{"uid":"cap_S5njLGhbOQFjatQHIfdyz","slug":"youtube-transcript-lexical-search-melchior-labs-8f14a314","name":"YouTube Transcript Lexical Search — Melchior Labs","description":"Pay per request for structured YouTube transcripts, lexical passage search, chunks, and timestamp citations over x402.","url":"https://transcript.melchiorlabs.com/v1/youtube/search?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"url":{"type":"string","pattern":"^https://(?:www\\.|m\\.)?(?:youtube\\.com|youtu\\.be)/","description":"Public youtube.com or youtu.be video URL"},"query":{"type":"string","maxLength":500,"minLength":1,"description":"Phrase or terms to match lexically in the transcript"},"language":{"type":"string","default":"en","description":"Caption language code, such as en or es"},"maxResults":{"type":"integer","default":5,"maximum":10,"minimum":1},"preferManual":{"type":"boolean","default":true},"contextSegments":{"type":"integer","default":1,"maximum":5,"minimum":0}}},"responseSchema":{"type":"json","example":{"query":"never gonna give you up","usage":{"cache":"hit","matchedSegments":2,"returnedMatches":1,"candidateSegments":60},"video":{"id":"dQw4w9WgXcQ","url":"https://www.youtube.com/watch?v=dQw4w9WgXcQ","title":"Video title"},"matches":[{"rank":1,"text":"Never gonna give you up...","score":17,"citation":{"url":"https://www.youtube.com/watch?v=dQw4w9WgXcQ&t=42s","label":"0:42–0:49"},"endSeconds":49,"matchedTerms":["give","never"],"startSeconds":42}],"requestId":"0b0ef10e-ff50-4a45-9c4e-b7344aa93f63"}},"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":{"p10Cents":"0.5000","medianCents":"0.5000","p90Cents":"0.5000","minCents":"0.5000","maxCents":"0.5000","p95Cents":"0.5000","sampleCount":1,"varies":false,"failureChargeRate":1},"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_dHackl3nOGqFp0bsC_OC-","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":"Searches a YouTube video's transcript for passages matching a query, returning ranked text snippets with timestamp citations.","exampleAgentPrompt":"Search the transcript of this YouTube video (https://www.youtube.com/watch?v=dQw4w9WgXcQ) for the phrase 'never gonna give you up' and give me up to 3 timestamped passages where it appears, with 1 segment of surrounding context.","exampleUseCases":[{"title":"Fact-check a speaker's claim in a lecture","prompt":"In this university lecture on YouTube (https://www.youtube.com/watch?v=abc123XYZ), find every passage where the professor mentions 'placebo effect' — give me the timestamps so I can jump straight to those moments, top 5 results please."},{"title":"Pull a quote with citation from a podcast","prompt":"I need the exact words and a timestamp link for when the guest in this podcast (https://www.youtube.com/watch?v=pod456ABC) talks about 'supply chain disruption' — search the English transcript and return the top 2 matches with surrounding context."},{"title":"Locate a coding tutorial step by timestamp","prompt":"In this Python tutorial video (https://youtu.be/tut789DEF), find where the instructor explains 'list comprehension' and give me the timestamp so I can link directly to that part of the video."}],"resultDescription":"Returns a ranked list of transcript passage matches, each with the matched text, a score, the specific terms matched, start and end timestamps in seconds, and a direct YouTube URL with a timestamp parameter (e.g. &t=42s). Also includes video metadata (ID, title, URL), usage stats (cache hit/miss, segment counts), and a request ID for tracing.","failureModes":["Video is private or unavailable — transcript cannot be fetched","No captions available in the requested language — returns empty matches or error","Query returns zero matches if none of the terms appear in the transcript","Invalid YouTube URL format — rejected by pattern validation","maxResults or contextSegments out of allowed range — schema validation error","Rate limiting or payment failure over x402 protocol"],"whenToPreferThis":"Choose this endpoint when you need to find specific passages, quotes, or topic mentions within a single YouTube video by keyword or phrase, and you want timestamped citations back. It is purpose-built for lexical transcript search with citation output, making it ideal for research, fact-checking, podcast navigation, or linking directly to a moment in a video. Prefer it over generic transcript-fetch endpoints when you need ranked relevance and timestamp links rather than a full raw transcript dump.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-22T23:29:17.130Z","isFirstParty":false,"canonicalSlug":"youtube-transcript-lexical-search-melchior-labs-8f14a314"}