GitHub Copilot in Visual Studio September update
The September 2026 update to GitHub Copilot in Visual Studio adds pull request exploration through the Git agent, moves Bring Your Own Model to a new Agent (Preview) mode, and lets Copilot fix vulnerable NuGet packages from the Error List. The BYOM change is breaking, so check your model setup before updating.
Key points
- The Git agent can summarize a pull request in Copilot Chat with links to its comments and files; a GitHub or Azure DevOps MCP server must be connected.
- BYOM is in preview and supports Microsoft Foundry, OpenAI, Anthropic and Ollama providers.
- Breaking change: BYOM now runs only in the new Agent (Preview) mode, and the Ask and older Agent modes no longer support it.
- After updating, re-add any Ollama models you had configured for BYOM.
- For the NuGet fix action, sign in to GitHub Copilot and enable the NuGet MCP server from the Copilot Chat tools menu.
- The features are available on every Copilot plan, including Free.
GitHub Copilot in Visual Studio 2026 gets three notable changes in the September 2026 update. The Git agent can now read a pull request for you: attach it from the Git Repository window and you get a summary with links to the relevant comments and files. That requires an MCP server connection to GitHub or Azure DevOps.
Bring Your Own Model is now in preview and works with your own deployments or Copilot models, even without signing in to GitHub. The catch is that BYOM now runs only in the new Agent (Preview) mode, built on the Copilot SDK harness. Ask and the older Agent mode no longer support it, and Ollama models must be added again after updating. The third change targets NuGet Audit warnings in the Error List, which now offer a fix action that opens agent mode and uses the NuGet MCP server to update vulnerable packages.
Real-world use
- Summarizing a large pull request inside Visual Studio before review, with links back to the comments and files it mentions.
- Pointing Visual Studio at your team's own model deployment, such as Microsoft Foundry or a local Ollama server.
- Clearing NuGet Audit vulnerability warnings in a solution by letting the agent update the affected packages.
Why it matters
If you use BYOM, update your setup after installing the release: switch to Agent (Preview) and re-add Ollama models. NuGet vulnerability warnings can now be handed to the agent directly from the Error List.