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x402 Wallet Balance Lookup
x402
x402 Wallet Balance Lookup is a paid API for AI agents from x402tap.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-13).
Returns native token (ETH/MATIC/etc.) and optional ERC-20 token balances for a wallet address on major EVM chains
Price / call$0.01
Success—
StatusUnknown
How this service works
Native and (optional) ERC-20 token balance for a wallet address across major EVM chains (base, ethereum, polygon, arbitrum, optimism)
Output
A JSON object containing the wallet address, the chain name, the native token symbol and balance (e.g. ETH: 1.24), and — if an ERC-20 contract was specified — the token symbol, contract address, decimal precision, and formatted token balance (e.g. USDC: 500.0).
Example use cases
DeFi portfolio balance check
“Can you check how much ETH and USDC (token address 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913) are in my wallet 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045 on Base?”
Pre-transaction liquidity verification
“Before I send a transaction, check if wallet 0xAbCd1234567890abcdef1234567890abcdef1234 has at least some ETH available on Arbitrum — what's its native balance?”
Monitor token holdings on Polygon
“Look up the MATIC balance and the USDT token balance at contract 0xc2132D05D31c914a87C6611C10748AEb04B58e8F for wallet 0x1234abcd5678efgh90ijklmnopqrstuvwxyz1234 on Polygon.”
Technical details
Endpoint
GEThttps://x402tap.com/api/wallet-balance?utm_source=zero.xyzWhen to prefer
Choose this endpoint when you need on-chain wallet balance data across Base, Ethereum, Polygon, Arbitrum, or Optimism in a single call, especially when you also want ERC-20 token balances alongside native balances. It's ideal for agents that need to verify wallet liquidity, check holdings before executing transactions, or enrich user portfolio views. The x402 micropayment model makes it cost-effective for high-frequency per-address lookups.
Side effects
- Invalid or malformed wallet address returns an error response
- Unsupported chain name causes a 400 or error response
- Invalid ERC-20 token contract address returns null or error for the token field
- Network/RPC issues for a specific chain may cause timeouts
- Payment failure (402) if USDC balance is insufficient for the $0.002 call fee
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Output
Schema · Response
{
"type": "json",
"example": {
"chain": "Base",
"token": {
"symbol": "USDC",
"address": "0x8335...",
"balance": "500.0",
"decimals": 6
},
"native": {
"symbol": "ETH",
"balance": "1.24031"
},
"address": "0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045"
}
}Tags
x402
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