On October 12, 2026, Google announced a change for integrations using Workspace MCP servers. From November 11, the servers will reject requests from applications whose OAuth client is not marked as being for an AI agent. Small businesses with custom connections between an assistant and their work services should ask their developer to check the integration before that date.
Who is affected
This concerns access through Model Context Protocol servers, not ordinary Gmail use or every Workspace connection. Google explicitly says non-agent applications that only call REST APIs are unaffected.
The setting is “Use this client for an AI-powered agent” in Google Auth Platform → Clients. According to Google, clients left unmarked by November 12 will remain unable to call Workspace MCP servers; using MCP afterward will require a new client marked for an AI agent and an application update. To avoid rejected requests, work to the earlier date, November 11.
What to ask the integration owner
Our editorial recommendation is to start by confirming whether the connection actually uses Google Workspace MCP. Calling a product an “AI assistant” does not establish that.
If it does, ask the developer to inspect the OAuth client and prepare an approved change and testing plan. When one client serves both agent and non-agent functions, Google recommends a separate client for the AI agent while retaining the existing client for other functions. Do not alter working connections blindly or paste client secrets into a chat.
The Gmail MCP documentation describes early access through the Developer Preview Program and connection testing after setup. This is therefore not a general-availability announcement. The documentation also recommends reviewing assistant actions and considering hidden instructions in third-party emails.
The takeaway: identify the connection type, its owner and a verification plan before November 11. Marking a client does not replace controls over the data an assistant reads or the actions it may take.
Read also: where human review is needed.
