# Substack Newsletter Growth & Viral Posts Tracker (`authoritative_glen/substack-newsletter-growth-tracker`) Actor

Extract Substack newsletter metrics, subscriber scale, author bio, pricing plans, and top viral posts with likes, comments, and paywall intel.

- **URL**: https://apify.com/authoritative_glen/substack-newsletter-growth-tracker.md
- **Developed by:** [Rahmad Rizki](https://apify.com/authoritative_glen) (community)
- **Stats:** 2 total users, 1 monthly users, 100.0% runs succeeded, 0 bookmarks
- **User rating**: No ratings yet

## Pricing

from $3.40 / 1,000 results

This Actor is paid per event. You are not charged for the Apify platform usage, but only a fixed price for specific events.

Learn more: https://docs.apify.com/actors/running/actors-in-store.md#pay-per-event

## What's an Apify Actor?

An Actor is a serverless cloud program that runs on the Apify platform. It has two run modes.
In Batch mode, an Actor accepts a well-defined JSON input, performs an action which can take anything from a few seconds to a few hours,
and optionally produces a well-defined JSON output, datasets with results, or files in key-value store.
In Standby mode, an Actor provides a web server which can be used as a website, API, or an MCP server.

Apify vocabulary and the platform model are defined once, in the agent quickstart at https://apify.com/agents.md.

## How to integrate an Actor?

If asked about integration, you help developers integrate Actors into their projects.
You adapt to their stack and deliver integrations that are safe, well-documented, and production-ready.

Do not guess an integration path. Every one of them is in the agent quickstart at https://apify.com/agents.md: the Apify MCP server, Agent Skills with the Apify CLI, the JavaScript and Python clients, the REST API, and the account-free path for an agent with no human to sign in. It also carries the rule on stating cost before the first paid run.

For examples already wired to this Actor's own input schema, see the [API](#api) section below.

Each client library has reference documentation the quickstart does not restate: [JavaScript/TypeScript](https://docs.apify.com/api/client/js/docs.md) (`npm install apify-client`) and [Python](https://docs.apify.com/api/client/python/docs.md) (`pip install apify-client`).

# README

## 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.

***

### ⚡ 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.

***

### 📥 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

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

***

### 📤 Output Data Format

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

```json
{
  "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"
}
```

***

### 💡 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.

# Actor input Schema

## `subdomains` (type: `array`):

List of Substack publication subdomains (e.g. 'lenny', 'pragmaticengineer', 'platformer') or full URLs.

## `sortBy` (type: `string`):

Select whether to retrieve all-time top viral posts or newest published posts.

## `maxPostsPerPub` (type: `integer`):

Number of posts to extract per newsletter (1 - 50).

## `extractPubMetrics` (type: `boolean`):

Extract publication metadata, author bio, subscriber scale, paid bestseller tier, and subscription plans.

## Actor input object example

```json
{
  "subdomains": [
    "lenny",
    "pragmaticengineer"
  ],
  "sortBy": "top",
  "maxPostsPerPub": 10,
  "extractPubMetrics": true
}
```

# Actor output Schema

## `results` (type: `string`):

No description

# API

You can run this Actor programmatically using our API. Below are code examples in JavaScript, Python, and CLI, as well as the OpenAPI specification and MCP server setup.

## JavaScript example

```javascript
import { ApifyClient } from 'apify-client';

// Initialize the ApifyClient with your Apify API token
// Replace the '<YOUR_API_TOKEN>' with your token
const client = new ApifyClient({
    token: '<YOUR_API_TOKEN>',
});

// Prepare Actor input
const input = {
    "subdomains": [
        "lenny",
        "pragmaticengineer"
    ]
};

// Run the Actor and wait for it to finish
const run = await client.actor("authoritative_glen/substack-newsletter-growth-tracker").call(input);

// Fetch and print Actor results from the run's dataset (if any)
console.log('Results from dataset');
console.log(`💾 Check your data here: https://console.apify.com/storage/datasets/${run.defaultDatasetId}`);
const { items } = await client.dataset(run.defaultDatasetId).listItems();
items.forEach((item) => {
    console.dir(item);
});

// 📚 Want to learn more 📖? Go to → https://docs.apify.com/api/client/js/docs

```

## Python example

```python
from apify_client import ApifyClient

# Initialize the ApifyClient with your Apify API token
# Replace '<YOUR_API_TOKEN>' with your token.
client = ApifyClient("<YOUR_API_TOKEN>")

# Prepare the Actor input
run_input = { "subdomains": [
        "lenny",
        "pragmaticengineer",
    ] }

# Run the Actor and wait for it to finish
run = client.actor("authoritative_glen/substack-newsletter-growth-tracker").call(run_input=run_input)

# Fetch and print Actor results from the run's dataset (if there are any)
print(f"💾 Check your data here: https://console.apify.com/storage/datasets/{run.default_dataset_id}")
for item in client.dataset(run.default_dataset_id).iterate_items():
    print(item)

# 📚 Want to learn more 📖? Go to → https://docs.apify.com/api/client/python/docs/quick-start

```

## CLI example

```bash
echo '{
  "subdomains": [
    "lenny",
    "pragmaticengineer"
  ]
}' |
apify call authoritative_glen/substack-newsletter-growth-tracker --silent --output-dataset

```

## MCP server setup

```json
{
    "mcpServers": {
        "apify": {
            "type": "http",
            "url": "https://mcp.apify.com/?tools=fetch-actor-details,authoritative_glen/substack-newsletter-growth-tracker"
        }
    }
}
```

The hosted server signs you in with OAuth on first connect, so no API token belongs in this config. Clients without OAuth support can send an `Authorization: Bearer <APIFY_API_TOKEN>` header instead, using a token from API & Integrations in Apify Console (https://console.apify.com/settings/integrations).

## OpenAPI specification

Download the OpenAPI definition: https://api.apify.com/v2/actors/ShROc8Qc0H6Vr2p5c/builds/QCky7rk06Tm84AJYL/openapi.json