CLI tool for fast domain availability checking across 1,200+ TLDs with RDAP/WHOIS support and batch processing
domain-check is a domain availability checker that queries over 1,200 TLDs using RDAP-first protocol with automatic WHOIS fallback. It supports up to 100 concurrent checks and includes IANA server discovery for ccTLDs that lack RDAP support like .es, .co, .eu, and .jp. The tool handles both single domain queries and batch processing from files.
The CLI includes domain name generation capabilities with pattern expansion (\w for letters, \d for digits), prefix/suffix permutations, and 11 curated presets for different use cases like startup, tech, creative, and finance domains. Users can preview generated names with --dry-run before running actual availability checks. Output formats include pretty-printed grouped results, JSON, CSV, and detailed info mode showing registrar data and expiration dates.
The tool is designed for automation workflows with --yes and --force flags to skip prompts, non-TTY detection, and streaming results for large batches. It includes TOML configuration files, environment variable support, and custom preset definitions. The same engine powers three components: the CLI tool, a Rust library (domain-check-lib), and an MCP server (domain-check-mcp) that exposes domain checking tools to AI coding agents through the Model Context Protocol.
# via Homebrew
brew install domain-check
# via Cargo
cargo install domain-check
# via Cargo (MCP)
cargo install domain-check-mcp