How to Automatically Add Your Substack Subscribers to Kit (formerly ConvertKit)

A simple 3-step automation to consolidate your email subscribers—no API or complex coding required.

Here's something that has been frustrating me for the last month or so as I’ve migrated my newsletter - getting my Substack subscribers into Kit (formerly ConvertKit). Like many creators, I wanted all my email subscribers in one place while staying true to where people signed up and what they expected to receive.

The challenge?

Substack doesn't have a public API and doesn't work with Zapier. I kept hitting dead ends until I discovered an awesome solution that was right in front of me.

Let me walk you through the exact steps:

1. Set Up Gmail Filtering. Every time someone subscribes to your Substack, you get an email notification with their email address. Create a Gmail filter based on:

• From: The Substack no-reply address

• Subject line: new free subscriber to <your publication name>!

• Action: Apply a label (e.g. "Subscriber_Substack")

2. Configure Your Zap In Zapier:

• Trigger: New Labeled Email

• Select your Gmail label from step 1

• Add a Formatter step using Text formatting

• Select "Extract Email Address"

• Input: Body HTML from the labeled email

• Final step: Add subscriber to Kit with a "Substack" tag

This creates a simple 3-step automation that moves subscribers while maintaining clear tracking of where they came from.

A note on mindful list management: Remember that every email address represents a real person who trusted you with their attention. I'm careful to respect the original context of how someone subscribed.

Would you find this helpful for your email workflow? Let me know if you need any clarification on the technical setup.

P.S. - This works with any email platform that connects with Zapier - not just Kit. You can adapt the final step for Mailchimp, ActiveCampaign, Beehiiv or your preferred tool.