🚀 How to Launch the New Version of Aztec Node

This guide will help you install and launch the new version of the Aztec validator node on the Sepolia testnet.

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🧩 1. Install Required Packages

sudo apt update && sudo apt upgrade -y
sudo apt install -y curl git build-essential

Install Node.js 20.x:

curl -fsSL https://deb.nodesource.com/setup_20.x | sudo -E bash -
sudo apt install -y nodejs

Install Foundry:

curl -L https://foundry.paradigm.xyz | bash
source ~/.bashrc
foundryup
cast --version

Install Aztec CLI:

bash -i <(curl -s https://install.aztec.network)

When prompted, press y to confirm the installation.

Add Aztec CLI to your PATH:

echo 'export PATH="$HOME/.aztec/bin:$PATH"' >> ~/.bashrc
source ~/.bashrc
aztec --version

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🔐 2. Approve Stake for the New Contract

Use your old private key (the one used with your previous node):

cast send 0x139d2a7a0881e16332d7D1F8DB383A4507E1Ea7A   "approve(address,uint256)" 0xebd99ff0ff6677205509ae73f93d0ca52ac85d67 200000ether   --private-key <YOUR_OLD_PRIVATE_KEY>   --rpc-url <YOUR_SEPOLIA_RPC_URL>

• Approval contract: 0x139d2a7a0881e16332d7D1F8DB383A4507E1Ea7A
• Rollup contract: 0xebd99ff0ff6677205509ae73f93d0ca52ac85d67
• Amount approved: 200000ether

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🆕 3. Generate a New Address

Create new validator keys:

aztec validator-keys new --fee-recipient 0x0000000000000000000000000000000000000000000000000000000000000000

After running this, a new ETH address will be generated and stored in:

/root/.aztec/keystore/key1.json

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🔑 4. Extract ETH and BLS Private Keys

Extract the private keys from your keystore:

jq -r '.validators[0].attester.eth' /root/.aztec/keystore/key1.json
jq -r '.validators[0].attester.bls' /root/.aztec/keystore/key1.json

• The first command gives you the ETH private key
• The second gives you the BLS private key

⚠️ Important: Save the new address and both private keys (ETH and BLS) in a safe and secure place.
Never store them in plain text or share them publicly.

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🧾 5. Register the Validator

Register your new validator using the old private key and your new keys:

aztec add-l1-validator   --l1-rpc-urls <YOUR_RPC_URL>   --network testnet   --private-key <YOUR_OLD_PRIVATE_KEY>   --attester <NEW_ETH_ADDRESS_FROM_STEP_3>   --withdrawer <NEW_ETH_ADDRESS_FROM_STEP_3>   --bls-secret-key <YOUR_BLS_PRIVATE_KEY_FROM_STEP_4>   --rollup 0xebd99ff0ff6677205509ae73f93d0ca52ac85d67

If the transaction is successful, your validator registration is complete ✅

Now fund your new ETH address from Step 3 with Sepolia test ETH.

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⚙️ 6. Start the Validator Node

Open a new screen session to keep the node running in the background:

screen -S aztec

Start your node:

aztec start --node --archiver --sequencer   --network testnet   --l1-rpc-urls <YOUR_SEPOLIA_RPC_URL>   --l1-consensus-host-urls <YOUR_BEACON_SEPOLIA_RPC>   --sequencer.validatorPrivateKeys <NEW_PRIVATE_KEY_FROM_STEP_4>   --sequencer.coinbase <NEW_ETH_ADDRESS_FROM_STEP_3>   --p2p.p2pIp <YOUR_SERVER_IP>

After starting:

• Check logs to ensure there are no errors.
• The node will begin syncing and participating in the network.

Detach from the screen session (keep the node running):

Ctrl + A, then D

To reconnect later:

screen -r aztec

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✅ Done!

🎉 Congratulations!
You have successfully launched the new version of the Aztec Validator Node on the Sepolia testnet skcrypto-x
Guide for launching the new Aztec validator node (Testnet, 2025)