Connect ChatGPT, Gemini, Cursor and n8n to Flomixy

Flomixy's connection address is the same for every assistant: https://mcp.flomixy.com/mcp. What differs is how each assistant signs in: some can sign in with your Flomixy login (OAuth), some only accept an API key.

Which assistant, which sign-in

If you are not sure, use OAuth where it is offered: there is nothing to copy and nothing to leak.

Sign in with OAuth (Claude web, ChatGPT)

Only the workspace owner can connect an assistant this way. If you are not the owner, the consent screen tells you so; ask the owner to approve the request.

1. In the assistant, add a custom connector (in ChatGPT: a custom app, see the ChatGPT steps below) with the address https://mcp.flomixy.com/mcp. Leave any API key field empty.
2. Start the sign-in from the connector (the wording may differ slightly).
3. Sign in to Flomixy if you are not already.
4. Pick the workspace you want to connect.
5. Review the permissions on the Authorize access screen, then click Allow. Click Deny to cancel.

You are sent back to the assistant, which can now work with that workspace. Every post it creates still waits for human approval by default.

ChatGPT

ChatGPT connects only with OAuth. An API key does not work here, so do not spend time pasting one.

Use chatgpt.com in a browser; the desktop app may not offer custom connectors. Menu names below are as shown in the English interface (verified live, October 2026).

1. Open Settings → Security and turn on Developer mode (named "Developer mode" in English, "Programerski režim" in Serbian). It is only available on some plans.
2. Open Apps (the sidebar entry, in Settings it is "Apps"), click the + at the top right, and choose New app.
3. Fill in Name (for example "Flomixy"), leave Description empty, set the connection to Server URL with https://mcp.flomixy.com/mcp, and set Authentication to OAuth.
4. Tick I understand and want to continue, then click Create.
5. Open the new app, click the ... menu → Manage, then Connect another account and Sign in with your Flomixy account.
6. A Flomixy page asks you to Authorize access. Pick the workspace and click Allow. Only the workspace owner or a platform super admin sees Allow.
7. Start a new chat, make sure Flomixy is attached in the message box, and ask for something harmless such as "Show my last 5 Flomixy posts".

What ChatGPT is allowed to do

After you click Allow, ChatGPT can read and create posts, list your connected accounts and brands, read and upload media, read the posting schedule and best times, and read analytics. The schedule and analytics permissions are only offered when the workspace owner signs in.

Every post ChatGPT creates waits for a person to approve it. ChatGPT cannot be given the skip-approval permission: it is not available through sign-in, so nothing it creates is published on its own.

If you connected ChatGPT before October 2026, disconnect it and connect it again to get these permissions. If you see a 401 or 500 error while signing in, see Troubleshooting your AI assistant connection.

Gemini

• Gemini CLI connects with an API key. Add this to your settings.json (usually ~/.gemini/settings.json), with your own key in place of YOUR_API_KEY:

{
  "mcpServers": {
    "flomixy": {
      "httpUrl": "https://mcp.flomixy.com/mcp",
      "headers": {
        "x-api-key": "YOUR_API_KEY"
      }
    }
  }
}

Restart the CLI and run /mcp to check that flomixy is listed as connected. Create the key as described in Connect an AI assistant to Flomixy.

• The Gemini web app connects with OAuth (no API key). It is available to personal Google accounts only, aged 18 or over and in the US, with Keep Activity turned on; work and school accounts are not supported.

  1. On gemini.google.com open Settings → Connected Apps (if you do not see it, click Personal Intelligence first).
  2. Under Custom apps enter https://mcp.flomixy.com/mcp and click Next, then Connect and Agree and continue.
  3. On the Flomixy Authorize access page pick the workspace you want Gemini to use and click Allow (workspace owner or platform super admin only). Check the workspace name before you click Allow.
  4. In a new chat type @ and pick the Flomixy app, then ask for your accounts or a draft post. Gemini asks you to allow each tool call.

  Every post Gemini creates waits for human approval, same as with ChatGPT.

Cursor and n8n

Both use an API key. Create a key first (Settings → API keys), starting with read-only scopes.

Cursor: add the server in Cursor's MCP settings, or edit ~/.cursor/mcp.json directly:

{
  "mcpServers": {
    "flomixy": {
      "url": "https://mcp.flomixy.com/mcp",
      "headers": {
        "x-api-key": "YOUR_API_KEY"
      }
    }
  }
}

n8n: add an MCP Client Tool node to your AI agent and set:

• Endpoint: https://mcp.flomixy.com/mcp
• Server Transport: HTTP Streamable (not the deprecated SSE option)
• Authentication: Header Auth, with the header name x-api-key and your API key as the value

Store the key in n8n credentials, never directly in a workflow you share or export.

Disconnect

• Assistants connected with OAuth: open Connected apps in your Flomixy settings, find the app, click Revoke, then confirm Revoke access?. The app loses access immediately and you can connect it again later.
• Assistants connected with an API key: open Settings → API keys and revoke the key. Every tool using that key stops working at once.

Troubleshooting

• I see a 401 or 500 error while signing in with ChatGPT. The cause is on Flomixy's side, not in ChatGPT or your settings, so recreating the app will not help. Contact Flomixy support with the time of the attempt and the workspace name.
• ChatGPT says authentication failed. Make sure you chose OAuth and left the API key empty; ChatGPT cannot use a key.
• The consent screen says only the owner can connect. Ask the workspace owner to do the sign-in.
• "This authorization link is invalid or has expired." Start the connection again from the assistant.
• "Unauthorized" with an API key. The key was copied wrong, revoked, or lacks the scope for that action. Create a new key.
• The assistant cannot see the tools. Check that the connector is switched on in the chat, or that /mcp shows it connected.