web-summaries-mcp

A Streamable HTTP MCP (Model Context Protocol) server that fetches YouTube transcripts and lets an LLM semantically search within them.

Tools

• get_transcript — fetches the full transcript of a YouTube video, given a video ID or URL (watch, youtu.be, embed, shorts links all work).

• search_transcript — semantically searches a transcript by meaning. Chunks the transcript, embeds each chunk and the query with a local sentence-embedding model (Xenova/bge-base-en-v1.5 via @huggingface/transformers), and ranks chunks by cosine similarity (dot product on normalized vectors). Returns the top-k matching passages with timestamps.

Transcripts are fetched via YouTube's InnerTube API (the same one the YouTube Android app uses) and parsed from the caption track XML.

Related MCP server: youtube-summarize

Setup

npm install
npm start

The server listens on http://localhost:8080/mcp (Streamable HTTP transport — POST/GET/DELETE).

Project layout

• mcp_server.js — Express + @modelcontextprotocol/sdk server, tool definitions, embedding/search logic.

• transcript_core.js — InnerTube fetch + transcript XML parsing, shared by the server and the CLI script.

• fetch_transcript.js — standalone CLI for downloading a transcript to a file.

• htmlroot/ — static assets served alongside the MCP endpoint.