Substack API/FAQ
Does Substack have an API?
Yes — a small official one. Substack does not offer a general-purpose public API for posts, search, or publication archives. That gap is what unofficial live APIs fill.
Does Substack have an official API?
Yes, but it is narrow. In 2026 Substack published a Developer API that looks up a public creator profile from a LinkedIn handle. Access is gated: you apply, accept their terms, and mint a token. It is not a general API for posts, search, feeds, comments, or archives.
What about Substack’s official MCP?
Substack also runs a remote MCP server for publication analytics. That is OAuth-gated and aimed at admins of Bestseller publications. It does not expose public search or archive reads.
How do you read public posts, search, and archives?
Per-publication RSS covers a slice of posts. For search, feeds, comments, profiles, and full archives, developers use unofficial APIs that wrap Substack’s public web JSON. GloStream’s Substack Live API is that read surface, sold on RapidAPI.
Is the GloStream API affiliated with Substack?
No. It is unofficial, independent, and can break when Substack changes their site. It does not publish posts, manage subscribers, or use your Substack login.
Official vs unofficial
Use Substack’s Developer API when you need a verified creator profile from a LinkedIn handle. Use GloStream Substack Live when you need public search, feeds, comments, profiles, or archives. Checkout is on RapidAPI. Routes are on the docs.