Substack Publication Recommendations API

Endpoint

GET /v1/substack/publication/recommendations

Parameters

publication

Publication subdomain (lenny), host (lenny.substack.com, www.lennysnewsletter.com) or any URL on it (max 500 characters). Provide either publication or publication_id.

publication_id

Numeric publication ID, as returned in publication_id. Provide either publication or publication_id.

Response fields

publication

The publication (publication_id, name, subdomain, url, logo_url)

recommends

Publications this publication recommends

publication_id

Publication ID

name

Publication name

subdomain

Substack subdomain

url

Publication home URL

logo_url

Logo URL

description

Publication tagline

author

Primary author's handle

author_name

Primary author's display name

author_id

Primary author's user ID

author_url

Link to the primary author's profile

language

Language code

paid_enabled

Whether paid subscriptions are enabled

blurb

The recommender's note about the publication, empty when none

date

Date the recommendation was made (UTC)

recommended_by

Publications that recommend this publication (the most recent 50), same fields

recommends_count

Number of outgoing recommendations returned

recommended_by_count

Number of incoming recommendations returned

Example Request

curl "https://apidirect.io/v1/substack/publication/recommendations?publication=lenny"   -H "X-API-Key: YOUR_API_KEY"

import requests

response = requests.get(
    "https://apidirect.io/v1/substack/publication/recommendations",
    headers={"X-API-Key": "YOUR_API_KEY"},
    params={"publication": "lenny"}
)
print(response.json())

Example Response

{
  "publication": {
    "logo_url": "https://substackcdn.com/image/fetch/$s_!8MSN!,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2F…",
    "name": "Lenny's Newsletter",
    "publication_id": "10845",
    "subdomain": "lenny",
    "url": "https://www.lennysnewsletter.com"
  },
  "recommended_by": [
    {
      "author": "deepthiconnects",
      "author_id": "496409115",
      "author_name": "Deepthi",
      "author_url": "https://substack.com/@deepthiconnects",
      "blurb": "",
      "date": "2026-10-11 04:59:17",
      "description": "My personal Substack",
      "language": "en-gb",
      "logo_url": "https://substack-post-media.s3.amazonaws.com/public/images/3e9d7ce7-391a-454e-b54e-a5732b0dde33_1254x1254.png",
      "name": "YStartUps",
      "paid_enabled": false,
      "publication_id": "11624830",
      "subdomain": "ystartups",
      "url": "https://ystartups.substack.com"
    }
  ],
  "recommended_by_count": 50,
  "recommends": [
    {
      "author": "merlindotinc",
      "author_id": "510813323",
      "author_name": "Merlin",
      "author_url": "https://substack.com/@merlindotinc",
      "blurb": "",
      "date": "2026-05-25 20:11:01",
      "description": "learn about silicon valley companies, people, jobs, and ideas through the eyes of two startup junkies.",
      "language": "",
      "logo_url": "https://substack-post-media.s3.amazonaws.com/public/images/1e2e78d1-1693-48ab-9755-ea88a06e2f23_1080x1080.png",
      "name": "early days",
      "paid_enabled": false,
      "publication_id": "9047553",
      "subdomain": "earlydaysbymerlin",
      "url": "https://earlydaysbymerlin.substack.com"
    }
  ],
  "recommends_count": 11
}

Frequently asked questions

Is recommended_by complete?

Substack returns the most recent 50 publications recommending a given publication. recommends (outgoing) is complete.

How does pricing work?

You only pay for successful requests. The Substack Publication Recommendations API costs $0.003 per request. There are no monthly fees or commitments. You get 50 free requests per endpoint every month.

Do I need a credit card to start?

No. You can sign up and use the free tier (50 requests/endpoint/month) without adding a payment method. You only need to add a card when you want to exceed the free tier.

Are there rate limits?

Yes, there's a concurrency limit of 10 simultaneous requests per endpoint per user. If you need more, just get in touch.