Substack does not offer a third-party OAuth path for bulk subscribers. The honest workflow is a guided export — and it is still the fastest way to see who is actually on your list.
Minutes 0–2: export
- Publication dashboard → Subscribers → All subscribers
- ⋯ menu → Export → all columns
- Save the CSV locally
Minutes 2–6: import
- Open ListFunnel → Connections → Substack Connection Studio
- Name the publication (optional) and upload the CSV
- ListFunnel maps email, free/paid type, signup date, and opens automatically
Minutes 6–10: report + resolve
- Open the generated audience report (free vs paid, opens)
- Run identity resolution on the new list
- Read core readers and active non-buyers before you write the next issue
Optional: if Substack enabled the Publisher API for your pub, paste the key in the studio for counts and email lookup. It is not a full list sync — do not expect Mailchimp-style continuous pull.
Run this on your own list.