Beta: The Mixmax MCP server is in beta, available through Mixmax Labs at no extra cost. As it matures, some capabilities may become part of specific Mixmax plans.
Mixmax is an approved partner app in the ChatGPT app store - but there are two different ways to connect it, and they don't give ChatGPT the same access. Which one you pick depends on what you want ChatGPT to be able to do.
Note: The official app store listing only gives ChatGPT read access to your meetings and sequences — nothing else, regardless of what you've turned on in MCP settings. To use the full set of capabilities, including any write actions like sending email or managing tasks, connect manually instead. See Two ways to connect below.
Before you start
Turn on the MCP server experiment in Mixmax Labs: open Settings & feedback in the sidebar's Mixmax Labs section and toggle the experiment on. Enabling it adds MCP settings to your sidebar, where per-capability permissions live. For how Labs works, see Mixmax Labs overview.
Two ways to connect
Method | What ChatGPT can access |
Official app store listing | Read-only access to meetings and sequences. Nothing else is available through this listing, even if you've turned on write capabilities in MCP settings. |
Manual (custom connector) | The full toolset — every capability listed in MCP settings, on the same reads-on/writes-opt-in basis as any other client. |
If you only need meeting and sequence data, the app store listing is the faster setup. If you want ChatGPT to act for you — draft and send email, manage tasks or reminders, build sequences — use the manual method.
Install from the ChatGPT app store (meetings and sequences)
In ChatGPT, open Settings, then Apps & Connectors.
Find Mixmax in the directory and click Connect.
A browser window opens. Sign in to Mixmax and approve access.
This connects you to meeting and sequence reads only. If you need anything more, use the manual method below instead — turning on write levers in MCP settings won't add tools to this connection.
Connect manually (full toolset)
In ChatGPT, open Settings, then Apps & Connectors, then Advanced, and turn on Developer mode. (Developer mode is available on Plus, Pro, Business, Enterprise, and Edu plans.)
Go back to Apps & Connectors and click Create.
Enter a name (Mixmax) and the server URL:
https://mcp.mixmax.com/mcp, then save.A browser window opens. Sign in to Mixmax and approve access.
With this method, what ChatGPT can actually do is controlled entirely by your MCP settings — reads are on by default, and each write capability is a lever you turn on yourself.
Signing in
The first time ChatGPT calls Mixmax, the server answers with a 401. That's expected, not an error — it kicks off the sign-in flow:
A browser window opens to the Mixmax sign-in page.
Sign in and approve access.
ChatGPT retries the original request and your data appears.
You stay signed in after that. You'll only be asked again after 90+ days of inactivity, or if an admin revokes access.
Try your first query
Start with a question you already know the answer to:
"What meetings do I have this week?"
"List my sequences."
When you recognize the answer, you're connected. If you connected through the app store listing, that's as far as it goes — reads only. If you connected manually, write capabilities (sending email, building sequences, and more) are separate per-user levers in MCP settings.
Troubleshooting
Symptom | What it means |
Connected through the app store, but ChatGPT can only see meetings and sequences | Expected, not a bug. The app store listing is scoped to meetings and sequences only. Connect manually for the full toolset. |
Connected manually, but a tool is missing or a write returns a permission error | That's your permission lever, not a bug. Reads are on by default; writes are opt-in. Turn the capability on in MCP settings in Mixmax. |
The Labs experiment card isn't visible | Your admin turned it off or locked it, or the rollout hasn't reached your workspace yet. |
401 on the first call | Expected. It triggers the browser sign-in flow. |
Asked to sign in again | Happens after 90+ days of inactivity, or when an admin revoked access. |
ChatGPT can't see Mixmax at all | Check the experiment is on in Mixmax Labs, then check the app was installed (or the connector added) in ChatGPT's Apps & Connectors settings. |
Learn more
Mixmax Labs overview — what admins control, and how to opt in to an experiment.
Manage your MCP settings — turn individual capabilities on or off.
Connect other AI clients to Mixmax (MCP) — Cursor, Windsurf, and any other MCP client.