VS Code 1.140: What's New, Copilot Harness and How to Update

Visual Studio Code 1.140 is out, and the headline change is a shared "harness" that now runs Copilot's agent the same way inside the editor, in the standalone GitHub Copilot app, and in the Copilot CLI. Microsoft's release also adds an experimental multi-model orchestration system called HydraFusion, experimental multi-folder agent sessions, experimental remote task delegation to other machines, and experimental worktree folder sharing to cut down on duplicate dependency installs.

What's new in VS Code 1.140

According to Microsoft's official VS Code 1.140 release notes, this release is built almost entirely around agent workflows: how Copilot's agent behaves across Microsoft's different products, how multiple AI models can be coordinated on a single coding task, how one agent session can span more than one repository, and how work can be handed off to a separate, more powerful machine. A handful of smaller changes — an accessibility tweak for confetti animations, sharper terminal text rendering on macOS, and new enterprise controls for OpenTelemetry telemetry — round out the update.

Most of the new agent capabilities are gated behind settings and ship as experimental or preview features rather than defaults, so most users will not see their day-to-day workflow change immediately after installing the update. That pattern is consistent with how Microsoft has rolled out agent tooling in recent VS Code releases: new capabilities typically land behind a flag for a release or two, get refined based on feedback filed against the open-source microsoft/vscode repository, and only later graduate to being on by default. Developers who want to try the new features early will need to dig into settings.json rather than relying on the Settings editor UI, since several of the toggles described below are intentionally left out of that graphical view while they remain experimental.

Copilot harness: one agent engine, three Copilot products

The biggest structural change in 1.140 is the Copilot harness, a new way of running Copilot's coding agent inside VS Code. Per Microsoft, the harness "is powered by the Copilot SDK, so its behavior and capabilities are consistent with other Copilot products, including the standalone GitHub Copilot app and the Copilot CLI." In practice, that means the same agent logic and tool set now drives Copilot whether someone is working in the VS Code chat panel, in the separate Copilot desktop app, or from a terminal via the CLI, instead of each surface maintaining its own agent implementation.

The harness runs in a dedicated agent host process built on what Microsoft calls the Agent Host Protocol (AHP), documented in its agent host concepts page. Because the agent lives in its own process rather than inside a single editor window, the same running agent session can be reattached from multiple VS Code windows. Microsoft published a companion blog post on the agent host architecture and a how-to guide for working with the Copilot harness for developers who want the deeper technical picture. Users can pick the Copilot harness from the harness selector in the chat input, and Microsoft notes it may already be the default selection for some users in this release.

This consolidation matters beyond VS Code: it is the clearest sign yet that GitHub is standardizing Copilot's agent behavior across its whole product lineup, similar to how other vendors are converging their assistants around a single underlying engine — the same dynamic playing out among general AI assistants, as Pandromeda covered in its comparison of Claude, Grok, and ChatGPT.

HydraFusion: a research preview for orchestrating multiple models

VS Code 1.140 also introduces HydraFusion, described in the release notes as "an adaptive model orchestration system that chooses the models and workflow for each coding task." Rather than a developer manually picking which AI model handles a given request, HydraFusion can solve a task with a single model, escalate to a stronger (and presumably costlier) model when needed, or route a result through a second model that critiques and revises it before it reaches the user.

Microsoft frames the goal as balancing output quality against speed and cost without requiring manual model-juggling. GitHub's own engineering blog, in a post titled "Project HydraFusion: Frontier quality via multi-model orchestration," frames it as part of a broader push to get "frontier" quality results without locking developers into any single model. In VS Code 1.140, HydraFusion is labeled a research preview, and the release notes say it's available to "eligible users with preview features enabled," who can select it directly from the model picker. That eligibility gating, plus the research-preview label, suggests Microsoft is still validating the approach before wider rollout.

Multi-folder sessions: one agent session, several repos or worktrees

Multi-folder sessions, also experimental in this release, let a single agent session coordinate work that spans more than one folder. Previously, every chat inside a multi-chat agent session shared one folder and one checkout; now, per Microsoft, "each chat can use its own folder or worktree without changes leaking between chats." Each chat keeps its own terminal, tasks, file changes, pull request, and merge state, and chats pointed at the same folder share that state.

Microsoft's two illustrated use cases are implementing a feature that touches two separate repositories at once (one chat per repo), and spinning up several peer chats that each work from a fresh Git worktree of the same repository to compare different implementation approaches side by side, each with its own branch and draft pull request. The feature is disabled by default and has no toggle in the Settings editor UI — it has to be turned on by hand in user-scoped settings.json, with separate flags depending on which agent harness is active (chat.agentHost.copilotAgent.multiRootEnabled, chat.agentHost.claudeAgent.multiRootEnabled, or chat.agentHost.codexAgent.multiRootEnabled).

Remote delegation: letting an agent hand off work to another machine

A separate experimental feature lets an agent delegate tasks to other, already-connected machines instead of doing everything locally. Microsoft's remote agent sessions documentation describes new built-in tools that let an agent list available remote hosts and their resources, start a new session on one of them, check on a running remote session, and pass messages back and forth with the chat that kicked the work off.

Placement can be automatic: a developer can ask an agent, in plain language, to start a session "on a connected Linux host with at least 16 GiB of memory and eight logical CPUs," and VS Code will match an eligible host, favoring whichever one has the fewest sessions already running. Remote sessions start with no workspace attached unless one is specified, and Microsoft is explicit that the tooling does not clone or copy the originating workspace — any repository work has to use a folder or worktree that already exists, and already-trusted, on the target host. The feature is off by default behind the chat.remoteAgentHostsEnabled setting and only appears in the Agents window.

Shared worktree folders: skipping duplicate installs

Developers who rely heavily on Git worktrees — including, increasingly, for running isolated agent sessions — have a long-standing annoyance: every new worktree needs its own fresh node_modules or build output, even if nothing in that folder actually changed. VS Code 1.140 addresses this with an experimental setting, git.worktreeSymlinkFolders, that accepts .gitignore-style patterns for folders to treat this way. Per the release notes, "when VS Code creates a new worktree, including for an agent session, it creates symlinks to matching folders in the current checkout," instead of letting tools reinstall or rebuild them from scratch. Microsoft's branches and worktrees documentation has the broader background on how VS Code's worktree support works.

Other notable changes in 1.140

Beyond the agent-focused headliners, the release notes list several smaller updates: an accessibility option so screen reader and sound users are notified when a confetti celebration animation appears in chat; sharper, higher-fidelity terminal text rendering on macOS, also marked experimental; the ability to archive individual chats inside an agent session to declutter the sessions list; automatic cleanup of unused Dev Containers; faster Dev Container startup times; and, on the enterprise side, new controls for setting an organization-wide default "Auto" model tier and capturing user identity in OpenTelemetry traces for usage auditing. None of these individually rival the agent-platform changes, but together they show Microsoft continuing to harden VS Code's container, accessibility, and enterprise-management tooling release over release.

The MCP (Model Context Protocol) side of VS Code also got a smaller update in 1.140: the editor now supports adding MCP servers to portable configuration files, making it easier for a team to check a shared set of MCP server definitions into a repository rather than having each developer configure their own servers locally. Combined with the remote delegation and multi-folder session work above, it is another sign that this release leans heavily toward making agent and tooling configuration easier to share across a team rather than keeping it scoped to one person's machine.

VS Code 1.140 features at a glance

How to update to VS Code 1.140

VS Code checks for updates automatically by default, so most desktop installs will prompt to restart and apply version 1.140 on their own. To check manually, open the Command Palette or the Help menu and choose "Check for Updates" (on macOS, this lives under the Code menu). Users on Linux distributions that install VS Code through a system package manager should update through that package manager rather than waiting on the in-app updater, since that path follows the distribution's own release cadence. The full, line-by-line list of changes — including every setting name mentioned above — is published on Microsoft's VS Code 1.140 update page. Since several of the new agent features touch tooling adjacent to Microsoft's wider Copilot ecosystem, readers weighing whether to turn on the AI-assisted side of VS Code at all may also want Pandromeda's explainer on what Copilot PC branding actually requires and includes, since VS Code's agent features work independently of that hardware label.

What's next

Every new capability in this release besides the Copilot harness itself ships as experimental or a research preview, which is Microsoft's usual signal that a feature is still being validated before a wider, default-on rollout in a future monthly release. Multi-folder sessions and remote delegation in particular point toward VS Code's agent tooling increasingly treating multiple repositories, worktrees, and even separate physical machines as components of one coordinated coding session rather than as isolated workspaces. Whether HydraFusion's model-orchestration approach graduates out of research preview — and whether Microsoft widens eligibility for it — is likely to be one of the more closely watched threads in VS Code's release notes over the next few monthly updates.

VS Code typically ships a new stable minor version roughly once a month, with an Insiders build previewing changes ahead of each stable release. Given how much of 1.140 is scoped to agent infrastructure rather than user-facing editor features, the next release or two will likely show whether features like multi-folder sessions and shared worktree folders move from opt-in settings toward being turned on for everyone by default, and whether the Copilot harness fully replaces the agent implementations it is designed to unify.

Written byFelix Moreau

Felix Moreau writes Pandromeda's software coverage and how-to guides. He covers Windows, macOS and Linux updates, the apps people rely on, emulators and developer tools, and turns official documentation into clear, numbered steps that work on the current version.

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