Address: 0x0000000000000000000000000000000000000400 Related Module: Address conversion utilities The Bech32 precompile provides address format conversion functionality between Ethereum hex addresses and Cosmos bech32 addresses.

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Overview

The Bech32 precompile exposes simple conversion helpers so Solidity contracts can:
  1. Convert an Ethereum address to a Bech32 string with a desired prefix (e.g. cosmos).
  2. Convert any Bech32 address string back into an EVM address.
It is a thin wrapper around the Cosmos address‐conversion library and lives at 0x0000000000000000000000000000000000000400.

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Gas Costs

Both methods use a configurable base gas amount that is set during chain initialization. The gas cost is fixed regardless of string length within reasonable bounds.

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Primary Methods

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hexToBech32

Signature: hexToBech32(address addr, string memory prefix) → string memory Description: Converts an Ethereum hex address to Cosmos bech32 format using the specified prefix. 
import { ethers } from "ethers";

// Connect to the network
const provider = new ethers.JsonRpcProvider("<RPC_URL>");

// Precompile address and ABI
const precompileAddress = "0x0000000000000000000000000000000000000400";
const precompileAbi = [
  "function hexToBech32(address addr, string memory prefix) returns (string memory)"
];

// Create a contract instance
const contract = new ethers.Contract(precompileAddress, precompileAbi, provider);

// Inputs
const ethAddress = "0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045"; // Placeholder
const prefix = "cosmos";

async function convertToBech32() {
  try {
    const bech32Address = await contract.hexToBech32(ethAddress, prefix);
    console.log("Bech32 Address:", bech32Address);
  } catch (error) {
    console.error("Error converting to Bech32:", error);
  }
}

convertToBech32();
Parameters:
  • addr (address): The Ethereum hex address to convert
  • prefix (string): The bech32 prefix to use (e.g., “cosmos”)
Returns: String containing the bech32 formatted address

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bech32ToHex

Signature: bech32ToHex(string memory bech32Address) → address Description: Converts a Cosmos bech32 address to Ethereum hex format. 
import { ethers } from "ethers";

// Connect to the network
const provider = new ethers.JsonRpcProvider("<RPC_URL>");

// Precompile address and ABI
const precompileAddress = "0x0000000000000000000000000000000000000400";
const precompileAbi = [
  "function bech32ToHex(string memory bech32Address) returns (address)"
];

// Create a contract instance
const contract = new ethers.Contract(precompileAddress, precompileAbi, provider);

// Input
const bech32Address = "cosmos1qql8ag4cluz6r4dz22pdenrmwliufqss8c9j0e"; // Placeholder

async function convertToHex() {
  try {
    const hexAddress = await contract.bech32ToHex(bech32Address);
    console.log("Hex Address:", hexAddress);
  } catch (error) {
    console.error("Error converting to Hex:", error);
  }
}

convertToHex();
Parameters:
  • bech32Address (string): The bech32 formatted address to convert
Returns: Ethereum address in hex format

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Full Interface & ABI

Bech32 Solidity Interface
// SPDX-License-Identifier: LGPL-3.0-only
pragma solidity >=0.8.17;

/// @dev The Bech32I contract's address.
address constant Bech32_PRECOMPILE_ADDRESS = 0x0000000000000000000000000000000000000400;

/// @dev The Bech32I contract's instance.
Bech32I constant BECH32_CONTRACT = Bech32I(Bech32_PRECOMPILE_ADDRESS);

interface Bech32I {
    function hexToBech32(address addr,string memory prefix) external returns (string memory bech32Address);
    function bech32ToHex(string memory bech32Address) external returns (address addr);
}
Bech32 ABI
{
  "_format": "hh-sol-artifact-1",
  "contractName": "Bech32I",
  "sourceName": "solidity/precompiles/bech32/Bech32I.sol",
  "abi": [
    {
      "inputs": [
        { "internalType": "string", "name": "bech32Address", "type": "string" }
      ],
      "name": "bech32ToHex",
      "outputs": [
        { "internalType": "address", "name": "addr", "type": "address" }
      ],
      "stateMutability": "nonpayable",
      "type": "function"
    },
    {
      "inputs": [
        { "internalType": "address", "name": "addr", "type": "address" },
        { "internalType": "string", "name": "prefix", "type": "string" }
      ],
      "name": "hexToBech32",
      "outputs": [
        { "internalType": "string", "name": "bech32Address", "type": "string" }
      ],
      "stateMutability": "nonpayable",
      "type": "function"
    }
  ],
  "bytecode": "0x",
  "deployedBytecode": "0x",
  "linkReferences": {},
  "deployedLinkReferences": {}
}

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Implementation Details

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Address Validation

Both methods perform validation on the address format:
  • hexToBech32: Validates that the hex address is exactly 20 bytes and the prefix is non-empty
  • bech32ToHex: Validates that the bech32 address contains the separator character “1” and decodes to 20 bytes

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Prefix Handling

For hexToBech32:
  • The prefix parameter determines the human-readable part of the bech32 address
  • Common prefixes include account addresses, validator addresses, and consensus addresses
  • Empty or whitespace-only prefixes result in an error with suggested valid prefixes
For bech32ToHex:
  • The prefix is automatically extracted from the bech32 address
  • No prefix parameter is required as it’s embedded in the address

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State Mutability

While both methods are marked as nonpayable in the ABI, they function as read-only operations and do not modify blockchain state.