# Polyform Crypto Balance Lookup

> Polyform Crypto Balance Lookup is a paid API for AI agents from api.polyform.org, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-02).

Returns the ETH and USDC token balances for a given wallet address on the Base chain

## Facts

- Endpoint: GET https://api.polyform.org/v1/crypto/balance?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/polyform-crypto-balance-lookup-a23ce903
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_EnnimhuKyZlIuORgr82Sl

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 polyform-crypto-balance-lookup-a23ce903
```

Example prompt: What are the current ETH and USDC balances for the Base wallet 0xAbCd1234...? Pay with USDC on Base via x402 at $0.003 per call.

## When to prefer this

Choose this endpoint when you need a quick, no-account, pay-per-call lookup of ETH and USDC balances specifically on the Base network. It is ideal for AI agents using the x402 micropayment protocol that need to avoid API key management. Prefer this over general-purpose blockchain APIs when low overhead and per-call pricing are priorities.

## Known failure modes

- Invalid or malformed wallet address returns an error response
- Address with no activity on Base may return zero balances rather than an error
- Network issues or Base RPC downtime may cause timeout or 5xx errors
- Insufficient x402 USDC payment results in 402 Payment Required response
- Unsupported chain or non-Base addresses may return unexpected results

## How this service works

Pay-per-call data endpoints for AI agents. USDC on Base via x402. No account, no API key — one micropayment per call.

## Output

A JSON object containing the ETH balance (float), USDC balance (float), the chain identifier ('base'), and the queried wallet address. For example: {"eth": 0.5, "usdc": 1200.5, "chain": "base", "address": "0x…"}.

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

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "eth": 0.5,
  "usdc": 1200.5,
  "chain": "base",
  "address": "0x…"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/polyform-crypto-balance-lookup-a23ce903/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.polyform.org](https://www.zero.xyz/host/api.polyform.org/llms.txt)