# Delx Commerce — EVM Address Checksum Validator

> Delx Commerce — EVM Address Checksum Validator is a paid API for AI agents from commerce.delx.ai, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-01).

Validates and returns the ERC-55 keccak256 checksummed (mixed-case) version of an EVM address, confirming validity and whether it matches the input.

## Facts

- Endpoint: POST https://commerce.delx.ai/api/v1/x402/address-checksum-evm?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-01
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/delx-commerce-evm-address-checksum-validator-d0ddfa2b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Wc02ZbbFwEb2NNDHW3Bzf

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 delx-commerce-evm-address-checksum-validator-d0ddfa2b -d '<json body>'
```

Example prompt: Can you validate and return the proper ERC-55 checksummed version of this Ethereum address: 0x95222290dd7278aa3ddd389cc1e1d165cc4bafe5?

## When to prefer this

Use this endpoint when you need a fast, pay-per-call (no signup, no API key) ERC-55 checksum validation for EVM addresses, especially in agent pipelines that already use the x402 micropayment protocol. Ideal for lightweight, one-off address normalization without managing API credentials.

## Known failure modes

- Invalid or malformed hex string returns valid:false
- Address shorter or longer than 40 hex characters fails validation
- Non-hex characters in address cause rejection
- Payment failure via x402 results in 402 response before processing
- Network timeout if Base or Solana payment rail is congested

## How this service works

Pay-per-result APIs for agents. No signup. Exact price. Verifiable delivery. USDC on Base + Solana via x402.

## Output

Returns a JSON object with: a boolean `valid` indicating if the address is a well-formed EVM address, the `checksum_address` in ERC-55 mixed-case format, the `algorithm` used (keccak256), a `matches_input` boolean indicating whether the input already matched the checksum, and a `schema` identifier string.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "address": {
   "type": "string",
   "description": "EVM address (40 hex chars, optional 0x)."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "valid": true,
  "schema": "delx/util-address-checksum-evm/v1",
  "algorithm": "keccak256",
  "matches_input": true,
  "checksum_address": "0x95222290DD7278Aa3Ddd389Cc1E1d165CC4BAfe5"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/delx-commerce-evm-address-checksum-validator-d0ddfa2b/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from commerce.delx.ai](https://www.zero.xyz/host/commerce.delx.ai/llms.txt)