VS Code 1.128: Multi-Chat Agent Sessions Explained

Visual Studio Code 1.128, released July 8, 2026, lets a single Claude agent-host session hold multiple related chats instead of one linear thread — developers can branch a chat from an earlier turn, run a peer chat alongside the main one, and send turns to several chats at once, all inside what still looks like one session in the sidebar.

What multi-chat sessions actually add

Before this release, comparing two approaches to the same task meant opening two entirely separate top-level sessions, each with its own history and no shared context. VS Code 1.128 restructures that: a Claude agent-host session can now contain several peer chats, and each one keeps an independent history, title and model selection while staying grouped under the parent session. Fork a chat from any earlier turn to explore an alternative without losing the original thread, switch between peer chats with keyboard navigation, and — the part that matters most for throughput — send turns to more than one chat concurrently rather than waiting for each to finish in sequence.

Microsoft's own example is a single Claude session split three ways: the main chat adds a /health endpoint to an Express app, a peer chat writes tests for that endpoint in parallel, and a forked chat explores a different implementation from an earlier turn. All three restore together the next time the session reopens.

How to turn it on

Multi-chat sessions are gated behind a setting, not on by default:

{
  "chat.agentHost.enabled": true
}

With that enabled, select Claude from the harness picker in the Agents window. The feature is scoped to Claude agent-host sessions specifically in 1.128 — it is not yet available across every chat provider VS Code supports.

Quick chats: a separate but related change

The same release adds quick chats: press Cmd+K Cmd+N (Ctrl+K Ctrl+N on Windows/Linux) to open a chat in the Agents window without selecting a workspace first. Quick chats live in their own Chats section, skip workspace-specific panels, and persist across a reload — useful for a fast question that has nothing to do with the project currently open. They are distinct from multi-chat sessions: quick chats solve "I don't want to open a workspace," multi-chat sessions solve "I want several related threads inside the workspace session I already have open."

What else shipped in 1.128

Multi-chat sessions are the headline agent feature, but three other changes in the same release affect day-to-day Copilot Chat use:

• Copilot Vision reached general availability — attach images and PDFs by pasting them into chat, dragging and dropping, or using the context menu.
• OS-level keyboard shortcuts. Adding "systemWide": true to a keybinding in keybindings.json makes that shortcut fire even when VS Code does not have focus.
• Read-only subagent transcripts in the Agents window (Preview), so a developer can inspect what a spawned subagent actually did without that transcript being editable.

Why this matters for agentic workflows

Running one task per session was a real bottleneck once AI coding agents became capable enough to handle multi-step work unattended: a developer exploring two implementations, or running an implementation chat and a test-writing chat side by side, had to juggle separate sessions with no shared view of what the other was doing. Grouping related chats under one session — with independent history but shared context of "these are the same task, approached differently" — is the same parallelization pattern coding-agent orchestration tools have been adding at the CLI level, now built directly into the editor's chat UI instead of requiring a separate terminal workflow.

For teams standardizing on Claude as their VS Code agent-host provider, the practical upgrade is comparison without context-switching: fork before a risky refactor, keep the original chat as a fallback, and only merge the fork's changes if it actually works out — no need to remember which of two unconnected sessions was the "safe" one.