Facebook Group Monitor

Facebook Group Monitor Skill

Overview

Playwright-based headless browser scraper for Facebook groups. Default behavior: captures a stitched "feed strip" (scrolls 3× viewport, crops to feed column, stitches into 1 JPEG) → agent calls vision model once with a custom prompt to extract and interpret all new posts in a single LLM call.

Requires one-time manual login via terminal to establish a persistent browser session.

Setup

See references/SETUP.md for installation and first-time login instructions.

File Locations (after install)

Commands

1. Check login session

scripts/fb-group-monitor.sh status

{"success": true, "action": "status", "message": "Session active — logged in to Facebook."}

2. Scrape new posts (with feed strip screenshot)

scripts/fb-group-monitor.sh scrape  [--limit N] [--shots-dir ]

Parameters:

Example:

scripts/fb-group-monitor.sh scrape "https://www.facebook.com/groups/123456789" --limit 10 --shots-dir ./temp-screenshots

Output JSON (with feed strip screenshot):

{
  "success": true,
  "action": "scrape",
  "group_name": "Example Group Name",
  "group_url": "https://www.facebook.com/groups/123456789",
  "total_scraped": 6,
  "new_count": 3,
  "feed_screenshot": "/path/to/temp-screenshots/feed_abc12345_1741800000.jpg",
  "posts": [
    {
      "author": "Poster Name",
      "text": "Post content (may be truncated by Facebook's 'See more')...",
      "url": "https://facebook.com/groups/123456/posts/789",
      "images": 3
    },
    {
      "author": "Another Poster",
      "text": "Text-only post, no images...",
      "url": "https://facebook.com/groups/123456/posts/790",
      "images": 0
    }
  ],
  "message": "Found 3 new posts / 6 total."
}

> Note: feed_screenshot is a single stitched JPEG covering the full feed (3 viewport scrolls). > Individual posts no longer have a screenshot_path — use feed_screenshot (top-level) instead.

3. Clean old screenshots

scripts/fb-group-monitor.sh clean-shots

4. Login (one-time, from terminal)

scripts/fb-group-monitor.sh login

Agent Workflow

When triggered by cron or user request to check a group:

Step 1: Scrape

scripts/fb-group-monitor.sh scrape "" --limit 10 --shots-dir ./temp-screenshots

Step 2: Analyze feed screenshot + combine with text

If feed_screenshot is present (1 stitched image covering the full feed):

  image tool:
    image: 
    prompt: "Facebook group feed. Find and analyze posts by these people (new posts to process):
    - [Author 1]: "[first few words of text from JSON]" — N images
    - [Author 2]: "[first few words of text from JSON]"
    ...
    For EACH post, do 2 things:
    1. EXTRACT: book/product name, author/publisher (read from cover), price (including handwritten prices), condition (new/used/marked/yellowed).
    2. INTERPRET: is the deal worth it (price vs market if known), is the item rare/valuable, actual condition assessment from photos."
  

If feed_screenshot is absent (screenshot failed):

Step 3: Report to user

MUST include the original post link in each item for verification.

Format per new post:
📌 *[Title/Summary]*
👤 Author: [author]
💰 Price: [price or "unknown"]
📝 Condition: [description]
💡 Note: [deal assessment or insight, if any]
🔗 [post URL]

Step 4: If no new posts → stay silent (no notification)

Step 5: If success == false → report error briefly

⚠️ Anti-duplicate rule

Important Notes

See references/SETUP.md for installation and first-time login instructions.