Account Model

Every account on Monolythium has two addresses -- a Cosmos mono1... address and an EVM 0x... address -- derived from the same private key. This dual-address system enables seamless interaction with both Cosmos SDK modules and EVM smart contracts.

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Dual Address System

A single private key produces both address formats:

Private Key (EthSecp256k1)
    │
    ├── Compress to 33-byte public key
    │
    ├── Keccak256 hash → last 20 bytes → 0x... (EVM address)
    │
    └── RIPEMD160(SHA256(pubkey)) → Bech32 encode → mono1... (Cosmos address)

Both addresses reference the same account. Sending LYTH to either address credits the same balance.

Address Formats

Format	Prefix	Length	Example
Cosmos (Bech32)	mono1	44 characters	mono1qypqxpq9qcrsszg2pvxq6rs0zqg3yyc5lzv7xu
EVM (Hex)	0x	42 characters	0x5aAeb6053F3E94C9b9A09f33669435E7Ef1BeAed
Validator Operator	monovaloper1	~52 characters	monovaloper1qypqxpq9qcrsszg2pvxq6rs0zqg...
Validator Consensus	monovalcons1	~52 characters	monovalcons1qypqxpq9qcrsszg2pvxq6rs0zqg...
Public Key	monopub1	variable	monopub1addwnpepqg...

---

Key Derivation

Monolythium uses EthSecp256k1 keys with HD derivation path m/44'/60'/0'/0/0.

Parameter	Value
Curve	secp256k1
Signing algorithm	EthSecp256k1 (Ethereum-compatible ECDSA)
HD path	m/44'/60'/0'/0/0
Coin type	60
Bech32 prefix	mono

Why Coin Type 60?

Standard Cosmos chains use coin type 118 (the ATOM coin type). Monolythium uses coin type 60 (the Ethereum coin type) because:

1. MetaMask compatibility: MetaMask and other EVM wallets derive keys using coin type 60. Using the same coin type means the same mnemonic produces the same addresses in both Cosmos and EVM wallets.
2. Ledger support: Hardware wallets use the Ethereum app (coin type 60) to sign Monolythium transactions. No custom Ledger app required.
3. Key reuse: A single mnemonic works across the Monolythium Browser Wallet, MetaMask, Keplr, and Ledger -- all producing the same account.

Cosmos Wallet Configuration

When importing a Monolythium mnemonic into Keplr or Leap, make sure to select coin type 60 (not the default 118). Using coin type 118 will derive a different address from the same mnemonic.

Comparison with Standard Cosmos Chains

Property	Standard Cosmos (e.g. ATOM)	Monolythium
Coin type	118	60
HD path	m/44'/118'/0'/0/0	m/44'/60'/0'/0/0
Key algorithm	Secp256k1	EthSecp256k1
Address derivation	SHA256 + RIPEMD160	Keccak256 (last 20 bytes)
EVM compatible	No	Yes
MetaMask support	No	Yes

---

Converting Between Formats

CLI

# Convert any address format to both Cosmos and EVM
monod debug addr mono1qypqxpq9qcrsszg2pvxq6rs0zqg3yyc5lzv7xu

# Output:
# Address bytes: [20-byte hex]
# Address (hex): 0x...
# Address (EIP-55): 0x...
# Bech32 Acc: mono1...
# Bech32 Val: monovaloper1...

# Convert from EVM hex
monod debug addr 0x5aAeb6053F3E94C9b9A09f33669435E7Ef1BeAed

Programmatically (TypeScript)

import { fromBech32, toBech32 } from "@cosmjs/encoding";

// Bech32 → EVM hex
function bech32ToHex(bech32Address: string): string {
  const { data } = fromBech32(bech32Address);
  return "0x" + Buffer.from(data).toString("hex");
}

// EVM hex → Bech32
function hexToBech32(hexAddress: string): string {
  const bytes = Buffer.from(hexAddress.slice(2), "hex");
  return toBech32("mono", bytes);
}

// Examples
const evmAddr = bech32ToHex("mono1qypqxpq9qcrsszg2pvxq6rs0zqg3yyc5lzv7xu");
const cosmosAddr = hexToBech32("0x5aAeb6053F3E94C9b9A09f33669435E7Ef1BeAed");

Programmatically (Go)

package main

import (
    "encoding/hex"
    "fmt"

    "github.com/cosmos/cosmos-sdk/types/bech32"
)

func bech32ToHex(addr string) (string, error) {
    _, bytes, err := bech32.DecodeAndConvert(addr)
    if err != nil {
        return "", err
    }
    return "0x" + hex.EncodeToString(bytes), nil
}

func hexToBech32(hexAddr string) (string, error) {
    bytes, err := hex.DecodeString(hexAddr[2:]) // strip "0x"
    if err != nil {
        return "", err
    }
    return bech32.ConvertAndEncode("mono", bytes)
}

func main() {
    evmAddr, _ := bech32ToHex("mono1qypqxpq9qcrsszg2pvxq6rs0zqg3yyc5lzv7xu")
    fmt.Println("EVM:", evmAddr)

    cosmosAddr, _ := hexToBech32("0x5aAeb6053F3E94C9b9A09f33669435E7Ef1BeAed")
    fmt.Println("Cosmos:", cosmosAddr)
}

---

Account Sequence (Nonce)

Each account has a sequence number that increments with every transaction. This prevents replay attacks.

• The Cosmos sequence and EVM nonce are kept in sync.
• Querying via eth_getTransactionCount returns the same value as monod query auth account.
• Concurrent transactions must be ordered by sequence. Gaps cause rejection.

# Query account info (includes sequence)
monod query auth account mono1abc... --output json

# Query EVM nonce
cast nonce 0xAddress... --rpc-url https://evm.testnet.mononodes.xyz

---

Account Types

Type	Description
Base Account	Standard user account with a keypair
Module Account	Internal accounts owned by SDK modules (e.g., distribution, staking). Cannot be controlled externally.
Contract Account	EVM smart contract. Has code and storage but no private key.

First Transaction

Accounts are created on-chain when they first receive tokens or submit a transaction. There is no explicit account creation step.

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Wallet Compatibility

Because Monolythium uses coin type 60 and EthSecp256k1 keys, the same mnemonic works across:

Wallet	Address Format	Configuration
Monolythium Browser Wallet	Both	Native support
Monolythium Desktop Wallet	Both	Native support
Monolythium Mobile Wallet	Both	Native support
MetaMask	0x...	Add custom network (chain ID 6940/6941)
Trust Wallet	0x...	Add custom network
Keplr	mono1...	Set coin type to 60
Leap	mono1...	Set coin type to 60
Ledger	Both	Use Ethereum app

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Related

• Address Formats -- User guide for address types
• Wallets -- Wallet setup and configuration
• Keyring Setup -- Key storage backends for CLI usage
• JavaScript & TypeScript SDK -- Programmatic account interactions