# Tollkit Chain Balance

> Tollkit Chain Balance is a paid API for AI agents from attest.tollkit.dev, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-10).

Retrieves native and ERC-20/SPL token balances for a given wallet or contract address on Base, Ethereum, or Solana, paid per-call via x402 USDC micropayment.

## Facts

- Endpoint: POST https://attest.tollkit.dev/chain/balance?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-10
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/tollkit-chain-balance-15257d71
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_h8gN9mOGp908_mSS-WqNH

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 tollkit-chain-balance-15257d71 -d '<json body>'
```

Example prompt: What's the current ETH and USDC balance for wallet 0xAbC123...def456 on Base? Also include the WETH token at 0x4200...0006.

## When to prefer this

Choose this endpoint when you need a pay-per-call, zero-account-setup balance lookup across Base, Ethereum, or Solana. It is ideal for agents that need on-chain balance data intermittently without committing to an API subscription, or when embedding micropayment-gated blockchain queries in an automated workflow.

## Known failure modes

- Invalid address format returns a validation error
- Unsupported chain value returns an enum mismatch error
- More than 20 token contracts in the tokens array returns an input size error
- Address with no on-chain history may return zero balances
- Micropayment failure via x402 results in a 402 Payment Required response and no balance data
- Network congestion or RPC outage may cause timeouts

## How this service works

Pay-per-call product page extraction. No account, no API key: pay in-band with x402 in USDC on Base or Solana.

## Output

Returns native token balances and, optionally, balances of specified ERC-20 (Ethereum/Base) or SPL (Solana) tokens for the queried address on the selected chain. Includes balance amounts per token contract and the native coin balance.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "chain": {
   "enum": [
    "base",
    "ethereum",
    "solana"
   ],
   "type": "string",
   "default": "base",
   "description": "Which chain to read: \"base\" (default), \"ethereum\" or \"solana\"."
  },
  "tokens": {
   "type": "array",
   "items": {
    "type": "string",
    "pattern": "^(0x[0-9a-fA-F]{40}|[1-9A-HJ-NP-Za-km-z]{32,44})$"
   },
   "maxItems": 20,
   "description": "Extra ERC-20 contracts (or SPL mints on Solana) to include."
  },
  "address": {
   "type": "string",
   "pattern": "^(0x[0-9a-fA-F]{40}|[1-9A-HJ-NP-Za-km-z]{32,44})$",
   "description": "Wallet (or contract) address to check."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/tollkit-chain-balance-15257d71/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from attest.tollkit.dev](https://www.zero.xyz/host/attest.tollkit.dev/llms.txt)