n8n Webhook: Repurpose YouTube Transcripts with OpenAI

Turn any YouTube video into a full newsletter + social posts—automatically

This n8n workflow repurposes YouTube content by receiving a YouTube URL through a webhook, extracting (or accepting) the transcript, and using OpenAI Chat Completions to generate a newsletter issue plus ready-to-publish repurposed content (key takeaways, an X thread, and a LinkedIn post). It returns both structured JSON and newsletter-ready Markdown.

What this workflow does

• Receives a POST webhook request containing a url field (YouTube link) and an optional transcript.
• Extracts and validates the YouTube video ID from the provided URL.
• Uses your transcript if provided, otherwise fetches captions from youtubetranscript.com and converts them into plain text.
• Calls OpenAI Chat Completions with the transcript and strict instructions to return a JSON payload containing newsletter and repurposed content fields (e.g., subject line, sections, takeaways, X thread, LinkedIn post).
• Parses and normalizes the response into structured fields and generates a formatted newsletter Markdown document.
• Returns the full result as a JSON response to the webhook caller.

Use cases

• Transform a weekly YouTube upload into a consistent newsletter edition for subscribers.
• Create an X thread and LinkedIn post from the same long-form video to repurpose content faster.
• Build an internal content pipeline where automation engineers trigger generation via a webhook.
• Recover gracefully when caption retrieval fails by sending a raw transcript in the webhook payload.

Technical details

• n8n nodes/tools: Webhook, Code, HTTP Request, Respond to Webhook.
• External services: youtubetranscript.com for caption fetching (when no transcript is provided), and OpenAI via https://api.openai.com/v1/chat/completions.
• Setup steps: add your OpenAI API key in the Authorization header for the HTTP request, then POST JSON with {"url": "...", "transcript": "..."} (transcript optional).