# EIP-55 Ethereum Address Checksum & Validator

> EIP-55 Ethereum Address Checksum & Validator is a paid API for AI agents from twin.unykorn.org, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-01).

Applies EIP-55 mixed-case checksumming to an Ethereum address and validates whether a given address already has a correct checksum

## Facts

- Endpoint: POST https://twin.unykorn.org/eth-checksum-address?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-01
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/eip-55-ethereum-address-checksum-validator-1b990687
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_A6TQAH8EH_7Gt4ztPRPY6

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 eip-55-ethereum-address-checksum-validator-1b990687 -d '<json body>'
```

Example prompt: Can you checksum this Ethereum address for me: 0x5aaeb6053f3e94c9b9a09f33669435e7ef1beaed — I need the properly EIP-55 formatted version.

## When to prefer this

Choose this endpoint when you need a pay-per-call, API-accessible EIP-55 checksum operation without running your own Ethereum library — especially useful in agent workflows where address normalization is a discrete step and you want an auditable receipt for each call. Prefer it over local computation when you need verifiable, receipted operations on the UnyKorn network.

## Known failure modes

- Invalid or malformed Ethereum address returns an error response
- Non-hex or non-40-character address strings rejected
- Payment failure via x402 protocol results in 402 response before processing
- Network or upstream service unavailability may return 5xx errors

## How this service works

EIP-55 checksum an Ethereum address, and check one — Genesis402 / UnyKorn Operator Network

## Output

Returns a JSON object indicating success, the checksummed or validation result for the provided Ethereum address, along with a receipt containing a transaction hash, USD amount paid, and a unique receipt ID for the pay-per-call transaction.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "params": {
   "type": "object",
   "properties": {
    "address": {
     "type": "string"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "type": "eth-checksum-address",
  "receipt": {
   "tx_hash": "0x<64hex>",
   "amount_usd": 0.001,
   "receipt_id": "g402-<16hex>"
  },
  "generated_at": "<iso8601>"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/eip-55-ethereum-address-checksum-validator-1b990687/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from twin.unykorn.org](https://www.zero.xyz/host/twin.unykorn.org/llms.txt)