# Crypto Wallet Balance Lookup

> Crypto 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 2026-10-11).

Fetches the native and ERC-20 token balances for a given Ethereum or Base wallet address

## Facts

- Endpoint: GET https://x402-gateway-production-1f21.up.railway.app/crypto-wallet-balance?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-11
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/crypto-wallet-balance-lookup-5e263450
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Boj8U2OyKZ6lmJiAZaUJP

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 crypto-wallet-balance-lookup-5e263450
```

Example prompt: What's the current balance of wallet 0xAbCd1234...5678 on Base — including any ERC-20 tokens at contract addresses 0xTokenA and 0xTokenB?

## When to prefer this

Use this endpoint when you need a quick, pay-per-call on-chain balance lookup for any Ethereum or Base wallet without setting up your own RPC node or Web3 infrastructure. It's ideal for AI agents that need real-time token balance data as part of a broader workflow (e.g. portfolio checks, pre-transaction validation, or monitoring), especially when the x402 micropayment model fits the usage pattern better than a subscription-based blockchain data provider.

## Known failure modes

- Invalid or malformed wallet address (not a valid 0x... Ethereum address) returns an error
- Unsupported network value (not 'base' or 'ethereum') returns a validation error
- Invalid ERC-20 contract address in tokens list may cause partial or failed response
- Payment not fulfilled causes a 402 Payment Required response
- Network RPC timeouts or node unavailability may cause delayed or failed responses

## How this service works

Machine-payable x402 utilities for hashing, Base64, UUID generation, unit and timezone conversion, realtime crypto market data, webpage/document extraction, URL-to-Markdown, metadata, RAG ingestion and deterministic website change detection.

## Output

Returns a JSON object with the native token balance and, if ERC-20 contract addresses were supplied, the balance of each specified token for the given wallet address on the requested network (Base or Ethereum).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "address"
     ],
     "properties": {
      "tokens": {
       "type": "string",
       "description": "Optional comma-separated ERC-20 contract addresses."
      },
      "address": {
       "type": "string",
       "pattern": "^0x[a-fA-F0-9]{40}$"
      },
      "network": {
       "enum": [
        "base",
        "ethereum"
       ],
       "type": "string",
       "default": "base"
      }
     },
     "additionalProperties": false
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "status": "ready"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/crypto-wallet-balance-lookup-5e263450/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)