On November 10, the Visual Studio team announced that Copilot in Visual Studio just got a major upgrade. Starting with Visual Studio 2026 version 18.12, Copilot Chat runs on the Microsoft Copilot SDK, developed by GitHub, which also powers GitHub Copilot CLI, the GitHub Copilot app, and VS Code. Underneath it is the Microsoft Copilot harness, the same harness that Copilot Studio renamed from the GitHub Copilot harness two weeks ago.
This matters to the Power Platform community for a simple reason. Dataverse plug-ins, custom APIs, PCF controls, and much of the code behind code apps are written in Visual Studio. The developers who build the server-side logic that low-code makers depend on now have an agentic engine turned on by default, and the post that announces it says nothing about admin controls.
What changed
| Area | What the announcement says |
|---|---|
| Release | Visual Studio 2026 version 18.12 and later |
| Default | On; developers opt out under Tools, Options, GitHub, Copilot, Copilot Chat, then restart |
| Engine | Microsoft Copilot SDK on the Microsoft Copilot harness |
| Results | On a .NET team benchmark of 157 real C# tasks with GPT-5.6 Sol, 124 resolved versus 103 before |
| New in chat | Mid-task steering, step inspection, subagent cards, folder-level working directory, per-request cost |
| Agents | /security-review, /rubber-duck, specialized agents for debugging, profiling, builds, and modernization, plus .NET and Azure skills |
| Not yet available | Plan mode and chat exports |
The benchmark result is a meaningful jump, from about 66 percent to about 79 percent of tasks resolved, where a task counts only if failing tests pass without breaking tests that already passed. It is Microsoft’s own benchmark on C# work, and the post describes results for C++, Python, and other languages only qualitatively.
1. It is on by default, and the opt-out is per developer
Updating Visual Studio switches developers to the new experience. The only opt-out the post describes is a checkbox each developer clears on their own machine. There is no mention of an organization setting, so plan on everyone who updates being on the new engine.
2. Agents now act until the task is done
The post says the harness “keeps Copilot working until the task is done.” Copilot runs commands, starts subagents in parallel, works across any folder a developer points it at, and uses MCP servers the developer has already configured. That is what produces the better results, and it is also what changes the risk profile.
For Power Platform teams, the MCP point deserves attention. A developer with a Dataverse MCP server or PAC CLI authenticated against a production environment has handed that access to an agent that runs until it finishes. Development tooling should point at development environments, and production credentials should not sit on developer machines by default. The same principle applies to service principals used for plug-in registration and solution deployment.
There is good news on the review side. The new /security-review agent runs a security-focused review of changes, and /rubber-duck has a different model critique Copilot’s plan before it acts. Both are worth adding to the team’s definition of done for plug-in and custom API changes.
3. Content exclusion does not cover agent modes
Many organizations rely on GitHub Copilot content exclusion to keep files such as connection settings, deployment parameters, or proprietary algorithms out of Copilot’s context. GitHub’s content exclusion documentation is explicit: “Content exclusion is currently not supported in Edit and Agent modes of Copilot Chat in Visual Studio Code and other editors.” It also notes that Copilot “may use semantic information from an excluded file if the information is provided by the IDE indirectly.”
With the new Visual Studio experience centered on agents, assume exclusions do not protect a file from the agent until GitHub documents otherwise for Visual Studio. The durable fix is the old one: keep secrets out of source entirely. Environment variables in solutions, Azure Key Vault, and connection references exist for exactly this.
4. Every request now shows a cost
The chat now shows what each request costs, with an example in the post of a request that used 9.0 credits. The post does not explain the billing model behind that number. Agentic tasks that run subagents and keep going until done will use more than a single question did, so if your organization pays for GitHub Copilot centrally, watch usage after the update rolls out.
The controls that do exist
Microsoft’s specialized agents documentation describes two organization-level levers that apply in Visual Studio: custom agents published by GitHub organization or enterprise owners, which Visual Studio picks up automatically for repositories in that organization from version 18.9, and organization-level custom instructions from 18.8. Custom agents can also limit their tools through a tools list. For a Power Platform team, an organization agent that encodes your plug-in standards, such as no hard-coded environment URLs, tracing through ITracingService, and solution-aware deployment, is a practical way to steer the agent rather than only restrict it.
GitHub’s MCP management page describes an MCP servers in Copilot policy and allowlists, but it does not list Visual Studio among the clients, so confirm enforcement before relying on it.
One engine, one set of skills
The post notes that an agent skill written once now works in Visual Studio, VS Code, Copilot CLI, and the GitHub Copilot app without changes. Microsoft’s harness announcement lists Copilot Studio among the products on the same harness. For organizations that build both low-code agents and pro-code extensions, that is a reason to manage skills, instructions, and MCP server approvals as one estate rather than per tool.
A checklist for Power Platform pro-code teams
- Tell developers the new engine is on after updating to 18.12, and how to opt out if plan mode or chat exports are required.
- Keep production credentials, PAC CLI profiles, and Dataverse MCP connections for production off developer machines.
- Move any secret still in source into environment variables or Key Vault, since content exclusion does not cover agent modes.
- Add /security-review to the review step for plug-in, custom API, and PCF changes.
- Publish an organization-level custom agent or instructions that encode your Dataverse coding standards.
- Watch GitHub Copilot usage for a month after the rollout.
What the documentation does not cover yet
As of November 10, 2026, the announcement does not describe admin policies, data handling, or how the per-request credits relate to GitHub Copilot plans. GitHub’s content exclusion and MCP management pages do not state Visual Studio’s support for agent features explicitly. Microsoft’s Visual Studio admin page for GitHub Copilot could not be retrieved for this article; check it before setting policy.
Sources
- Copilot in Visual Studio just got a major upgrade, Visual Studio Blog, November 10, 2026
- Introducing the Microsoft Copilot harness, Official Microsoft Blog, October 28, 2026
- Specialized agents in Visual Studio, Microsoft Learn
- Content exclusion for GitHub Copilot, GitHub Docs
- MCP management, GitHub Docs