Substack Newsletter Growth & Viral Posts Tracker

An Apify Actor to track top-performing Substack newsletters, viral posts, engagement analytics, subscriber growth tiers, and subscription pricing.

Ideal for content creators, newsletter operators, growth marketers, and AI research agents building competitive intelligence.

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⚡ Features

• Multi-Newsletter Scraping: Process single or multiple Substack newsletters in parallel by subdomain (lenny, pragmaticengineer, platformer) or full domain URL.
• Viral & Top Posts Discovery: Sort articles by top (highest all-time engagement & likes) or new (latest published).
• Engagement Metrics: Extracts raw heart reactions / likes, user comment counts, and post dates.
• Paywall Intelligence: Detects whether an article is free (everyone) or locked behind a paid membership (only_paid).
• Growth & Monetization Intel: Extracts subscriber size scale (e.g., Over 1,200,000 subscribers), bestseller tier badges, and active pricing plans (monthly/annual subscription tiers).
• Zero Browser Overhead: Pure HTTP API & metadata extraction—fast, lightweight, and cost-effective.
• MCP & AI-Ready: Fully structured JSON output adhering to standard dataset and Model Context Protocol schemas.

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📥 Input Parameters

Parameter	Type	Default	Description
subdomains	Array (stringList)	["lenny", "pragmaticengineer"]	(Required) List of Substack subdomains or URLs to analyze.
sortBy	String (select)	"top"	Ranking order: top (highest engagement) or new (most recent).
maxPostsPerPub	Integer	10	Maximum number of posts to fetch per newsletter (1–50).
extractPubMetrics	Boolean	true	Extract publisher scale, subscriber tier, and pricing plan details.

Sample Input

{
  "subdomains": [
    "lenny",
    "pragmaticengineer"
  ],
  "sortBy": "top",
  "maxPostsPerPub": 5,
  "extractPubMetrics": true
}

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📤 Output Data Format

Each item pushed to the default dataset represents an individual article with attached publication context:

{
  "publication": "Lenny's Newsletter",
  "subdomain": "lenny",
  "author": "Lenny Rachitsky",
  "subscriberTier": "Over 1,200,000 subscribers",
  "paidTier": "Tens of thousands of paid subscribers",
  "pricingPlans": [
    "20 USD/custom",
    "200 USD/custom",
    "400 USD/custom"
  ],
  "title": "How to turn your AI into a world-class designer",
  "subtitle": "A step-by-step framework to get stunning visuals, prototypes, and landing pages from Claude, ChatGPT, and Midjourney.",
  "description": "A step-by-step framework to get stunning visuals...",
  "likes": 1171,
  "comments": 23,
  "audience": "only_paid",
  "postDate": "2026-09-01T12:45:59.568Z",
  "postUrl": "https://www.lennysnewsletter.com/p/how-to-turn-your-ai-into-a-world-class-designer",
  "postId": 148382912,
  "type": "newsletter"
}

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💡 Use Cases

1. Content Ideation & Topic Mining: Uncover what hooks, topics, and frameworks drive 1,000+ likes on Substack.
2. Pricing & Packaging Benchmarking: Analyze monthly vs. annual pricing points across leading writers in your niche.
3. Lead Generation for PR & Sponsorships: Identify top-tier newsletter operators with verifiable subscriber reach for sponsorship outreach.
4. AI Agent Research Feeds: Provide real-time competitive intelligence to your LLM-based writing and research workflows.