# Cloud vendors adopt session-first agent runtimes > Source: > Published: 2026-06-26 14:11:18+00:00 According to The New Stack, AWS, Microsoft, Google, and Anthropic have converged on the session - not the request - as the primary unit of execution in managed AI agent runtimes. Three vendors shipped nearly identical managed runtime architectures within six weeks in spring 2026: Anthropic launched Claude Managed Agents on April 8 (at $0.08 per session hour), AWS extended Bedrock AgentCore on April 22, and Google followed with Managed Agents via Antigravity at I/O. Each collapses model API, sandbox, orchestration, and hosting into configuration files, with per-session isolation. The vendors now agree the session is the right unit but disagree on how to isolate it - AWS uses hardware-level microVM sandboxing, while Microsoft Foundry and Google use software-level sandboxing. The AGENTS.md and SKILL.md config format is emerging as a portable standard across all three platforms, stearded by the Linux Foundation and present in over 60,000 open-source repositories.