{"uid":"cap__avJm4fgugaQeWALS0tmN","slug":"api-existence-oracle-symbol-exists-6fb8b751","name":"API-existence Oracle: Symbol Exists","description":"Deterministic symbol existence for PyPI and npm packages: functions, classes, methods, constants with signatures and deprecation flags, extracted from real artifacts. Negative answers include closest matches and signed proof. $0.005 USDC per check.","url":"https://attester.dev/v1/symbol/exists","method":"POST","headers":{},"bodySchema":{"$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":"0.005","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_IDJogF3OCZRurbSME_baX","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":"Checks whether a named symbol (e.g. function, class, or variable) exists in a given codebase or package registry.","exampleAgentPrompt":"Can you check whether the symbol `createClient` actually exists and is exported in the `@supabase/supabase-js` package?","exampleUseCases":[{"title":"Verify function before code generation","prompt":"Before you write any code that calls `useQuery` from the `@tanstack/react-query` package, can you confirm that symbol actually exists and is exported so we don't generate broken imports?"},{"title":"Check deprecated method still available","prompt":"I need to know if `connect` is still defined and accessible in the `mongoose` package — can you verify it exists before I update our database initialization code?"},{"title":"Validate type exists in SDK","prompt":"Can you check whether the `AuthSession` type is actually exported from the `@supabase/auth-helpers-nextjs` package? I want to make sure it's there before I use it in our TypeScript interfaces."}],"resultDescription":"Returns a boolean indicating whether the specified symbol exists, along with any available metadata about the symbol such as its type, export status, or location within the package.","failureModes":["Symbol name or package not provided — returns validation error","Unknown or misspelled package name — returns not-found or error response","Symbol exists but is not exported — may return false or qualified result","Payment not provided or insufficient — returns 402 Payment Required","Rate limit exceeded — returns 429 or payment error"],"whenToPreferThis":"Use this endpoint when you need to programmatically verify whether a named symbol (function, class, type, variable) is defined and accessible within a package or codebase, especially before generating code that depends on it or before making API calls that reference it. Prefer this over a full package diff endpoint when you only need a targeted existence check rather than change history.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-16T00:38:12.038Z","isFirstParty":false}