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Keccak-256 Hash (Ethereum-Compatible)
x402
Keccak-256 Hash (Ethereum-Compatible) is a paid API for AI agents from landingen24h.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-30).
Computes the Ethereum-native Keccak-256 hash of a UTF-8 string or hex bytes, returning the full hash and the 4-byte function selector
Price / call$0.001
Success—
StatusUnknown
How this service works
Landing page para tu negocio en 24 horas: textos, diseño para celular y botón de WhatsApp. Boceto gratis: ves la primera versión antes de pagar. USD 39 de lanzamiento.
Output
Returns a JSON object with: the full 32-byte keccak256 hex digest, the 4-byte Ethereum function selector (first 4 bytes of hash), the number of input bytes processed, and the encoding used. Also notes that this is original Keccak padding, not NIST SHA3-256.
Example use cases
Derive Solidity function selector
“I need the 4-byte function selector for the ERC-20 'transfer(address,uint256)' function — can you run it through Keccak-256 with UTF-8 encoding and give me the selector?”
Hash arbitrary string for Ethereum signing
“Hash the UTF-8 string 'Hello, Ethereum!' with Keccak-256 using the original Keccak padding (not SHA3-256) and give me the full 32-byte hex digest.”
Verify ABI encoding from hex bytes
“I have some hex-encoded bytes '0x7472616e73666572' — can you run them through Keccak-256 with hex encoding and tell me the resulting hash and how many input bytes there were?”
Technical details
Endpoint
POSThttps://landingen24h.com/api/x402/util/keccak?utm_source=zero.xyzWhen to prefer
Choose this endpoint when you need Ethereum-native Keccak-256 (original Keccak padding), NOT NIST SHA3-256 — the two produce different outputs. Ideal for deriving ERC-20/ERC-721 function selectors, computing event topic hashes, or any Web3 use case requiring the exact Keccak variant used by Ethereum's EVM. Costs only $0.001 USDC per call via x402, making it suitable for on-demand hashing in agent pipelines without running local crypto libraries.
Side effects
- Input text exceeds 3500 character limit — truncate or split input
- Invalid encoding value (must be 'utf8' or 'hex') — defaults to utf8 if omitted
- Malformed hex string when encoding is 'hex' — returns error
- Empty input string — may return hash of empty byte array
- Payment failure via x402 protocol — endpoint returns 402 before processing
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| text | string | UTF-8 text, function signature, or hex bytes |
| encoding | string |
Output
Schema · Response
{
"type": "json",
"example": {
"note": "Ethereum Keccak-256 (original Keccak padding, not NIST SHA3-256).",
"encoding": "utf-8",
"selector": "0xa9059cbb",
"keccak256": "0xa9059cbb2ab09eb219583f4a59a5d0623ade346d962bcd4e46b11da047c9049b",
"input_bytes": 25
}
}Tags
x402
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