jailbreak-mcp

Created By

kranners8 months ago

Break free of your MCP Client constraints 🦹

Content

jailbreak-mcp

A MCP server wrapper for using the entire Model Context Protocol without tool limits, missing concepts, or context overload.

WARNING

This tool is actively being developed. Watch out! 🐉

Why does this exist?

MCP servers could be ✨ amazing ✨ but using them comes with a few caveats.

Your client is probably missing most of the actual protocol. There are many capabilities listed in the MCP:

Tools, which are like functions.
Resources, which are like values.
Prompts, which are prompts.

As of writing, almost no MCP client (Cursor, Claude Desktop, Cherry Studio) implements all of them. If you are a Cursor user, you can only use tools.

See the Model Context Protocol documentation to see what your MCP client of choice is lacking.

Admittedly this isn't the biggest deal - most servers just use tools anyway. This may become a bigger deal in future if more servers start to implement more of the protocol.

Jailbreak-MCP remedies this by exposing configured resources and prompts as tools, so even the most restrictive implementations are fully usable.

MCP servers fill the context window

The more tools you have configured, the more your MCP servers are taking up of the all-important context window of your agent.

If you wanted to use tools or information from multiple MCP servers at once, your context window becomes very small very fast.

To remedy this, some clients have implemented warnings about having too many tools configured at once. Cursor has implemented a hard restriction of 40 tools, but hides which tools are disabled at any given moment.

Some servers expose many tools at the same time. The GitHub MCP server alone fills the entire Cursor tool cap.

The best thing you can do currently is manually enable and disable which MCP servers you want to have turned on at any given moment.

JailbreakMCP fixes this by providing configurable "modes" which expose only the exact tools and resources you need to do a given task, and tools to switch between modes on the fly.

Installation

Example installation will be assuming you're using Cursor.

Start by making a backup of your current mcp.json file.

TIP

The default location is ~/.cursor/jailbreak.mcp.json. To rename your existing Cursor config: mv ~/.cursor/mcp.json ~/.cursor/jailbreak.mcp.json

Create a new mcp.json file where the old one was, with these contents:

{
  "mcpServers": {
    "jailbreak": {
      "command": "npx",
      "args": [
        "jailbreak-mcp@latest",
        "/optional/path/to/jailbreak.mcp.json",
      ],
      "env": {
        "CONFIG_PATH": "/optional/path/to/jailbreak.mcp.json"
      }
    }
  }
}

The server will prefer arguments over environment variables over ~/.cursor/jailbreak.mcp.json.

From here, you need to configure a default mode.

{
  "mcpServers": {
    ...
  },
  "modes": {
    "default": {
      "everything": {
        "tools": [
          "echo",
          "add",
          "longRunningOperation"
        ],
        "prompts": [
          "simple_prompt",
          "complex_prompt",
          "resource_prompt"
        ],
        "resources": [
          "test://static/resource/1",
          "test://static/resource/2"
        ]
      },
      "time": true
    }
  }
}