Mirasim — VS Code extension

Run Mirasim agent sessions inside VS Code, scoped to the current folder (no multi-workspace management). Built on @pikiloom/kernel, embedded in-process in the extension host; the UI is a lightweight React webview that talks to the host over postMessage (the VS Code-native analogue of pikiloom's dashboard ↔ pikichannel).

Features

• Sessions sidebar — lists this folder's sessions (persisted across restarts); ＋ New Chat.
• Multi-window — each conversation is its own editor WebviewPanel, so sessions tile natively via VS Code editor groups.
• Thinking activity — streamed reasoning, a tool/activity trail, and plan cards, all as collapsible sections (rendered from the kernel's accumulating UniversalSnapshot).
• In-chat agent / model / effort switcher — a cascade picker in the composer; the selection rides the next message (switching agent starts a new linked session).
• Queueing — send while a turn is in flight; queued prompts can be reordered or recalled before they run (a host-managed outbox, flushed when the turn settles).
• Agents — claude, codex, the built-in harness, plus echo (a credential-free test agent). Availability is detected per agent.
• Recording (on by default) — every model call is captured verbatim through the local hijack proxy to ~/.mirasim/recordings/<session>/ (raw HTTP facts + blobs; no wire parsing).

Build

npm run build -w mirasim      # host (esbuild → dist/extension.cjs) + webview (vite → webview/dist)
npm run package -w mirasim        # → mirasim.vsix  (vsce, --no-dependencies)
code --install-extension mirasim.vsix --force

Open a folder, then Mirasim: New Chat (Command Palette) or the Mirasim view in the Activity Bar.

Layout

• src/ — extension host (Node, bundled to CJS). host/loom-host.ts embeds the kernel and bridges it to webviews; host/{catalog,recording,harness-driver}.ts fill the kernel's catalog / recording / built-in-agent seams. src/shared/ holds pure logic shared with the webview (snapshot.ts, queue-logic.ts, protocol.ts).
• webview/ — the VS Code shell around the SHARED UI (@mirasim/ui: workbench + config pages, the same codebase the web SPA renders). main.tsx boots the postMessage HostClient + webview-state storage; PluginApp.tsx multiplexes the init mode (session / workspace / settings / sidebar); theme-bridge.css maps --vscode-* vars onto the shared --th-* design tokens so components look native in both editor themes.