Substack Posts Tracker

Substack Posts Tracker fetches posts from any Substack newsletter — returning title, subtitle, publication date, word count, reading time, reactions, comments, and post URL. Supports multiple publications, keyword filtering, date range, and free-only mode. Substack's public API, no authentication required. $0.002/post.

Substack has become the primary publishing platform for independent analysis in crypto, tech, finance, and politics. The best alpha and insight lives in newsletters that don't have RSS readers. This actor makes any Substack programmatically accessible for research, monitoring, and content pipelines.

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Why use Substack Posts Tracker?

1. Research and analysis pipeline — Track the most-cited newsletters in your domain. High-reaction posts from top writers often precede mainstream coverage of emerging ideas.
2. Investment research reading list — Monitor crypto/finance newsletters (e.g. Bankless, Delphi Digital, The Block) for new posts and route them to your reading workflow automatically.
3. Content curation for newsletters — Pull top-performing posts (reactions_count descending) from multiple publications to curate weekly roundups.
4. Competitive intelligence — Monitor how competitors are positioning their content and what topics get the most engagement in your niche.
5. Academic and media research — Track publication frequency, word count trends, and topic evolution for specific writers over time.

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How to use

1. Open the actor on Apify Store and click Try for free.
2. Set publications to a list of Substack subdomains or custom domains (e.g. ["gwern.substack.com", "stratechery.com"]).
3. Set keyword to filter to specific topics, or leave blank for all posts.
4. Set since to limit to recent posts only.
5. Click Start. Returns structured post records from each publication.

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Input

Field	Type	Default	Description
publications	string[]	required	Substack URLs or subdomains (e.g. "gwern.substack.com", "stratechery.com")
maxPostsPerPublication	integer	25	Max posts per newsletter (1–500)
keyword	string	—	Filter by keyword in title or subtitle (case-insensitive)
freeOnly	boolean	true	Skip paywalled posts (only return publicly accessible content)
since	string	—	ISO 8601 date cutoff — skip posts older than this (e.g. "2024-01-01")

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Output

{
  "publication": "Gwern's Newsletter",
  "publication_url": "https://gwern.substack.com",
  "id": 123456,
  "title": "GPT-4 Capability Overview",
  "subtitle": "A deep dive into what GPT-4 can and cannot do",
  "slug": "gpt-4-capability-overview",
  "url": "https://gwern.substack.com/p/gpt-4-capability-overview",
  "type": "newsletter",
  "audience": "everyone",
  "post_date": "2024-03-15T12:00:00.000Z",
  "word_count": 4200,
  "reading_time_minutes": 21,
  "reactions_count": 312,
  "comments_count": 47,
  "cover_image": "https://substackcdn.com/..."
}

Key output fields

Field	Type	Description
type	string	newsletter, podcast, or thread
audience	string	everyone (free), public, or paid (paywalled)
word_count	integer	Full word count of the post
reading_time_minutes	integer	Estimated at 200 words per minute
reactions_count	integer	Total likes/emoji reactions
comments_count	integer	Total comments

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Cost estimation

Pay-Per-Event: $0.005 actor start + $0.002 per post returned.

Use case	Posts	Estimated cost
25 posts from 1 newsletter	25	~$0.055/run
100 posts from 3 newsletters	100	~$0.205/run
Weekly monitoring (50 new posts)	50	~$0.105/week
500 posts from 5 newsletters	500	~$1.005/run

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FAQ

Does it work with custom domains (not .substack.com)? Yes — custom domains like stratechery.com or mattstoller.substack.com are supported. Enter the primary domain and the actor resolves the Substack API endpoint automatically.

Can I get the full post content (body text)? The actor returns metadata, title, subtitle, and audience type. Full post body is only accessible from the post URL itself (and may be paywalled for paid audience posts).

What does freeOnly: true do? When enabled (default), the actor skips posts with audience: "paid" — only publicly accessible posts are returned. Set to false to see all post metadata including paywalled titles (body still won't be accessible without a subscription).

Does it support multiple publications at once? Yes — pass multiple subdomains in publications. Requests run 3 concurrent publications at a time with rate-limit backoff.

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Related actors

• Tech News Aggregator — Aggregate news from 6 tech publications alongside Substack newsletters
• Reddit Subreddit Tracker — Reddit community discussion to complement newsletter analysis
• Crypto News Sentiment Analyzer — AI sentiment scoring for crypto-focused newsletter content

Feedback

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