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Tempo API method that returns the Keccak-256 hash of the given data. This is the same hashing algorithm used by Ethereum for various purposes.

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Parameters

  • data — the data to hash (hex encoded)

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Response

  • result — the Keccak-256 hash of the input data

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Use case

The web3_sha3 method is useful for:
  • Computing function selectors (first 4 bytes of keccak256 of function signature)
  • Computing event topics
  • General-purpose hashing

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web3_sha3 code examples

const ethers = require('ethers');
const NODE_URL = "CHAINSTACK_NODE_URL";
const provider = new ethers.JsonRpcProvider(NODE_URL);

const sha3Example = async () => {
    // Hash hex-encoded data via RPC
    const hash = await provider.send("web3_sha3", ["0x68656c6c6f"]); // "hello" in hex
    console.log(`Hash of 'hello': ${hash}`);

    // Compare with ethers.js local computation
    const localHash = ethers.keccak256("0x68656c6c6f");
    console.log(`Local hash: ${localHash}`);
    console.log(`Hashes match: ${hash === localHash}`);

    // Compute a function selector
    const transferSelector = await provider.send("web3_sha3", [
      ethers.toUtf8Bytes("transfer(address,uint256)").reduce(
        (hex, byte) => hex + byte.toString(16).padStart(2, '0'),
        '0x'
      )
    ]);
    console.log(`\nTransfer function selector: ${transferSelector.slice(0, 10)}`);
  };

sha3Example();