# CDP Wallet Balance Lookup

> CDP Wallet Balance Lookup is a paid API for AI agents from x402-gateway-production-1f21.up.railway.app, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-10).

Returns the ETH and USDC token balances for a given wallet address on Base (eip155:8453) or Ethereum mainnet (eip155:1).

## Facts

- Endpoint: GET https://x402-gateway-production-1f21.up.railway.app/wallet-balance/cdp?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-10
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/cdp-wallet-balance-lookup-feaee9b4
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_NUSP_UglTMGSPZ_ajXukV

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability cdp-wallet-balance-lookup-feaee9b4
```

Example prompt: What are the ETH and USDC balances for wallet address 0xAbCd1234...5678 on the Base network?

## When to prefer this

Use this endpoint when you need a quick, machine-payable lookup of ETH and USDC balances for any EVM-compatible wallet on Base or Ethereum mainnet, especially in agent workflows where micropayment-based access (x402) is already in use and you want a lightweight alternative to running your own RPC node or integrating a full blockchain SDK.

## Known failure modes

- Invalid or malformed address (not matching ^0x[a-fA-F0-9]{40}$) returns an error
- Unsupported chain ID (anything other than eip155:8453 or eip155:1) returns an error
- Payment failure (insufficient USDC or x402 protocol error) blocks the request
- Network or RPC node downtime may cause timeout or empty response
- Newly funded wallets may have a short propagation delay before balance reflects

## How this service works

List a wallet's native ETH and USDC balances with human-readable amounts. Canonical wallet-balance contract for autonomous agents: address plus optional CAIP-2 chain.

## Output

A JSON object containing the queried wallet address and an array of token balances, each with a symbol (e.g. 'ETH', 'USDC') and a numeric amount representing the current on-chain balance.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "address"
     ],
     "properties": {
      "chain": {
       "enum": [
        "eip155:8453",
        "eip155:1"
       ],
       "type": "string",
       "default": "eip155:8453",
       "description": "CAIP-2 chain id."
      },
      "address": {
       "type": "string",
       "pattern": "^0x[a-fA-F0-9]{40}$",
       "description": "The wallet address."
      }
     },
     "additionalProperties": false
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "required": [
      "address",
      "balances"
     ],
     "properties": {
      "address": {
       "type": "string"
      },
      "balances": {
       "type": "array",
       "items": {
        "type": "object",
        "required": [
         "symbol",
         "amount"
        ],
        "properties": {
         "amount": {
          "type": "number"
         },
         "symbol": {
          "type": "string"
         }
        },
        "additionalProperties": false
       }
      }
     },
     "additionalProperties": false
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "address": "0x0000000000000000000000000000000000000000",
  "balances": [
   {
    "amount": 0,
    "symbol": "ETH"
   },
   {
    "amount": 0,
    "symbol": "USDC"
   }
  ]
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/cdp-wallet-balance-lookup-feaee9b4/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-gateway-production-1f21.up.railway.app](https://www.zero.xyz/host/x402-gateway-production-1f21.up.railway.app/llms.txt)