How To Set Up A Validator For Aleph Zero Testnet On OnFinality

7 min readNov 19, 2022

OnFinality is a blockchain infrastructure platform that saves web3 builders time and makes their lives easier. We deliver easy-to-use, reliable and scalable API endpoints for the biggest blockchain networks and empower developers to automatically test, deploy, scale and monitor their own blockchain nodes in minutes.

We are already supporting over 60 networks across Layer-1 ecosystems such as Polkadot, Avalanche and Cosmos, and are continuously expanding these mission-critical services to other ecosystems to help developers build the decentralised future, faster!


In this How-To Guide, you will learn how to set up your own Validator for the Aleph Zero testnet, enabling you to test-drive the interface before staking on mainnet. This guide should be used alongside Aleph Zero’s official guide which is kept up to date and more detailed.

Aleph Zero Testnet

Aleph Zero is a privacy-enhancing public blockchain built for enterprise, Web 3.0, and DeFi use-cases. Aleph Zero aims to solve the current blockchain shortcomings by ensuring that developers can focus on innovation without being limited by the technology stack.

Testnet is a part of the development process for Aleph Zero to battle-test different solutions within their community.

Why Run A Validator For Aleph Zero Testnet

Like all Proof-of-Stake networks, Validators play a crucial role in securing and ensuring the success of the Aleph Zero network. As a Validator, you can accrue rewards proportionally to your stake (and the stake delegated to you).

By running a validator on testnet, you can familiarise yourself with the interface before going on to stake actual AZERO on the mainnet when it launches for community validators in December 2022.

Mainnet validators who continue to operate Testnet nodes after the Mainnet validator program launch will continue to get monthly reward airdrops.

Useful Links


Running a Collator or Validator comes with a high risk and requires a high level of technical knowledge and skill. As per our Terms of Service, OnFinality is neither responsible for any rewards nor losses, such as from slashing, incurred when running a Validator or Collator node on OnFinality. Users should read and fully understand the relevant documentation for the Network before setting up the node, and get in touch directly with the Network if they have any questions or concerns.


1. Log In To OnFinality

Create an account and log in to OnFinality, then add a payment method.

2. Create Dedicated Node

Select the Dedicated Nodes menu and press “Deploy New Node”

2.1 Select Network

Search for Aleph Zero Testnet and then click “Deploy Node”

2.2 Configure Node

Enter an easily identifiable Display Name and choose “Validator Node” Node Type. Select the latest Image Version.

Scroll down to set the Cloud Provider and Region where you will run the node. Networks may have a preference of where you should run your validator or collator, so check with their official documentation.

Use at least the recommended configuration suggested by the network, then press “Next”

2.3 Configure Launch Arguments

Next, review the node’s Launch Configuration. The recommended settings are usually sufficient, but we recommend comparing with Aleph Zero’s own documentation to be certain.

Press “Next”

2.4 Review Node

Finally, review the node’s settings and press “Deploy Node”

3. Sync Your Dedicated Node

Once your node is successfully deployed, you can find it in the “Dedicated Nodes” section on our portal. Click on your node and confirm the following:

  • Relay chain/parachain blocks are syncing appropriately
  • No configuration errors in the console log. You can find your console by clicking on “Console logs” on the top right hand.
  • CPU, Memory, and Storage are within reasonable range of use.

You can cross-reference the respective network blocks on the PolkadotJS App.

4. Set Up Accounts And Stake

To run a validator you will need to set up two accounts:

Stash account

This account holds funds bonded for staking, but delegates some functions to the Controller account. It can be kept in a cold wallet, meaning it can stay offline all the time.

Controller account

This account acts on behalf of the Stash account, signalling decisions and necessary execution for staking. It only needs enough funds to pay transaction fees.

Follow the Aleph Zero instructions to Set Up Your Stake.

5. Generate Session Keys

Session keys are what links the validator or collator to your account.

First, locate your Dedicated Node’s RPC endpoints under API Endpoints. Access is secured by an API Key at the end of the URL, so keep it safe and private.

Option 1 — Polkadot-JS:

Copy your RPC — Websocket endpoint into the Polkadot-JS Custom Endpoint and press save to connect to the node

Navigate to Developer > RPC Calls and submit an author rotateKeys call.

Record the result.

Option 2 — CLI:

Generate the session keys on your Dedicated Node via the author_rotateKeys RPC Request, using your Dedicated Node’s RPC — Http url.

Example request

curl **Node’s RPC Http endpoint here** -H \ “Content-Type:application/json;charset=utf-8” -d \





“params”: []


You will get a response like this


“jsonrpc”: “2.0”, “result”:”0xc05a9d093e4db4c1bde31977716e7a0a39d6f3d1f1bf749e7fec8371147de730af6860aeef81a11130c9fcd317b96e736f6c36141c28f382a18f9faf6e7df797eaa951ead00d12db10937003f0956e3d3444d1774d452ed045dbc1b84d1bf1471abf5d77bf5033845f01be1188a852c6f0ba703042b4d06d14314841c1096c50",



The content after “result” is the session keys of your validator node.

6. Set Session Keys

In polkadot-js, Open Network > Staking

Next, you will need to link the session keys to your account on-chain using the response from author_rotateKeys.

Click “Session Keys” and enter the session keys from step 5

7. Configure Your Validator

Finally, you will need to configure your validator’s settings, such as the session keys, stake value, and commission, on chain.

Click “Validate”

Set the value of reward commission percentage, which is the rate that your validator will be commissioned with. The remaining rewards will be split among your nominators.

Choose whether to accept new nominations and Click “Bond & Validate”.

The validator set is refreshed every era. In the next era, if there is a slot available and your node is selected to join the validator set, your node will become an active validator.


If you have followed all of these steps, and been selected to be a part of the validator set, you are now running an Aleph Zero Testnet validator!

More Resources:

Developer documentation:

About OnFinality

OnFinality is a blockchain infrastructure platform that saves web3 builders time and makes their lives easier. OnFinality delivers scalable API endpoints for the biggest blockchain networks and empowers developers to automatically test, deploy, scale and monitor their own blockchain nodes in minutes. To date, OnFinality has served over 277 billion RPC requests across 60 networks including Polkadot, Kusama, Moonbeam, Astar, Avalanche and Cosmos, and is continuously expanding these mission-critical services so developers can build the decentralised future, faster!

App | Website | Twitter | Telegram | LinkedIn




OnFinality empowers Web3 developers with easy-to-use, reliable and scalable blockchain infrastructure. Build smarter with