# Microsoft introduces a Copilot harness in Foundry Agent Service in public preview

> Original title: Introducing the Microsoft Copilot harness in Foundry Agent Service

- Source: Microsoft Foundry Blog
- Published: 2026-10-28T16:45:06.000Z
- Bad Influence: https://badinfluence.news/items/a7o3hieyqik3jc5w7579xmg2l
- Original: https://devblogs.microsoft.com/foundry/microsoft-copilot-harness-in-foundry/

## Summary

Microsoft introduces the Copilot harness in Foundry Agent Service in public preview, a managed system that runs the agent loop and sandbox for agents defined declaratively. Developers supply skills, tools, and instructions, and the preview includes skills, connected Foundry and MCP tools, file and code execution, subagents, and source-controlled definitions.

## Why it matters

The post shows how a managed harness, reusable skills, and hosted-agent checkpointing divide work between Microsoft and the developer, useful for deciding how much agent infrastructure to build.