Substack API Documentation

Endpoint URL

https://substack.com/api/v1/publication/search

Method

Parameters

{
  query: string,     // Search term
  skipExplanation: 'false',
  sort: 'relevance',
  page: number,      // Page number (0-based)
  limit: number      // Results per page (max 100)
}

Required Headers

{
  'User-Agent': 'Mozilla/5.0',
  'Accept': 'application/json',
  'Origin': 'https://substack.com',
  'Referer': 'https://substack.com/discover'
}

Description

Search for Substack newsletters. Returns publication details including subscriber counts, engagement metrics, and metadata.

Example

GET https://substack.com/api/v1/publication/search?query=tech&page=0&limit=10

Endpoint URL

https://{publication}.substack.com/api/v1/posts/{post_slug}

Method

Required Headers

{
  'Accept': 'application/json',
  'User-Agent': 'Mozilla/5.0'
}

Description

Fetch engagement statistics for a specific post including likes, comments, and restacks.

Example

GET https://technews.substack.com/api/v1/posts/welcome-post

Endpoint URL

https://{publication}.substack.com/{format}

Method

Description

Fetch publication's RSS feed containing recent posts.

Example

GET https://technews.substack.com/feed

Endpoint URL

https://{publication}.substack.com/p/{article-slug}

Method

Description

Fetch full article content. Returns HTML that contains the article's content and metadata.

Example

GET https://technews.substack.com/p/welcome-post

Description

• Implement reasonable delays between requests • Handle API errors gracefully • Cache results when possible • Respect Substack's terms of service

Description

• Use proper user agent headers • Include error handling • Cache frequently accessed data • Implement pagination for large result sets • Handle redirects for RSS feeds • Process multiple posts in parallel using async requests