Image: Microsoft / code.visualstudio.com VS Code 1.129 Gives AI Agents Their Own Process and Lets Multiple Windows Share a Session
VS Code 1.129 ships a dedicated agent host that runs AI sessions in their own process, a new editor panel in the Agents window for reviewing diffs inline, a ! shortcut for running terminal commands from chat, and an experimental modern UI with floating cards.
VS Code 1.129 landed July 15, with a servicing update (1.129.1) two days later. The release is mostly about infrastructure: Microsoft is rethinking how agent sessions live inside the editor, and the changes set up a cleaner foundation for multi-window and multi-agent work.
Agent host
The biggest change is the agent host, a dedicated process that runs AI sessions outside the main VS Code process. Sessions operate via the Agent Host Protocol, and because each session lives in its own process, multiple VS Code windows can connect to the same session simultaneously. You can open the same Copilot, Claude, or Codex session from different windows or monitors, and the session survives window restarts.
To enable it, turn on chat.agentHost.enabled, then pick a harness from the dropdown in the Agents window. The supported harnesses are Copilot, Claude, and Codex.
Agents window editor panel
The Agents window now includes an editor panel. You can review agent-generated files and diffs inline, inside the same pane as chat, rather than having to context-switch to a separate editor tab. The panel supports both inline and side-by-side diff views, togglable from within the panel.
Agents can also enumerate, create, and manage multiple sessions without manual switching using new session-management tools, which is useful when you’re running parallel tasks.
Running terminal commands with !
In agent host sessions, prefixing a chat message with ! runs it as a terminal command directly. It’s a shortcut for the common pattern of copying what the agent suggests into a terminal. Useful in quick back-and-forth workflows where you’re iterating with the agent on shell output.
Modern UI preview
An experimental workbench redesign is available via workbench.experimental.modernUI. Sidebars and the bottom panel become floating cards with rounded corners and visible gaps between sections. The 1.129.1 patch that followed fixed several regressions the Modern UI introduced. It’s enabled by default in Insiders builds.
GitHub Enterprise and BYOK
Copilot authentication now works with GitHub Enterprise instances. BYOK (bring-your-own-key) models also work inside the Copilot harness in the Agents window, so teams using custom model endpoints can stay in the same harness without switching.
Full release notes are at code.visualstudio.com/updates/v1_129.