Connect ChatMaxima MCP with Gemini Enterprise

Overview

This guide shows how to connect ChatMaxima MCP with Gemini Enterprise, Google's AI assistant for organizations, so your team can build and inspect chatbots, WhatsApp templates and WhatsApp Flows from Gemini. ChatMaxima is added in Google Cloud as a Custom MCP Server data store.

Gemini Enterprise works differently from Claude and the Gemini CLI. It does not register itself automatically, so it needs a client ID and a client secret that you create in ChatMaxima and type into the Google Cloud form. One set of credentials serves your whole organization. Each person still signs in with their own ChatMaxima account, so Gemini only gets the access that person has.

Note: Using the Gemini CLI on your own computer? Follow Connect with Gemini instead. It needs no client credentials.

Prerequisites

Before you begin, make sure you have:

• A ChatMaxima workspace admin. Only admins can create or revoke client credentials.
• A Gemini Enterprise subscription and access to its settings in the Google Cloud console.
• A Google Cloud organization policy administrator, who may need to allow custom MCP servers (Step 2).
• A ChatMaxima account for each person who will use the connector, with a role that can use the builder, templates or Flows.

Step 1: Create client credentials in ChatMaxima

1. In the ChatMaxima dashboard, open Developers, then MCP Server.
2. Select the Gemini Enterprise tab.
3. Under Client credentials, click Create client credentials.
4. A window shows the Client ID and the Client secret. Copy both and keep them somewhere safe, then click I have copied it.

Note: The client secret is shown only once. ChatMaxima stores only a hash of it and cannot show it again. If you lose it, revoke those credentials and create a new set.

Each workspace can have up to 5 active sets of client credentials. The list on the same tab shows who created each set, when, and when it was last used.

Step 2: Allow custom MCP servers in Google Cloud

Your organization may block custom MCP servers by default. A Google Cloud organization policy administrator should:

1. Turn off the policy Disable custom MCP server connector for Gemini Enterprise.
2. Allow the domain chatmaxima.com for outbound traffic, if your organization restricts egress domains.

Step 3: Add ChatMaxima as a custom MCP server

1. In Gemini Enterprise in the Google Cloud console, open Data stores.
2. Choose Create data store, then Custom MCP Server.
3. Select OAuth 2.0 as the authentication method.
4. Fill in the form with the values below. The Gemini Enterprise tab in ChatMaxima lists the same values with copy buttons.

Google Cloud field	Value
MCP Server URL	https://chatmaxima.com/mcp/
Authorization URL	https://chatmaxima.com/api/v2/mcp-oauth-authorize/
Token URL	https://chatmaxima.com/api/v2/mcp-oauth-token/
Client ID	The client ID from Step 1 (starts with cmgc_)
Client secret	The client secret from Step 1 (starts with cmgs_)
Scopes	builder
Enable PKCE Support	On

Google sets the redirect URI itself, so you do not enter it. It is https://vertexaisearch.cloud.google.com/oauth-redirect, and ChatMaxima accepts only this address for Gemini Enterprise credentials.

Step 4: Verify the connection

1. Click Verify Auth.
2. A ChatMaxima window opens. Sign in to your ChatMaxima account.
3. The consent screen shows Gemini Enterprise with a Verified badge, because the request comes from Google's own address. If you belong to more than one team, choose the workspace to connect.
4. Review the access and click Allow.

Google confirms the authorization and you can finish creating the data store.

Step 5: Enable the ChatMaxima actions

1. Choose Reload custom actions so Gemini Enterprise fetches the ChatMaxima tools.
2. Enable the actions you want your team to use.

Read-only actions, such as listing bots or reading a template, run without a confirmation prompt. Gemini may ask you to confirm before running an action that creates or changes something. The actions a person can actually run depend on their role in the connected workspace.

Step 6: Build something

Ask Gemini Enterprise in plain language, for example:

Using ChatMaxima, create an appointment booking chatbot for a dental clinic.
Ask for the patient's name, preferred date and time, and phone number,
then confirm the booking. Run a test when done.

Gemini calls ChatMaxima tools to create the bot, add and connect blocks, organize the canvas and run a test. Open the bot in your ChatMaxima dashboard to review and publish it.

How access and security work

• Per-person sign-in. The client credentials identify your organization's connector. Every person still signs in with their own ChatMaxima account and only gets that account's access.
• Short-lived access. Access tokens last one hour and are refreshed automatically. Every refresh checks the client secret again.
• Secret stored as a hash. ChatMaxima keeps only a SHA-256 hash of the client secret, never the secret itself.

Manage or revoke access

• Revoke the credentials: in Developers, then MCP Server, then Gemini Enterprise, click Revoke next to the client ID. Gemini Enterprise can no longer sign in or refresh with it, and people already connected through it lose access within an hour.
• Revoke one person's connection: in Settings, then Connected Apps, revoke the Gemini Enterprise connection. It stops working immediately.
• Rotate a secret: create a new set, update the client ID and secret in the Google Cloud data store, then revoke the old set.

Troubleshooting

Verify Auth shows "Application not recognized"

1. Confirm the client ID was copied in full and starts with cmgc_.
2. Check that the credentials have not been revoked on the Gemini Enterprise tab.
3. If they were revoked, create a new set and update the data store.

Verify Auth fails after sign-in

1. Re-enter the client secret. It must match exactly, with no spaces before or after it.
2. Confirm the Token URL is https://chatmaxima.com/api/v2/mcp-oauth-token/, including the trailing slash.
3. Confirm the Scopes field is builder.

The Create client credentials button is missing

1. Only workspace admins can create credentials. Ask an admin of your workspace.
2. If the workspace already has 5 active sets, revoke one before creating another.

Custom MCP Server is not available in Google Cloud

1. Ask your organization policy administrator to turn off Disable custom MCP server connector for Gemini Enterprise.
2. Confirm chatmaxima.com is allowed for outbound traffic.

Actions do not appear in Gemini

1. Choose Reload custom actions on the data store again.
2. Confirm your role in the connected workspace has builder, template or Flow access.

Next Steps

• What is ChatMaxima MCP →
• Create a Chatbot with MCP →
• Connect with Gemini CLI →
• Connect with Claude →