DomainCheckr
Check domain name availability via RDAP. Single, bulk, and smart suggestions. No API key needed.
Install
Add this to your client's MCP configuration (Claude Desktop: claude_desktop_config.json; Cursor: .cursor/mcp.json; VS Code and others use the same "mcpServers" shape).
claude mcp add --transport http domaincheckr 'https://domaincheckr.fly.dev/mcp'{
"mcpServers": {
"domaincheckr": {
"type": "http",
"url": "https://domaincheckr.fly.dev/mcp"
}
}
}Documentation
From the project's README on GitHub, refreshed weekly. Links open on GitHub.
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/mcpCursor
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
Frequently asked questions
What is DomainCheckr?
Check domain name availability via RDAP. Single, bulk, and smart suggestions. No API key needed.
How do I install DomainCheckr?
It runs as a remote server. In Claude Code: claude mcp add --transport http domaincheckr 'https://domaincheckr.fly.dev/mcp'. For other clients, paste the JSON configuration from this page into their MCP settings.
Does DomainCheckr need an API key?
Its registry entry lists no required key or secret. Some features may still need an account with the service it connects to.
Is DomainCheckr open source?
Yes. Its code is on GitHub under the MIT license.
Who maintains DomainCheckr?
It is published by nach-dakwale. AI.tn lists it but does not maintain or endorse it.
From the official MCP Registry. Listing is not an endorsement: review a server's code and permissions before giving it access to your data.