mcp-config-example

Generate example .mcp.json files by automatically masking sensitive environment variables.

Features

• Automatically detects and masks sensitive environment variables (API keys, tokens, secrets, passwords)
• Preserves JSON structure and formatting
• Masks absolute file paths with generic placeholders
• Normalizes all placeholder values to uppercase with underscores
• Simple CLI interface

Installation

pnpm add -D mcp-config-example

Or use directly with bunx:

bunx mcp-config-example

Usage

CLI

Generate an example config from .mcp.json:

mcp-example

Specify custom input file:

mcp-example custom-config.json

Specify both input and output:

mcp-example .mcp.json my-example.json

Programmatic

import { generateExampleConfig } from 'mcp-config-example';

generateExampleConfig('.mcp.json', '.mcp.json.example');

How It Works

The tool automatically masks:

1. Environment Variables: Any key containing API_KEY, TOKEN, SECRET, PASSWORD, CREDENTIALS, AUTH, or KEY will have its value replaced with the key name.

   // Before
   "env": {
     "SUPABASE_ACCESS_TOKEN": "sbp_abc123def456"
   }
   
   // After
   "env": {
     "SUPABASE_ACCESS_TOKEN": "SUPABASE_ACCESS_TOKEN"
   }

2. File Paths: Absolute paths are normalized by replacing specific usernames with generic placeholders.

   // Before
   "MEMORY_BANK_ROOT": "/Users/seungwonan/Dev/memory-bank"
   
   // After
   "MEMORY_BANK_ROOT": "/Users/username/Dev/memory-bank"

3. Bearer Tokens: Authorization headers with Bearer tokens are masked.

   // Before
   "args": ["--header", "Authorization: Bearer hf_abc123"]
   
   // After
   "args": ["--header", "Authorization: Bearer YOUR_TOKEN"]

4. Placeholder Values: Angle bracket placeholders are removed, converted to uppercase, and hyphens/spaces are normalized to underscores.

   // Before
   "args": ["--project-ref=<project-ref>"]
   
   // After
   "args": ["--project-ref=PROJECT_REF"]

   // Before
   "env": {
     "NAVER_CLIENT_ID": "your-client-id"
   }
   
   // After
   "env": {
     "NAVER_CLIENT_ID": "YOUR_CLIENT_ID"
   }

Example

Given a .mcp.json file:

{
  "mcpServers": {
    "supabase": {
      "command": "npx",
      "args": ["-y", "@supabase/mcp-server-supabase@latest"],
      "env": {
        "SUPABASE_ACCESS_TOKEN": "sbp_real_token_here"
      }
    }
  }
}

Running mcp-example generates .mcp.json.example:

{
  "mcpServers": {
    "supabase": {
      "command": "npx",
      "args": ["-y", "@supabase/mcp-server-supabase@latest"],
      "env": {
        "SUPABASE_ACCESS_TOKEN": "SUPABASE_ACCESS_TOKEN"
      }
    }
  }
}

Development

# Install dependencies
pnpm install

# Build
pnpm build

# Format code
pnpm format

# Lint code
pnpm lint

# Check and fix
pnpm check

License

MIT