Microsoft brings the multi-model Copilot harness to Microsoft Foundry

Microsoft announced on 28 October 2026 that the Copilot harness, the core agent execution engine developed with GitHub that powers Copilot Code, Copilot Studio, the GitHub Copilot app, CLI, and VS Code, is now available directly to enterprise developers through Microsoft Foundry. Teams can embed the harness as a downloadable SDK inside their own infrastructure or run it as a managed cloud service inside Foundry.

To reduce cold-start overhead and improve streaming responsiveness during long tool-use loops, Microsoft and GitHub recently ported the harness runtime to Rust, lowering memory use and time-to-first-token across multi-step agent sessions. The harness coordinates more than 20 frontier models alongside custom enterprise checkpoints and bring-your-own-key (BYOK) endpoints, so a single workflow can pair fast drafting models with deeper reasoning or code-review models in the same session.

Out of the box, the harness includes native support for the Model Context Protocol (MCP), reusable agent skills, and third-party plugins, while inheriting Microsoft Foundry’s enterprise identity, role-based access controls, audit logging, and policy guardrails. Microsoft has not published separate per-hour hosting fees beyond standard Foundry model and compute consumption.