# DevX Agent Tools – Multichain USDC Balance Checker

> DevX Agent Tools – Multichain USDC Balance Checker is a paid API for AI agents from devx-x402-tools.nextill-pos.workers.dev, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-29).

Returns USDC and native token balances for a crypto address across one or more EVM/Solana chains, paid per-call via x402 USDC on Base.

## Facts

- Endpoint: GET https://devx-x402-tools.nextill-pos.workers.dev/v1/wallet/balances?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/devx-agent-tools-multichain-usdc-balance-checker-8c371b93
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_B2wx0iJfY9mWfN_Lpmyoo

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 devx-agent-tools-multichain-usdc-balance-checker-8c371b93
```

Example prompt: What's the USDC balance for 0xAbC123...def on Base and Ethereum — and is it a contract or regular wallet?

## When to prefer this

Choose this endpoint when you need a quick, keyless, pay-per-call multichain USDC and native balance lookup without setting up your own RPC infrastructure. Ideal for AI agents that need to verify wallet solvency, monitor treasury balances, or audit addresses across multiple chains in a single call. Prefer over self-hosted RPC solutions when low operational overhead matters and call volume is moderate.

## Known failure modes

- Invalid or malformed wallet address returns an error without charge
- Unsupported chain identifier returns an error
- Upstream RPC node unavailability may cause a failed response without charge
- Address with no activity may return zero balances but still succeeds
- Malformed query parameters result in a 400-level error

## How this service works

Pay-per-call utilities for AI agents, no API key or signup: read any web page as clean Markdown ($0.002), link/SEO metadata ($0.001), domain DNS + SPF/DMARC email-security audit ($0.003), ERC-20 token safety pre-check ($0.005), crypto address validation, on-chain payment verification, EIP-681/BIP21/Solana Pay payment requests with QR, multichain USDC balances ($0.01). x402 v2, USDC on Base. Invalid input / upstream failure is never charged.

## Output

Returns a JSON object with the queried address and an array of balance entries per chain, each containing USDC balance (decimal), native token balance (decimal), chain name, native token symbol, and a boolean indicating whether the address is a smart contract.

## 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": {
      "chains": {
       "type": "string"
      },
      "address": {
       "type": "string"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "address": "0x...",
  "balances": [
   {
    "usdc": 12.5,
    "chain": "base",
    "native": 0.01,
    "is_contract": false,
    "native_symbol": "ETH"
   }
  ]
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/devx-agent-tools-multichain-usdc-balance-checker-8c371b93/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from devx-x402-tools.nextill-pos.workers.dev](https://www.zero.xyz/host/devx-x402-tools.nextill-pos.workers.dev/llms.txt)