How to Set Up a Validator for Polkadot on OnFinality

Introduction

Polkadot is a pioneering blockchain platform designed to enable interoperability among specialized blockchains (parachains). Validators play a critical role in securing the network and earning staking rewards. This guide walks you through setting up a Polkadot validator using OnFinality’s infrastructure, streamlining the process for developers.

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What Is Polkadot?

Polkadot ($DOT) is a multi-chain network that facilitates cross-chain communication, enabling decentralized applications (dApps) to operate seamlessly across interconnected blockchains. Its unique architecture includes:

• Relay Chain: The central chain coordinating consensus and security.
• Parachains: Independent blockchains with specialized functionalities.
• Validators: Nodes that secure the network by validating transactions and participating in consensus.

Why Run a Polkadot Validator?

Running a validator offers:

• Network Security: Contribute to Polkadot’s decentralized governance.
• Staking Rewards: Earn $DOT tokens for validating transactions.
• Decentralization: Strengthen the ecosystem’s resilience.

👉 Explore validator rewards

Prerequisites

Before starting, ensure you have:

1. An OnFinality account.
2. A funded wallet (for staking bonds).
3. Basic familiarity with Polkadot’s official validator documentation.

Step-by-Step Guide

1. Log In to OnFinality

• Sign up or log in at OnFinality.
• Add a payment method to deploy nodes.

2. Deploy a Dedicated Node

1. Navigate to Dedicated Nodes > Deploy New Node.
2. Search for Polkadot and select Validator Node Type.

Node Configuration

• Display Name: Assign a recognizable name.
• Image Version: Choose the latest stable release.
• Cloud Provider: Select a region aligned with Polkadot’s recommendations.
• Hardware: Use at least the recommended specs (e.g., 4 vCPUs, 16GB RAM).

3. Sync the Node

• Monitor synchronization via Console Logs in the OnFinality portal.
• Verify block height against PolkadotJS Explorer.

4. Set Up Stash and Controller Accounts

• Stash Account: Holds bonded funds (keep offline for security).
• Controller Account: Manages validator operations (requires minimal funds for fees).

5. Generate Session Keys

Option 1: Polkadot-JS

1. Connect to your node’s WebSocket endpoint in Polkadot-JS.
2. Navigate to Developer > RPC Calls and execute author_rotateKeys.

Option 2: CLI

curl [Your_Node_RPC_Endpoint] -H "Content-Type:application/json" -d '{"jsonrpc":"2.0","id":1,"method":"author_rotateKeys","params":[]}'

• Save the resulting session keys.

6. Link Session Keys to Your Account

• In Polkadot-JS, go to Network > Staking > Session Keys.
• Input the keys from Step 5.

7. Activate the Validator

1. Click Validate in Polkadot-JS.

2. Set:

   • Commission Rate: Your validator’s reward percentage.
   • Bond Amount: Funds to stake.
3. Submit the transaction.

FAQs

How long does node synchronization take?

Syncing depends on network activity but typically takes 12–48 hours.

What’s the minimum stake for a Polkadot validator?

The minimum varies; check the Polkadot Staking Dashboard for current requirements.

Can I run multiple validators?

Yes, but each requires a separate stash/controller account and session keys.

What’s the risk of slashing?

Validators may lose staked funds for malicious behavior or downtime. Mitigate risks by:

• Using reliable infrastructure (e.g., OnFinality).
• Monitoring node performance.

Final Thoughts

Running a Polkadot validator is a technical but rewarding endeavor. By leveraging OnFinality’s tools, you simplify deployment and focus on maximizing staking rewards.

Recommended Resources:

• Polkadot Validator Documentation
• OnFinality Support Portal

👉 Start staking today

Disclaimer: Running a validator involves risks, including slashing. OnFinality is not liable for rewards or losses incurred during validation.