# Delx EIP-55 Checksum Verifier

> Delx EIP-55 Checksum Verifier is a paid API for AI agents from api.delx.ai, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-13).

Checks whether a given EVM address already matches its EIP-55 mixed-case checksum form, returning a deterministic boolean result without any live RPC call

## Facts

- Endpoint: POST https://api.delx.ai/api/v1/x402/eip55-check
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/delx-eip-55-checksum-verifier-592edfa6
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_NW_JR3XxVBT1eyeVfil1F

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-eip-55-checksum-verifier-592edfa6 -d '<json body>'
```

Example prompt: Can you check whether 0x742d35Cc6634C0532925a3b844Bc454e4438f44e is already in valid EIP-55 checksum form?

## When to prefer this

Choose this endpoint when you need a fast, stateless, offline EIP-55 checksum verification with no RPC dependency, no rate limits from a node provider, and no side effects. It is ideal for input hygiene pipelines, smart contract address validation, and pre-flight checks where you only need to know if the address is already correctly checksummed — not to convert or correct it.

## Known failure modes

- Invalid or malformed address string (wrong length, non-hex characters) — likely returns an error or validation failure JSON
- Missing required address field — returns a schema validation error
- Address with incorrect length (not 40 hex chars) — rejected before checksum logic runs

## How this service works

Check whether an address already matches its EIP-55 checksum form — call when verifying an address already matches EIP-55 form. Use for chain input hygiene without live RPC—adjacent to OneSource-class small chain reads, but static/local only so rights and margin stay clear. Returns deterministic machine-readable JSON for $0.003 USDC via x402 on Base. Execution is first-party, local-only, stateless, and memory-only with no paid upstream, no input retention, and no claim of live chain tip, web se…

## Output

A deterministic JSON response indicating whether the provided EVM address already matches its EIP-55 mixed-case checksum encoding — no live chain data, purely local computation. The response is machine-readable and suitable for use as a boolean gate in pipelines.

## 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-eip55-check/v1",
  "expected": "0x95222290DD7278Aa3Ddd389Cc1E1d165CC4BAfe5",
  "algorithm": "keccak256",
  "is_checksummed": true
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/delx-eip-55-checksum-verifier-592edfa6/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.delx.ai](https://www.zero.xyz/host/api.delx.ai/llms.txt)