GitHub - retlehs/quien: A better WHOIS lookup tool

3 min read Original article ↗

A better WHOIS lookup tool. Interactive TUI with tabbed views for WHOIS, DNS, mail, SSL/TLS, HTTP headers, tech stack detection, and SEO analysis.

quien demo

Try it without installing: ssh quien.sh

Install

Homebrew

brew tap retlehs/tap
brew install retlehs/tap/quien

Ubuntu / Debian

curl -fsSL https://apt.quien.dev/install.sh | sudo sh

Arch Linux (AUR)

Go

go install github.com/retlehs/quien@latest

Usage

# Interactive prompt
quien

# Domain lookup (interactive TUI)
quien example.com

# IP address lookup
quien 8.8.8.8

# JSON output
quien --json example.com

Features

  • RDAP-first lookups with WHOIS fallback for broad TLD coverage
  • IANA referral for automatic WHOIS server discovery
  • Mail configuration audit — MX, SPF, DMARC, DKIM, and BIMI with VMC chain validation
  • SEO analysis — indexability (robots.txt, canonical, sitemap), on-page (title, description, headings, images), structured data (JSON-LD, Open Graph, Twitter Cards), and performance hints (compression, caching, render-blocking resources)
  • Core Web Vitals — LCP, INP, CLS, FCP, and TTFB field data with historical trends via the CrUX API (optional)
  • Tech stack detection including WordPress plugins, JS/CSS frameworks, and external services parsed from HTML
  • IP lookups with reverse DNS, network info, abuse contacts, and ASN discovery via RDAP
  • BGP fallback for origin ASN/prefix when RDAP does not include ASN data
  • PeeringDB enrichment for ASN context (network/org, peering policy, peering locations, traffic profile, IX/facility counts)
  • Automatic retry with exponential backoff on all lookups
  • JSON subcommands for scripting: quien dns, quien mail, quien tls, quien http, quien seo, quien stack, quien all

Core Web Vitals

The SEO tab includes local checks out of the box. For Core Web Vitals field data (real-user metrics from Chrome), set a CrUX API key:

export QUIEN_CRUX_API_KEY=your-api-key

This enables LCP, INP, CLS, FCP, and TTFB p75 values with good/needs-improvement/poor ratings, plus an 8-25 week trend sparkline.

Getting a CrUX API key
  1. Go to the Google Cloud Console
  2. Create a new project (or select an existing one)
  3. Go to APIs & Services > Library
  4. Search for Chrome UX Report API and enable it
  5. Go to APIs & Services > Credentials
  6. Click Create Credentials > API key
  7. Click Edit API key, then under API restrictions select Restrict key and choose Chrome UX Report API from the list
  8. Copy the key and set it as QUIEN_CRUX_API_KEY

The CrUX API is free. Not all domains have field data — a site needs enough Chrome traffic to be included in the Chrome User Experience Report.

Theme

quien automatically detects your terminal background and picks light or dark colors. If detection gets it wrong (common in tmux, screen, or remote shells), override it:

export QUIEN_THEME=light  # force light palette
export QUIEN_THEME=dark   # force dark palette
export QUIEN_THEME=auto   # auto-detect (default)

Tip

If you want quien to replace your default WHOIS tool, you can add an alias to your shell config:

Agent skill

Add quien as a agent skill so agents use it for domain and IP lookups:

npx skills add retlehs/quien