Prerequisites for Glean in Gemini chat

Use this page to prepare access, the Gemini Tools server, and a Glean OAuth client before you create the Gemini Enterprise data store.

Who is involved

This setup involves two admin personas and one end-user persona.

Persona	Responsibilities
Glean admin	Copy the Gemini Tools server URL, confirm the tools you want to use are available, and create the Glean OAuth client.
Google Cloud or Gemini Enterprise admin	Create the custom MCP server data store, enable actions, connect the data store to a Gemini app, and publish the app.
End user	Authorize Glean the first time they use the app, then ask questions in Gemini chat.

The two admin roles are often handled by different people.

Required access

Glean admin

You need:

• Glean admin access
• Access to the MCP admin page
• Access to the Third-party OAuth admin page

Google Cloud or Gemini Enterprise admin

You need:

• Google Cloud or Gemini Enterprise admin access
• A Google Cloud project where you can create Gemini Enterprise resources
• Permission to create and manage Gemini Enterprise data stores

Google Cloud requirements

Before you create the custom MCP server data store, make sure the following are in place:

• The organization policy that blocks custom MCP data stores is overridden for the project.
• The Glean MCP and OAuth domains are allowed for egress. If the project uses VPC Service Controls, add custom_mcp to its allowed data sources.
• The admin creating the data store has the roles/discoveryengine.editor role.
• Gemini Enterprise is registered as an OAuth client application with the authorization redirect URL set to https://vertexaisearch.cloud.google.com/oauth-redirect.

For the exact org policy name and redirect URL registration steps, see Google's Custom MCP Server setup guide.

Network and transport limitations

Custom MCP server data stores currently have these limits:

• Only StreamableHTTP transport is supported.
• Server-Sent Events (SSE) transport is not supported.

Gemini MCP server

Use the dedicated Gemini Tools server in the Glean Admin console. It is configured with seven baseline tools:

• search
• read_document
• code_search
• user_activity
• memory
• memory_schema
• employee_search

Confirm that the server is enabled and exposes the tools you want Gemini to use. Some tools appear only when their requirements are met. You can add tools to the server.

Create the Gemini OAuth client

Open the Glean Third-party OAuth admin page and create a new static client with these values:

Field	Value
Client name	Gemini MCP
Grant type	Authorization code
Redirect URL	https://vertexaisearch.cloud.google.com/oauth-redirect
Scopes	MCP

important

The client secret is shown only when you create the client. Store it somewhere safe, such as a password manager. If you lose it, you must create a new client.

Save the client ID and secret for the Gemini Enterprise data store.

Gather connection values

Collect these values from Glean before you start the Gemini-side setup. Your Glean backend URL follows the pattern https://<tenant_id>-be.glean.com. You can find it in About Glean under Server instance (QE).

Value	Where to get it	Example
MCP server URL	Gemini Tools in the Glean Admin console	https://your-company-be.glean.com/mcp/managed/gemini
Authorization URL	Your Glean backend URL + /oauth/authorize	https://your-company-be.glean.com/oauth/authorize
Token URL	Your Glean backend URL + /oauth/token	https://your-company-be.glean.com/oauth/token
Client ID	Glean Third-party OAuth admin page	Generated when you create the client
Client secret	Glean Third-party OAuth admin page	Generated when you create the client

Copy the full URL from Gemini Tools. It ends in /mcp/managed/gemini. Do not append this server path to the authorization URL or token URL.

Next step

Continue to the Installation guide.