DomainCheckr MCP Server
Check domain name availability instantly using RDAP. No API key or installation required. Works as a remote MCP server.
Quick Start
This is a remote MCP server -- no local installation needed. Just add the URL to your MCP client.
Claude Desktop
Add to your claude_desktop_config.json:
{
"mcpServers": {
"domaincheckr": {
"url": "https://domaincheckr.fly.dev/mcp"
}
}
}
Config file location:
- macOS:
~/Library/Application Support/Claude/claude_desktop_config.json - Windows:
%APPDATA%\Claude\claude_desktop_config.json
Claude Code
claude mcp add domaincheckr --transport http https://domaincheckr.fly.dev/mcp
Cursor
Add to ~/.cursor/mcp.json:
{
"mcpServers": {
"domaincheckr": {
"url": "https://domaincheckr.fly.dev/mcp"
}
}
}
Windsurf
Add to ~/.codeium/windsurf/mcp_config.json:
{
"mcpServers": {
"domaincheckr": {
"url": "https://domaincheckr.fly.dev/mcp"
}
}
}
Tools
| Tool | Description |
|---|---|
check_domain | Check if a single domain name is available for registration. Returns registrar, creation date, expiry, and nameservers for taken domains. |
check_domains_bulk | Check up to 50 domain names at once. Returns per-domain results with summary counts. |
suggest_domains | Generate and check domain name ideas for a keyword or business description. Creates 15 variations across .com, .io, .ai, .dev, .co and common prefixes/suffixes. |
Example Prompts
Try asking your AI assistant:
- "Is coolstartup.com available?"
- "Check if these domains are available: acmecorp.com, acmehq.com, getacme.com"
- "Find me a domain for a pet grooming business"
- "I'm building a fintech app called PayFlow, find me a domain"
How It Works
DomainCheckr uses the RDAP protocol (Registration Data Access Protocol) to check domain availability in real time. RDAP is the modern replacement for WHOIS, standardized by the IETF.
- Queries Verisign RDAP for .com/.net domains
- Queries PIR RDAP for .org domains
- Falls back to rdap.org for all other TLDs
- HTTP 404 = available, HTTP 200 = taken
No scraping, no third-party APIs, no rate-limited services. Direct registry queries.
REST API
The same service is available as a REST API for building your own integrations or ChatGPT Actions.
| Endpoint | Description |
|---|---|
GET /check/{domain} | Check a single domain |
POST /check | Bulk check (body: {"domains": ["a.com", "b.com"]}, max 50) |
GET /suggest?keyword=fintech | Generate and check domain ideas |
GET /health | Health check |
GET /docs | Interactive API documentation |
GET /openapi.json | OpenAPI spec (for ChatGPT Actions) |
Base URL: https://domaincheckr.fly.dev
License
MIT