XMTP transactions

Send and receive token transactions using wallet_sendCalls (EIP-5792) specification.

When to apply

Reference these guidelines when:

• Sending USDC or other tokens
• Creating transaction requests
• Handling transaction confirmations
• Checking token balances
• Working with smart contract wallets

Rule categories by priority

Priority	Category	Impact	Prefix
1	Send	CRITICAL	send-
2	Receive	CRITICAL	receive-
3	Balance	HIGH	balance-

Quick reference

Send (CRITICAL)

• send-usdc-transfer - Create USDC transfer requests
• send-wallet-calls - Send wallet_sendCalls messages

Receive (CRITICAL)

• receive-transaction-reference - Handle transaction confirmations

Balance (HIGH)

• balance-check - Check USDC balance

Supported networks

Network	Chain ID	USDC Address
Base Sepolia	84532	0x036CbD53842c5426634e7929541eC2318f3dCF7e
Base Mainnet	8453	0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913

Quick start

Use the SDK 2.2.0 transaction helpers with viem chains and bigint amounts:

import {
  createERC20TransferCalls,
  getERC20Balance,
  getERC20Decimals,
  validHex,
} from "@xmtp/agent-sdk";
import { formatUnits, parseUnits } from "viem";
import { base, baseSepolia } from "viem/chains";

const CHAIN = baseSepolia; // or base for mainnet
const USDC_ADDRESS = "0x036CbD53842c5426634e7929541eC2318f3dCF7e"; // Base Sepolia

// Get decimals (e.g. 6 for USDC)
const decimals = await getERC20Decimals({ chain: CHAIN, tokenAddress: USDC_ADDRESS });

// Check balance (returns bigint; format for display)
const balance = await getERC20Balance({
  chain: CHAIN,
  tokenAddress: USDC_ADDRESS,
  address: validHex(address),
});
await ctx.conversation.sendText(`Your balance: ${formatUnits(balance, decimals)} USDC`);

// Create USDC transfer calls (EIP-5792)
const calls = createERC20TransferCalls({
  chain: CHAIN,
  tokenAddress: USDC_ADDRESS,
  from: validHex(fromAddress),
  to: validHex(toAddress),
  amount: parseUnits("1", decimals), // 1 USDC
  description: `Transfer 1 USDC on ${CHAIN.name}`,
});
await ctx.conversation.sendWalletSendCalls(calls);

Implementation snippets

USDC addresses (viem chains):

import { base, baseSepolia } from "viem/chains";

const CHAIN = baseSepolia; // or base
const USDC_ADDRESS = CHAIN.id === 8453
  ? "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913"   // Base Mainnet
  : "0x036CbD53842c5426634e7929541eC2318f3dCF7e";  // Base Sepolia

Get ERC-20 balance (SDK 2.2.0):

import { getERC20Balance, getERC20Decimals } from "@xmtp/agent-sdk";
import { formatUnits } from "viem";

const balance = await getERC20Balance({
  chain: CHAIN,
  tokenAddress: USDC_ADDRESS,
  address: validHex(address),
});
const decimals = await getERC20Decimals({ chain: CHAIN, tokenAddress: USDC_ADDRESS });
const formatted = formatUnits(balance, decimals);

Create ERC-20 transfer calls (SDK 2.2.0):

import { createERC20TransferCalls } from "@xmtp/agent-sdk";
import { parseUnits } from "viem";

const walletSendCalls = createERC20TransferCalls({
  chain: CHAIN,
  tokenAddress: USDC_ADDRESS,
  from: validHex(senderAddress),
  to: validHex(recipientAddress),
  amount: parseUnits("2.5", 6), // 2.5 USDC
  description: "Transfer 2.5 USDC",
});
await ctx.conversation.sendWalletSendCalls(walletSendCalls);

How to use

Read individual rule files for detailed explanations:

rules/send-usdc-transfer.md
rules/receive-transaction-reference.md
rules/balance-check.md