Transcriptor MCP

An MCP server (stdio; remote HTTP/SSE via mcp-proxy) that fetches video transcripts/subtitles via yt-dlp, with pagination for large responses. Supports YouTube, Twitter/X, Instagram, TikTok, Twitch, Vimeo, Facebook, Bilibili, VK, Dailymotion, Reddit. Whisper fallback — transcribes audio when subtitles are unavailable (local or OpenAI API). Works with Cursor and other MCP hosts.

Overview

This repository primarily ships a stdio MCP server (node dist/mcp.js):

• stdio: for local usage (e.g., Cursor running a local command).
• Remote HTTP/SSE: expose stdio through mcp-proxy (e.g. VPS + Tailscale); see MCP quick start and docker-compose.example.yml.

It also includes an optional REST API (Fastify), but MCP is the primary focus.

Supported platforms

Unlike YouTube-only tools, Transcriptor MCP works across 11 major video platforms:

YouTube · Twitter/X · Instagram · TikTok · Twitch · Vimeo · Facebook · Bilibili · VK · Dailymotion · Reddit

All URL-based tools (get_transcript, get_raw_subtitles, get_available_subtitles, get_video_info, get_video_chapters, get_playlist_transcripts) accept video URLs from any supported platform. The search_videos tool is YouTube-specific (yt-dlp ytsearch).

When to use Transcriptor MCP

Transcriptor MCP is the best choice when you need transcripts and metadata for AI, summarization, or content analysis — without downloading video or audio files:

• Transcripts and subtitles — cleaned text or raw SRT/VTT; multi-language; Whisper fallback when subtitles are unavailable (local or OpenAI).
• Multi-platform — YouTube, Twitter/X, Instagram, TikTok, Twitch, Vimeo, Facebook, Bilibili, VK, Dailymotion, Reddit.
• Remote and production — stdio + mcp-proxy for HTTP/SSE, optional auth at a reverse proxy, Redis cache, Prometheus metrics on the REST API.
• No media downloads — we focus on text and metadata only. For downloading videos or audio.

Use the sections in this README for setup, tools, and deployment patterns.

How to connect

Choose one of these two main paths:

1) Local MCP (Docker)

Best when you want a fast local setup without Node on host.

docker run --rm -i artsamsonov/transcriptor-mcp:latest

Cursor MCP config:

{
  "mcpServers": {
    "transcriptor": {
      "command": "docker",
      "args": ["run", "--rm", "-i", "artsamsonov/transcriptor-mcp:latest"]
    }
  }
}

Detailed local + self-hosted HTTP/SSE instructions are in How to connect and MCP quick start.

2) Remote MCP via HTTP/SSE (mcp-proxy)

Expose stdio over HTTP/SSE with mcp-proxy. See docker-compose.example.yml for a full stack (optional REST API + MCP).

After you deploy mcp-proxy (and optionally TLS or Bearer auth at a reverse proxy), point MCP clients at your endpoint, for example:

https://your-host.example/mcp

Streamable HTTP uses POST /mcp; SSE uses GET /sse. The MCP Node process does not validate Bearer tokens — configure auth on the proxy in front of mcp-proxy if needed.

Features

• Multi-platform — YouTube, Reddit, Twitter/X, Instagram, TikTok, Twitch, Vimeo, Facebook, Bilibili, VK, Dailymotion.
• Transcripts + raw subtitles: cleaned text or raw SRT/VTT.
• Language support: official subtitles with auto-generated fallback.
• Video metadata: extended info (title, channel, tags, thumbnails, etc.) and chapter markers.
• Pagination: safe for large transcripts.
• Whisper fallback: when subtitles are unavailable, transcribes video audio via Whisper (local self-hosted or OpenAI API); configurable via environment variables.
• Optional Redis cache: cache subtitles and metadata to reduce yt-dlp calls; configurable via environment variables.
• Docker-first: ready for local + remote deployment.
• Production-friendly HTTP: optional auth + allowlists for the REST API; remote MCP uses stdio + mcp-proxy and is usually fronted by your own reverse proxy for Bearer/TLS.
• Prometheus: metrics on the REST API (GET /metrics); MCP tool counters (mcp_*) are updated inside the MCP Node process but this repo no longer exposes GET /metrics on the MCP image.

Self-configurable: Whisper & caching

You can enable these features independently; both are off by default.

• Whisper fallback — When native subtitles are unavailable, transcribe video audio via Whisper (local self-hosted or OpenAI API). Configure via WHISPER_MODE, WHISPER_BASE_URL, WHISPER_API_KEY, etc.
• Redis caching — Cache subtitles and metadata to reduce yt-dlp calls. Configure via CACHE_MODE=redis and CACHE_REDIS_URL.

MCP quick start

For full setup options (local Docker and self-hosted HTTP/SSE with mcp-proxy), use:

• How to connect
• MCP Server (stdio)

MCP tools

MCP tool reference

All URL-based tools share the same base input:

• url (string, required) – Video URL from a supported platform or YouTube video ID. Supported: YouTube, Twitter/X, Instagram, TikTok, Twitch, Vimeo, Facebook, Bilibili, VK, Dailymotion, Reddit.

get_raw_subtitles supports pagination; get_transcript returns the first chunk only (no pagination input). Pagination parameters for get_raw_subtitles:

• response_limit (number, optional) – max characters per response, default 50000, min 1000, max 200000.
• next_cursor (string, optional) – opaque offset returned from the previous page; pass it to fetch the next chunk.

Each tool returns:

• content – human-readable text (for MCP chat UIs).
• structuredContent – strongly typed JSON payload you can consume from automations or code.

get_transcript

Purpose: Fetch cleaned subtitles as plain text (no timestamps, HTML, or speaker metadata).

Input: Only url (video URL or ID). Type and language are auto-discovered; the tool returns the first chunk with default size (no pagination parameters).

Structured response:

• videoId – resolved YouTube ID.
• type, lang – effective subtitle type and language.
• text – current text chunk.
• is_truncated – true if more text is available.
• total_length – total length of the full transcript.
• start_offset, end_offset – character offsets of this chunk.
• next_cursor – present in response when truncated (omitted on the last page). Not accepted as input for this tool.

get_raw_subtitles

Purpose: Fetch raw subtitle file content (SRT or VTT) with pagination support.

Extra input fields:

• type – "official" or "auto", optional.
• lang – subtitle language code, optional.
• response_limit, next_cursor – pagination (optional).

Structured response:

• videoId, type, lang – same semantics as above.
• format – "srt" or "vtt" (auto-detected from content).
• content – raw subtitle text for this page.
• is_truncated, total_length, start_offset, end_offset, next_cursor – same pagination fields as get_transcript.

get_available_subtitles

Purpose: Inspect which languages are available for a video, split into official vs auto-generated tracks.

Input:

• url – YouTube URL or video ID.

Structured response:

• videoId – resolved YouTube ID.
• official – sorted list of language codes with official subtitles.
• auto – sorted list of language codes with auto-generated subtitles.

This is useful to first discover languages and then pick type/lang for get_raw_subtitles (or other tools).

get_video_info

Purpose: Fetch extended metadata about a video (based on yt-dlp JSON output).

Input:

• url – YouTube URL or video ID.

Structured response (key fields):

• videoId – resolved YouTube ID.
• title, description.
• uploader, uploaderId.
• channel, channelId, channelUrl.
• duration – in seconds.
• uploadDate – YYYYMMDD string if available.
• webpageUrl.
• viewCount, likeCount, commentCount.
• tags, categories.
• liveStatus, isLive, wasLive, availability.
• thumbnail – primary thumbnail URL.
• thumbnails – list of thumbnail variants { url, width?, height?, id? }.

See src/mcp-core.ts and src/youtube.ts for the full JSON schema used by the MCP SDK.

get_video_chapters

Purpose: Get chapter markers extracted by yt-dlp.

Input:

• url – YouTube URL or video ID.

Structured response:

• videoId – resolved YouTube ID.
• chapters – array of { startTime: number; endTime: number; title: string }.

If the video has no chapters, chapters is an empty array; if yt-dlp cannot fetch chapter data at all, the tool returns an MCP error instead of structured chapters.

get_playlist_transcripts

Purpose: Fetch cleaned transcripts for multiple videos from a playlist in one call.

Input:

• url (string, required) – Playlist URL or watch URL with list= (e.g. https://www.youtube.com/playlist?list=XXX).
• type – "official" or "auto", optional.
• lang – Subtitle language code, optional.
• format – Subtitle format (srt, vtt, ass, lrc), optional.
• playlistItems – yt-dlp -I spec (e.g. 1:5, 1,3,7, -1), optional.
• maxItems – Max videos to process, optional.

Structured response:

• results – array of { videoId, text } for each video in the playlist.

search_videos

Purpose: Search videos on YouTube via yt-dlp (ytsearch). Returns a list of videos with metadata.

Input:

• query (string, required) – Search query.
• limit (number, optional) – Max results (default 10, max 50).
• offset (number, optional) – Skip first N results (pagination).
• uploadDateFilter (string, optional) – Filter by upload date: hour, today, week, month, or year.
• response_format (string, optional) – Human-readable format: json (default) or markdown.

Structured response:

• results – array of { videoId, title, url, duration, uploader, viewCount, thumbnail }.

Requirements

• Docker (recommended for production)
• Node.js >= 20.0.0 (for local development)
• yt-dlp (included in Docker image)

REST API (optional)

The repository also ships an HTTP API (Fastify).

Quick Docker usage

• Build the image:
  bash

  docker build -t transcriptor-mcp-api -f Dockerfile --target api .
  

• Run on the default port:
  bash

  docker run -p 3000:3000 transcriptor-mcp-api
  

For a more complete REST quick start (including docker-compose and local Node.js), use REST API (optional) and API Documentation.

Swagger / OpenAPI

Once the REST API is running, interactive API docs are available at:

http://localhost:3000/docs

If you change PORT / HOST, adjust the URL accordingly, e.g. http://<HOST>:<PORT>/docs.

Troubleshooting: restricted / sign-in required videos

If yt-dlp is blocked by age gate, sign-in, or region restrictions, you will likely need an authenticated cookies.txt file and the COOKIES_FILE_PATH environment variable.

The root of this repository includes a sample [cookies.example.txt](cookies.example.txt) showing the expected Netscape cookies format. For a full guide on:

• exporting real cookies
• wiring them into Docker / docker-compose / local Node.js
• and keeping them secure

keep credentials local and use COOKIES_FILE_PATH with a non-committed cookie file.

Run in background

docker run -d -p 3000:3000 --name transcriptor transcriptor-mcp-api

E2E smoke tests (REST API + MCP, Docker)

Before publishing Docker images, you can run a small e2e smoke test that:

• Starts a REST API container and checks Swagger + POST /subtitles with a stable YouTube video
• Optionally starts an MCP container and checks MCP stdio (initialize over stdin/stdout), streamable HTTP (POST /mcp with initialize), and SSE (GET /sse) against mcp-proxy + stdio (same stack as docker-compose.example.yml)

Run the smoke test (requires built images):

npm run build
docker build -t artsamsonov/transcriptor-mcp-api:latest -f Dockerfile --target api .
docker build -t artsamsonov/transcriptor-mcp:latest -f Dockerfile --target mcp .
npm run test:e2e:api

Environment variables:

Example: skip MCP and use a custom video:

SMOKE_SKIP_MCP=1 SMOKE_VIDEO_URL="https://www.youtube.com/watch?v=YOUR_ID" npm run test:e2e:api

View logs

docker logs -f transcriptor

Stop the container

docker stop transcriptor
docker rm transcriptor

API Documentation

For detailed REST API endpoint documentation (request/response schemas, examples, etc.), use the built-in Swagger UI at:

http://localhost:3000/docs

or use REST API (optional).

MCP Server (stdio)

The MCP server runs on stdio (dist/mcp.js) and can be used via:

• local Docker (docker run --rm -i artsamsonov/transcriptor-mcp:latest)
• local Node (node dist/mcp.js)
• remote HTTP/SSE through mcp-proxy (/mcp and /sse)

Use How to connect as the main guide for MCP setup variants; optional Bearer auth is configured on a reverse proxy in front of mcp-proxy.

How It Works

1. The API receives a video URL (YouTube or other supported platform) and parameters (subtitle type and language) from the client
2. Extracts the video ID from the URL
3. Uses yt-dlp to download subtitles with the specified parameters:

• Single yt-dlp command call with explicit type (--write-subs or --write-auto-subs) and language (--sub-lang)

4. Parses the subtitle file (SRT/VTT) and removes:

• Timestamps
• Subtitle numbers
• HTML tags
• Formatting

5. Returns clean plain text (for /subtitles) or raw content (for /subtitles/raw)

Development

Prerequisites

• Node.js >= 20.0.0
• npm or yarn
• yt-dlp installed and available in PATH

Versioning

The app version is read from package.json at runtime ([src/version.ts](src/version.ts)). When cutting a release, update the version field in package.json, then create a git tag (e.g. v0.4.7). Changelog entries under [Unreleased] should be moved to the new version before tagging.

Scripts

• npm run build - Build the TypeScript project
• npm start - Run the compiled application
• npm run dev - Run with hot reload using ts-node-dev
• npm run start:mcp - Run the MCP server (stdio)
• npm run dev:mcp - Run the MCP server with hot reload
• npm test - Run tests
• npm run test:watch - Run tests in watch mode
• npm run test:coverage - Run tests with coverage report
• npm run lint - Lint the code
• npm run lint:fix - Fix linting errors
• npm run type-check - Type check without building
• npm run format - Format code with Prettier
• npm run format:check - Check code formatting

Project Structure

├── src/
│   ├── index.ts                    # HTTP API (Fastify)
│   ├── mcp.ts                      # MCP server (stdio)
│   ├── mcp-core.ts                 # MCP tools registration
│   ├── validation.ts               # Request validation
│   ├── youtube.ts                  # Subtitle download and parsing (yt-dlp)
│   ├── yt-dlp-check.ts             # yt-dlp availability checks
│   ├── whisper.ts                  # Whisper API client
│   ├── whisper-jobs.ts             # Async Whisper jobs
│   ├── cache.ts                    # Response / subtitle caching
│   ├── metrics.ts                  # Prometheus metrics (/metrics)
│   ├── lifecycle.ts                # Graceful shutdown hooks
│   ├── instrument.ts               # Sentry initialization
│   ├── logger-sentry-breadcrumbs.ts
│   ├── errors.ts                   # Error types and HTTP mapping
│   ├── env.ts                      # Environment configuration
│   ├── version.ts                  # App version (from package.json)
│   ├── changelog.ts                # Changelog data for API
│   ├── e2e/                        # API / MCP smoke tests (Docker)
│   │   ├── api-smoke.ts
│   │   ├── mcp-smoke.ts
│   │   ├── docker-utils.ts
│   │   └── smoke-env.ts
│   └── *.test.ts                   # Unit tests (Jest), co-located
├── dist/                           # Compiled JavaScript (npm run build)
├── load/                           # Load-test scripts (k6)
├── .github/workflows/              # CI and Docker Hub publish
├── Dockerfile                      # API and MCP images (--target api|mcp)
├── docker-compose.example.yml      # Example API + MCP stack
├── docker-compose.yml
├── package.json
├── tsconfig.json
├── eslint.config.mjs
├── jest.config.cjs
└── README.md

Technologies

• TypeScript - Type-safe JavaScript
• Node.js - Runtime environment
• Fastify - Fast and low overhead web framework
• yt-dlp - YouTube content downloader
• Docker - Containerization
• Jest - Testing framework
• ESLint - Code linting
• Prettier - Code formatting

Security

Data and keys: Video URLs are sent to yt-dlp for subtitle extraction. Keys and tokens are stored only in your environment; we never log or share them.

Do not commit or log sensitive values. Use environment variables or a secret manager (e.g. vault, cloud secrets) for:

• **WHISPER_API_KEY** – required when using Whisper API; never log or expose in client responses.
• **CACHE_REDIS_URL** – Redis connection string when CACHE_MODE=redis; may contain credentials.
• MCP Bearer secrets – if you terminate auth at a reverse proxy in front of mcp-proxy, store tokens only in env/secrets on that edge.
• **COOKIES_FILE_PATH** – path to cookies; ensure the file is not committed and has restricted permissions.

Use cookies.example.txt as a format template and keep real cookies outside git.

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

1. Fork the repository
2. Create your feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'Add some amazing feature')
4. Push to the branch (git push origin feature/amazing-feature)
5. Open a Pull Request

Please make sure your code passes all tests and linting checks before submitting.

License

MIT License

Copyright (c) 2025 samson-art

See LICENSE file for details.

Support

• Bug reports: GitHub Issues
• Feature requests: GitHub Issues
• Contact: GitHub Profile