{"uid":"cap_u2pu0byILLd8VhEPB6dys","slug":"keccak-256-hash-f9d6e3e4","name":"Keccak-256 Hash","description":"60 paid endpoints with no metering, no API key and no account. Each endpoint has one flat price per call, whatever the size of the request: LLM completions with automatic failover across several large models, read-only EVM tooling over Base, Ethereum, Polygon, Arbitrum and Optimism, and pure crypto utilities that touch no network.","url":"https://flat-rate-llm.kikoribera03.workers.dev/v1/util/keccak256","method":"POST","headers":{},"bodySchema":{"type":"object","required":["input"],"properties":{"input":{"type":"string","description":"Plain text, or a 0x-prefixed hex payload to hash as bytes."}}},"responseSchema":{"type":"object","properties":{"hash":{"type":"string"},"bytes":{"type":"number"}}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.0025","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.0025/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.0025","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.0025","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_7PSzeCHF4JKBusWxgy00y","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.0025","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Computes the Keccak-256 hash of any string or hex-encoded byte payload — the specific hash function Ethereum uses internally, distinct from SHA3-256.","exampleAgentPrompt":"What's the Keccak-256 hash of the string 'Transfer(address,address,uint256)'? I need the Ethereum-style hash, not SHA3.","exampleUseCases":[{"title":"Derive Ethereum function selector","prompt":"Give me the Keccak-256 hash of 'transfer(address,uint256)' so I can extract the first 4 bytes as the ERC20 function selector."},{"title":"Compute CREATE2 salt hash","prompt":"I need the Keccak-256 hash of this hex payload 0xdeadbeef1234 to use as a salt when computing a CREATE2 contract address."},{"title":"Get Solidity event topic hash","prompt":"Hash the event signature 'Transfer(address,address,uint256)' with Keccak-256 so I can identify this event's topic0 in Ethereum logs."}],"resultDescription":"Returns a JSON object with a `hash` field containing the 0x-prefixed Keccak-256 hex digest and a `bytes` field indicating the byte length of the input that was hashed.","failureModes":["Missing or empty `input` field returns an error response","Malformed 0x-prefixed hex (odd length or invalid characters) may cause a parsing error","Very large payloads may time out or be rejected","Network errors or Cloudflare Worker cold-start failures return non-2xx HTTP status"],"whenToPreferThis":"Choose this endpoint when you need the exact Keccak-256 hash that Ethereum uses natively — for computing function selectors, event topic hashes, CREATE2 address salts, or any on-chain hash verification. Do not substitute SHA3-256 (NIST), which produces different output. Prefer this over running a local hash library when operating inside an agent workflow that already uses x402 micropayments.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T19:00:17.355Z","isFirstParty":false}