Gemini Enterprise: 3-legged OAuth for A2A agents GA, plus single-user quota limits

Gemini Enterprise: 3-legged OAuth authentication with Agent Identity auth manager for A2A agents

Support for 3-legged OAuth (3LO) authentication with Agent Identity auth manager for Agent2Agent (A2A) agents is generally available (GA).

This integration lets A2A agents built with the Agent Development Kit (ADK) and deployed on Agent Runtime authenticate to downstream Model Context Protocol (MCP) servers, Google Cloud services, and third-party APIs on behalf of the signed-in Gemini Enterprise user. When a tool requires user consent, Gemini Enterprise automatically prompts the user, validates the callback at https://vertexaisearch.cloud.google.com/validateUserId, finalizes credentials with Agent Identity auth manager, and resumes the A2A conversation.

For more information, see the following resources:

• Configure 3-legged OAuth with Agent Identity auth manager for A2A agents
• Authenticate using 3-legged OAuth with auth manager

Gemini Enterprise: Single-user quota limits for AI developer tools

Single-user quota limits apply to AI developer tools, including Google Antigravity, in the Gemini Enterprise Standard and Gemini Enterprise Plus editions. For AI developer tools, the quota multiplier applies to the weekly quota and resets on each user's seven-day cycle.

This feature is generally available (GA). For more information, see Single-user quota limits and Configure a single-user quota limit.