VS Code 1.138 runs agent sessions inside a project's Dev Container

Microsoft published Visual Studio Code 1.138 on 16 September 2026. The release notes read as a single theme: the Agent Host that arrived in earlier builds now runs sessions inside a project's Dev Container, files a pull request without switching tools, and lets a user swap between Copilot-backed and ChatGPT-backed models on the same turn.

Agent sessions inside a Dev Container

Microsoft describes the change as: "Keep agent work aligned with your project's toolchain by running a session inside a local folder's Dev Container." A session that opts in gets the compiler, package manager, and system libraries the repository declares in its .devcontainer folder, instead of whatever happens to be on the developer's machine. Docker must be installed. The behaviour is behind the chat.agentHost.devContainer.enabled setting and rolling out gradually rather than on by default.

The consequence is that when the agent runs the test suite or a build, it runs the exact commands and versions a fresh clone on a teammate's machine would. Failure output no longer reflects a mismatch between the agent's environment and CI.

Pull request creation from the Agents window

The Agents window now opens a pull request itself. Microsoft says: "Create pull requests from Agent Host sessions in the Agents window using one form to review and edit generated titles and descriptions, choose draft status, and configure available merge options." The form is inside the session that produced the change, so the review of the title, body, and merge settings happens without leaving the window where the work was done.

Two smaller housekeeping features arrive with it. When every pull request tied to an inactive session has merged, the Agents window offers to mark that session as done, with an optional grace period after which it is deleted. A taskbar or dock badge appears on the VS Code icon when a session needs input, so a run left in the background gets attention when it stops progressing.

Two subscriptions on one turn

The Codex integration now covers a case that used to force a copy-paste between apps. "If you sign in to both, switch between Copilot-backed and ChatGPT-backed models from the model picker without losing the current conversation." Codex quick chats inside the desktop app can be promoted to a workspace session with their history, model, and permissions carried across, and the same session can continue in the ChatGPT desktop app and come back to VS Code.

How it fits together

The whole release is agent features: the release notes do not name a terminal, editor, or extension change. Microsoft has been releasing the Agent Host in pieces since spring, and 1.138 is the first release where the features work as one product rather than three: a place a session runs, a place its output is sent from, and a place its history is kept. The Dev Container support is the most consequential of the three, because it is the one that decides whether the agent and CI are looking at the same repository.

Two of the seven items in the notes are marked Preview or Experimental, including a unified workspace picker that lists local folders, GitHub repositories, and remote targets in one search, and a voice-mode change that navigates parallel sessions without leaving voice input. Those are worth trying on a copy of a workspace before adopting in daily work.

Source

Visual Studio Code August 2026 (version 1.138), Microsoft, 16 September 2026.