# YouTube Transcript, Captions & Chapters > YouTube Transcript, Captions & Chapters is a paid API for AI agents from youtube.use.x402atlas.com, paid per call via x402, $0.02/call, live (last probed 2026-10-23, last successful call 2026-10-06). Agents call it through Zero, which pays per call: no API key and no wallet of your own. New accounts start with $5. Fetches the full transcript, timestamped caption segments, chapter markers, and available caption tracks for any YouTube video by ID or URL. ## Facts - Endpoint: GET https://youtube.use.x402atlas.com/transcript?utm_source=zero.xyz - Price: $0.02/call - Payment: x402 - Status: healthy - Last checked: 2026-10-23 - Last successful call: 2026-10-06 - Success rate: 67% of calls made through Zero - Rating: 4.8 / 5 from 2 reviews - Activations on Zero: 3 - Tags: x402 - Canonical page: https://www.zero.xyz/c/youtube-transcript-captions-chapters-19f9ac9d - Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_M0tGYgUrT-2iQT-C_OVaW Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently. ## How to call it through Zero Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`): ```sh zero fetch --capability youtube-transcript-captions-chapters-19f9ac9d ``` Example prompt: Can you grab the full transcript of this YouTube video — https://www.youtube.com/watch?v=dQw4w9WgXcQ — including the timestamped segments and chapter markers? ## When to prefer this Choose this endpoint when you need to extract spoken content from a YouTube video as text, need timestamped segments for quote attribution or search, want to enumerate available caption languages before fetching in a specific language, or need chapter markers to navigate long-form video content. It requires no API key and costs a flat $0.02 USDC per call, making it ideal for lightweight, one-off transcript fetches without YouTube Data API quota concerns. ## Known failure modes - Video ID not found or invalid — returns error if the 11-character ID or URL cannot be resolved - No captions available — some videos have no caption tracks at all - Private or age-restricted videos — transcript may be inaccessible - Network or upstream YouTube API timeout — transient errors possible - Malformed URL input — if the URL cannot be parsed to extract a valid video ID ## How this service works Full transcript of any YouTube video by video id or URL: captions/subtitles as clean plain text plus timestamped segments, the video's chapter markers, and every caption track it offers so an agent can pick a language and re-fetch. YouTube transcript, video to text, captions extraction, subtitle download, closed captions, speech to text, multilingual, asr and authored tracks. No API key. ## Output Returns the full video transcript as a plain-text block, an array of timestamped caption segments (each with start_ms, optional end_ms, and display-formatted start time), an array of chapter markers with titles and time offsets, the language code of the served track, the normalized 11-character video ID, the query timestamp, and a list of all available caption tracks (including whether each is auto-generated or authored, its language code, and whether it was selected). ## Request schema (JSON Schema) ```json { "type": "object", "$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": [ "v" ], "properties": { "v": { "type": "string", "maxLength": 500, "description": "YouTube video id (11 characters) or a full YouTube video URL" } } } }, "additionalProperties": false }, "output": { "type": "object", "required": [ "type" ], "properties": { "type": { "type": "string" }, "example": { "type": "object", "required": [ "video_id", "queried_at", "text", "segments", "chapters", "available_transcripts" ], "properties": { "note": { "type": "string", "description": "Present only on the sample response (a call with no v): a hint that this is a canned example. The paid request ran; no upstream call was made." }, "text": { "type": "string", "description": "Whole transcript as one plain-text block" }, "chapters": { "type": "array", "items": { "type": "object", "properties": { "title": { "type": "string" }, "end_ms": { "type": "integer" }, "start_ms": { "type": "integer" }, "start_time_text": { "type": "string" } } }, "description": "Chapter markers; empty for videos without chapters" }, "segments": { "type": "array", "items": { "type": "object", "required": [ "start_ms", "text" ], "properties": { "text": { "type": "string" }, "end_ms": { "type": "integer", "description": "Line end offset in milliseconds; absent on tracks that carry only starts" }, "start_ms": { "type": "integer", "description": "Line start offset in milliseconds" }, "start_time_text": { "type": "string", "description": "Line start as displayed, e.g. 0:43" } } } … (truncated) ``` ## Response schema (JSON Schema) ```json { "type": "json", "example": { "text": "Good morning. How are you? (Audience) Good. It's been great, hasn't it?", "chapters": [ { "title": "Introduction", "end_ms": 42000, "start_ms": 0, "start_time_text": "0:00" }, { "title": "Three themes", "end_ms": 115000, "start_ms": 42000, "start_time_text": "0:42" } ], "segments": [ { "text": "Good morning. How are you?", "end_ms": 29678, "start_ms": 27103, "start_time_text": "0:27" }, { "text": "(Audience) Good.", "end_ms": 31105, "start_ms": 29702, "start_time_text": "0:29" } ], "video_id": "iG9CE55wbtY", "queried_at": "2026-07-24T12:00:00Z", "language_code": "en", "available_transcripts": [ { "selected": true, "language_code": "en" }, { "type": "asr", "language_code": "en" }, { "language_code": "fr" } ] } } ``` ## More - Live health (JSON, refreshed every minute): https://www.zero.xyz/c/youtube-transcript-captions-chapters-19f9ac9d/health.json - [Zero catalog index](https://www.zero.xyz/llms.txt) - [Other services from youtube.use.x402atlas.com](https://www.zero.xyz/host/youtube.use.x402atlas.com/llms.txt)