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EVM Wallet Balance Lookup API
x402
EVM Wallet Balance Lookup API is a paid API for AI agents from x402-safe-upgrade-api.onrender.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-12).
Retrieves native and ERC-20 token balances for a given EVM wallet address on Base or Base Sepolia networks.
Price / call$0.02
Success—
StatusUnknown
How this service works
Evidence-backed npm package upgrade decisions for coding agents.
Output
Returns a JSON object containing the wallet's native balance in Wei and, if a token contract address was provided, the ERC-20 token's raw balance and contract address.
Example use cases
DeFi agent pre-trade balance check
“Before executing this swap, check how much ETH and USDC the wallet 0xAbCd...1234 holds on Base mainnet so I know if there's enough to cover the trade.”
Testnet funding verification
“Can you confirm that my testnet wallet 0xDead...Beef on Base Sepolia has received funds? Show me the native balance in Wei.”
Portfolio dashboard balance sync
“Pull the current raw token balance for ERC-20 contract 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 on Base for wallet address 0x9F8F...3321 so I can update my portfolio tracker.”
Technical details
Endpoint
POSThttps://x402-safe-upgrade-api.onrender.com/v1/wallet-balance?utm_source=zero.xyzWhen to prefer
Use this endpoint when you need a quick, paid on-demand balance lookup for a wallet on Base mainnet or Base Sepolia testnet, especially in agentic workflows where trustless, evidence-backed financial state verification is needed before executing transactions or making decisions.
Side effects
- Invalid or malformed 0x address returns an error
- Unsupported chain value (not 'base' or 'base-sepolia') causes rejection
- Invalid ERC-20 contract address returns token balance as zero or error
- Network connectivity issues with the Base RPC may cause timeouts
- Payment failure (402) if USDC payment is not correctly attached
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| chain | string | |
| address | string | Public 0x-prefixed EVM address. |
| tokenAddress | string | Optional public ERC-20 contract address. |
Output
Schema · Response
{
"type": "json",
"example": {
"token": {
"address": "0x...",
"balanceRaw": "0"
},
"nativeBalanceWei": "0"
}
}Tags
x402
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