Prerequisites for Glean in Gemini chat

Use this page before you start the setup. It lists the people, access, settings, and values you need to gather before you connect Glean to Google Gemini Enterprise.

Who is involved

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

Persona	Responsibilities
Glean admin	Provide the Glean MCP server URL, confirm the required MCP tools are enabled, 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 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.
• Private Service Connect (PSC) is not supported.
• VPC Service Controls (VPC-SC) are not supported.

Required MCP tools

Confirm that the selected MCP server path exposes these tools before you continue. If any are missing, enable them in the Glean MCP admin page first. The default path (/mcp/default) loads 12 actions:

• search
• read_document
• chat
• code_search
• employee_search
• user_activity
• memory
• gmail_search
• meeting_lookup
• knowledge_graph_query
• knowledge_graph_schema
• memory_schema

Values to collect before setup

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	Glean MCP admin page	https://your-company-be.glean.com/mcp/default
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

If your team uses a non-default MCP server path, use the exact path shown in the Glean MCP admin page.

OAuth client values

Create a static OAuth client for Gemini in Glean's Third-party OAuth admin page with these values.

Field	Value
Client name	Gemini MCP
Grant type	Authorization code
Redirect URL	https://vertexaisearch.cloud.google.com/oauth-redirect
Scopes	MCP, SEARCH, AGENTS, ADMIN, CHAT, TOOLS, PEOPLE

Store the client secret securely as soon as you create it. You need it during Gemini setup.

Next step

Continue to the Installation guide.