Substack MCP Server: Official vs Open Source (2026)

"Substack MCP" searches have grown fast in 2026, and the answer depends on who you are. If you are an admin of a Bestseller publication, Substack has an official server for you. If you aren't, the choice is between open-source servers you run yourself and hosted services, and they differ a lot in what they touch and how much risk they carry. This page compares all three as of October 2026.

newsletterapi is independent and not affiliated with Substack. We describe our own MCP server for Substack writers at the end, after the options from Substack and the community.

The problem

You've seen beehiiv and Kit writers drive their newsletters from Claude, and you want the same. Then you discover Substack's MCP server only works for Bestseller admins, or you never hear about it at all. On X, one writer said: "Can't believe Substack still doesn't have n MCP" (@_MsLinda). Another: "Substack has been annoying lately with no MCP or API/CLI support." (@ka1n0s).

In our review of public Reddit, X, Hacker News and GitHub posts, October 2026, MCP came up in 38 X posts about Substack from 35 different authors in 2026 alone (a keyword count, so treat it as an estimate). Many were writers asking for an MCP that already exists but is gated, like the post above; others were reacting to news of Substack's own MCP, as in this post. Below: what each kind of Substack MCP actually does, and which one fits if you are not a Bestseller. Other reader problems live on /problems.

Does Substack have an official MCP server?

Substack's help article, "How to connect Substack to your AI Assistant", describes a remote server at https://mcp.substack.com/api/v1/mcp. You add it as a custom connector in Claude, ChatGPT, Cursor or "any MCP-compatible client", sign in to Substack, and allow access.

Key facts as of October 2026:

• Eligibility: "You must be an Admin on the publication" and "Your publication must be a Bestseller publication."
• Data: "read-only access to publication data such as dashboard metrics, traffic data, and publication settings." The article's example prompts ask about subscriber count and revenue, paid retention, top traffic sources and free subscribers gained since January.
• Limits: it "cannot publish posts, send Notes, or modify your account" and "cannot access profile data or Notes activity."
• Auth: OAuth. The server's protected-resource metadata lists two scopes, mcp:read and mcp.user.read.
• Tools: the tool list is not public; it is only visible after you connect.

If you qualify, use it. It is the only Substack MCP that needs no API key, no password and no workaround.

What can I use if I'm not a Bestseller?

Developers have built their own because the official one is gated. They fall into two groups by how they reach Substack.

Built on the official Publisher API. dkships/substack-publisher-mcp wraps Substack's read-only Publisher API. Its tools list and search posts, get post stats, return daily subscriber counts by type, and look up one subscriber by email. You need a Publisher API key, and its README warns the option "may not be enabled for your publication yet." It is the cleanest open-source choice if you have a key.

Built on your browser session. The more popular servers log in as you:

Server	Notable tools	Access method
marcomoauro/substack-mcp	Draft posts, analytics reports, list and export subscribers, upload images	Session token
conorbronsdon/substack-mcp	Drafts, Notes, publication stats, growth sources, subscriber lookup, consented add, dry-run mode	Session cookie stored in the OS keychain
ma2za/python-substack	Draft from Markdown; also a CLI and MCP	Session cookie

Some of these are thoughtfully built. conorbronsdon's server, for example, keeps long-form posts as drafts ("so your agent can't send a newsletter on accident!", as its author put it) and asks for consent evidence before adding a subscriber. But they all depend on undocumented endpoints that change without notice. Substack's Terms of Use also forbid uses that "jeopardize the security of your Substack account", including "allowing someone else to log into Substack as you", and processes that run "while you are not logged into Substack". Running one locally, for your own publication, is a judgement call you make with your own account. We don't recommend pointing one at a publication you don't own.

Are hosted Substack MCP services safe to use?

Two commercial services sell Substack access as an API plus MCP:

• Cotlet offers about 50 Substack tools (posts, Notes, subscriber add, tag and export, stats). It runs a cloud browser that stays signed in to your Substack account, sells credit packs, and by default asks first before write actions.
• apisubstack sells a posting API with an MCP for a flat monthly fee, at 1 request per second.

Both reach Substack through a logged-in session held on their side. That is exactly the pattern Substack's terms target ("allowing someone else to log into Substack as you"), and if Substack acts on it, the risk falls on your account, not the vendor's. We describe these services so you can compare them. We don't recommend handing any third party your Substack login.

Which Substack MCP should I choose?

	Official Substack MCP	Publisher API wrapper	Session-based OSS servers	Hosted session services
Who can use it	Bestseller admins	Publications with a Publisher API key	Anyone	Anyone who pays
Read stats	Yes	Yes	Yes	Yes
Read posts	Not documented	Yes	Yes	Yes
Write posts or Notes	No	No	Yes (drafts, Notes)	Yes
Credentials	OAuth, in your client	Per-publication key	Your session	Your session, held by the vendor
Where it runs	Hosted by Substack	Self-hosted	Self-hosted, mostly local	Hosted by the vendor
Terms risk	None	Low (official surface, terms not public)	Account risk	Higher account risk
Breaks when Substack changes	Unlikely	Possible	Often	Often

For Notes specifically there is a cleaner path than any of these: Buffer's Substack integration lets Notes be created and scheduled through Buffer's API and MCP server, using Substack's partner authorization rather than your session.

How do I add a Substack MCP server to Claude?

For the official server, Substack's own steps are short:

1. In Claude (desktop or web), open Customize, then Connectors.
2. Click Add custom connector and enter https://mcp.substack.com/api/v1/mcp.
3. Click Add, sign in to Substack, and click Allow access. If you have several publications, choose the Bestseller one.
4. Start a new chat and ask about your publication.

Claude's custom connector guide adds two things worth knowing: on Claude's Free plan you are limited to one custom connector, and Team or Enterprise owners add connectors under Organization settings first. It also warns that custom connectors reach services Anthropic has not verified, so connect only to servers you trust.

Local open-source servers are different: they run as a process on your machine and are configured in Claude Desktop or Claude Code, not through the web connector screen. The full walkthrough, including what to do if you aren't a Bestseller, is in how to connect Claude to Substack.

What can no Substack MCP do today?

• No official write. No official surface publishes long-form posts. Notes go through Buffer or Typefully.
• No subscriber list. The official MCP talks about counts and retention; the Publisher API looks up one email at a time.
• No events. None of them can tell an agent "someone just subscribed." Substack has no webhooks; see Substack webhooks for the workarounds.
• Gated access. The official MCP needs Bestseller status; the Publisher API needs a key that not every publication has.

Will there be a Substack MCP that doesn't need my password?

The newsletterapi MCP server is a hosted, read-only server for Substack writers that works from your publication URL, public feeds and your own exports, so it needs no Substack password and no Bestseller badge. It sits next to Substack's official server in your agent; it doesn't replace it. A matching Posts API exposes the same archive as JSON. For the wider picture of what Substack offers developers, read does Substack have an API, and for other platforms see newsletter MCP servers compared.