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Become a Validator on Berachain ​

This guide walks you through the process of becoming a validator node on Berachain.

Requirements ​

  • A fully-synced full node - See Quickstart
  • Foundry
  • Berachain Wallet with a minimum of 250,000 $BERA (or the current minimum to meet the Active Set) + gas to process the transaction

If you haven't, please read through the overview that explains the lifecycle of a validator.

Our goal is to deposit your stake and establish a connection between your validator identity on the consensus layer, your operator identity on the execution layer, and the withdrawal address where your stake is returned when you stop being a validator.

Step 1: Check beacond and Set Up Environment ​

A point of reassurance about beacond: it cannot transact on your behalf on either the execution or consensus layers. By invoking beacond on the command line you are not playing with TNT strapped to your stake.

You can ask beacond help for a list of commands, then beacond help command for help on a certain command. Have a look at beacond help deposit create-validator.

beacond wants a --home option specifying the data directory. This should be provided every time you use this command. In this guide, we will use an environment variable we set up and refer to with --home $BEACOND_HOME.

Below is an example of setting up and verifying the environment and establishing that you are operating with a properly-configured beacond installation. It's okay, even encouraged, that when depositing your stake you do so on your validator's full node, so that you have the CometBFT private keys available to you.

bash
# !/bin/bash

export BEACOND_HOME=/full/path/to/beacond-data;
export RPC_URL="https://rpc.berachain.com"; # mainnet
export DEPOSIT_ADDR="0x4242424242424242424242424242424242424242"; # mainnet
export VAL_PUB_KEY="<YOUR_VAL_PUB_KEY>";
export VAL_OPERATOR_ADDRESS="<YOUR_VAL_OPERATOR_ADDRESS>";
export WITHDRAW_ADDRESS="<YOUR_WITHDRAW_ADDRESS>";

alias beacond="/path/to/beacond --home $BEACOND_HOME";
beacond genesis validator-root $BEACOND_HOME/config/genesis.json;

# [Expected Output - MUST BE THIS EXACTLY]
# DO NOT PROCEED UNLESS THIS OUTPUT MATCHES
# 0xdf609e3b062842c6425ff716aec2d2092c46455d9b2e1a2c9e32c6ba63ff0bda

export GENESIS_ROOT=0xdf609e3b062842c6425ff716aec2d2092c46455d9b2e1a2c9e32c6ba63ff0bda # mainnet

The 0xdf6..0bda hash output confirms that you have the right mainnet genesis file.

  • BEACOND_HOME: The path to your beacond data directory.
  • RPC_URL: The URL of the RPC endpoint you are using. You can use your own if you want.
  • DEPOSIT_ADDR: The address of the deposit contract.
  • VAL_PUB_KEY: The public key of your validator from CometBFT (see below).
  • VAL_OPERATOR_ADDRESS: The address of the ETH account (EOA) that will become your operator address on the execution layer. This is used to interact with contracts such as BeraChef.
  • WITHDRAW_ADDRESS: The address where your deposit stake is returned when you stop being a validator (state 'Exited' on the lifecycle). This can be an address of your choice, or if you are staking money from investors, they will require a specific address.

Your CometBFT identity was created by beacond when you did beacond init, and is held in the priv_validator_key.json file. You can view the corresponding public key for this identity with beacond deposit validator-keys:

bash
# !/bin/bash

beacond deposit validator-keys;

# [Example Output]:
# ...
# Eth/Beacon Pubkey (Compressed 48-byte Hex):
# 0x9308360bb1e8c237c2a4b6734782426e6e42bc7a43008ba5e3d9f3c70143227ea1fb2a08b21cbbedf87cebf27e81669d

This is your beacon chain public key, and in this tutorial is placed in the VAL_PUB_KEY environment variable.

Step 2: Prepare registration transaction ​

WARNING

  1. Ensure you calculate a signature for the parameters and deposit amount you are going to send to the deposit contract. If you change anything after calculating the signature, the deposit will fail and the funds will be burnt.

The first registration transaction is the most important. It establishes the association between your validator key and your presence in the consensus layer. Mistakes in this step can result in a permanent loss of funds.

  1. Set up and fund your funding account on Berachain. You should be equipped so that you can use metamask or cast to send transactions from the funding account.

  2. Confirm your CometBFT identity has not been used before. If your validator has exited the active set or failed a deposit transaction, you will need to create a new identity. Check for previous use of your identity with the following command. If this returns non-zero, start over with a new beacond identity (as described in the Quickstart).

    bash
    cast call $DEPOSIT_ADDR 'getOperator(bytes)' $VAL_PUB_KEY -r $RPC_URL;

  3. Have beacond calculate the parameters for the transaction you will send with ./beacond deposit create-validator which takes:

    1. withdrawal-addr is described in Step 1
    2. stake-amount is the initial stake amount (as GWei). We strongly recommend using the minimum -- 10,000 $BERA.
    3. genesis-root: as confirmed in Step 1.
    bash
    STAKE_AMOUNT_ETH="10000";
STAKE_AMOUNT_GWEI="${STAKE_AMOUNT_ETH}000000000"

beacond deposit create-validator \
  $WITHDRAW_ADDRESS              \
  $STAKE_AMOUNT_GWEI             \
  $GENESIS_ROOT;

# [Expected Output]:
#  "pubkey": "<VAL_PUB_KEY>",
#  "credentials": "0x010000000000000000000000<WITHDRAW_ADDRESS>",
#  "amount": "0x9184e72a000",
#  "signature": "0x94349ab1...fb4b1d6",

DEPOSIT_SIGNATURE="0x9434...";  # from the above output
VAL_WITHDRAW_CREDENTIAL="0x01000..."; # from the above output

    The credentials should contain the withdrawal address verbatim, and the public key confirms the public key matching the private key used to generate the signature. In the above, we have placed the signature and withdraw credentials in variables for the next step.

  4. Finally, verify that beacond will accept this signature with beacond deposit validate which should produce no error message.

    bash
    beacond deposit validate   \
  $VAL_PUB_KEY             \
  $VAL_WITHDRAW_CREDENTIAL \
  $STAKE_AMOUNT_GWEI       \
  $DEPOSIT_SIGNATURE       \
  $GENESIS_ROOT;
echo $?;

# [Expected Output]:
# 0

You now have everything needed to deposit the initial 10,000 BERA.

Step 3: Send registration transaction ​

You will now send the above transaction onto the chain. We are calling the deposit function on the BeaconDeposit contract:

function deposit(
    bytes calldata pubkey,
    bytes calldata credentials,
    bytes calldata signature,
    address operator
)
    external
    payable
  • pubkey is the CometBFT public key.
  • credentials and signature are the values generated by beacond in the previous step.
  • operator is the EOA address you created in the "Preliminaries" step.
bash
# Non-Ledger Version
cast send $DEPOSIT_ADDR \
'deposit(bytes,bytes,bytes,address)' \
"$VAL_PUB_KEY" \
"$VAL_WITHDRAW_CREDENTIAL" \
"$DEPOSIT_SIGNATURE" \
"$VALIDATOR_OPERATOR_ADDRESS" \
--private-key  \
--value "${STAKE_AMOUNT_ETH}ether" \
-r $RPC_URL;

# Ledger Version
cast send $DEPOSIT_ADDR \
'deposit(bytes,bytes,bytes,address)' \
"$VAL_PUB_KEY" \
"$VAL_WITHDRAW_CREDENTIAL" \
"$DEPOSIT_SIGNATURE" \
"$VALIDATOR_OPERATOR_ADDRESS" \
--ledger \
--value "${STAKE_AMOUNT_ETH}ether" \
-r $RPC_URL;

Step 4: Confirm successful registration ​

The following traits denote a successful registration:

  1. The deposit contract tx was successful (check block explorer or observe the cast command’s output).
  2. The balance in the funding account (wallet that sent the deposit contract tx) decreased by the 10,000 $BERA
  3. Most importantly, the validator's public key is present in the beacon state. The beacon state (available from your node’s beacon API at curl http://localhost:3500/eth/v1/beacon/states/head/validators | jq .data) should show your validator’s public key, likely at the end of the list. The validator registration is reflected in the Beacon Chain 2 blocks after the deposit contract transaction is processed. NOTE: the beacon API must be enabled on your node (in app.toml : [beacon-kit.node-api]).

Step 5: Activation or top-up ​

Having completed the registration, you can now deposit additional $BERA. The floor for becoming a validator is 250,000 $BERA, and you must be among the top 69 validators, ordered by $BERA staked.

These subsequent deposits are done by calling the same deposit function, with only the public key required; the other elements may be zero, but must still be the right length.

When your validator passes the threshold necessary to become active, it passes into the Activation part of the lifecycle. At the conclusion of second epoch after you pass the threshold -- in other words, no sooner than 13 minutes -- you become eligible for minting blocks.

bash
STAKE_AMOUNT_ETH=240000;

cast send "0x4242424242424242424242424242424242424242" \
'deposit(bytes,bytes,bytes,address)' \
"$VAL_PUB_KEY" \
"0x0000000000000000000000000000000000000000000000000000000000000000" \
"0x000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000" \
"0x0000000000000000000000000000000000000000" \
--ledger \
--value "${STAKE_AMOUNT_ETH}ether" \
-r $RPC_URL;

Post-activation checks ​

After 2+ epochs after your activation deposit, do the following checks:

  1. beacond status. Verify that the voting power is equal to the effective balance. If voting power is 0, the node is NOT active.
  2. your operator address received $BGT when it produces blocks (this will take a few hours).
  3. The comet API on the node will confirm your validator's presence in the set. Look for your validator's public key in the list of validators:
bash
$ curl  http://localhost:26657/validators?page=1&per_page=100 | jq .

# [Example Output]:
# {
#   "jsonrpc": "2.0",
#   "id": -1,
#   "result": {
#     "block_height": "477021",
#     "validators": [
#       {
#         "address": "5951C4349AB792BFB3A63956512663CC3B733D6E",
#         "pub_key": {
#           "type": "cometbft/PubKeyBls12_381",
#           "value": "A/1TcQt1whFb0KrBKLc565+p4mJgPazfg0Awq7G/TIpsALtysxTBI9d/T/QM1NSaCgz/u+e0aLH/zEKYQWYVBMJAky+Kn4V3JX6562r5yJbCh0BqLLKStdeAXwGO0j+n"
#         },
#         "voting_power": "10000000000000000",
#         "proposer_priority": "12250000000000000"
#       },
#       {
#         "address": "9DB42D740B0D0C6A08543D679BF50CED94CA8E3C",
#         "pub_key": {
#           "type": "cometbft/PubKeyBls12_381",
#           "value": "A9D5DN7arBRQyNwIz6ZErgL1kYVyBBwvyn34tVM2aCy17bzK3W53Ep3kJYROFH0CBYU5e8fS/pywwNjC9RqT+Pz/2yGRQA1Dy5mGRXivGiRggXVWcFQzFpHk7upct4tt"
#         },
#         "voting_power": "10000000000000000",
#         "proposer_priority": "12250000000000000"
#       },
#       ...
#     ],
#     "count": "69",
#     "total": "69"
# }

Steps After Becoming A Validator ​

Perform the following steps after becoming a validator.

Step 1 - Add To Default Validator List ​

Make a PR to the following GitHub repository to add your validator to the validator list on the Berachain Hub.

https://github.com/berachain/metadata

If you have a logo you'd like us to use, attach it to the pull request according to the instructions in https://github.com/berachain/metadata/blob/main/CONTRIBUTING.md.

Step 2 - Send Berachain Team Wallet Addresses ​

Reach out to the Berachain validator relations team with your validator's CometBFT public keys to help us find you if your node begins having trouble, hopefully before it gets slashed. If you aren't known to the validator relations team, speak up on the #node-support channel on our Discord.

Send us the output of beacond deposit validator-keys.