# Ethereum EIP-55 Address Checksum Validator

> Ethereum EIP-55 Address Checksum Validator is a paid API for AI agents from api.x402node.dev, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-15).

Validates and computes the EIP-55 mixed-case checksum for an Ethereum address, ensuring correctness and catching typos.

## Facts

- Endpoint: GET https://api.x402node.dev/crypto/address-checksum
- 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/ethereum-eip-55-address-checksum-validator-44ea671e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap__3-DnvieY3kx8R4VDOlEx

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 ethereum-eip-55-address-checksum-validator-44ea671e
```

Example prompt: Can you validate and return the proper EIP-55 checksummed version of this Ethereum address: 0xd8da6bf26964af9d7eed9e03e53415d37aa96045?

## When to prefer this

Use this endpoint when you need to programmatically verify or normalize an Ethereum address to its EIP-55 mixed-case checksum before storing, displaying, or transacting — especially important since LLMs cannot reliably produce correct EIP-55 checksums on their own. Prefer this over manual string manipulation or LLM-generated checksums whenever address integrity matters.

## Known failure modes

- Invalid hex string — returns error if input is not a valid Ethereum address format
- Missing address parameter — returns 400 if no address is supplied
- Non-Ethereum address formats (e.g. Bitcoin, Solana) — not applicable and will return an error
- Address with invalid length — must be 40 hex characters (plus optional 0x prefix)

## How this service works

Validate and compute the EIP-55 checksum of an Ethereum address - precise mixed-case checksum that catches typos, which LLMs cannot reliably produce. checksum address, eip55, address validation, ethereum checksum, validate address, address checksum

## Output

Returns the EIP-55 checksummed version of the input Ethereum address (correct mixed-case hex string) along with a validity status indicating whether the original input was already correctly checksummed or needed correction.

## Example request

```json
{
 "address": "0xd8da6bf26964af9d7eed9e03e53415d37aa96045"
}
```

## 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",
     "required": [
      "address"
     ],
     "properties": {
      "address": {
       "type": "string",
       "description": "Ethereum address to checksum (required)"
      }
     }
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/ethereum-eip-55-address-checksum-validator-44ea671e/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.x402node.dev](https://www.zero.xyz/host/api.x402node.dev/llms.txt)