# Synthora ETH Balance (rpc-balance.hergertsynthora.com)

> Synthora ETH Balance (rpc-balance.hergertsynthora.com) is a paid API for AI agents from rpc-balance.hergertsynthora.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-15).

Returns the native ETH balance (in both wei and ETH) for a given address on a specified chain via eth_getBalance, with Ed25519-signed deterministic responses.

## Facts

- Endpoint: POST https://rpc-balance.hergertsynthora.com/service
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/synthora-eth-balance-rpc-balance-hergertsynthora-com-9899d306
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_VQP6MConi6-7B9E8bCaSa

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 synthora-eth-balance-rpc-balance-hergertsynthora-com-9899d306 -d '<json body>'
```

Example prompt: What's the current ETH balance of wallet 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045 on Ethereum mainnet — give me both the wei and ETH amounts?

## When to prefer this

Use this endpoint when you need a cryptographically signed, verifiable ETH native balance (wei + ETH) for a given address and want deterministic results you can audit. Prefer it over generic RPC calls when you need Ed25519-signed proof of the balance, or when cost matters (first 3 calls per wallet are free, and upstream failures are not charged). Best suited for agents that need trusted on-chain balance checks with minimal cost.

## Known failure modes

- Invalid Ethereum address format — returns error, no charge
- Unsupported or unrecognized chain identifier — returns error
- Upstream RPC node failure — returns error with no charge applied
- Missing or malformed X-WALLET header on first 3 free calls — may not apply free tier correctly
- Network timeout or connectivity issue with the upstream node

## How this service works

Native balance (wei + eth) for an address via eth_getBalance. Deterministic, Ed25519-signed.

## Output

Returns the native balance of the specified address in both wei (raw integer) and ETH (decimal), cryptographically signed with Ed25519 for verifiability. Response is deterministic — the same query to the chain state returns the same signed result.

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "niche": "rpc-balance",
  "result": {
   "op": "balance"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/synthora-eth-balance-rpc-balance-hergertsynthora-com-9899d306/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from rpc-balance.hergertsynthora.com](https://www.zero.xyz/host/rpc-balance.hergertsynthora.com/llms.txt)