# Polygon PoS Wallet Balance Checker

> Polygon PoS Wallet Balance Checker is a paid API for AI agents from onchaincheck.dev, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-29).

Returns the native POL balance and up to 20 ERC-20 token balances for a given Polygon PoS wallet address, with human-readable formatting using each token's symbol and decimals.

## Facts

- Endpoint: GET https://onchaincheck.dev/polygon/balances?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/polygon-pos-wallet-balance-checker-2ca5d64a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Qmuyyij4DGXkr5flu2esg

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 polygon-pos-wallet-balance-checker-2ca5d64a
```

Example prompt: What's the live POL balance and USDC/LINK token balances for the Polygon PoS wallet 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045? Check ERC-20 contracts 0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359 (USDC) and 0x53E0bca35eC356BD5ddDFebbD1Fc0fD03FaBad39 (LINK).

## When to prefer this

Choose this endpoint when you need live, formatted ERC-20 and native POL balances specifically on the Polygon PoS network, especially when you want multiple token balances in a single call. Prefer it over generic blockchain explorers when you need machine-readable decimal-formatted output without parsing raw wei values yourself. Use it over Ethereum or other chain endpoints when the wallet activity is on Polygon PoS.

## Known failure modes

- Invalid wallet address format returns a validation error (address must match 0x + 40 hex chars)
- Invalid or non-existent ERC-20 contract address may return zero balance or an error
- More than 20 token addresses in the tokens parameter will be rejected
- Network or RPC unavailability may cause timeouts or 5xx errors
- Non-Polygon addresses (e.g. Ethereum mainnet-only contracts) may return zero or unexpected data

## How this service works

Native POL balance of a Polygon PoS wallet plus the balances of up to 20 ERC-20 tokens you list, formatted with each token's symbol and decimals, read live from Polygon PoS.

## Output

A JSON object containing the wallet address, the native POL balance as a human-readable string, and an array of token objects each with: the ERC-20 contract address, symbol, decimals, raw balance integer string, and formatted decimal balance string. All values are read live from Polygon PoS.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "address"
     ],
     "properties": {
      "tokens": {
       "type": "string",
       "pattern": "^(0x[0-9a-fA-F]{40})(,0x[0-9a-fA-F]{40}){0,19}$",
       "description": "Comma-separated ERC-20 contract addresses on Polygon PoS, up to 20"
      },
      "address": {
       "type": "string",
       "pattern": "^0x[0-9a-fA-F]{40}$",
       "description": "Wallet address on Polygon PoS"
      }
     },
     "additionalProperties": false
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "chain": "polygon",
  "tokens": [
   {
    "raw": "9885164",
    "token": "0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359",
    "symbol": "USDC",
    "balance": "9.885164",
    "decimals": 6
   },
   {
    "raw": "2622273351494",
    "token": "0x53E0bca35eC356BD5ddDFebbD1Fc0fD03FaBad39",
    "symbol": "LINK",
    "balance": "0.000002622273351494",
    "decimals": 18
   }
  ],
  "address": "0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045",
  "nativeSymbol": "POL",
  "nativeBalance": "592.719767156691654977"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/polygon-pos-wallet-balance-checker-2ca5d64a/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from onchaincheck.dev](https://www.zero.xyz/host/onchaincheck.dev/llms.txt)