{"uid":"cap_g7E7Yum5jKdynWy_8ejyd","slug":"swift-bot-labs-evm-selector-lookup-59d627f3","name":"Swift Bot Labs EVM Selector Lookup","description":"62 small, deterministic utility APIs (DNS and e-mail checks, web extraction, EVM decoding, x402 checks, IP math, JSON/CSV, hashing, conversions). No account or API key: pay per call in USDC with x402.","url":"https://x402-toolbox.swiftbotlab.workers.dev/v1/evm/selector-lookup?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET","HEAD"],"type":"string"},"headers":{"type":"object","additionalProperties":{"type":"string"}},"queryParams":{"type":"object","required":["selectors"],"properties":{"selectors":{"type":"string","description":"Selectors/topics, comma separated or array"}},"additionalProperties":false},"discoverable":{"type":"boolean"}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":{"type":"json","example":{"ok":true,"tool":"evm-selector-lookup","result":{"events":{"0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef":[{"verified":true,"signature":"Transfer(address,address,uint256)"}]},"functions":{"0xa9059cbb":[{"verified":true,"signature":"transfer(address,uint256)"}]}}}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.005","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":"$0.005/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_VEJhjA6nup39RLaZwGC4f","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.005","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Resolves EVM function selectors (4-byte) and event topics (32-byte) to their human-readable ABI signatures","exampleAgentPrompt":"Can you look up what these EVM selectors mean: 0xa9059cbb and 0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef — I need their ABI signatures.","exampleUseCases":[{"title":"Decode transaction calldata selector","prompt":"I'm analyzing an Ethereum transaction and the calldata starts with 0x23b872dd — can you look up what function that selector maps to?"},{"title":"Identify smart contract event topics","prompt":"I have these two event topic hashes from a contract log: 0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef and 0x8c5be1e5ebec7d5bd14f71427d1e84f3dd0314c0f7b2291e5b200ac8c7c3b925 — what are their Solidity event signatures?"},{"title":"Audit contract interaction signatures","prompt":"During a smart contract audit I found selectors 0x70a08231, 0xa9059cbb, and 0x095ea7b3 in the bytecode — can you resolve all three to their function signatures so I know what they do?"}],"resultDescription":"A JSON object containing matched function signatures and event signatures for each queried selector. Each entry includes the selector/topic hash, a verified flag indicating whether the signature is confirmed, and the human-readable Solidity signature string (e.g. 'transfer(address,uint256)'). Multiple signature matches per selector are possible when collisions exist.","failureModes":["Unknown selector returns empty results array for that hash rather than an error","Malformed selector (wrong length, non-hex) may return a 400 error","Selector not in the database returns ok:true with empty results for that selector","Payment failure (x402) results in 402 response before lookup is attempted","Network timeout on the Cloudflare Worker edge"],"whenToPreferThis":"Choose this endpoint when you need fast, pay-per-use EVM selector and event topic resolution without setting up an account or API key. It supports batch lookups of multiple selectors in a single call and returns verification status alongside signatures. Prefer this over running a local Ethereum node or querying Etherscan's API when you need lightweight, deterministic decoding with USDC micropayment billing via x402.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-31T18:41:28.948Z","isFirstParty":false,"canonicalSlug":"swift-bot-labs-evm-selector-lookup-59d627f3"}