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FlockStack

MCP server

Newsletter MCP server for Claude and AI agents

FlockStack's MCP server lets an AI assistant run your newsletter: draft issues, send tests, schedule and send campaigns, add subscribers, build segments and automations and read reports. It gives the assistant one tool for each of the dashboard's actions, under the same checks and limits, and the tools that send are marked as actions that can't be undone, so assistants ask you first. It comes with every plan, the Free plan included.
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  • One tool per action234 tools, 97 of them read-only, with the same inputs and errors as the REST API.
  • Sign in, no key to copyChatGPT, Claude and Grok Bot connect with OAuth: you sign in to FlockStack and allow them.
  • Sending asks firstTools that send can't be undone, and say so, so most clients ask you before running them.
  • Yours to revokeConnected apps are listed on the API keys page; revoke one and its tokens stop working at once.

What your assistant can do

Everything the dashboard does is a tool: 234 of them, in 38 groups. A few of them:

  • Write a draft from your notes, in Markdown or HTML (create_campaign), then send a test (send_test_email).
  • Schedule it or send it now (schedule_campaign, send_campaign), after you confirm.
  • Read how the last issue did: delivery, opens, clicks, bounces and unsubscribes (get_campaign_report).
  • Add subscribers or import a list, with the same checks as the dashboard's CSV import (add_contact, import_contacts).
  • Build a segment from rules, or a welcome series that runs on its own (create_segment, create_automation).

Things to ask once it's connected:

  • "Draft this week's issue from these links, and send me a test."
  • "How did last Tuesday's issue do compared with the one before?"
  • "Make a segment of readers who opened anything in the last 30 days."
  • "Schedule the draft for Thursday at 9am my time."

Connect your assistant

Each assistant connects one of two ways:

Assistant How it connects Setup
Claude Custom connector, sign in to FlockStack Claude setup
ChatGPT Custom MCP server, sign in to FlockStack ChatGPT setup
Grok Bot Ask it to add the server, then sign in Grok Bot setup
Claude Code One command, with a full access API key Claude Code setup
Codex Its config file or one command, with a full access API key Codex setup
Cursor Its mcp.json, with a full access API key Cursor setup

The server's address is https://flockstack.io/mcp. In Claude Code, with the key in FLOCKSTACK_API_KEY:

Terminal
claude mcp add --transport http --scope user flockstack https://flockstack.io/mcp \
  --header "Authorization: Bearer $FLOCKSTACK_API_KEY"

In Cursor, ~/.cursor/mcp.json:

JSON
{
  "mcpServers": {
    "flockstack": {
      "url": "https://flockstack.io/mcp",
      "headers": {
        "Authorization": "Bearer ${env:FLOCKSTACK_API_KEY}"
      }
    }
  }
}

ChatGPT offers custom MCP servers on some plans and workspaces only; the setup page lists which.

Sending asks you first

schedule_campaign, send_campaign, send_campaign_to_more, resend_campaign, resume_campaign, activate_automation are marked as destructive, and the server's instructions tell the assistant to show you the subject and how many contacts it goes to, and to ask you to confirm, before running them. Most clients ask before running them. A test email goes to the account owner unless you name up to 10 addresses, and nobody on your list gets it. A campaign that is already sending answers conflict, so a retry never sends twice.

The assistant works under the same rules as you do in the dashboard: plan limits, the from address and postal address checks, campaigns that pause when bounces or complaints climb, and blocked accounts.

Access you can take back

An app you connect with OAuth gets the same access as a full access key, in your account only. The API keys page lists connected apps with when each was last used; revoke one and its tokens stop working right away. A signups only key sees one tool, add_contact, and nothing else.

Protocol details

  • Streamable HTTP, stateless: every request carries a key or a token, with no sessions.
  • OAuth follows the MCP authorization spec, with the authorization code flow and PKCE. Access tokens last an hour; refresh tokens keep the connection for 90 days after its last use.
  • Keys start with mc_, or mc_eu_ for an account in the European Union, which connects to https://eu.flockstack.io/mcp.

The MCP documentation has each client's steps and every tool. To call the same actions from your own code instead, use the newsletter API.

Questions

What is a newsletter MCP server?
An MCP server gives an AI assistant tools it can call. FlockStack's gives it the newsletter's actions, so an assistant like Claude or ChatGPT can draft, schedule and send issues, manage subscribers and read reports for you.
Which AI assistants work with FlockStack's MCP server?
ChatGPT, Claude and Grok Bot connect by signing in to FlockStack. Claude Code, Codex and Cursor connect with a full access API key.
Can the assistant send a newsletter without asking me?
The tools that send or start emails (schedule_campaign, send_campaign, send_campaign_to_more, resend_campaign, resume_campaign, activate_automation) are marked as actions that can't be undone, and the server's instructions tell the assistant to confirm with you first. Most clients ask before running them. Approving a send is still your call, so read what it's about to do.
Do I need an API key?
Not for ChatGPT, Claude and Grok Bot: they sign in with OAuth. Claude Code, Codex and Cursor use a full access key from the API keys page.
Does it work for accounts in the EU region?
Yes. EU accounts connect to https://eu.flockstack.io/mcp, and their keys start with mc_eu_. Keys only work at their own region's address.
Is the MCP server included in my plan?
Yes, on every FlockStack Cloud plan, the Free plan included, and on every self-hosted server. Emails it sends count toward your plan like any other.

Connect your assistant

Create your account, then add FlockStack to Claude, ChatGPT or your code editor.

Start with FlockStack