Visual Studio Code 1.135 introduces Rubber Duck agent

Microsoft released Visual Studio Code 1.135 on August 26, introducing the Rubber Duck agent, an experimental AI mode that provides a second opinion from a different model, and UX improvements to the Agents window. The update also lets users view and continue recent Copilot or Claude agent sessions from other applications, and adds a redesigned chat response footer showing per-model token usage.

Microsoft’s latest update to Visual Studio Code https://www.infoworld.com/article/2254808/get-started-with-visual-studio-code.html , released August 26 https://code.visualstudio.com/updates/v1 135 , features a Rubber Duck agent for a second model opinion as well as UX improvements to the Agents window. VS Code also now can show recent Copilot or Claude agent sessions created in other applications and allow users to continue them. Downloads of Visual Studio Code https://code.visualstudio.com/Download? exp download=fb315fc982 are available for Mac, Windows, and Linux. VS Code 1.135 features Rubber Duck, an experimental AI mode that debuted in GitHub Copilot CLI in April https://github.blog/ai-and-ml/github-copilot/github-copilot-cli-combines-model-families-for-a-second-opinion/ . The Rubber Duck agent is a built-in critic that provides a constructive second opinion on plans, code, and tests of the primary agent, using a different AI model from the one driving the session. Rubber Duck helps surface missed details or edge cases, according to Microsoft. Also with VS Code 1.135, the agent host now lets users connect to the same agent session from multiple VS Code windows. The agent host runs agent harnesses in a dedicated process based on the Agent Host Protocol https://microsoft.github.io/agent-host-protocol/ . Its Copilot agent is powered by the Copilot SDK https://www.npmjs.com/package/@github/copilot-sdk , which aligns its behavior and functionality with the Copilot CLI https://www.infoworld.com/article/4181851/github-adds-new-copilot-features-as-usage-based-billing-takes-effect.html , the standalone GitHub Copilot app, and other Copilot products, Microsoft said. In addition, the Sessions list in VS Code now can show recent Copilot or Claude agent sessions created in other applications. Users can select a session from the Sessions list to view the conversation and continue it in VS Code with their Copilot subscription. To give better insight into chat usage, Microsoft has redesigned the chat response footer. Hovering over the footer shows a per-model breakdown of the input, cached input, and output tokens used in the chat turn. Also, Agents window UX improvements allow developers to work with a streamlined side layout, simplified session controls, and session information that is easier to find, Microsoft said.