Introducing the Microsoft Copilot Harness in Foundry Agent Service
Microsoft, Wednesday, October 28th, 2026
Microsoft puts the Copilot harness in public preview in Foundry Agent Service and makes long-running resilience for hosted agents GA.
The harness is a managed execution system for agents defined declaratively in Foundry Agent Service: Microsoft runs the agent loop and sandbox while customers supply knowledge, procedures and tools.
It addresses the repeated work of coordinating model and tool calls, maintaining context, managing files and continuing multi-step tasks.
The preview combines four building blocks, beginning with reusable skills that package instructions, scripts and resources into procedures.
Together with long-running resilience for hosted agents, now generally available, it aims to make complex agent workflows more reliable.