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Agent402 UK Ethereum Address Validator
x402
Agent402 UK Ethereum Address Validator is a paid API for AI agents from agent402.co.uk, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-13).
Validates that a string is a correctly formatted Ethereum address (0x + 40 hex chars) and returns its lowercase-normalized form
Price / call$0.001
Success—
StatusUnknown
How this service works
Don't burn tokens on deterministic work. Go/no-go jobs first: payout preflight, text firewall (PII/secrets), budget check — then rails, calendars, finmath. x402 USDC on Base. UK + global. agent402.co.uk — not agent402.tools. $0.001–$0.002 USDC on Base. No API keys.
Output
Returns a JSON object with a 'valid' boolean indicating whether the input conforms to the Ethereum address format (0x followed by exactly 40 hexadecimal characters), and a 'normalized' field containing the lowercase version of the address if valid.
Example use cases
Pre-transfer wallet address gate
“The user just pasted their ETH wallet address '0x9eF92B278a3867C429751390Ec427736Eb4baBB2' into the withdrawal form — can you verify it's a properly formatted Ethereum address before I submit the transfer?”
DeFi agent input sanitization
“I'm about to call a smart contract with this address: '0xAbCdEf1234567890abcdef1234567890ABCDEF12' — validate it's a legitimate Ethereum address format and normalize it to lowercase so I can pass it safely.”
User onboarding wallet validation
“A new user signed up and entered '0xGHIJKL1234567890abcdef1234567890abcdef12' as their wallet address — is that a valid Ethereum address or should I ask them to re-enter it?”
Technical details
Endpoint
POSThttps://agent402.co.uk/v1/utils/eth-addressWhen to prefer
Use this endpoint as a lightweight format gate immediately before any on-chain Ethereum operation, user input acceptance, or address storage step. Prefer it over rolling your own regex validation to ensure consistent hex-format and length rules. It also normalizes casing, reducing downstream checksum errors. Not a substitute for on-chain account existence checks or EIP-55 checksum validation — use it purely for structural format gating.
Side effects
- Address missing '0x' prefix — valid returns false
- Address has wrong length (not 40 hex chars after 0x) — valid returns false
- Address contains non-hex characters — valid returns false
- Malformed or missing 'address' field in request body — likely 400 error
- Empty string input — valid returns false
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| address | string | 0x address |
Output
Schema · Response
{
"type": "json",
"example": {
"valid": true,
"normalized": "0x9ef92b278a3867c429751390ec427736eb4babb2"
}
}Tags
x402
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