Interactive Security Tool

Permission Scope Visualizer

Understand what MCP servers can access. Visualize permission scopes, calculate attack surface scores, and compare servers side by side.

Install

Get the CLI Tool

Run the permission visualizer locally as an MCP server, or try it online below.

npx @clinetools/permission-viz
Requires Node.js 18+
  • Analyze permission scopes of any MCP server
  • Calculate attack surface scores (0-100)
  • Compare two servers side by side
  • Works as a standalone MCP server tool
  • Zero config — just run with npx
Tutorial

How to Use It

Three ways to analyze MCP server permissions — pick the one that fits your workflow.

1

Try Online

Use the interactive demo below to explore permission scopes and compare servers — no install needed.

↓ Jump to interactive demo
2

Use via CLI

Run as a local MCP server and connect any MCP-compatible client.

npx @clinetools/permission-viz
3

Add to Cline / Claude Code

Add the tool to your MCP settings for instant access from your AI assistant.

"permission-viz": { "command": "npx", "args": ["@clinetools/permission-viz"] }

MCP Client Configuration 

{
  "mcpServers": {
    "permission-viz": {
      "command": "npx",
      "args": ["@clinetools/permission-viz"]
    }
  }
}

Example: analyze_permissions 

// Call the tool with a server name:
analyze_permissions({ server: "filesystem" })

// Output:
{
  "server": "Filesystem",
  "permissions": {
    "file_read": "granted",
    "file_write": "granted",
    "network_in": "unused",
    "network_out": "unused",
    "process_spawn": "unused",
    "env_access": "unused",
    "database": "unused",
    "browser": "unused"
  },
  "attack_surface_score": 35,
  "risk_level": "moderate",
  "granted_count": 2,
  "limited_count": 0,
  "unused_count": 6
}

Example: compare_permissions 

// Compare two servers:
compare_permissions({ server_a: "filesystem", server_b: "puppeteer" })

// Output:
{
  "server_a": {
    "name": "Filesystem",
    "score": 35,
    "risk": "moderate"
  },
  "server_b": {
    "name": "Puppeteer",
    "score": 55,
    "risk": "high"
  },
  "differences": [
    { "scope": "file_read",     "a": "granted", "b": "unused" },
    { "scope": "file_write",    "a": "granted", "b": "unused" },
    { "scope": "network_in",    "a": "unused",  "b": "granted" },
    { "scope": "network_out",   "a": "unused",  "b": "granted" },
    { "scope": "process_spawn", "a": "unused",  "b": "limited" },
    { "scope": "browser",       "a": "unused",  "b": "granted" }
  ],
  "recommendation": "Filesystem has a smaller attack surface (35 vs 55)"
}
Live Demo

Try It Online

Select an MCP server to visualize its permission scopes and attack surface score.

Select a server above

Attack Surface Score

--
out of 100

Select an MCP server to see its attack surface score.

Compare

Side-by-Side Comparison

Pick two MCP servers to compare their permission scopes and attack surface scores.

vs
Learn

Why Permission Scope Matters

Every permission an MCP server holds is a potential vector for exploitation. Understanding scope is your first line of defense.

Principle of Least Privilege

MCP servers should request only the minimum permissions they need. Overly broad access means a compromised server can do far more damage. Always question why a tool needs file write or network access.

Attack Surface Reduction

Each granted permission expands the attack surface. File + network access enables data exfiltration. Process spawn enables arbitrary code execution. Fewer permissions mean fewer exploitable vectors.

Network Boundaries

Outbound network access enables data exfiltration. Even if a server only reads files locally, adding network-out means those files can be sent anywhere. Restrict network scopes carefully.

Credential Exposure

Servers with env variable access can read API keys, passwords, and tokens. Combined with network access, a malicious server could harvest credentials and send them to an external endpoint.

Review Before You Approve

Before granting access, compare similar tools and choose the smallest footprint. A search tool should not need file-write. Database permissions can expose PII. Review requirements before installing any MCP server.

Want a Full Security Audit?

Submit your MCP server for a comprehensive permission and security review by our team.

Submit for Review