Deposit Contract

Validator deposit contract ABI and address constants

ABI and address constants for Seismic's Eth2-style validator deposit contract.

Overview

The deposit contract is a genesis contract that manages validator deposits for the Seismic network. Validators deposit ETH (minimum 1 ETH, typically 32 ETH) along with their public keys, signatures, and withdrawal credentials to join the validator set.

The contract maintains a Merkle tree of deposits and emits a DepositEvent for each successful deposit.

Constants

DEPOSIT_CONTRACT_ADDRESS

The canonical deposit contract address, deployed at a fixed genesis address on all Seismic networks.

from seismic_web3 import DEPOSIT_CONTRACT_ADDRESS

# Genesis address matching Ethereum's deposit contract
DEPOSIT_CONTRACT_ADDRESS: str = "0x00000000219ab540356cBB839Cbe05303d7705Fa"

DEPOSIT_CONTRACT_ABI

Complete ABI for the IDepositContract interface.

from seismic_web3 import DEPOSIT_CONTRACT_ABI

DEPOSIT_CONTRACT_ABI: list[dict[str, Any]]

Import

from seismic_web3 import (
    DEPOSIT_CONTRACT_ABI,
    DEPOSIT_CONTRACT_ADDRESS,
)

ABI Contents

Functions

Function	Parameters	Returns	Description
deposit()	node_pubkey, consensus_pubkey, withdrawal_credentials, node_signature, consensus_signature, deposit_data_root	None	Deposit ETH to become a validator (payable)
get_deposit_count()	None	bytes	Get total number of deposits (view)
get_deposit_root()	None	bytes32	Get Merkle root of all deposits (view)
supportsInterface()	interfaceId	bool	Check ERC-165 interface support (pure)

Events

Event	Parameters	Description
DepositEvent	node_pubkey, consensus_pubkey, withdrawal_credentials, amount, node_signature, consensus_signature, index	Emitted on successful deposit

Full ABI

DEPOSIT_CONTRACT_ABI: list[dict[str, Any]] = [
    {
        "type": "function",
        "name": "deposit",
        "inputs": [
            {"name": "node_pubkey", "type": "bytes", "internalType": "bytes"},
            {"name": "consensus_pubkey", "type": "bytes", "internalType": "bytes"},
            {
                "name": "withdrawal_credentials",
                "type": "bytes",
                "internalType": "bytes",
            },
            {"name": "node_signature", "type": "bytes", "internalType": "bytes"},
            {"name": "consensus_signature", "type": "bytes", "internalType": "bytes"},
            {
                "name": "deposit_data_root",
                "type": "bytes32",
                "internalType": "bytes32",
            },
        ],
        "outputs": [],
        "stateMutability": "payable",
    },
    {
        "type": "function",
        "name": "get_deposit_count",
        "inputs": [],
        "outputs": [{"name": "", "type": "bytes", "internalType": "bytes"}],
        "stateMutability": "view",
    },
    {
        "type": "function",
        "name": "get_deposit_root",
        "inputs": [],
        "outputs": [{"name": "", "type": "bytes32", "internalType": "bytes32"}],
        "stateMutability": "view",
    },
    {
        "type": "function",
        "name": "supportsInterface",
        "inputs": [
            {"name": "interfaceId", "type": "bytes4", "internalType": "bytes4"},
        ],
        "outputs": [{"name": "", "type": "bool", "internalType": "bool"}],
        "stateMutability": "pure",
    },
    {
        "type": "event",
        "name": "DepositEvent",
        "inputs": [
            {
                "name": "node_pubkey",
                "type": "bytes",
                "indexed": False,
                "internalType": "bytes",
            },
            {
                "name": "consensus_pubkey",
                "type": "bytes",
                "indexed": False,
                "internalType": "bytes",
            },
            {
                "name": "withdrawal_credentials",
                "type": "bytes",
                "indexed": False,
                "internalType": "bytes",
            },
            {
                "name": "amount",
                "type": "bytes",
                "indexed": False,
                "internalType": "bytes",
            },
            {
                "name": "node_signature",
                "type": "bytes",
                "indexed": False,
                "internalType": "bytes",
            },
            {
                "name": "consensus_signature",
                "type": "bytes",
                "indexed": False,
                "internalType": "bytes",
            },
            {
                "name": "index",
                "type": "bytes",
                "indexed": False,
                "internalType": "bytes",
            },
        ],
        "anonymous": False,
    },
]

Usage Examples

Creating a Contract Instance

from seismic_web3 import (
    create_wallet_client,
    DEPOSIT_CONTRACT_ABI,
    DEPOSIT_CONTRACT_ADDRESS,
)

# Create client
w3 = create_wallet_client(
    rpc_url="https://gcp-1.seismictest.net/rpc",
    private_key="0x...",
)

# Create deposit contract instance
deposit_contract = w3.eth.contract(
    address=DEPOSIT_CONTRACT_ADDRESS,
    abi=DEPOSIT_CONTRACT_ABI,
)

Query Deposit Count

# Get total number of deposits
count_bytes = deposit_contract.functions.get_deposit_count().call()

# Decode as little-endian 8-byte integer
count = int.from_bytes(count_bytes[:8], byteorder="little")
print(f"Total deposits: {count}")

Query Deposit Root

# Get current Merkle root
root = deposit_contract.functions.get_deposit_root().call()
print(f"Deposit root: {root.hex()}")

Making a Validator Deposit

from seismic_web3 import (
    make_withdrawal_credentials,
    compute_deposit_data_root,
)

# Prepare deposit data
node_pubkey = bytes.fromhex("...")  # 32-byte ED25519 pubkey
consensus_pubkey = bytes.fromhex("...")  # 48-byte BLS12-381 pubkey
withdrawal_address = "0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266"

# Generate withdrawal credentials
withdrawal_credentials = make_withdrawal_credentials(withdrawal_address)

# Sign deposit data (external signing process)
node_signature = bytes.fromhex("...")  # 64-byte ED25519 signature
consensus_signature = bytes.fromhex("...")  # 96-byte BLS12-381 signature

# Deposit amount (32 ETH in gwei)
amount_gwei = 32_000_000_000

# Compute deposit data root
deposit_data_root = compute_deposit_data_root(
    node_pubkey=node_pubkey,
    consensus_pubkey=consensus_pubkey,
    withdrawal_credentials=withdrawal_credentials,
    node_signature=node_signature,
    consensus_signature=consensus_signature,
    amount_gwei=amount_gwei,
)

# Make deposit (send 32 ETH)
tx_hash = deposit_contract.functions.deposit(
    node_pubkey,
    consensus_pubkey,
    withdrawal_credentials,
    node_signature,
    consensus_signature,
    deposit_data_root,
).transact({
    'value': 32 * 10**18,  # 32 ETH in wei
    'gas': 500_000,
})

print(f"Deposit tx: {tx_hash.hex()}")

Listening to Deposit Events

# Get recent deposit events
events = deposit_contract.events.DepositEvent.get_logs(
    from_block="latest" - 10000,
)

for event in events:
    node_pub = event.args['node_pubkey'].hex()
    consensus_pub = event.args['consensus_pubkey'].hex()
    amount_bytes = event.args['amount']
    index_bytes = event.args['index']

    # Decode amount (little-endian 8-byte gwei)
    amount_gwei = int.from_bytes(amount_bytes[:8], byteorder="little")
    amount_eth = amount_gwei / 10**9

    # Decode index (little-endian 8-byte integer)
    index = int.from_bytes(index_bytes[:8], byteorder="little")

    print(f"Deposit #{index}: {amount_eth} ETH")
    print(f"  Node pubkey: {node_pub[:16]}...")
    print(f"  Consensus pubkey: {consensus_pub[:16]}...")

Check Interface Support

# Check if contract supports ERC-165
interface_id = bytes.fromhex("01ffc9a7")  # ERC-165 interface ID
supported = deposit_contract.functions.supportsInterface(interface_id).call()
print(f"Supports ERC-165: {supported}")

Deposit Requirements

Minimum Deposit

• Minimum: 1 ETH

• Standard validator deposit: 32 ETH

• Amount must be specified in both gwei (for root computation) and wei (for transaction value)

Required Keys

1. Node Public Key (32 bytes)

   • ED25519 public key for node identity

   • Used for node-to-node communication

2. Consensus Public Key (48 bytes)

   • BLS12-381 public key for consensus participation

   • Used for block signing and attestations

Required Signatures

1. Node Signature (64 bytes)

   • ED25519 signature over deposit data

   • Proves ownership of node private key

2. Consensus Signature (96 bytes)

   • BLS12-381 signature over deposit data

   • Proves ownership of consensus private key

Withdrawal Credentials

32-byte ETH1-style withdrawal credentials:

• Format: 0x01 + 11 zero bytes + 20-byte Ethereum address

• Use make_withdrawal_credentials() helper to generate

Deposit Data Root

32-byte SHA-256 hash of the deposit data:

• Computed using SSZ hash tree root

• Use compute_deposit_data_root() helper to compute

• Must match on-chain verification

Deposit Process

1. Generate ED25519 and BLS12-381 key pairs

2. Create withdrawal credentials from Ethereum address

3. Sign deposit message with both private keys

4. Compute deposit data root

5. Call deposit() with all parameters + ETH value

6. Contract verifies signatures and root

7. Contract adds deposit to Merkle tree

8. Emits DepositEvent with deposit details

Security Considerations

Key Management

• Never reuse validator keys across networks

• Store private keys securely (hardware wallet or HSM recommended)

• Back up withdrawal credentials separately

• Use different keys for node and consensus

Withdrawal Address

• Set withdrawal credentials to a secure address you control

• Cannot be changed after deposit (in most configurations)

• Consider using a multi-sig or cold wallet

Deposit Root Verification

• Always verify deposit_data_root matches expected value

• Contract will reject mismatched roots

• Use the provided compute_deposit_data_root() helper

Gas Estimation

• Deposit function requires approximately 300-500k gas

• Set sufficient gas limit to avoid failed deposits

• Failed deposits will revert and refund ETH

When to Use

Use the deposit contract when:

• Becoming a Seismic validator

• Increasing validator stake (additional deposits)

• Building validator onboarding tools

• Monitoring validator deposits

• Verifying deposit Merkle tree

Contract Source

This ABI matches the IDepositContract interface defined in:

contracts/src/seismic-std-lib/DepositContract.sol

See Also

• compute_deposit_data_root() - Compute deposit data root

• make_withdrawal_credentials() - Generate withdrawal credentials

• DIRECTORY_ABI - Viewing key directory

• SRC20_ABI - Privacy token standard

• Client Documentation - Client creation and configuration