io.github.saidutt46/domain-check

Official

by saidutt46 · Rust

Fast domain availability checker with RDAP/WHOIS — batch checks, TLD presets, and name generation.

Check domain availability via RDAP/WHOIS with batch checks and name generation.

Topics

clidomain-checkrustrust-crateasyncconcurrencydomainslibraryrdapwhoisdomain-check-lib

README.md12 KBView on GitHub

domain-check

Universal domain exploration engine: fast domain availability checks across the internet — as a CLI, Rust library, and MCP server for AI agents.

Why domain-check

1,200+ TLDs out of the box — IANA bootstrap loads the full registry automatically. No config needed. 32 hardcoded TLDs work offline as fallback.
Dual-protocol engine — RDAP-first with automatic WHOIS fallback. IANA server discovery covers ~189 ccTLDs that lack RDAP (.es, .co, .eu, .jp).
Fast — up to 100 concurrent checks, streaming results as they complete. 2.7 MB release binary.
Domain generation — pattern expansion (\w=letter, \d=digit, ?=either), prefix/suffix permutations, and --dry-run to preview before checking.
11 curated presets — startup, tech, creative, finance, ecommerce, and more. Or define your own in config.
Rich output — grouped pretty display, JSON, CSV. Registrar info, creation/expiration dates, and status codes with --info.
CI and automation friendly — --json/--csv to stdout, --yes to skip prompts, --force for large runs, automatic non-TTY detection.
Configurable — TOML config files, DC_* environment variables, custom presets, and clear precedence rules.
Agent-native — MCP server exposes all tools to AI coding agents (Claude, Codex, Gemini, Cursor, VS Code Copilot, and any MCP client).
CLI + library + MCP — same engine powers the CLI, domain-check-lib (Rust library), and domain-check-mcp (MCP server).

Installation

Method	Command	Notes
Homebrew (macOS)	`brew install domain-check`	Easiest install for macOS users
Cargo (CLI)	`cargo install domain-check`	Works on all Rust-supported platforms
Cargo (MCP)	`cargo install domain-check-mcp`	MCP server for AI agents
GitHub Releases	Download binaries	CLI + MCP binaries for macOS, Linux, Windows

Quick Start

bash

# Check a single domain
domain-check example.com

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

# Use a curated preset
domain-check myapp --preset startup --pretty

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

# Add prefixes and suffixes
domain-check myapp --prefix get,try --suffix hub,ly -t com,io

# Get registrar and date info
domain-check target.com --info

# Check every known TLD
domain-check brand --all --batch

Pretty output:

text

domain-check v0.9.1 — 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

Use Cases

bash

# Startup naming — scan tech TLDs for your brand
domain-check coolname --preset startup --pretty

# Brand protection — audit every TLD for your trademark
domain-check mybrand --all --json > audit.json

# Pre-purchase validation — check registrar and expiry before buying
domain-check target.com --info

# Bulk pipeline — feed a list, export results
domain-check --file ideas.txt --preset tech --csv > results.csv

# Name generation — explore prefix/suffix combos
domain-check app --prefix get,my,try --suffix hub,ly -t com,io --dry-run

Output Formats

Default — one line per domain, colored status:

text

myapp.com TAKEN
myapp.io AVAILABLE
myapp.dev TAKEN

Pretty (--pretty) — grouped by status with summary:

text

── Available (1) ──────────────────────────────
  myapp.io

── Taken (2) ──────────────────────────────────
  myapp.com
  myapp.dev

3 domains in 0.4s  |  1 available  |  2 taken  |  0 unknown

JSON (--json) — structured, pipe to jq:

json

[
  {
    "domain": "myapp.com",
    "available": false,
    "method": "RDAP"
  },
  {
    "domain": "myapp.io",
    "available": true,
    "method": "RDAP"
  }
]

CSV (--csv) — import into spreadsheets or databases:

text

domain,status,method
myapp.com,TAKEN,RDAP
myapp.io,AVAILABLE,RDAP

Info (--info) — registrar, dates, and status codes:

text

myapp.com TAKEN
  Registrar: Example Registrar, Inc.
  Created: 2015-03-12  Expires: 2026-03-12
  Status: clientTransferProhibited

Full reference: docs/CLI.md

Smart Presets

11 built-in presets covering common domains strategies:

Preset	TLDs	Use case
`startup`	com, org, io, ai, tech, app, dev, xyz	Tech startups
`popular`	com, net, org, io, ai, app, dev, tech, me, co, xyz	General coverage
`classic`	com, net, org, info, biz	Traditional gTLDs
`enterprise`	com, org, net, info, biz, us	Business and government
`tech`	io, ai, app, dev, tech, cloud, software, + 5 more	Developer tools
`creative`	design, art, studio, media, photography, + 5 more	Artists and media
`ecommerce`	shop, store, market, sale, deals, + 3 more	Online retail
`finance`	finance, capital, fund, money, investments, + 4 more	Fintech
`web`	web, site, website, online, blog, page, + 3 more	Web services
`trendy`	xyz, online, site, top, icu, fun, space, + 6 more	New gTLDs
`country`	us, uk, de, fr, ca, au, br, in, nl	International

bash

domain-check --list-presets                          # See all presets with full TLD lists
domain-check mybrand --preset creative --pretty      # Use a preset

Define custom presets in your config file:

toml

[custom_presets]
my_stack = ["com", "io", "dev", "app"]

Configuration

Create domain-check.toml in your project directory:

toml

[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:

bash

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

Automation & CI

bash

# 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

# Large batch with no prompts
domain-check --file huge-list.txt --all --force --yes --csv > results.csv

CI-friendly behavior:

--yes / --force skip all confirmation prompts
Non-TTY environments (piped, CI) never prompt — scripts are never blocked
Spinner writes to stderr; stdout stays clean for piping
--no-bootstrap for deterministic, offline-safe checks against 32 hardcoded TLDs

Automation guide: docs/AUTOMATION.md

Library

Use domain-check-lib directly in Rust projects:

toml

[dependencies]
domain-check-lib = "1.0.2"

rust

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

MCP Server

domain-check-mcp exposes domain checking as tools for AI coding agents via the Model Context Protocol. Works with any MCP-compatible client.

bash

# Install
cargo install domain-check-mcp

# Add to your agent (Claude Code example — works similarly for Codex, Gemini CLI, etc.)
claude mcp add domain-check -- domain-check-mcp

6 tools available: check_domain, check_domains, check_with_preset, generate_names, list_presets, domain_info.

Then ask your agent naturally: "Is coolstartup.com available?" or "Check mybrand across the startup preset".

Supports: Claude Code, Claude Desktop, VS Code Copilot, Cursor, Windsurf, JetBrains, OpenAI Codex CLI, Gemini CLI, and any MCP stdio client.

Full setup: domain-check-mcp/README.md

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).

Troubleshooting and expected edge cases: docs/FAQ.md

Project Docs

CLI reference: docs/CLI.md
Library: domain-check-lib/README.md | docs.rs
MCP server: domain-check-mcp/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 either of

at your option.

Install

mcpb

mcpb: https://github.com/saidutt46/domain-check/releases/download/v1.0.2/domain-check-mcp-linux-x86_64.mcpb

mcpb

mcpb: https://github.com/saidutt46/domain-check/releases/download/v1.0.2/domain-check-mcp-linux-x86_64-musl.mcpb

mcpb

mcpb: https://github.com/saidutt46/domain-check/releases/download/v1.0.2/domain-check-mcp-macos-x86_64.mcpb

mcpb

mcpb: https://github.com/saidutt46/domain-check/releases/download/v1.0.2/domain-check-mcp-macos-aarch64.mcpb

mcpb

mcpb: https://github.com/saidutt46/domain-check/releases/download/v1.0.2/domain-check-mcp-windows-x86_64.mcpb