Definition
Microsoft Execution Containers (MXC) is a cross-platform, policy-driven sandbox for running untrusted AI agent code on Windows, Linux, and macOS. Announced at Build 2026, it provides a unified JSON schema and TypeScript SDK (@microsoft/mxc-sdk) mapping workloads to layered containment backends.
Key Points
- Backends: ProcessContainer, Windows Sandbox, LXC, Bubblewrap, macOS Seatbelt, Isolation Session, MicroVM (roadmap)
- Agent 365 integration: Policy enforcement via Microsoft Entra and Intune
- Early adopters: github-copilot CLI, partners NVIDIA, openai, OpenClaw, Hermes, Manus
- Repository:
microsoft/mxc(MIT license, Rust + TypeScript) - 2026-10-07: Generally available on windows-11 for process/session/WSLc backends; Intune policy for process containers coming (2026-10-07-microsoft-mxc-ga-blog)
- Maturity: Experimental backends (MicroVM, isolation session) still flagged; stable processcontainer on Win11 24H2+