Substack

Retrieve posts from any Substack newsletter via its internal API, with full authenticated access to paid/subscriber-only content.

Built using the website-to-api pattern. If this skill breaks, use the website-to-api meta-skill to re-discover the API.

If This Breaks

This skill uses Substack's internal, undocumented API. If commands fail:

1. Read the error — 401/403 likely means expired cookie or renamed cookie.
2. Re-discover using the website-to-api meta-skill.
3. Update this skill — fix the script and SKILL.md with the new API shape.

Known past changes: the session cookie was renamed from connect.sid to substack.sid. The COOKIE_NAME constant in the script controls this.

Prerequisites