Image: Microsoft / code.visualstudio.com VS Code 1.134 Ships a Dedicated Agent Host, Side-by-Side Chats, and Prompt Timeline
Microsoft's August release pulls autonomous agent work out of the extension host and into its own process, while also adding grouped side-by-side chats, a prompt timeline gutter, and in-conversation search.
VS Code 1.134 landed on August 19, 2026, with one architectural change that will matter more once agent sessions get longer and heavier: autonomous work now runs in a dedicated Agent Host process, separate from the extension host that powers everything else in the editor.
Agent Host
The Agent Host is a standalone process that runs agent harnesses using the open Agent Host Protocol (AHP), which Microsoft published as MIT in the previous 1.133 release. The Copilot agent uses the Copilot SDK, putting it on the same behavioral footing as Copilot in the CLI and the standalone desktop app.
The practical consequences: agent sessions can now attach to multiple VS Code windows at the same time, agent lifecycles don’t depend on the editor’s extension host, and remote execution becomes cleaner because the host process runs independently.
The harness dropdown in the editor window shows which harness is active. For most users today, this is a behind-the-scenes change. For teams running long multi-session agent workflows, or anyone waiting for remote agent execution to stabilize, it matters.
Side-by-side chat groups
Chat panes can now be arranged in horizontal or vertical groups. You drag a chat into a group, or use Alt+click to open a conversation beside an existing one. Subagent chats open in the same group as their parent by default.
The use case is comparing parallel approaches, or keeping a side chat open while a main agent turn runs. You can ask a question in the side chat and get an answer without interrupting what the other agent is doing.
Prompt timeline
Long sessions now have a gutter timeline. Each dot in the timeline represents a prompt. The current position is highlighted. Hovering shows you a preview of the prompt. Clicking jumps to that point in the conversation.
For prompts that modified files, the timeline shows the line change count alongside the dot. This makes it practical to scan back through a long session and find the specific turn where a particular change happened, without scrolling through everything.
Find in chat
Pressing Cmd+F (Ctrl+F on Windows/Linux) opens a search bar inside the chat panel. It searches the complete conversation, including content that has scrolled offscreen. The search supports case matching, whole-word filters, and regular expressions.
Other changes
The integrated browser can now be set as the default editor for local HTML files via workbench.editorAssociations. This lets you preview .html files directly without switching to a browser. The detail panel in single-pane mode now respects workbench.editor.showTabs settings and holds its size across sessions.
Full release notes are at code.visualstudio.com/updates/v1_134.