Reddit Monitor - Real-Time Reddit Post & Keyword Tracker

A lightweight, reliable Apify Store Actor to monitor one subreddit for new posts containing specified keywords, with instant Email and Webhook alert notifications.

Unlike heavy scrapers designed for extracting historical data, Reddit Post Monitor is specifically built for low request volume, cost efficiency, human-paced stealth navigation, and continuous automated execution using Apify Schedules.

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🚀 Key Features

• Subreddit Monitoring: Monitors new posts in real-time from any public subreddit.
• Human-Paced Sequential Inspection: Visits new posts individually in the browser with realistic delays (1.2s – 2.5s) to read full body content without triggering bot blocks.
• Flexible Input Normalization: Accepts plain names (webscraping), prefixed names (r/webscraping), or full Reddit URLs (https://www.reddit.com/r/webscraping).
• Strict Whole-Word Matching: Case-insensitive matching with strict word boundaries to eliminate false positives (e.g. matching cat will not trigger on category or concatenate).
• Stealth & Anti-Bot Bypassing: Integrates Crawlee browser fingerprints, Apify Residential Proxies, and multi-endpoint fallbacks (www.reddit.com -> old.reddit.com -> JSON feeds).
• Built-in Notifications:
  • Email Alerts: Automatic email notifications delivered via Apify's official apify/send-mail Actor.
  • Webhook Integration: HTTP POST JSON payloads sent directly to your custom webhook endpoint or automation server (n8n, Make, Zapier).
• Persistent Checkpoint Management: Uses named Key-Value Stores (reddit-monitor-sub-{subreddit}) to guarantee state persistence across separate scheduled runs with zero duplicate alerts.
• 24-Hour Expiration & Safety: Automatic state recovery if a checkpoint post is deleted, or if the schedule has been paused for more than 24 hours.

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📋 Input Configuration

Configure the Actor via the Apify console UI or JSON payload:

Parameter	Type	Required	Description
subreddit	String	Yes	Subreddit to monitor (e.g. webscraping, r/webscraping, or full URL).
keywords	Array	Yes	List of keywords to search for in post titles and body text.
notificationEmail	String	Yes	Target email address to receive alert notifications. (See Email Policy Note below)
webhookUrl	String	No	HTTP POST URL endpoint to receive JSON alert payloads.

[!IMPORTANT] Apify Email Delivery Policy:

• Free / Trial Apify Accounts: Apify's security policy restricts email sending only to the email address registered with your Apify account.
• Paid Apify Plans: Full capability to send email notifications to any external email address or team address.

Example Input JSON

{
  "subreddit": "r/webscraping",
  "keywords": ["apify", "playwright", "crawlee"],
  "notificationEmail": "your-registered-email@example.com",
  "webhookUrl": "https://example.com/api/webhooks/reddit"
}

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🔄 Monitoring Workflow & Checkpoint Rules

1. First-Run Initialization

On its very first run, the Actor fetches the subreddit /new listing, identifies the newest visible post, and saves its ID as the baseline checkpoint in the persistent Key-Value Store. No notifications are sent during initialization to avoid flooding you with historical alerts.

2. Normal Scheduled Runs

On subsequent runs:

1. The Actor loads the stored lastPostId from the persistent store and checks its age (lastRunAt).
2. If lastRunAt is under 24 hours old, the Actor identifies all posts published after lastPostId.
3. The Actor opens each new post individually in the browser with human-like pacing (1.2s - 2.5s delay) to extract the full body text.
4. Each post is evaluated against your target keywords (title and full body text).
5. If matching keywords are found, Email and/or Webhook notifications are triggered immediately.
6. The persistent checkpoint is updated with the newest post ID visible at the start of the run.

3. 24-Hour Checkpoint Expiration

If the Actor has not executed for more than 24 hours (e.g., if a schedule was paused or interrupted), the old checkpoint is safely expired. The Actor sets a new baseline checkpoint from the current newest post and exits without sending historical notifications.

4. Deleted Post Recovery

If a previously checkpointed post was deleted or removed by Reddit moderators, the Actor logs a warning, processes all visible posts safely, and updates the checkpoint without crashing.

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📩 Notification Formats

Email Alerts

Sent directly to your notificationEmail using apify/send-mail. Includes post title, subreddit name, matched keywords, post excerpt, and a direct link to the post.

Webhook JSON Payload

Sent as an HTTP POST request to webhookUrl:

{
  "event": "REDDIT_POST_MATCH",
  "subreddit": "webscraping",
  "matchedKeywords": ["apify"],
  "post": {
    "id": "1v65ksd",
    "title": "How to build an Apify Actor with Playwright",
    "url": "https://www.reddit.com/r/webscraping/comments/1v65ksd/how_to_build_an_apify_actor_with_playwright/",
    "createdAt": "2026-07-25T11:13:45.985Z"
  }
}

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⏰ Setting Up an Automated Schedule

To monitor subreddits continuously:

1. Save an Apify Task: Save your input settings as a Task in the Apify Console.
2. Create a Schedule: Navigate to Schedules in the Apify Console menu.
3. Add Task to Schedule: Select your saved Task and set your desired frequency (e.g., every 15 minutes, every hour).

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⚙️ Technical Specifications & Permissions

• Tech Stack: Built with TypeScript, Apify SDK v3, Crawlee, and Playwright.
• Permissions: Requires standard Limited Permissions. Does not require full account access.
• State Storage: Uses persistent named Key-Value Stores (reddit-monitor-sub-{subreddit}) to preserve checkpoint state across scheduled runs.

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❌ Out of Scope / Limitations

To maintain high speed, low cost, and stability, this Actor does NOT:

• Monitor post comments or comment threads.
• Support multiple subreddits simultaneously (create multiple Apify Tasks for multiple subreddits).
• Perform historical catch-up scraping.
• Use AI, regex syntax in input keywords, or semantic search.