Integrate Stables

This guide walks through adding support for Mento stable assets in your application. Mento stables are ERC-20 tokens that track the value of fiat currencies. In Mento V3, stables are either reserve-backed (e.g. USDm, EURm), backed by collateral in the Reserve, or CDP-backed (e.g. GBPm), minted via the Liquity v2–style CDP system. For integration purposes they are standard ERC-20s; the backing model does not change how you read balances, transfer, or display values.

Available Stable Assets

Mento supports a growing ecosystem of stable assets that track various fiat currencies, including USD, EUR, BRL, KES, GBP, and many more. Each stable asset is an ERC-20 token that maintains a peg to its respective fiat currency.

For the complete list of available stables and their contract addresses, see:

• Mento Reserve — Live view of all supported stables with supply information

• Deployments > Addresses — Smart contract addresses per chain

Common Use Cases

DeFi Protocols

Accept Mento stables as collateral, enable lending/borrowing, or create liquidity pools with stable pairs.

Wallets

Display balances, enable transfers, and show accurate fiat values for Mento stable assets.

Payment Applications

Process merchant payments, remittances, or payroll using region-specific stable currencies.

Exchanges & Aggregators

List Mento stable pairs for spot trading or include in routing algorithms.

Integration Steps

Step 1: Add Token Contracts

Add the contract addresses for the stables you want to support:

// Example addresses (USDm and EURm on mainnet)
const STABLE_ADDRESSES = {
  USDm: "0x765DE816845861e75A25fCA122bb6898B8B1282a",
  EURm: "0xD8763CBa276a3738E6DE85b4b3bF5FDed6D6cA73",
  // ... add other stables as needed
};

For the complete list of stable addresses across all networks, see Deployments > Addresses.

Step 2: Configure Token Metadata

Add token symbols, decimals, and display information:

const TOKEN_CONFIG = {
  USDm: {
    symbol: "USDm",
    decimals: 18,
    name: "Mento Dollar",
    icon: "path/to/usdm-icon.svg"
  },
  // ... other tokens*
};

Note: All token metadata can be read from the smart contract using standard ERC-20 metadata functions (name(), symbol(), decimals()). Token icons are available in the frontend monorepo.

Step 3: Implement Standard ERC-20 Operations

Use your existing ERC-20 handling for:

• Reading balances: balanceOf(address)

• Transfers: transfer(to, amount)

• Approvals: approve(spender, amount)

• Allowances: allowance(owner, spender)

Step 4: Handle Fiat Display Values

Mento stables maintain a peg with their respective fiat currencies under normal conditions (e.g., 1 USDm ≈ 1 USD, 1 EURm ≈ 1 EUR).

For precise exchange rates, use the pool’s oracle (see Oracles, price feeds & circuit breakers) or the Mento SDK for quotes.

Step 5: Enable cross-stable swaps (optional)

If your application needs to swap between Mento stables, use the Mento SDK to get quotes and build swap transactions against Mento V3 FPMM pools. Swaps execute at the oracle rate (minus fee). See the SDK Guides for getting exchange pairs and initiating a swap, and Swap & liquidity for the user-facing flow.

Working Examples

For complete, runnable examples of integrating Mento stables and swaps, check out the Mento SDK Examples repository. It includes:

• Pair discovery queries

• Swap implementations

• TypeScript examples

Best Practices

Decimal Handling

All Mento stables use 18 decimals. Always use appropriate libraries for decimal math to avoid precision errors.

Gas Optimization

When supporting multiple operations, consider batching transactions or using multicall patterns.

User Experience

• Show both token amounts and fiat values

• Use familiar currency symbols ($, €, R$, CFA)

Network Support

Mento stables are deployed on Celo and other supported chains. For cross-chain use cases, work with official bridges:

• Wormhole (USDm)

• Portal Bridge

Testing

1. Get testnet CELO from the Celo Faucet, then swap for your desired token on the Mento App

2. Use Alfajores testnet addresses for development

3. Test all ERC-20 operations (transfer, approve, etc.)

4. Verify fiat value display matches user expectations

Support

• Discord: #general for any questions

• Token Icons: Available in the frontend monorepo

Next steps

• For swap functionality, see Mento SDK and Swap & liquidity

• For oracle-backed price feeds (V3 OracleAdapter), see Integrate Oracles

• For contract addresses and ABIs, see Deployments and Smart Contracts