Domain Checker

Fast domain availability checker for Model Context Protocol (MCP). DNS + RDAP/WHOIS verification.

Built by Brave Labs

Features

• Hybrid DNS + RDAP/WHOIS checking - Fast DNS lookup, then RDAP (with WHOIS fallback) for accuracy
• Bulk checking - Check up to 100 domains in parallel
• Parallel processing - Batched verification queries for optimal throughput
• Name expansion - Check a base name across all popular TLDs automatically
• Flexible filtering - Return only available, only taken, or all results
• Error reporting - Clear error handling for timeouts and failures

Installation

npm install -g @wearebravelabs/domain-checker-mcp

Configuration

Claude Desktop

Add to your claude_desktop_config.json:

{
  "mcpServers": {
    "domain-checker": {
      "command": "npx",
      "args": ["-y", "@wearebravelabs/domain-checker-mcp"]
    }
  }
}

Claude Code

Add to your MCP settings:

{
  "mcpServers": {
    "domain-checker": {
      "command": "npx",
      "args": ["-y", "@wearebravelabs/domain-checker-mcp"]
    }
  }
}

Tools

check_domains

Check specific domains for availability with full DNS + WHOIS verification.

// Check multiple domains
check_domains({
  domains: ["myapp.com", "myapp.io", "myapp.dev"]
})

// Filter to only available domains
check_domains({
  domains: ["example.com", "randomname123.com"],
  filter: "available"
})

Parameters:

• domains (required): Array of domain names to check
• filter (optional): "available" or "taken" - omit for all results

check_names

Check base names across popular TLDs automatically.

// Check "myproject" across all popular TLDs
check_names({
  names: ["myproject"]
})

// Check multiple names with specific TLDs
check_names({
  names: ["startup", "launchpad"],
  tlds: ["com", "io", "co", "app"],
  filter: "available"
})

Parameters:

• names (required): Array of base names to check
• tlds (optional): Specific TLDs to check (defaults to: com, net, org, io, co, app, dev, ai, xyz, me, info, biz, us, uk, ca, au)
• filter (optional): "available" or "taken" - omit for all results

check_domains_quick

Fast DNS-only check without WHOIS verification. Use when speed matters more than accuracy.

check_domains_quick({
  domains: ["example.com", "test.io"]
})

Parameters:

• domains (required): Array of domain names to check
• filter (optional): "available" or "taken" - omit for all results

Note: DNS-only checks may show false positives for available domains. Use check_domains for verification.

Example Response

{
  "summary": {
    "total": 4,
    "available": 2,
    "taken": 2,
    "errors": 0,
    "totalTime": "634ms"
  },
  "available": [
    "myproject.io",
    "myproject.dev"
  ],
  "taken": [
    "myproject.com",
    "myproject.app"
  ]
}

With errors:

{
  "summary": {
    "total": 3,
    "available": 1,
    "taken": 1,
    "errors": 1,
    "totalTime": "10234ms"
  },
  "available": ["available-domain.com"],
  "taken": ["google.com"],
  "errors": [
    { "domain": "example.xyz", "error": "WHOIS timeout" }
  ]
}

How It Works

1. DNS Check (Fast) - All domains are checked via DNS in parallel. If DNS resolves, the domain is definitely taken.

2. RDAP/WHOIS Verification (Accurate) - Domains that pass DNS (no records found) are verified via RDAP (preferred) or WHOIS (fallback) to confirm availability. RDAP servers are loaded dynamically from the IANA bootstrap registry.

3. Parallel Processing - Verification queries run in parallel batches of 20 for optimal throughput.

This hybrid approach gives you the speed of DNS checking with the accuracy of RDAP/WHOIS verification.

Development

# Install dependencies
npm install

# Build
npm run build

# Run locally
npm start

More from Brave Labs

bravelabs.com.au

License

MIT © Brave Labs