Running your block attestation service

Introduction

You are at the final chapter on the Starknet staking guide! The block attestor service allows validators to fulfill a new requirement with the Staking V2 phase that Starknet introduced in SNIP-28. The new change enforces existing and new validators to attest to a block within an epoch to be eligible for staking rewards. The idea behind it is that it is a way for validators to show that they are actively preserving the history of the network while proving it by submitting attestations to randomly assigned blocks in each epoch. You can think of an epoch as a way to group number of blocks (currently 40 blocks per epoch) and each epoch acts as a checkpoint for finalizing every validator’s stakes.

The attestor service will communicate directly with our node therefore, make sure that your node is already running and it’s synced to the latest block. Depending on your chosen node client, use the corresponding block attestation service provided by that client.

Juno

1	Clone the Starknet Staking V2 repository

git clone https://github.com/NethermindEth/starknet-staking-v2
cd starknet-staking-v2

1	Compile the validator tool

make validator

1	Create a configuration file named config.json based on the template below

{
  "provider": {
    "http": "http://localhost:6060/v0_8",
    "ws": "ws://localhost:6061/v0_8"
  },
  "signer": {
    "operationalAddress": "0x123",
    "privateKey": "0x456"
  }
}

1	Once your Juno node is fully synced, start the attestation service:

./build/validator --config config.json --log-level debug

Pathfinder

You can run the block attestor service by running the following docker command

docker run -it --rm --network host \
  -e VALIDATOR_ATTESTATION_OPERATIONAL_PRIVATE_KEY="0xdeadbeef" \
  ghcr.io/eqlabs/starknet-validator-attestation \
  --staking-contract-address 0x03745ab04a431fc02871a139be6b93d9260b0ff3e779ad9c8b377183b23109f1 \
  --attestation-contract-address 0x03f32e152b9637c31bfcf73e434f78591067a01ba070505ff6ee195642c9acfb \
  --staker-operational-address 0x02e216b191ac966ba1d35cb6cfddfaf9c12aec4dfe869d9fa6233611bb334ee9 \
  --node-url http://localhost:9545/rpc/v0_8 \
  --local-signer

The VALIDATOR_ATTESTATION_OPERATIONAL_PRIVATE_KEY must be changed to your private key for your operation address and staker-operational-address should be your operation wallet address. The source of other addresses comes from the important address page.

Checking the status of your block attestor service

If the service is running successfully, it should have the following output where you can see information like your staker_address, operational_address, stake, epoch_id, epoch_start, epoch_length, attestation_window:

Current attestation info staker_address=0x48f8ddc0bc864f33d4c47b79a1f0e1460e0777d0b0224d8c291f1039523306e operational_address=0x48f8ddc0bc864f33d4c47b79a1f0e1460e0777d0b0224d8c291f1039523306e stake=100000000000000000000 epoch_id=1201 epoch_start=712773 epoch_length=40 attestation_window=16

And on the next upcoming epochs, your block attestor service should start submitting attestations.

2025-04-22T11:04:22.716449Z  INFO starknet_validator_attestation::state: New epoch started staker_address=0x48f8ddc0bc864f33d4c47b79a1f0e1460e0777d0b0224d8c291f1039523306e operational_address=0x48f8ddc0bc864f33d4c47b79a1f0e1460e0777d0b0224d8c291f1039523306e stake=100000000000000000000 epoch_id=1205 epoch_start=712933 epoch_length=40 attestation_window=16
2025-04-22T11:11:00.263344Z  INFO starknet_validator_attestation::state: Attestation transaction sent transaction_hash=0x79f9f5ec8dbfca48a132e8d23caad15455c6e0dc98ec517a7013c374d7d5501
2025-04-22T11:11:03.017827Z  INFO starknet_validator_attestation::state: Attestation confirmed staker_address=0x48f8ddc0bc864f33d4c47b79a1f0e1460e0777d0b0224d8c291f1039523306e epoch_id=1205

Claiming your staking rewards

After submitting few attestations, you can check to see if you have accumulated any rewards by calling claim_reward from the staking contract by passing the reward address!

You can view this example transaction that has successfully claimed 0.33 STRK to their reward wallet address.

Now, you are successfully running your own validator and block attestor service on Sepolia testnet! This means that you will start earning rewards for every successful attestation while preserving the state of Starknet blockchain.