mcp-domain-availability is a Model Context Protocol (MCP) server whose main purpose is to enable Claude Desktop to check domain availability across more than 50 popular top-level domains (TLDs). Users can ask Claude questions in natural language, and the server performs domain queries and returns results.
Main capabilities:
- Domain availability checks: supports popular TLDs (such as .com, .io, .ai), country TLDs (such as .us, .uk, .de), and new TLDs (such as .app, .dev, .tech).
- Authoritative verification: prioritizes RDAP (the protocol that replaces WHOIS), falling back to WHOIS and DNS for the few TLDs that do not have RDAP services.
- Smart suggestions: organizes TLD suggestions by popularity.
- Search capabilities: exact TLD matching to check a specific domain; bulk checks of a given name across all supported extensions; parallel processing to speed up queries; organizes results by TLD category.
- Integration features: easy installation via uvx package management, seamless integration with Claude Desktop, real-time availability status updates, and performance metrics and timing information.
- AI assistant features: natural language domain queries via Claude, automated domain suggestion workflows, and availability-based smart recommendations.
Usage:
- Environment requirements: Python 3.10 or later (3.12 recommended), uv package manager.
- Install the uv package manager: official installer (recommended), Homebrew (macOS/Linux), or run /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"。
- The MCP server automatically manages Python dependencies via uvx.
- Supports direct installation without cloning the repository, using uvx for package management.
- Claude Desktop configuration file locations: macOS is ~/Library/Application Support/Claude/claude_desktop_config.json; Windows is %APPDATA%\Claude\claude_desktop_config.json; Linux is ~/.config/Claude/claude_desktop_config.json. Edit this file and add the mcp-domain-availability configuration.
- Can be installed automatically via Smithery.
- Development or local testing: clone the repository and install dependencies.
- Deploy to Google Cloud Run using Docker: the server supports two transport modes, stdio (default, for Claude Desktop integration) and sse (for HTTP/Web deployments, such as Google Cloud Run). When deploying to Cloud Run, the MCP_TRANSPORT environment variable must be set to sse. Requires the Google Cloud SDK installed and authenticated, Docker installed and running, and a Google Cloud project with the Cloud Run and Container Registry APIs enabled. You can use the deploy.sh script or run the commands manually. No environment variables are required for local Claude Desktop use.
- Available tools: as of 0.5.0 the --domain flag is no longer required, and you can ask about domains in natural language; the flag is still accepted for compatibility with existing prompts. Bulk TLD checks have been moved to a separate tool.
Supported TLD categories include: popular (com, net, org, io, ai, app, dev, co, xyz, me, info, biz), country (us, uk, ca, au, de, fr, it, es, nl, jp, kr, cn, in, br, mx, ar, cl, pe, ru, pl, cz, ch, at, se, no, dk, fi, be, pt, gr, tr, za, eg, ma, ng, ke), new TLD category (tech, online, site, website, store, shop, cloud, digital, blog, news, etc.).
Verification mechanism: In January 2025, ICANN deprecated WHOIS as the required registration data protocol and switched to RDAP (RFC 7482/9082), so RDAP is the primary source. RDAP discovers the registry RDAP services for about 1,200 TLDs through the IANA bootstrap registry and is authoritative: unregistered domains return 404, registered ones return 200. WHOIS is used only for TLDs without an RDAP service (such as .io, .co, .me, .de, .es and some other country-code TLDs), finding the registry WHOIS server through IANA referrals and querying directly via port 43, interpreting only the first few lines of the response. DNS is used to confirm that successfully resolved names are registered. Each domain returns one of three statuses: available, unavailable, or indeterminate. The indeterminate status exists because older versions would report a domain as available when a WHOIS query errored (including when the whois binary was not installed on the machine), causing all domains to appear free; now untrustworthy results are marked as such. Domains are checked concurrently, with at most 10 in progress, to comply with registry rate limits.
Results include: the status of the requested domains (if a specific TLD was provided), available domains (confirmed unregistered, sorted alphabetically), unavailable domains (confirmed registered), indeterminate domains (no authoritative answer, with reason), summary statistics (broken down by TLD category: popular, country, new TLD), performance metrics (check duration and answer source: rdap, whois, or dns).
Testing and command line: an offline test suite can be run (no network required), and domains can also be checked from the command line.
Troubleshooting: on connection errors, verify the uvx installation (uvx --version, reinstall uv if necessary), check the Python version (3.10+). MCP Python SDK version 2.0 removed mcp.server.fastmcp, and versions before 0.5.0 did not pin the SDK version, causing startup failure; 0.5.0 is written for SDK 2.x. If errors still occur, refresh the cache installation: uvx --refresh --from git+https://github.com/imprvhub/mcp-domain-availability mcp-domain-availability; if it is a persistent tool, run uv tool upgrade mcp-domain-availability; remove old workarounds (such as "--with", "mcp<2.0.0" in the configuration). DNS resolution issues: check network connectivity, DNS server reachability, rate limits (large batch checks may trigger limits; the tool uses a semaphore to limit concurrent requests to 20). MCP server does not start: verify the configuration JSON syntax, restart Claude Desktop.
Security considerations: this tool makes network requests to external DNS servers and WHOIS services. Domain queries may be logged by DNS providers; WHOIS queries are usually logged and may be rate-limited; no personal information is transmitted other than the domains being checked; all queries are read-only and do not modify any external systems.
The project is licensed under the Mozilla Public License 2.0. Contributions are welcome, and directions for improvement include: adding support for more TLD categories, implementing a caching mechanism to speed up repeated queries, enhancing WHOIS parsing to obtain more detailed domain information, and improving error handling and retry mechanisms.
Limitations: the materials do not provide specific information on fees, pricing, or commercial use terms; detailed API documentation or complete configuration examples are not provided; other unmentioned features or platform support information is not currently provided.
