Turns out Substack does have an API 🤯

You can automate everything:

• Reading posts

• Importing subscribers

• Getting stats

Here's how:

1. Go to Substack/Notes for web

2. Enable Google Developer Tools (F12)

3. Perform an action you want to automate. You will see a network request. Note:

   1. Action (POST or GET)

   2. URL of a specific endpoint, e.g., .../api/v1/subscriber/add

   3. Body (Payload), e.g., {email = “***”, subscribtion = “***”, sendEmail = “***”}

   4. Cookie - extract only connect.sid, ignore other values, e.g., { “cookie”: “connect.sid=*************”}

4. Use a tool like n8n to perform the same web request in your workflow. You only need GET/POST, endpoint URL, body (payload), and Cookie (with connect.sid).

That’s it. Examples below.

New to n8n?

My post (below) might help.

Important

The authentication token (connect.sid) stays valid for months if you do not sign out — even with MFA enabled.

Store it securely. Consider creating an extra account with only the necessary permissions. Rotate it regularly by signing out and signing in again (even if you do not use the API).

The API has been reliable in all my tests, but remember it’s not official or documented. According to my tests: avoid sending more than 1 request/sec.

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After 3 years, this completely changed my workflows. I wish I had found it earlier.

Hope that helps others too.