domain-check

Universal domain exploration engine: fast domain availability checks across the internet, as both a CLI and Rust library.

Quick Links: Installation | Quick Start | Why domain-check | Configuration | Automation | Presets | Library | FAQ | Contributing

Why domain-check

• Broad TLD coverage: check across 1200+ known TLDs with --all (bootstrap enabled by default).
• Dual-protocol engine: RDAP-first with intelligent WHOIS fallback and IANA-based discovery.
• Fast and scalable: concurrent checks up to 100 domains at a time, with streaming or batch output modes.
• Domain generation built in: pattern expansion (\w, \d, ?), prefix/suffix permutations, dry-run previews.
• Strong UX for humans: grouped pretty output, progress indicators, summaries, and detailed domain metadata.
• Automation-ready output: JSON/CSV modes, non-TTY-safe behavior, and explicit non-interactive flags.
• Configurable workflows: config files, environment variables, custom presets, and deterministic CI setups.
• CLI + library ecosystem: same core capabilities available in both domain-check and domain-check-lib.

Installation

Quick Start

# Check one fully qualified domain
domain-check example.com

# Expand base name across TLDs
domain-check mystartup -t com,org,io,dev --batch

# Use curated TLD groups
domain-check myapp --preset startup

# Generate names from a pattern (preview only)
domain-check --pattern "app\d" -t com --dry-run

# Check every known TLD (bootstrap-enabled)
domain-check brand --all --batch

Expected pretty output shape:

domain-check v0.9.0 — 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

Core Command Surface

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

Full reference: docs/CLI.md

Configuration

Create domain-check.toml in your project directory:

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

[custom_presets]
my_startup = ["com", "io", "ai", "dev", "app"]

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

Config lookup order: ./domain-check.toml > ~/.domain-check.toml > ~/.config/domain-check/config.toml

Common environment variables:

DC_CONCURRENCY=50
DC_PRESET=startup
DC_TLD=com,io,dev
DC_PRETTY=true
DC_TIMEOUT=10s
DC_BOOTSTRAP=true
DC_CONFIG=config.toml
DC_FILE=domains.txt
DC_PREFIX=get,my
DC_SUFFIX=hub,ly

Automation & CI

# Non-interactive structured output
domain-check --file required-domains.txt --json

# Pipe to jq
domain-check --pattern "app\d" -t com --yes --json | jq '.[] | select(.available==true)'

# Stream live results for long runs
domain-check --file large-list.txt --concurrency 75 --streaming

Automation guide: docs/AUTOMATION.md

Smart Presets

Built-in presets: startup, popular, classic, enterprise, tech, creative, ecommerce, finance, web, trendy, country.

domain-check --list-presets
domain-check mybrand --preset creative --pretty
domain-check myshop --preset ecommerce --batch --json

Reliability Notes

• Domain status is network- and registry-dependent. Temporary errors can produce UNKNOWN states.
• WHOIS output is less standardized than RDAP; parsing quality varies by registry.
• For repeatable CI workflows, pin behavior with explicit flags (--batch, --json, --no-bootstrap, --concurrency).
• docs.rs reflects the latest published crate release and can lag repository main.

Troubleshooting and expected edge cases: docs/FAQ.md

Library

Use domain-check-lib directly in Rust projects:

[dependencies]
domain-check-lib = "0.9.1"

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?;
    println!("{} -> {:?}", result.domain, result.available);
    Ok(())
}

Library docs: domain-check-lib/README.md | docs.rs

Project Docs

• CLI reference: docs/CLI.md
• Docs index: docs/README.md
• Examples and workflows: docs/EXAMPLES.md
• Automation usage: docs/AUTOMATION.md
• FAQ: docs/FAQ.md
• Changelog: CHANGELOG.md
• Contributing: CONTRIBUTING.md
• Security policy: SECURITY.md

License

Licensed under the Apache License, Version 2.0. See LICENSE.