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Keccak-256 Hash Calculator
x402
Keccak-256 Hash Calculator is a paid API for AI agents from agent-data-tools.revmesh2074.workers.dev, paid per call via x402, $0.01/call, status unknown (last checked 2026-11-05).
Computes the Keccak-256 hash of a text string or hex bytes, returning the hash and the first 4-byte function selector
Price / call$0.01
Success—
StatusUnknown
How this service works
Keccak hash, keccak256. Keccak-256 hash (the Ethereum hash) of text or of 0x hex bytes, as used for function selectors, event topics and storage slots. Use when building or decoding EVM calls.
Output
A JSON object containing the original input string, the input type (text or hex), the 4-byte function selector (first 4 bytes of the hash, 0x-prefixed), and the full 32-byte keccak256 hash as a 0x-prefixed hex string.
Example use cases
Derive Solidity function selector
“What is the 4-byte function selector for the ERC-20 approve(address,uint256) function? I need the keccak256 hash to verify it matches what's in my contract ABI.”
Compute event topic hash
“Can you give me the keccak256 hash of the Solidity event signature Transfer(address,address,uint256)? I need the topic0 value so I can filter Ethereum logs for ERC-20 transfers.”
Hash arbitrary text or hex data
“Compute the keccak256 hash of the text 'Hello, world!' for me — I want to verify it matches the hash I computed locally.”
Technical details
Endpoint
GEThttps://agent-data-tools.revmesh2074.workers.dev/keccak?utm_source=zero.xyzWhen to prefer
Use this endpoint when you need to compute a Keccak-256 hash on-demand without setting up a local library, particularly for deriving Ethereum/Solidity function selectors and event topic hashes. Ideal for AI agents working with smart contract ABIs, log filtering, or verifying on-chain data. No API key required; pay $0.001 USDC per call via x402.
Side effects
- Input text exceeds 10,000 characters — request rejected
- Missing required 'text' query parameter — returns error
- Invalid 0x-prefixed hex that is malformed — may return error or hash raw bytes
- Payment not received — call is not charged and returns 402
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Output
Schema · Response
{
"type": "json",
"example": {
"input": "transfer(address,uint256)",
"selector": "0xa9059cbb",
"inputType": "text",
"keccak256": "0xa9059cbb2ab09eb219583f4a59a5d0623ade346d962bcd4e46b11da047c9049b"
}
}Tags
x402
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