TITLE: Microsoft Copilot Harness Opens to Enterprise Developers DATE: Wed Nov 04 2026 00:00:00 GMT+0000 (Coordinated Universal Time) COMPANY: Microsoft TOPIC: Agent Systems SUMMARY: Microsoft opened its Copilot harness to enterprise developers via Foundry Agent Service on 28 October 2026, entering public preview at no charge through 30 November. Developers can build multi-model agents using the same infrastructure that powers Copilot Studio, GitHub Copilot, and Microsoft 365. WHAT CHANGED: Microsoft announced the Copilot harness on 28 October 2026 in a post on the official Microsoft Blog. The harness is the orchestration layer the company uses internally to run Copilot Studio, GitHub Copilot, the VS Code extension, Copilot Code, and the CLI. That same infrastructure is now available to enterprise developers via Foundry Agent Service in public preview. The announcement positions Foundry as the developer-led path and Copilot Studio as the business-led path. Developers working in Foundry supply their own domain knowledge, instructions, and tools. Microsoft manages the execution loop and sandbox. Agents built this way can be published to Microsoft 365 Copilot and Teams without being rebuilt for each surface. Agent-to-agent (A2A) support also entered public preview with the announcement. A2A allows developers to build multiple specialised agents and wire them together, with one agent handing off to another based on the task at hand. The harness handles the routing, so developers do not need to build that orchestration from scratch. The pricing window is the detail most likely to drive near-term action. The harness runtime is free through 30 November 2026. Billing starts 1 December at $0.0994 per vCPU-hour for compute and $0.0118 per GiB-hour for memory. Model inference is charged on top of that. WHY IT MATTERS: The agent layer is becoming infrastructure. Microsoft is not building consumer features. It is opening the runtime that runs its own products to developers. This is the same strategic move Amazon made with AWS: take internal infrastructure, standardise it, and sell access to it. The Copilot harness becoming a developer product means agent orchestration is shifting from something you build to something you buy. Distribution matters as much as capability. Most enterprise AI projects fail because employees do not change their behaviour. An agent that surfaces inside Teams and Microsoft 365, where employees already spend their day, removes the adoption friction. Developers no longer need to build a custom interface and convince staff to open it. Multi-model support changes the procurement picture. Support for 20-plus frontier models means organisations are not locked into a single vendor's pricing or capability curve. A team that chose Claude for specific tasks can continue using it inside the Foundry infrastructure without switching runtimes. A2A is the step toward autonomous workflows. The agent-to-agent preview is the most forward-looking element of the announcement. It points toward workflows where a lead screening agent passes a prospect to a research agent, which passes a summary to a drafting agent, without a human initiating each handoff. The free window is an experiment budget. Four weeks of free compute is not long enough to build production infrastructure. It is long enough to run one proof of concept, understand real costs, and decide whether to invest. The window is worth taking deliberately, not waiting out. Small teams benefit from shared infrastructure. A 20-person firm cannot build and maintain a custom agent orchestration layer. It can build an agent definition and let Microsoft maintain the runtime. That asymmetry is what the harness opens up. DAVID & GOLIATH ANALYSIS: The pattern here is familiar: a hyperscaler opens internal infrastructure to the market, lowers the build cost for everyone, and shifts competition to the application layer. The implication for small and mid-size businesses is that the right question is not whether you can build this. It is what you should build first, and what you need in place before 1 December to know whether the spend is justified. For most businesses on Microsoft 365, the answer starts with one workflow. Not a strategy, not a roadmap, one specific task where an agent living in Teams would save a measurable amount of time. The free window is there to find that task, not to plan around it. The A2A preview is worth watching even if you have no immediate use for it. It is Microsoft signalling the architecture it expects enterprises to build toward: not monolithic AI assistants, but coordinated teams of specialised agents. That is the architecture David and Goliath's Employee Amplification Systems work is built on, and the underlying infrastructure is converging. RELEVANT SYSTEMS: Employee Amplification Systems, Secure AI Brain SOURCE URL: https://davidandgoliath.ai/daily-ai-briefing/microsoft-copilot-harness-foundry-enterprise-agents FEED URL: https://davidandgoliath.ai/daily-ai-briefing/feed --- Published by David & Goliath | https://davidandgoliath.ai Daily AI Briefing: one AI development per day, decoded for business operators. This is a structured companion file optimised for LLM retrieval and citation.