{"uid":"cap_BEqMYdCMyXi2sN2y2Fim7","slug":"api-existence-oracle-symbol-signature-lookup-3714cd86","name":"API-existence Oracle: Symbol Signature Lookup","description":"Full signature for a symbol in a PyPI or npm package at an exact version: structured params, docstring, deprecation flag with since-version, extracted from the real artifact with signed proof. $0.01 USDC per lookup.","url":"https://attester.dev/v1/symbol/signature","method":"POST","headers":{},"bodySchema":{"$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method","bodyType","body"],"properties":{"body":{"type":"object","required":["ecosystem","package","symbol"],"properties":{"symbol":{"type":"string"},"package":{"type":"string"},"version":{"type":["string","null"]},"ecosystem":{"enum":["pypi","npm"],"type":"string"}}},"type":{"type":"string","const":"http"},"method":{"enum":["POST"],"type":"string"},"bodyType":{"enum":["json"],"type":"string"}},"additionalProperties":false},"output":{"type":"object","required":["example"],"properties":{"example":{"type":"object"}}}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.01","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":"$0.01/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_QMDVAHtWOlNaK1UeuMT7I","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.01","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Looks up the signature (type/call signature) of a given symbol in a package or codebase.","exampleAgentPrompt":"What is the full type signature of the `useState` symbol in the React package? I need to know its parameter types and return value.","exampleUseCases":null,"resultDescription":"Returns the type/call signature of the requested symbol, including parameter names, parameter types, and return type metadata.","failureModes":["Symbol not found in the specified package — returns a not-found or null result","Package not recognized — unknown package identifier","Ambiguous symbol name with multiple matches — may return multiple signatures or an error","Payment not attached or insufficient — 402 Payment Required response","Malformed request body — 400 Bad Request"],"whenToPreferThis":"Use this endpoint when you need the precise type or call signature of a named symbol (function, method, class, etc.) within a known package or library. Prefer this over general code search when you already know the symbol name and need structured signature metadata rather than source code.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-16T00:32:39.815Z","isFirstParty":false}