# Web3 Tools – EVM Address EIP-55 Checksum Validator

> Web3 Tools – EVM Address EIP-55 Checksum Validator is a paid API for AI agents from web3-tools.x402tookit.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-21).

Validates an EVM address against its EIP-55 checksum and returns the correctly checksummed form along with a verdict.

## Facts

- Endpoint: GET https://web3-tools.x402tookit.com/evm-address?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-21
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/web3-tools-evm-address-eip-55-checksum-validator-a5817bbd
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_9gjE7PTFLwYqZxSPy2ymh

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 web3-tools-evm-address-eip-55-checksum-validator-a5817bbd
```

Example prompt: Can you validate this Ethereum address and give me the correctly checksummed EIP-55 version: 0x5aaeb6053f3e94c9b9a09f33669435e7ef1beaed?

## When to prefer this

Use this endpoint when you need to verify or normalize an EVM-compatible address (Ethereum, Base, Polygon, etc.) to its EIP-55 checksummed form before using it in a transaction, contract call, or display context. Prefer this over manual regex checks when you also need metadata like zero-address detection or known-special flags.

## Known failure modes

- Missing or malformed address query parameter (not 0x + 40 hex chars) returns an error
- Non-hex characters in address body cause validation failure
- Address shorter or longer than 42 characters rejected
- Payment not included or insufficient USDC causes 402 response
- Network timeout or service degradation returns degraded flag set to true

## How this service works

Check an EVM address (Ethereum, Base, Polygon...) against its EIP-55 checksum and return the correctly checksummed form.

## Output

Returns a JSON object containing: the original input address, the correctly checksummed EIP-55 form, the lowercase form, a boolean checksumVerified flag, a verdict string, a summary, reasons array explaining the result, whether the address is a known special address, whether it is the zero address, a timestamp (asOf), degraded flag, and a disclaimer.

## 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": "0x followed by 40 hex characters"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "asOf": {
       "type": [
        "null",
        "string"
       ]
      },
      "form": {
       "type": [
        "null",
        "string"
       ]
      },
      "input": {
       "type": [
        "null",
        "string"
       ]
      },
      "source": {
       "type": [
        "null",
        "string"
       ]
      },
      "reasons": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "summary": {
       "type": [
        "null",
        "string"
       ]
      },
      "verdict": {
       "type": [
        "null",
        "string"
       ]
      },
      "degraded": {
       "type": [
        "boolean",
        "null"
       ]
      },
      "lowercase": {
       "type": [
        "null",
        "string"
       ]
      },
      "disclaimer": {
       "type": [
        "null",
        "string"
       ]
      },
      "notChecked": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "checksummed": {
       "type": [
        "null",
        "string"
       ]
      },
      "knownSpecial": {},
      "isZeroAddress": {
       "type": [
        "boolean",
        "null"
       ]
      },
      "checksumVerified": {
       "type": [
        "boolean",
        "null"
       ]
      }
     }
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/web3-tools-evm-address-eip-55-checksum-validator-a5817bbd/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from web3-tools.x402tookit.com](https://www.zero.xyz/host/web3-tools.x402tookit.com/llms.txt)