Microsoft ships MXC 1.0, a policy sandbox for AI agents

Microsoft released MXC (Microsoft Execution Containers) 1.0, a policy-driven sandbox for running untrusted and model-generated code. One JSON schema and SDK sit on top of four isolation backends: process, session, WSL and MicroVM. GitHub Copilot, OpenAI Codex, Nvidia, Replit, LM Studio and Unsloth are already on board.

• Four backends: process, session, WSLc and experimental MicroVM
• Three modes: Enforcement, Learning with activity report, Permissive
• SDKs for Node, Rust and .NET; MIT license, about 2.6k stars
• Supported by Copilot, Codex, Nvidia, Replit, LM Studio and Unsloth