Chat with YouTube

Summary

The Chat with YouTube Agent answers questions about a video using its transcript. It pulls the video's metadata and full transcript, then summarizes, answers follow-ups, and generates chapter timestamps — each citation a clickable link straight to that moment. Reach for it to skim long talks, lectures, or podcasts without watching end to end.

Installation

bunnpmpnpmyarn
$ pnpm dlx shadcn@latest add @agentcn/mastra/chat-with-youtube
Copy

Composition

Copy├── config.ts                    # Agent definition (model + config)
├── instructions.md              # Comprehensive YouTube assistant instructions
├── memory.ts                    # Memory instance
├── lib/
│   └── youtube-utils.ts         # Video ID extraction + timestamp formatting
└── tools/
    ├── youtube-metadata.ts      # Fetch video title, author, description, duration
    └── youtube-transcript.ts    # Fetch timestamped transcript segments

How It Works

1. Get Metadata - fetch-youtube-metadata retrieves video title, author, description, and duration
2. Get Transcript - fetch-youtube-transcript fetches the full transcript with timestamps
3. Answer Questions - The agent answers based on transcript content with clickable timestamp citations
4. Generate Chapters - Creates chapter timestamps in YouTube description format

Customization

• Swap the model. Edit the model field in config.ts.
• Add chapters export. Add a tool that writes the chapter list back as a YouTube description or VTT file.
• Handle missing transcripts. Fall back to an STT service when a video has no captions.
• Swap metadata source. Use the YouTube Data API for richer metadata.