YTN Slack Bot

Summarize YouTube videos in Slack with /ytsummary.

How It Works

User → Slack → n8n webhook → transcript-service → Ollama → Slack response
                   ↓
            immediate "processing" ack

1. User types /ytsummary in any Slack channel
2. n8n receives webhook, immediately acknowledges with "Summarizing video..."
3. Transcript service fetches video metadata and transcript from YouTube
4. Ollama runs 2-stage summarization (extract key info → format for Slack)
5. Summary posted back to the channel

Usage

/ytsummary                              # Short summary of most recent YouTube video in channel
/ytsummary <https://youtube.com/...>    # Short summary of specific video
/ytsummary <https://youtube.com/...> medium   # Medium-detail summary
/ytsummary <https://youtube.com/...> long     # Comprehensive section-by-section breakdown
/ytsummary medium                       # Medium summary of most recent video in channel
/ytsummary long                         # Long summary of most recent video in channel

Summary Levels

Level	Output	Details
short (default)	TLDR + 3-4 bullets	Under 300 words
medium	TLDR + 5-8 detailed bullets	300-800 words
long	TLDR + sectioned breakdown	500-1500 words

All levels use the full transcript. The 2-stage Ollama pipeline compresses the full video into key notes (Stage 1), then formats for Slack at the requested detail level (Stage 2).

Note: Slack unfurls (expands) URLs automatically. To pass a URL directly, wrap it in angle brackets <url> to prevent unfurling.

Components

File	Purpose
app.py	Flask API - fetches transcripts/metadata from YouTube
Dockerfile	Python container with youtube_transcript_api
docker-compose.yml	Container config
n8n-workflow.json	n8n workflow to import
slack-app-manifest.yml	Slack app configuration template

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Setup Guide

Prerequisites

• Docker and docker-compose
• n8n instance (self-hosted or cloud)
• Ollama with a model installed (default: gpt-oss:20b-128k)
• Slack workspace admin access

Step 1: Deploy Transcript Service

cd slack-bot

# If using Docker networking, ensure your n8n network exists
# Edit docker-compose.yml to match your network name

# Start the service
docker-compose up -d

# Verify it's running
curl http://localhost:5001/health
# Should return: {"status":"ok"}

Network configuration:

The docker-compose.yml connects to an external Docker network so n8n can reach it. Update the network name to match your setup:

networks:
  your-n8n-network:
    external: true

Step 2: Import n8n Workflow

1. Open your n8n instance
2. Go to Workflows → Import from File
3. Select n8n-workflow.json

Configure the workflow:

1. Ollama nodes - Update the URL if Ollama is on a different host:

   • http://localhost:11434 - Ollama on same host
   • http://172.17.0.1:11434 - Ollama on Docker host (from container)
   • http://host.docker.internal:11434 - Docker Desktop

2. Transcript service - Update URL if using different hostname:

   • Default: http://ytn-transcript:5001 (Docker network name)

3. Create Slack credential:

   • Go to n8n Credentials → Add → Header Auth
   • Name: Slack YTN Bot Token
   • Header Name: Authorization
   • Header Value: Bearer xoxb-your-slack-bot-token

4. Activate the workflow

Step 3: Create Slack App

Option A: Use manifest (recommended)

1. Go to https://api.slack.com/apps
2. Click Create New App → From an app manifest
3. Select your workspace
4. Paste contents of slack-app-manifest.yml
5. Update the webhook URL to your n8n host
6. Click Create
7. Go to Install App → Install to Workspace
8. Copy the Bot User OAuth Token (starts with xoxb-) for the n8n credential

Option B: Manual setup

1. Create app at https://api.slack.com/apps → From scratch
2. Add slash command /ytsummary pointing to https://YOUR-N8N-HOST/webhook/slack-ytn
3. Add bot scopes: commands, chat:write, channels:history
4. Install to workspace

Step 4: Test

In any Slack channel:

/ytsummary

(With a YouTube URL posted recently in the channel)

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Troubleshooting

"No YouTube URL found" error

• Post a YouTube URL in the channel first, then run /ytsummary
• Or use angle brackets: /ytsummary <https://youtube.com/watch?v=...>

Summary never arrives

1. Check n8n execution history for errors
2. Verify transcript service is reachable from n8n
3. Check Ollama is running: curl http://localhost:11434/api/tags

Transcript service not starting

docker logs ytn-transcript

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Customization

Change Ollama model

Edit the "Prepare Stage 1 Request" and "Prepare Stage 2 Request" nodes in n8n:

model: "your-model-name"

Adjust summary prompts

Edit the prompt text in the same nodes to customize:

• What information is extracted (Stage 1)
• How the Slack message is formatted (Stage 2)

---

API Reference

GET /transcript

Param	Description
v	Video ID or full URL (required)
timestamps	true for [M:SS] format (optional)

GET /metadata

Param	Description
v	Video ID or full URL (required)

GET /health

Returns {"status":"ok"} if service is running.