domain-check — Claude Code MCP server: what it does, how to install
Checks domain availability through RDAP and embedded WHOIS directly from your AI agent. Helps discover project names or verify hundreds of extensions in batch.
Open on GitHubWhat domain-check does
This Rust-based engine queries registries via RDAP and switches to built-in WHOIS whenever RDAP endpoints are missing. No system whois package is needed. The tool discovers official IANA registries for over 1,200 top-level domains, with 34 hardcoded zones ready for offline runs. Batch scanning handles up to 100 concurrent lookups.
Apart from single lookups, the server expands custom patterns with letters and numbers, attaches prefixes or suffixes, and applies curated presets like startup or tech. It also reads RFC 10023 records to detect if registered domains are listed for sale with prices and contact details. Building through Cargo requires a local Rust toolchain.
What it helps with
- check availability across multiple TLDs for a startup brand
- generate naming variations with custom patterns, prefixes, or suffixes
- inspect registrar details and expiration dates for registered domains
- identify domain sale status and asking prices via RFC 10023
Example prompts for the agent
- Check if the domain mycoolapp is available using the startup preset
- Generate name ideas matching pattern brand\d for the io extension
- Look up registrar information and expiration status for target.com
How to install domain-check
Install
The MCP registry has no launch command for it: see the repository README
Step by step, with commands for each platform: How to add an MCP server to Claude Code, Codex, Cursor, VS Code, Gemini CLI and more
Questions about domain-check
How do I install domain-check in Claude Code?
Build the MCP binary using cargo install domain-check-mcp or download precompiled files from GitHub Releases. Then register the domain-check-mcp executable inside your client MCP settings.
What does domain-check do?
It enables coding assistants to query domain availability across 1,200+ extensions using RDAP and integrated WHOIS. It also handles batch scanning, name generation with patterns, and for-sale status lookups.
Is an external WHOIS client required?
No, WHOIS protocol support is implemented directly inside the compiled binary. The engine queries RDAP first and automatically falls back to native WHOIS when needed.
