# Keyronne Chain Balance

> Keyronne Chain Balance is a paid API for AI agents from keyronne.com, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-15).

Fetches native coin and ERC-20 token balances for any wallet address on Ethereum, Base, Arbitrum, Optimism, Polygon, or BNB Chain

## Facts

- Endpoint: POST https://keyronne.com/api/chain-balance
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/keyronne-chain-balance-16e94d34
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_V166SCqfK0XH-IZxS1G3Z

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 keyronne-chain-balance-16e94d34 -d '<json body>'
```

Example prompt: What's the ETH balance and USDC token balance (contract 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48) for wallet 0xB86F95EF5FA904318Ea9Df3b59AdCe099b478fC4 on Ethereum?

## When to prefer this

Use this endpoint when you need on-chain balance data for EVM-compatible wallets across the six supported chains (Ethereum, Base, Arbitrum, Optimism, Polygon, BNB Chain) without managing your own RPC nodes or API keys. It is ideal for agents that need both native coin and multiple ERC-20 token balances in a single call, returned in both raw and human-readable formats. Prefer alternatives if you need chains beyond the six supported, need historical balance snapshots, or require NFT/ERC-721 balances.

## Known failure modes

- Invalid or malformed wallet address returns an error
- Unsupported chain name returns validation error
- More than 10 token contract addresses provided triggers a schema rejection
- Invalid ERC-20 contract address (e.g. not a token contract) may return zero balance or RPC error
- RPC node unavailability may cause timeout or 5xx error
- Payment not received (x402) returns 402 Payment Required

## How this service works

Native coin balance for any address on Ethereum, Base, Arbitrum, Optimism, Polygon, or BNB Chain, plus ERC-20 token balances (pass up to 10 contract addresses). Reads public chain state over JSON-RPC; no API keys. Amounts given raw and human-formatted. POST a JSON body like: {"chain":"base","address":"0xB86F95EF5FA904318Ea9Df3b59AdCe099b478fC4"}

## Output

Returns native coin balance and up to 10 ERC-20 token balances for the requested wallet, each given in both raw (wei/smallest unit) and human-readable decimal format.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "chain": {
   "enum": [
    "ethereum",
    "base",
    "arbitrum",
    "optimism",
    "polygon",
    "bsc"
   ],
   "type": "string"
  },
  "tokens": {
   "type": "array",
   "items": {
    "type": "string"
   },
   "maxItems": 10,
   "description": "ERC-20 contract addresses to also read."
  },
  "address": {
   "type": "string",
   "description": "Wallet address (0x + 40 hex)."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/keyronne-chain-balance-16e94d34/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from keyronne.com](https://www.zero.xyz/host/keyronne.com/llms.txt)