Introducing the Microsoft Copilot Harness: Unlocking the Potential of Truly Multi-Model Agentic Work
Microsoft, Wednesday, October 28th, 2026
Microsoft offers the GitHub-built Copilot harness through Foundry so developers can build multi-model agents without maintaining a harness.
Microsoft says a harness is the orchestration layer around a model, supplying instructions, context, execution environment and controls, and that building one that works across models is hard.
The harness built by GitHub engineering and adopted company-wide powers Copilot Code, Copilot Studio, the GitHub Copilot app, the CLI and VS Code.
It is now offered through Microsoft Foundry as a fully managed option for agents that reason, use tools and complete long-running tasks, with support for open standards such as MCP, agent skills and plugins.
Developers can switch models without changing the harness or rest of their stack.