Address Precompile

Address: 0x0000000000000000000000000000000000001004

The Sei Address precompile allows EVM applications to interact directly with Sei’s address association system through standard smart contract calls. This enables querying and creating mappings between EVM addresses and their corresponding Cosmos addresses, enabling seamless cross-chain address management without needing separate Cosmos SDK integration.

What is a precompile? A precompile is a special smart contract deployed at a fixed address by the Sei protocol itself, that exposes custom native chain logic to EVM-based applications. It acts like a regular contract from the EVM’s perspective, but executes privileged, low-level logic efficiently.

How Does the Address Precompile Work?

The Address precompile at address 0x0000000000000000000000000000000000001004 exposes functions like associate(), associatePubKey(), getSeiAddr(), and getEvmAddr().

Direct Integration: EVM contracts and dApps can call address association functions like any other smart contract method.
Native Execution: Operations are executed at the Cosmos SDK level for maximum efficiency and security.
Seamless Bridge: No need for separate wallet integrations or complex cross-chain interactions.

Use Cases

Cross-Chain Identity: Link EVM and Cosmos addresses for unified user experiences across both execution environments.
Address Resolution: Build applications that can seamlessly work with both EVM and Cosmos address formats.
Wallet Integration: Enable users to associate their addresses once and use both EVM and native Sei functionality.
DeFi Applications: Create protocols that can interact with users regardless of their preferred address format.

What You’ll Learn in This Guide

By the end of this guide, you’ll be able to:

Integrate Address Operations - Call association and lookup functions directly from your EVM contracts and dApps
Handle Signature Verification - Master the signature format requirements for secure address association
Manage Address Mappings - Query and validate address relationships between EVM and Cosmos formats
Build Cross-Chain Tools - Implement unified address management for applications spanning both execution environments
Navigate Association Requirements - Understand when and how address association occurs automatically vs. manually

Functions

The Address precompile exposes the following functions:

Transaction Functions


/// Associates an account given it's signature of any custom message.
/// @param v The v component of the signature.
/// @param r The r component of the signature.
/// @param s The s component of the signature.
/// @param customMessage A custom message that was signed by the address to be associated.
/// @return seiAddr The associated Sei address.
/// @return evmAddr The associated EVM address.
function associate(
    string memory v,
    string memory r,
    string memory s,
    string memory customMessage
) external returns (string memory seiAddr, address evmAddr);
 
/// Associates an account given it's compressed pubkey in hex format (excluding the '0x')
/// @param pubKeyHex The Hex-encoded compressed pubkey of the account to be associated, excluding the '0x'
/// @return seiAddr The associated Sei address.
/// @return evmAddr The associated EVM address.
function associatePubKey(
    string memory pubKeyHex
) external returns (string memory seiAddr, address evmAddr);

Query Functions


/// Queries the corresponding Sei Address for some EVM address.
/// @param addr The EVM Address for which we want the corresponding Sei address.
/// @return response The corresponding Sei address.
function getSeiAddr(
    address addr
) external view returns (string memory response);
 
/// Queries the corresponding EVM Address for some Sei address.
/// @param addr The Sei Address for which we want the corresponding EVM address.
/// @return response The corresponding EVM address.
function getEvmAddr(
    string memory addr
) external view returns (address response);

Using the Precompile

Setup

Prerequisites

Before getting started, ensure you have:

Node.js (v16 or higher)
npm or yarn package manager
EVM-compatible wallet
SEI tokens for gas fees
Hardhat development environment set up

Install Dependencies

Install the required packages for interacting with Sei precompiles:


# Intitate a hardhat project
npx hardhat init
 
# Install ethers.js for smart contract interactions
npm install ethers dotenv
 
# Install Sei EVM bindings for precompile addresses and ABIs
npm install @sei-js/precompiles@2.1.2

Setup Hardhat Environment

Create a hardhat.config.js file with the following content:


require('@nomicfoundation/hardhat-toolbox');
require('dotenv').config();
 
/** @type import('hardhat/config').HardhatUserConfig */
module.exports = {
  solidity: '0.8.28',
  networks: {
    sei: {
      url: 'https://evm-rpc.sei-apis.com',
      chainId: 1329,
      accounts: [process.env.PRIVATE_KEY]
    }
  }
};

Create a .env file in the root directory with your private key and RPC URL:


PRIVATE_KEY=your_private_key_here
RPC_URL=https://evm-rpc.sei-apis.com

Import Precompile Components

JavaScript


// Import Address precompile address and ABI
// View the entire ABI here: https://github.com/sei-protocol/sei-chain/tree/main/precompiles/addr
import { ADDRESS_PRECOMPILE_ABI, ADDRESS_PRECOMPILE_ADDRESS } from '@sei-js/precompiles';
import { ethers } from 'ethers';

Precompile Address: The address precompile is deployed at 0x0000000000000000000000000000000000001004

Contract Initialization

JavaScript

Set up your provider, signer, and contract instance:


// Using EVM-compatible wallet as the signer and provider
const provider = new ethers.BrowserProvider(window.ethereum);
await provider.send('eth_requestAccounts', []);
const signer = await provider.getSigner();
 
// Create a contract instance for the addr precompile
const addr = new ethers.Contract(ADDRESS_PRECOMPILE_ADDRESS, ADDRESS_PRECOMPILE_ABI, signer);

When Does Association Happen?

Address association between EVM and Cosmos addresses occurs automatically in most cases:

Method	Trigger	Requirements
Automatic	First transaction broadcast	Wallet signs any transaction
Manual (Signature)	associate() function	Custom message signature
Manual (PubKey)	associatePubKey() function	Compressed public key

How Association Works

Automatic Association:

Occurs when a wallet first signs and broadcasts any transaction on Sei
No additional steps required for most users
Association is permanent once created

Manual Association:

Use associate() for signature-based association
Use associatePubKey() for public key-based association
Useful for advanced applications or when automatic association hasn’t occurred

Address Format Requirements

EVM Addresses:

Standard Ethereum format: 0x1234... (20 bytes, 40 hex characters)
Case-insensitive but typically lowercase

Sei Addresses:

Cosmos format with sei1... prefix for regular addresses
Validator addresses use seivaloper1... prefix
Bech32 encoding format

Step-by-Step Guide: Using the Address Precompile

Associate Address with Signature

JavaScript


// Associate addresses using a custom message signature
const message = `Associate my addresses - ${Date.now()}`;
 
try {
  // Get signature from user's wallet
  const signature = await signer.signMessage(message);
  const sig = ethers.Signature.from(signature);
 
  // Prepare the prefixed message (signMessage already applies this prefix)
  const messageBytes = new TextEncoder().encode(message);
  const customMessage = `\x19Ethereum Signed Message:\n${message}`;
 
  // Convert signature components to strings
  const v = (sig.v - 27).toString();
  const r = sig.r;
  const s = sig.s;
 
  // Call associate function
  const tx = await addr.associate(v, r, s, customMessage);
  const receipt = await tx.wait();
 
  console.log('Association successful:', receipt);
} catch (error) {
  console.error('Association failed:', error);
}

Associate Address with Public Key

JavaScript


// Associate addresses using a public key
try {
  // Create or get a wallet's public key
  const wallet = ethers.Wallet.createRandom();
  const pubKeyWithout0x = wallet.signingKey.compressedPublicKey.slice(2);
 
  // Call associatePubKey function
  const tx = await addr.associatePubKey(pubKeyWithout0x);
  const receipt = await tx.wait();
 
  console.log('Public key association successful:', receipt);
} catch (error) {
  console.error('Public key association failed:', error);
}

Query Sei Address from EVM Address

JavaScript


// Query the Sei address for a given EVM address
const evmAddress = '0x1234567890123456789012345678901234567890';
 
try {
  const seiAddress = await addr.getSeiAddr(evmAddress);
  console.log('Corresponding Sei address:', seiAddress);
} catch (error) {
  if (error.message.includes('not found') || error.message.includes('no association')) {
    console.log('No association found for this EVM address');
  } else {
    console.error('Error querying Sei address:', error);
  }
}

Query EVM Address from Sei Address

JavaScript


// Query the EVM address for a given Sei address
const seiAddress = 'sei1qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq6s8dpw';
 
try {
  const evmAddress = await addr.getEvmAddr(seiAddress);
  console.log('Corresponding EVM address:', evmAddress);
} catch (error) {
  if (error.message.includes('not found') || error.message.includes('no association')) {
    console.log('No association found for this Sei address');
  } else {
    console.error('Error querying EVM address:', error);
  }
}

Complete Integration Example

JavaScript


import { ADDRESS_PRECOMPILE_ABI, ADDRESS_PRECOMPILE_ADDRESS } from '@sei-js/precompiles';
import { ethers } from 'ethers';
 
async function addrExample() {
  // Setup
  const provider = new ethers.BrowserProvider(window.ethereum);
  await provider.send('eth_requestAccounts', []);
  const signer = await provider.getSigner();
  const addr = new ethers.Contract(ADDRESS_PRECOMPILE_ADDRESS, ADDRESS_PRECOMPILE_ABI, signer);
 
  const evmAddress = await signer.getAddress();
 
  try {
    // 1. Check if current EVM address has an associated Sei address
    console.log('=== Checking Current Association ===');
    try {
      const associatedSei = await addr.getSeiAddr(evmAddress);
      console.log('EVM address:', evmAddress);
      console.log('Associated Sei address:', associatedSei);
 
      // Verify reverse lookup
      const reverseEvm = await addr.getEvmAddr(associatedSei);
      console.log('Reverse lookup EVM address:', reverseEvm);
    } catch (error) {
      if (error.message.includes('not found') || error.message.includes('no association')) {
        console.log('No association found. You may need to make a transaction first or associate manually.');
 
        // 2. Demonstrate manual association with public key
        console.log('=== Creating Manual Association ===');
        const wallet = ethers.Wallet.createRandom();
        const pubKeyWithout0x = wallet.signingKey.compressedPublicKey.slice(2);
 
        const associateTx = await addr.associatePubKey(pubKeyWithout0x);
        const receipt = await associateTx.wait();
        console.log('Manual association completed:', receipt.transactionHash);
      } else {
        throw error;
      }
    }
 
    // 3. Demonstrate address resolution for different formats
    console.log('=== Address Resolution Examples ===');
 
    // Test with known Sei address format
    const testSeiAddr = 'sei1qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq6s8dpw';
    try {
      const correspondingEvm = await addr.getEvmAddr(testSeiAddr);
      console.log('Test Sei address:', testSeiAddr);
      console.log('Corresponding EVM address:', correspondingEvm);
    } catch (error) {
      console.log('Test address not associated:', testSeiAddr);
    }
  } catch (error) {
    console.error('Operation failed:', error);
  }
}

Solidity

Contract Example


// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
 
interface IAddrPrecompile {
    function associate(
        string memory v,
        string memory r,
        string memory s,
        string memory customMessage
    ) external returns (string memory seiAddr, address evmAddr);
 
    function associatePubKey(
        string memory pubKeyHex
    ) external returns (string memory seiAddr, address evmAddr);
 
    function getSeiAddr(address addr) external view returns (string memory response);
 
    function getEvmAddr(string memory addr) external view returns (address response);
}
 
contract CrossChainAddressManager {
    IAddrPrecompile constant ADDR = IAddrPrecompile(0x0000000000000000000000000000000000001004);
 
    struct UserProfile {
        address evmAddress;
        string seiAddress;
        bool isVerified;
    }
 
    mapping(address => UserProfile) public userProfiles;
    mapping(string => address) public seiToEvm;
 
    event UserRegistered(address indexed evmAddr, string seiAddr);
    event AddressAssociated(address indexed evmAddr, string seiAddr);
 
    /**
     * @dev Register user with automatic address association lookup
     */
    function registerUser() external {
        address userEvm = msg.sender;
 
        // Try to get associated Sei address
        try ADDR.getSeiAddr(userEvm) returns (string memory seiAddr) {
            // Association exists
            userProfiles[userEvm] = UserProfile({
                evmAddress: userEvm,
                seiAddress: seiAddr,
                isVerified: true
            });
 
            seiToEvm[seiAddr] = userEvm;
            emit UserRegistered(userEvm, seiAddr);
 
        } catch {
            // No association found
            revert("Address not associated. Please associate your addresses first.");
        }
    }
 
    /**
     * @dev Batch query multiple EVM addresses
     */
    function batchGetSeiAddresses(
        address[] memory evmAddresses
    ) external view returns (string[] memory seiAddresses) {
        seiAddresses = new string[](evmAddresses.length);
 
        for (uint256 i = 0; i < evmAddresses.length; i++) {
            try ADDR.getSeiAddr(evmAddresses[i]) returns (string memory seiAddr) {
                seiAddresses[i] = seiAddr;
            } catch {
                seiAddresses[i] = ""; // Empty string if not associated
            }
        }
    }
 
    /**
     * @dev Check if an address pair is associated
     */
    function areAddressesAssociated(
        address evmAddr,
        string memory seiAddr
    ) external view returns (bool) {
        try ADDR.getSeiAddr(evmAddr) returns (string memory result) {
            return keccak256(bytes(result)) == keccak256(bytes(seiAddr));
        } catch {
            return false;
        }
    }
}

Client Integration Example

Deploy the contract:


const { ethers } = require('hardhat');
 
const dotenv = require('dotenv');
dotenv.config();
 
async function main() {
  const provider = new ethers.JsonRpcProvider(process.env.RPC_URL);
  const deployer = new ethers.Wallet(process.env.PRIVATE_KEY, provider);
  console.log('Deploying contracts with the account:', deployer.address);
 
  const balance = await deployer.provider.getBalance(deployer.address);
  console.log('Account balance:', ethers.formatEther(balance));
 
  const AddressManager = await ethers.getContractFactory('CrossChainAddressManager');
  console.log('Deploying AddressManager...', AddressManager);
  const addressManager = await AddressManager.deploy({
    gasLimit: 5000000n // Set a reasonable gas limit
  });
  await addressManager.waitForDeployment();
 
  console.log('AddressManager deployed to:', await addressManager.getAddress());
}
 
main().catch((error) => {
  console.error(error);
  process.exitCode = 1;
});

Then run:


npx hardhat run scripts/deploy.js --network sei


const { ethers } = require('hardhat');
const addressManagerAbi = require('./artifacts/contracts/CrossChainAddressManager.sol/CrossChainAddressManager.json');
 
async function main() {
  const provider = new ethers.JsonRpcProvider(process.env.RPC_URL);
  const deployer = new ethers.Wallet(process.env.PRIVATE_KEY, provider);
  console.log('Deploying contracts with the account:', deployer.address);
 
  const balance = await deployer.provider.getBalance(deployer.address);
  console.log('Account balance:', ethers.formatEther(balance));
 
  const addressManagerAddress = '0xYourAddressManagerContractAddress'; // Replace with your deployed contract address
  const addressManager = new ethers.Contract(addressManagerAddress, addressManagerAbi.abi, deployer);
  console.log('AddressManager deployed to:', await addressManager.getAddress());
 
  // Register user (requires existing address association)
  try {
    const registerTx = await addressManager.registerUser();
    await registerTx.wait();
    console.log('User registered successfully');
 
    // Get user's profile
    const userProfile = await addressManager.userProfiles(deployer.address);
    console.log('User profile:', userProfile);
  } catch (error) {
    console.error('Registration failed:', error);
  }
}
 
main().catch((error) => {
  console.error(error);
  process.exitCode = 1;
});

Security Considerations & Risks

Association Permanence

Permanent Mapping: Once addresses are associated, the mapping cannot be changed or removed
Single Association: Each address can only be associated with one counterpart
Verification: Always verify associations before depending on them in critical operations

Signature Security

Custom Messages: Use unique, timestamped messages to prevent replay attacks
Message Format: Follow exact Ethereum Signed Message format for compatibility

Troubleshooting

Common Issues and Solutions


// Set appropriate gas limits for different operations
const associateTx = await addr.associate(v, r, s, customMessage, {
  gasLimit: 200000 // Association operations
});
 
const pubKeyTx = await addr.associatePubKey(pubKeyHex, {
  gasLimit: 150000 // Public key association
});

Error Code Reference

Error	Cause	Solution
`invalid signature`	Malformed v, r, s components	Verify signature parsing and format
`already associated`	Address already has association	Check existing association instead
`not found`	No association exists	Create association first
`invalid public key`	Malformed public key format	Use compressed format without 0x prefix
`invalid address format`	Wrong address format	Use proper EVM (0x…) or Sei (sei1…) format

Important Notes

Remember: Address associations are permanent and cannot be changed once created!

Address Formats

EVM Addresses: Use standard Ethereum format with 0x prefix
Sei Addresses: Use Cosmos format with sei1 prefix for regular addresses
Case Sensitivity: EVM addresses are case-insensitive, Sei addresses are case-sensitive

Association Timing

Automatic: Most users get associated automatically on their first transaction
Manual: Use precompile functions for programmatic association or when automatic association hasn’t occurred
Verification: Always verify associations exist before depending on them

Signature Requirements

Message Format: Must include Ethereum Signed Message prefix for associate() function
Component Format: v, r, s must be properly formatted hex strings
Replay Protection: Use unique messages to prevent signature replay attacks

Gas Considerations

Association operations: ~200,000 gas limit recommended
Query operations: Standard view function gas usage
Batch operations: Scale gas limits based on array size

View the Address precompile source code and the contract ABI here .

Address Precompile

How Does the Address Precompile Work?

Use Cases

What You’ll Learn in This Guide

Functions

Transaction Functions

Query Functions

Using the Precompile

Setup

Prerequisites

Install Dependencies

Setup Hardhat Environment

Import Precompile Components

JavaScript

Solidity

Contract Initialization

JavaScript

Solidity

When Does Association Happen?

How Association Works

Address Format Requirements

Step-by-Step Guide: Using the Address Precompile

Associate Address with Signature

JavaScript

Solidity

Associate Address with Public Key

JavaScript

Solidity

Query Sei Address from EVM Address

JavaScript

Solidity

Query EVM Address from Sei Address

JavaScript

Solidity

Complete Integration Example

JavaScript

Solidity

Security Considerations & Risks

Association Permanence

Signature Security

Troubleshooting

Common Issues and Solutions

Gas-Related Issues

Error Code Reference

Important Notes

Address Formats

Association Timing

Signature Requirements

Gas Considerations