Context Mode Mcp

---
name: context-mode-mcp
description: Privacy-first MCP virtualization layer that sandboxes tool calls to save context window space and maintain session continuity across compaction
triggers:
  - "set up context mode"
  - "install context-mode MCP"
  - "reduce context window usage"
  - "sandbox MCP tool calls"
  - "session continuity after compaction"
  - "context-mode not routing tools"
  - "configure context mode hooks"
  - "optimize AI agent context"
---

# Context Mode MCP

> Skill by [ara.so](https://ara.so) — Daily 2026 Skills collection.

Context Mode is a privacy-first MCP server that acts as a virtualization layer between AI coding agents and their tools. It solves two problems: (1) raw tool output floods the context window (a Playwright snapshot = 56 KB, 20 GitHub issues = 59 KB), and (2) conversation compaction causes agents to forget session state. Context Mode sandboxes tool calls in subprocesses — raw data never enters context — and tracks all activity in local SQLite with FTS5 search for retrieval after compaction. Nothing leaves your machine; no telemetry, no cloud sync.

## Installation

### Claude Code (Full Plugin — Recommended)

```bash
/plugin marketplace add mksglu/context-mode
/plugin install context-mode@context-mode

Restart Claude Code. The plugin auto-installs:

• MCP server with 6 sandbox tools
• PreToolUse/PostToolUse/PreCompact/SessionStart hooks
• CLAUDE.md routing instructions in your project root
• Slash commands (/context-mode:ctx-stats, /context-mode:ctx-doctor, /context-mode:ctx-upgrade)

Claude Code (MCP-only, no hooks)

claude mcp add context-mode -- npx -y context-mode

Other Platforms (Global Install)

npm install -g context-mode

Gemini CLI

Add to ~/.gemini/settings.json:

{
  "mcpServers": {
    "context-mode": {
      "command": "context-mode"
    }
  },
  "hooks": {
    "BeforeTool": [
      {
        "matcher": "",
        "hooks": [{ "type": "command", "command": "context-mode hook gemini-cli beforetool" }]
      }
    ],
    "AfterTool": [
      {
        "matcher": "",
        "hooks": [{ "type": "command", "command": "context-mode hook gemini-cli aftertool" }]
      }
    ],
    "SessionStart": [
      {
        "matcher": "",
        "hooks": [{ "type": "command", "command": "context-mode hook gemini-cli sessionstart" }]
      }
    ]
  }
}

VS Code Copilot

Create .vscode/mcp.json:

{
  "servers": {
    "context-mode": {
      "command": "context-mode"
    }
  }
}

Create .github/hooks/context-mode.json:

{
  "hooks": {
    "PreToolUse": [
      { "type": "command", "command": "context-mode hook vscode-copilot pretooluse" }
    ],
    "PostToolUse": [
      { "type": "command", "command": "context-mode hook vscode-copilot posttooluse" }
    ],
    "SessionStart": [
      { "type": "command", "command": "context-mode hook vscode-copilot sessionstart" }
    ]
  }
}

Cursor