We will soon roll out Google Workspace Model Context Protocol (MCP) servers that expose new functionality to external AI agents across Gmail, Drive, Calendar, and other Workspace apps using the open MCP. Ahead of this launch, we are introducing an “agentic” setting (is_agentic) on Google OAuth clients, so that Google and Workspace administrators can differentiate AI agent traffic from traditional app traffic. Only OAuth clients marked as agentic will be able to call Workspace MCP servers. [emphasis mine]
In our recent review of the Q3 2026 Google Workspace Developer Release Notes, we looked at the expansion of remote Google Workspace MCP servers across Gmail, Drive, Docs, Sheets, Slides, Calendar, and Chat. At the time, I noted that while MCP is great for connecting local developer tools like Google Antigravity, giving external agents broad access across user documents raises real enterprise governance questions.
Google has now started sending developer notifications announcing a foundational change to address this, a mandatory agentic classification (is_agentic) for OAuth 2.0 clients. If you have configured OAuth clients in the Google Cloud console for AI agents or MCP servers, there is a tight one-month window to update your existing credentials.
A couple of key details and technical requirements from the announcement and the updated Manage OAuth Clients documentation are worth highlighting:
Hard Enforcement and Permanent Lock-In (November 11–12, 2026): Starting October 12, 2026, developers can edit existing OAuth clients in the Google Cloud console (Google Auth Platform > Clients) and select the Use this client for an AI-powered agent checkbox. On November 11, 2026, Workspace MCP servers will begin rejecting requests from any OAuth client not marked as agentic. Crucially, on November 12, 2026, the is_agentic setting becomes permanent on existing clients, if you miss the November 11 window, you cannot toggle the setting on an existing client and will have to create a new OAuth Client ID and update your client configurations (such as ~/.gemini/config/mcp_config.json in Google Antigravity).
Separate OAuth Clients for Human vs. Agent Traffic: According to Google’s updated best practices for agent client isolation, if your solution provides both human-interactive features (calling standard Google REST APIs) and AI agent workflows, you must maintain separate OAuth 2.0 Client IDs for each workflow. Tagging an OAuth client as agentic does not grant extra scopes or bypass user consent, but it isolates agent traffic so Workspace administrators can apply dedicated agent access controls and security policies without disrupting human users on your standard app.
Traditional Apps Script and REST Integrations Are Unaffected: If your application or Apps Script project is not an AI agent and only calls standard Google Workspace REST APIs, no action is required. However, Google recommends marking any OAuth client used by an AI agent, even if that agent currently only calls Workspace REST APIs, so it is properly classified ahead of the November 12 lock-in. Romain Vialard has however highlighted that the client ID for Apps Script is not editable in GCP so it’s not possible to mark it as agentic. The only workaround at this point is using a standard GCP, creating your own client ID and using the OAuth2 Apps Script library.
Seeing this land makes a lot of sense. Before enterprise admins can confidently allow MCP integrations or external AI agents in production domains, they need a reliable way in the Admin console and Security Investigation Tool to distinguish an autonomous agent acting on behalf of a user from a conventional web app. Separating those identities at the OAuth client level is the logical first step toward granular agent governance.
If you have existing Google Cloud projects using Workspace MCP servers, Agent Development Kit (ADK) workflows, or Gemini Enterprise connectors, head over to the Google Auth Platform Clients page before 11 November 2026 to review and update your OAuth client settings.
Email Notifications for Impacted Projects: To help, developers should check their inbox for service communications from Google with the subject ‘[Action Required] Mark AI agent OAuth clients as agentic for Google Workspace MCP by Nov 11, 2026‘, as these list the affected Google Cloud projects.
