Marcode

Run several coding-agent sessions at once, in resizable split panes, in VS Code's secondary sidebar. Tool-permission requests show up as cards in the transcript and are answered from the UI. Transcripts survive a window reload.

It is an orchestrator, not another agent: it drives other vendors' coding-agent backends (Claude, Codex, OpenCode) side by side, in one panel, rather than shipping its own agent loop.

Features

• A roster of concurrent agent sessions, each its own conversation with its own status, model, effort level and permission mode.
• Split panes over the visible subset of that roster, with a persisted layout.
• Tool-permission requests surfaced as cards in the transcript, answered from the UI.
• Durable transcripts, paged on demand, that survive a window reload.
• Three agent backends behind one interface: the Claude Agent SDK, the Codex CLI, and the OpenCode CLI over the Agent Client Protocol (ACP) — configurable via marcode.enabledProviders.
• A fleet diff review tab (Marcode: Review fleet changes) showing every session's changes against a base ref, attributed to the session whose tool calls made them.
• Context-usage and plan-usage indicators per session and per panel.

Install

Two ways to run it: a throwaway Extension Development Host for iterating on the code, or a packaged .vsix installed into your real VS Code.

Both start from a build. dist/webview.css is produced by the Tailwind plugin inside esbuild.js, so any build script covers it — there is no separate CSS step.

yarn install

Extension Development Host

Press F5 (Run Extension in .vscode/launch.json). It builds via the default task and opens .vscode/dev.code-workspace — a separate window identity over this same folder, so VS Code doesn't refuse the launch with an already-open-folder conflict.

To iterate, run yarn watch in one terminal (esbuild, tsc --noEmit and Tailwind in parallel) and launch with F5. After a rebuild, reload the dev-host window with Ctrl+R. Because the extension host owns all state and the webview is rehydrated from it, a reload is a real test of persistence rather than a reset.

If the debugger itself is the problem or --disable-extensions is needed, launch via a VS Code task instead of F5 — add one to .vscode/tasks.json running code --extensionDevelopmentPath=. .vscode/dev.code-workspace [--disable-extensions].

Packaged .vsix

package.json has no publisher field yet, and vsce refuses to package without one. Add any string — a local install does not need a real Marketplace account:

{
  "name": "mar-code",
  "publisher": "HiiiiD",
  ...
}

Then:

yarn run package              # check-types + lint + production bundle
npx @vscode/vsce package      # -> mar-code-0.0.1.vsix
code --install-extension mar-code-0.0.1.vsix

Reload the window afterwards. To remove it: code --uninstall-extension HiiiiD.mar-code.

.vscodeignore excludes node_modules/** but re-includes @anthropic-ai/claude-agent-sdk and its win32-x64 native package, so the SDK ships inside the .vsix — see the platform note below.

Transcripts live under the extension's storage path, which is per profile and per workspace. The dev host and an installed .vsix therefore keep separate histories.

Setup: move the panel to the secondary sidebar

VS Code extensions cannot place a view in the secondary sidebar directly, so this is a one-time manual step:

1. Open the secondary sidebar — View → Appearance → Secondary Side Bar, or Ctrl+Alt+B.
2. Drag the Marcode icon from the activity bar into the secondary sidebar.
3. Widen it by dragging its inner edge — split panes need the room.

VS Code stores this per profile and workspace, so it only has to be done once. The extension also ships a walkthrough with the same steps — open it from the Command Palette with Get Started: Open Walkthrough... and pick "Set up the Marcode panel".

Requirements

Each backend needs its own CLI installed and authenticated before starting a session — this extension does not manage or prompt for authentication itself, except where noted:

• Claude — the claude CLI must be on PATH and authenticated.
• Codex — the codex CLI must be on PATH (or set via marcode.codex.path). Sign in from the Command Palette with Marcode: Sign in to Codex.
• OpenCode — the opencode CLI must be on PATH (or set via marcode.opencode.path).

Which providers this window registers is controlled by marcode.enabledProviders (default ["claude", "codex", "opencode"]); a provider left out is not probed and never appears in the panel. Changing the setting requires a window reload.

What v1 does not do

• No plan-usage windows or question-card support for the OpenCode backend — ACP carries no plan-usage data, and question cards are out of scope for v1.
• No transcript retention policy — transcripts accumulate under extension storage with no automatic pruning.
• No virtualized scrolling in the transcript view.

Platform note

This build runs on Windows x64 only. The Claude Agent SDK ships its native binaries as separate per-platform optional dependencies, and the packaged .vsix carries just the Windows x64 one. Other platforms need a .vsix built with their own native package — per-platform builds are not set up yet.