domain-check

Fast, powerful CLI tool for checking domain availability using RDAP and WHOIS protocols.

Key Features

• Domain Generation — pattern expansion (\w, \d, ?), prefix/suffix permutations, dry-run preview
• Universal Coverage — check against all 32 TLDs with --all or use smart presets
• Lightning Fast — concurrent processing up to 100 domains simultaneously
• Beautiful Output — colored results, progress counters, loading spinner, grouped pretty mode
• Multiple Formats — pretty terminal display, JSON, CSV for automation, detailed info mode
• Bulk Processing — process thousands of domains from files with real-time streaming
• Agent-Friendly — --yes skips prompts, non-TTY never blocks, --dry-run for previews
• Configuration Files — persistent settings with TOML configs, env vars, and custom presets
• Dual Protocol — RDAP-first with automatic WHOIS fallback for maximum accuracy

Installation

Homebrew (macOS)

brew install domain-check

Cargo (All Platforms)

cargo install domain-check

Pre-built Binaries

Download from GitHub Releases — available for macOS, Linux, and Windows.

Quick Start

# Check a single domain
domain-check example.com

# Check multiple TLD variations
domain-check mystartup -t com,org,net,dev --batch

# Generate domains with patterns (dry-run to preview)
domain-check --pattern "app\d" -t com --dry-run
# app0.com, app1.com, ..., app9.com (10 domains)

# Prefix/suffix permutations
domain-check myapp --prefix get,try --suffix hub -t com --dry-run
# getmyapphub.com, getmyapp.com, trymyapphub.com, trymyapp.com, myapphub.com, myapp.com

# Use smart presets (startup, enterprise, country)
domain-check myapp --preset startup

# Pretty mode — grouped results with section headers
domain-check rustcloud --preset startup --pretty --batch

Pretty mode output:

domain-check v0.7.0 — Checking 8 domains
Preset: startup | Concurrency: 20

── Available (3) ──────────────────────────────
  rustcloud.org
  rustcloud.ai
  rustcloud.app

── Taken (5) ──────────────────────────────────
  rustcloud.com
  rustcloud.io
  rustcloud.tech
  rustcloud.dev
  rustcloud.xyz

8 domains in 0.8s  |  3 available  |  5 taken  |  0 unknown

Command Reference

domain-check [OPTIONS] [DOMAINS]...

Core Options

Domain Generation

Output Options

Performance & Protocol

See the full CLI Reference for all options and advanced usage patterns.

Configuration

Config Files

Create a .domain-check.toml to set persistent defaults:

[defaults]
concurrency = 25
preset = "startup"
pretty = true
timeout = "8s"
bootstrap = true

[custom_presets]
my_startup = ["com", "io", "ai", "dev", "app"]
my_enterprise = ["com", "org", "net", "biz", "info"]

[generation]
prefixes = ["get", "my"]
suffixes = ["hub", "ly"]

Config file locations (checked in order): ./domain-check.toml > ~/.domain-check.toml > ~/.config/domain-check/config.toml

Environment Variables

DC_CONCURRENCY=50       # Default concurrency
DC_PRESET=startup       # Default preset
DC_TLD=com,io,dev       # Default TLD list
DC_PRETTY=true          # Enable pretty output
DC_TIMEOUT=10s          # Request timeout
DC_BOOTSTRAP=true       # Enable IANA bootstrap
DC_CONFIG=config.toml   # Config file path
DC_FILE=domains.txt     # Domains file path
DC_PREFIX=get,my        # Default prefixes for generation
DC_SUFFIX=hub,ly        # Default suffixes for generation

Examples

Domain Generation

# Pattern-based: check all "go0" through "go9" domains
domain-check --pattern "go\d" -t com,io --batch --json

# Prefix/suffix: explore brand variations
domain-check myapp --prefix get,try --suffix hub,ly -t com --pretty --batch

# Dry-run to preview what will be checked
domain-check --pattern "ai\d\d" --prefix cool --preset startup --dry-run

# Agent-friendly: no prompts, structured output
domain-check --pattern "app\d" -t com --yes --json | jq '.[] | select(.available==true)'

Automation & CI/CD

# Environment-driven configuration
DC_CONCURRENCY=50 DC_PRESET=enterprise domain-check --file domains.txt --json

# Pipe JSON results for downstream processing
domain-check --file required-domains.txt --json | jq '.[] | select(.available)'

Bulk Workflows

# Domain research pipeline
domain-check --file ideas.txt --preset startup --csv > research.csv

# Brand protection monitoring
domain-check --file brand-variations.txt --all --json > monitoring.json

# High-concurrency processing
domain-check --file large-list.txt --concurrency 75 --streaming

Custom Presets

# Define presets in .domain-check.toml, then use them
domain-check mystartup --preset my_startup

# Or via environment variable
DC_PRESET=my_startup domain-check mystartup

See Advanced Examples for more enterprise workflows.

Library

Building a Rust app? Use domain-check-lib directly:

[dependencies]
domain-check-lib = "0.8.0"

use domain_check_lib::DomainChecker;

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let checker = DomainChecker::new();
    let result = checker.check_domain("example.com").await?;

    match result.available {
        Some(true) => println!("{} is AVAILABLE", result.domain),
        Some(false) => println!("{} is TAKEN", result.domain),
        None => println!("{} is UNKNOWN", result.domain),
    }
    Ok(())
}

See the Library Documentation for streaming, bulk processing, and configuration APIs.

Resources

• CLI Reference & Examples
• Library API Docs
• Advanced Examples
• Changelog
• Contributing

Crates: domain-check (CLI) | domain-check-lib (Library)

License

Licensed under the Apache License, Version 2.0 — see the LICENSE file for details.