yvgude--lean-ctx/vscode-extension

lean-ctx VS Code Extension

VS Code sidebar extension for lean-ctx — the context engineering layer for AI agents. Works in VS Code, Cursor, VSCodium and Windsurf.

Features

• Dashboard — Token savings, session stats, and file activity at a glance
• Knowledge Panel — Browse decisions, discoveries, blockers, and insights from the current session
• Repo Map — Interactive view of the most important files in your project, ranked by relevance
• Semantic Search — Search your codebase by meaning, not just text
• Status Bar — Live token savings counter with one-click dashboard access
• Setup & Doctor — Configure shell + editors and run diagnostics from the command palette
• One-click MCP wiring — Write a workspace .vscode/mcp.json entry for lean-ctx
• Visualizer — Launch the lean-ctx call graph visualizer

Prerequisites

• lean-ctx installed (curl -fsSL https://leanctx.com/install.sh | sh). The extension auto-detects the binary on PATH, ~/.cargo/bin and Homebrew.
• VS Code 1.80.0 or later (or a compatible editor: Cursor, VSCodium, Windsurf)

Installation

From the VS Code Marketplace

In VS Code: open Extensions (Ctrl/Cmd+Shift+X), search lean-ctx, click Install — or:

code --install-extension LeanCTX.lean-ctx

From Open VSX (Cursor, VSCodium, Windsurf)

These editors use the Open VSX registry. Search lean-ctx in the Extensions view, or:

cursor --install-extension LeanCTX.lean-ctx     # Cursor
codium --install-extension LeanCTX.lean-ctx     # VSCodium

From Source

cd vscode-extension
npm install
npm run compile
npm run package
code --install-extension lean-ctx-0.1.0.vsix

Development

cd vscode-extension
npm install
npm run watch
# Press F5 in VS Code to launch Extension Development Host

Configuration

Setting	Default	Description
leanctx.binaryPath	"" (auto-detect)	Path to the lean-ctx binary. Empty → auto-detect on PATH, ~/.cargo/bin, Homebrew
leanctx.refreshInterval	30	Status bar refresh interval (seconds)

Commands

Command	Description
lean-ctx: Semantic Search	Opens a search input for semantic code search
lean-ctx: Show Repo Map	Switches to the repo-map tab in the sidebar
lean-ctx: Knowledge Panel	Switches to the knowledge tab in the sidebar
lean-ctx: Open Visualizer	Launches the lean-ctx call graph visualizer
lean-ctx: Refresh Dashboard	Manually refreshes all dashboard data
lean-ctx: Setup	Auto-configures shell + editors (lean-ctx setup)
lean-ctx: Doctor	Runs diagnostics (lean-ctx doctor) in an output channel
lean-ctx: Show Token Savings	Shows the savings recap (lean-ctx gain)
lean-ctx: Show Context Heatmap	Shows the context heatmap (lean-ctx heatmap)
lean-ctx: Open Web Dashboard	Opens the dashboard as a native editor tab (webview). Also reachable from the terminal via lean-ctx dashboard --vscode
lean-ctx: Configure MCP for this workspace	Writes a .vscode/mcp.json stdio entry for lean-ctx

Architecture

src/
├── extension.ts          # Entry point: activate/deactivate
├── leanctx.ts            # CLI interface + binary auto-detection
├── commands.ts           # Sidebar command handlers (search, repomap, …)
├── cli-commands.ts       # CLI-backed commands (setup, doctor, MCP wiring)
├── dashboard-panel.ts    # Native dashboard webview tab (owns a private server)
├── uri-handler.ts        # vscode://LeanCTX.lean-ctx/… deep links (--vscode)
├── statusbar.ts          # Status bar item with auto-refresh
└── sidebar/
    ├── provider.ts       # Webview view provider
    └── panel.html        # Dashboard UI (HTML/CSS/JS)

All communication with lean-ctx happens via CLI subprocess calls in leanctx.ts. The sidebar uses a webview with VS Code's native CSS variables for seamless theming.