{"api":"v1","generated_at":"2026-10-02T11:18:04.397Z","licence":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/","attribution":"TOLL, with a link to the page cited"},"page":"https://tollindex.com/e/api-duoleads-com-v1-chain-selector-5aef96","pinned_page":"https://tollindex.com/e/api-duoleads-com-v1-chain-selector-5aef96/at/2026-10-02T05-34Z","pinned":false,"method":"https://tollindex.com/ledger/method","snapshot_at":"2026-10-02T05:34:29.993Z","snapshot_stamp":"2026-10-02T05-34Z","endpoint":{"slug":"api-duoleads-com-v1-chain-selector-5aef96","canonical_url":"https://api.duoleads.com/v1/chain/selector","resource":"https://api.duoleads.com/v1/chain/selector","http_method":"GET","type":"http","x402_version":2,"registries":["cdp"],"primary_registry":"cdp","curated_by_coinbase":false,"description":"Compute the Keccak-256 hash of a Solidity function or event signature and derive the 4-byte function selector and the 32-byte event topic. Normalises the signature first — strips parameter names, expands uint to uint256 and the other aliases, flattens tuples — so a signature copied from source code produces the same selector as the canonical form. Also hashes arbitrary text or hex bytes with Keccak-256.","service_name":"Duo Data Utilities","declared_category":null,"declared_tags":["deterministic","no-api-key","chain","blockchain","solidity"],"route_template":null,"registry_updated":"2026-10-01T20:52:55.585Z"},"derived":{"note":"fields no registry supplies; TOLL derives them and marks them derived on the page","title":"chain selector","category":"market-data","first_observed_by_toll":"2026-09-29T05:42:18.847Z","last_observed_by_toll":"2026-10-02T05:34:29.993Z","observation_began":"2026-09-10"},"presence":{"listed_now":true,"first_absent_at":null,"delisting_confirmed_at":null,"events":[{"registry":"cdp","at":"2026-09-29T05:42:18.848Z","event":"listed"},{"registry":"cdp","at":"2026-10-01T05:50:06.230Z","event":"delisted"},{"registry":"cdp","at":"2026-10-01T13:10:50.124Z","event":"delisting_confirmed"},{"registry":"cdp","at":"2026-10-01T22:40:17.457Z","event":"relisted"}]},"accepts":[{"registry":"cdp","ordinal":0,"network":"eip155:8453","asset":"0x833589fcd6edb6e08f4c7c32d4f71b54bda02913","asset_name":"USD Coin","symbol":"USDC","decimals":6,"amount_display":"0.05 USDC","amount_units":0.05,"decimals_known":true,"pay_to":"0xCD673f7e1daD254347AEab6be0DEFe8b9C6b3A39","scheme":"exact"}],"counters":{"observed_at":"2026-10-02T05:34:29.993Z","calls_30d":2,"unique_payers_30d":1,"last_called_at":"2026-10-01T20:52:55.450Z"},"validation":{"latest":{"observed_at":"2026-09-30T06:58:03.126Z","state":"pass","failed_checks":[],"endpoint_http_status":402,"run_id":"daily-2026-09-30"},"uptime":[{"days":7,"observed":3,"passed":3,"ratio":1},{"days":30,"observed":3,"passed":3,"ratio":1},{"days":90,"observed":3,"passed":3,"ratio":1}],"history_90d":[{"observed_at":"2026-09-30T06:58:03.126Z","state":"pass","failed_checks":[],"run_id":"daily-2026-09-30","state_changed":false},{"observed_at":"2026-09-29T19:16:16.962Z","state":"pass","failed_checks":[],"run_id":"daily-2026-09-29","state_changed":false},{"observed_at":"2026-09-29T17:49:11.379Z","state":"pass","failed_checks":[],"run_id":"new-after-daily-2026-09-28","state_changed":true}]},"seller":{"wallet":"0xCD673f7e1daD254347AEab6be0DEFe8b9C6b3A39","page":"https://tollindex.com/seller/0xCD673f7e1daD254347AEab6be0DEFe8b9C6b3A39","endpoints":33,"hosts":1},"reports":0,"registry_record":{"cdp":[{"tags":["deterministic","no-api-key","chain","blockchain","solidity"],"type":"http","accepts":[{"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","extra":{"name":"USD Coin","version":"2"},"payTo":"0xCD673f7e1daD254347AEab6be0DEFe8b9C6b3A39","amount":"50000","scheme":"exact","network":"eip155:8453","maxTimeoutSeconds":120}],"quality":{"lastCalledAt":"2026-10-01T20:52:55.45Z","l30DaysTotalCalls":2,"l30DaysUniquePayers":1},"resource":"https://api.duoleads.com/v1/chain/selector","extensions":{"bazaar":{"info":{"input":{"type":"http","method":"GET","queryParams":{"signature":"transfer(address,uint256)"}},"output":{"type":"json","example":{"ok":true,"data":{"inputs":["address","uint256"],"topic0":null,"selector":"0xa9059cbb","canonical":"transfer(address,uint256)","keccak256":"0xa9059cbb2ab09eb219583f4a59a5d0623ade346d962bcd4e46b11da047c9049b","normalisations":[]},"meta":{"price_usd":"0.05","disclaimer":"Factual output of a deterministic computation over public data. Provided as is, with no warranty of accuracy, completeness or availability. Not investment, financial, legal, tax, medical or any other professional advice, and not a recommendation. Verify before relying on it. Terms: https://api.duoleads.com/terms","request_id":"01K6B7Q4ZC8H3F2M9WXR5TYN0D","computed_at":"2026-09-28T12:00:00.000Z","deterministic":true},"route":"/v1/chain/selector","version":"1.0.0"}}},"schema":{"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"],"type":"string"},"queryParams":{"type":"object","required":[],"properties":{"data":{"type":"string","maxLength":8192,"description":"Alternative to signature: raw data to Keccak-256 hash."},"kind":{"enum":["function","event","error"],"type":"string","default":"function","maxLength":64,"description":"function (default), event or error."},"encoding":{"enum":["utf8","hex"],"type":"string","default":"utf8","maxLength":64,"description":"Encoding of data: utf8 (default) or hex."},"signature":{"type":"string","maxLength":1024,"description":"Solidity function, event or error signature, e.g. transfer(address to, uint amount)."}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object","required":["ok","route","version","data","meta"],"properties":{"ok":{"const":true},"data":{"type":"object","required":["canonical","keccak256","selector","topic0","inputs","normalisations"],"properties":{"inputs":{"type":["array","null"],"items":{"type":"string"}},"topic0":{"type":["string","null"]},"encoding":{"type":"string"},"selector":{"type":["string","null"]},"canonical":{"type":["string","null"]},"keccak256":{"type":"string"},"input_bytes":{"type":"integer"},"normalisations":{"type":"array","items":{"type":"object","required":["from","to"],"properties":{"to":{"type":"string"},"from":{"type":"string"}}}}}},"meta":{"type":"object","required":["request_id","computed_at","price_usd","deterministic","disclaimer"],"properties":{"sources":{"type":"array","items":{"type":"object","required":["id","version","published"]}},"price_usd":{"type":"string"},"disclaimer":{"type":"string"},"request_id":{"type":"string"},"computed_at":{"type":"string","description":"RFC 3339 UTC with milliseconds"},"deterministic":{"type":"boolean"}}},"route":{"const":"/v1/chain/selector"},"version":{"type":"string"}}}}}}}}},"description":"Compute the Keccak-256 hash of a Solidity function or event signature and derive the 4-byte function selector and the 32-byte event topic. Normalises the signature first — strips parameter names, expands uint to uint256 and the other aliases, flattens tuples — so a signature copied from source code produces the same selector as the canonical form. Also hashes arbitrary text or hex bytes with Keccak-256.","lastUpdated":"2026-10-01T20:52:55.585Z","serviceName":"Duo Data Utilities","x402Version":2}]}}