Google Managed Agents API Review — Full Agent Sandbox in One API Call

Google launched the Managed Agents API in preview at Google I/O 2026. It provisions a full agent sandbox — ephemeral Linux environment, code execution, web browsing, MCP servers, and file access — with a single Gemini API call. We cover the architecture, AGENTS.md configuration, pricing model, ADK 2.0 context, and the real limitations before production deployment.