n8n Auto-Generate YouTube Video SEO Tags with GPT and Slack Notifications

Weekly scheduled fetch of new channel videos → AI analyzes titles and descriptions to generate 15–20 SEO tags → auto-write back to YouTube and notify team via Slack

Who

YouTube creators, channel admins, marketing teams, and agencies managing multiple channels that publish regularly

You get

Automatically generate and apply SEO-friendly tags to improve discoverability, with Slack team notifications

You need

n8n · slack

Steps

1. Configure credentials and channel information

   Set up three credentials in n8n: 1) YouTube OAuth2: create a Google Cloud project, enable YouTube Data API v3, configure an OAuth client, authorize with the Google account managing the channel, add the credential with scopes youtube.readonly and youtube/youtube.force-ssl. 2) Slack OAuth2: create or reuse a Slack App, install to workspace, capture the Bot Token, add slackOAuth2Api credential with chat:write scope. 3) OpenAI API: add openAiApi credential. Then set the channel ID in the Set Channel Information node (field name: Channel_Id).

2. Set up schedule trigger and video fetch

   Configure Weekly Schedule Trigger: select day/time for weekly runs (e.g., Mondays at 09:00). Configure 'Get all videos uploaded last week' node: resource=video, returnAll=true, filters.channelId mapped to {{ $json.Channel_Id }}, filters.publishedAfter currently set to {{ $today.minus(1,'days') }} (as in source template; adjust to 7 days if needed), options.order=date.

3. Fetch video details and feed to AI Agent

   'Get video detail' node: resource=video, operation=get, videoId mapped to {{ $json.id.videoId }} (from previous video list). This node outputs snippet.title, snippet.description, snippet.channelTitle, which flow via main connection to the Youtube Video Auto Tagging Agent.

4. AI generates SEO tags

   Youtube Video Auto Tagging Agent node uses OpenAI Chat Model (model options: gpt-4.1-mini / gpt-4.1 / gpt-4). This is an Agent node (typeVersion=2.1) with promptType=define. Map video detail fields to prompt variables: snippet.title → video title, snippet.description → video description, snippet.channelTitle → channel name.

   Execution prompt · Source text。Youtube Video Auto Tagging Agent node Options > System Message field

   Copy prompt

   You are an expert YouTube SEO strategist. 
   Your goal is to generate a list of highly relevant, diverse, and SEO-friendly tags for a YouTube video based on its title, description, and channel name. 
   The tags should:
   - Improve discoverability and ranking on YouTube search and recommendations
   - Cover both specific keywords (directly related to the video) and broader categories (general niche)
   - Include variations (short-tail and long-tail keywords)
   - Avoid duplicates, irrelevant terms, or hashtags (#)
   - Be limited to 15–20 tags, formatted as a clean comma-separated list
   - Prioritize high-search-intent keywords that align with the channel’s theme

   Execution prompt · Source text。Youtube Video Auto Tagging Agent node Text field (User Prompt)

   Copy prompt

   =Here is my YouTube video information:
   
   Title: {{ $json.snippet.title }}
   Description: {{ $json.snippet.description }}
   Channel Name: {{ $json.snippet.channelTitle }}
   
   Please analyze this information and provide me with the most relevant and SEO-friendly tags (15–20, comma-separated). 
   Focus on tags that increase reach, match viewer search intent, and balance between trending keywords and niche keywords.

5. Write tags back to YouTube and send Slack notification

   'Update video with AI generated tags' node: resource=video, operation=update, videoId mapped to {{ $('Get video detail').item.json.id }}, title preserved from original, updateFields.tags mapped to {{ $json.output }} (tag string from Agent), updateFields.description preserved from original. Note hardcoded categoryId=28 and regionCode=VN; modify as needed. Then 'Inform via slack message' node sends confirmation.

   Execution prompt · Source text。Inform via slack message node Text field

   Copy prompt

   =The video ”{{ $json.snippet.title }} - {{ $json.id }}” has been auto-tagged successfully with the following tags: {{ $('Youtube Video Auto Tagging Agent').item.json.output }}

You are an n8n workflow setup assistant. The user wants to replicate the 'Auto-Generate YouTube Video SEO Tags with GPT and Slack Notifications' template. First confirm they have: 1) access to an n8n instance; 2) a Google Cloud project with YouTube Data API v3 enabled; 3) Slack workspace admin rights to create an App; 4) an OpenAI API key. Then guide them through credential setup, node parameter mapping, prompt placement, and remind them to check the publishedAfter date range and regionCode settings.