If you have installed rust already, run this command to check whether there is a new version available.

Install polkadot PoC-4

Until support for the one-line installer is back up for PoC-4, you will need to build polkadot from source.

git clone
# To update your node. Run from this step.
cd polkadot
cargo clean
git checkout v0.4
git pull origin v0.4
cargo install --path ./ --force

This may take a while depending on your hardware!

Synchronize chain data

After installing all related dependencies, you can start your Polkadot node. Start to synchronize the chain by executing the following command:

polkadot --chain alex

It should take at least a few hours.

You can check the current highest block via Telemetry or PolkadotJS Block Explorer

Create accounts

To be a validator, you will need three separate accounts for managing your funds, namely stash, controller and Session. If you want to know more about it, please see here.

create account First, go to PolkadotJS => Account and click on the add account button.

To help you identify your accounts easily later on, make sure to use stash, controller and session in the name your accounts. A mnemonic seed phrase is given to you. You can save it in a safe place, offline, or you can choose to save your account using a JSON keyfile that will be generated automatically when clicking on Save. The password that is required to create an account will be used to sign any transaction made for each account. It will also be used to encrypt the JSON keyfile and will be required if you wish to restore your account using this file.

The mnemonic phrase for the session account needs to be used later in this guide to validate. Make sure you save it safely. Another particularity you need to be aware of: both stash and controller account can use the Schnorrkel (sr25519) as keypair crypto type in the Advanced creation options, however, you must use Edwards (ed25519) for the session account.

On the following screen, choose Create and backup account to store your JSON key file on your computer. Together with your password, this is a way to recover each account.

Once all accounts have been created, the overview should show you something like this. Note that the session account must be ed25519.

backup seed

Get testnet DOTs token

To continue the following steps, you are required to get some testnet DOTs token for the stash and controller accounts in order to submit transactions and use these DOTs as stake. The session account doesn't need any DOT. See the DOTs page for recommendations on getting testnet DOTs. Each of your accounts should have at least 150 milliDOTs to cover the existential deposit and transaction fees.

Bond DOTs

It is now time to setup our validator. We will do the following: - Bound the DOTs of the stash account. These DOTs will be put at stake for the security of the network and can be slashed. - Select the controller. This is the account that will decide when to start or stop validating. - Select the session account. This is the account whose seed will be used to run the node.

First, go to Staking section. Click on the "New stake" button.

dashboard bonding

  • Stash account - Select your stash account, we will bound 100 milliDOTs, make sure it has this amount of funds.
  • Controller account - select the controller account created earlier.
  • Value bonded - how many DOTs from the stash account you want to bond/stake. You can top up this amount and bound more DOTs later, however, withdrawing any bounded amount requires the bounding duration period to be over (several months at the time of writing).
  • Payment destination - where the rewards get sent. More info here.

Once everything is filled properly, click Bond and sign the transaction (with your stash account)

Set the session key

You should now see a new card with all your accounts. The bonded amount on the right corresponds to the funds bonded by the stash account.

dashboard validate

Click on Set Session Key.
Select the session account created previously and click on Set Session Key.


You should now be able to see both Validate and Nominate buttons. At this point and before validating, you should make sure your node is ready to validate. Open your terminal, if your node is fully synchronized, run your validator with the seed or the mnemonic from the session account, e.g:

polkadot --chain alex --validator --key="SESSION_ACCOUNT_SEED" --name NAME_ON_TELEMETRY

Make sure that the address generated from the seed corresponds to your session account's address. Don't worry if the last characters diverge, it's just the checksum that has recently changed.

terminal session key verification

To verify that your node is live and in sync, head to Telemetry, after a few seconds, your node information will be shown.

If everything looks good, go ahead and click on Validate in Polkadot UI.

dashboard validate dashboard validate

  • Unstake threshold - how often you want to be reported offline (and slashed) before being removed from the validator set.
  • Payment preferences - rewards you will keep, the rest will be shared among you and your nominators.

Click Validate

Go to Staking tab, you should see a list of active validators out there. At the top of the page, it shows how many validators slots are available and how many nodes are intended to be a validator.

staking queue

Your node will be shown on the next up queue. In the next era (up to 1 hour), if there is a slot available, your node will become an active validator.


If you want to run your validator as a systemd process see the short guide here.

Notice: As mainnet get closer, you can expect more slots will be available for testing.

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