Sending OUSD (or other ERC-20s)

Sending OUSD, or other ERC-20 tokens, is one of the most common actions taken by wallet users on Ethereum-based chains. This guide will walk you through how to format the transaction input data for these tokens, using OUSD as an example.

1. Get the OUSD contract address

OUSD is an ERC-20-compatible token on Tempo. Its contract address on Tempo mainnet is 0x20c0000000000000000000006a37da5c996874be. The examples below use Tempo mainnet (chain ID 4217). For network setup, refer to Using Tempo with Privy.

2. Format the transaction send input data

OUSD, and other ERC-20 tokens, are smart contracts. In order to send these tokens, your transaction needs to call the transfer function on the contract, which takes in two parameters:

to: The address of the recipient
value: The amount of tokens to send

When formatting the transaction input data, you must define the expected interface of the function you’re calling by providing an ABI. You can use helper packages like viem to provide the ABI and encode the function parameters. Additionally, each ERC-20 token defines a decimals value, which is the number of decimal places for the token. For OUSD, the decimals value is 6, but for most other ERC-20 tokens, it’s 18.

First, install the viem package if it is not installed yet.

npm install viem

Then, build the transaction input data.

import {encodeFunctionData, erc20Abi} from 'viem';

const recipientAddress = '0x...';
const amountToSend = 1; // Sender wants to send 1 OUSD
const decimals = 6; // OUSD has 6 decimals

const encodedData = encodeFunctionData({
  abi: erc20Abi,
  functionName: 'transfer',
  args: [recipientAddress, BigInt(amountToSend * 10 ** decimals)]
});

3. Send the transaction

You can send the transaction using the Privy API. Below are examples for React, React Native, and NodeJS; you can find other SDKs’ send transaction examples in the Send a transaction guide. You’ve successfully sent OUSD!

​1. Get the OUSD contract address

​2. Format the transaction send input data

​3. Send the transaction

1. Get the OUSD contract address

2. Format the transaction send input data

3. Send the transaction