Shield

Overview

Shield is a Model Context Protocol (MCP) server that acts as a stdio MCP auth proxy, wrapping any MCP server with per-tool permission enforcement. It enables MCP-compatible AI assistants to call Shield's tools directly while maintaining granular control over which tools can be accessed and by whom.

Shield runs locally on your machine via the npm package @bolyra/shield, communicating over stdio with no authentication setup required. The v0.1.0 release is published under the Apache-2.0 license, with source code available at bolyra/bolyra on GitHub.

Shield is categorized as AI & Agents on mcp.site and integrates with any MCP client including Claude Desktop, Claude Code, Cursor, VS Code, Windsurf, and Zed. If you maintain Shield at bolyra, claim this listing to verify ownership and keep the information up to date.

Installation

// claude_desktop_config.json
{
  "mcpServers": {
    "shield": {
      "command": "npx",
      "args": [
        "-y",
        "@bolyra/shield"
      ]
    }
  }
}