Agent skill

Domain Intel

by Tommy-yw in Tommy-yw/RunbookHermes

Passive domain reconnaissance using Python stdlib. An agent skill from Tommy-yw/RunbookHermes.

MITAuto-check passedSecurity

Install Domain Intel

skills CLI
$ npx skills add Tommy-yw/RunbookHermes --skill domain-intel -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI
$ gh skill install Tommy-yw/RunbookHermes domain-intel --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy
$ git clone --depth 1 https://github.com/Tommy-yw/RunbookHermes.git skills-src && mkdir -p .claude/skills && cp -r skills-src/optional-skills/research/domain-intel .claude/skills/domain-intel && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Facts

Skill name
domain-intel
GitHub stars
546
Used in
1 other repo
Token cost
~1.1k tokens
SKILL.md length
435 words
Files
2 (incl. scripts)
Skills in repo
38
Repo updated
First seen
Licence
MIT

At a glance

Passive domain reconnaissance using Python stdlib. An agent skill from Tommy-yw/RunbookHermes.

  • Tasks that involve Cloud networking
  • SKILL.md covers Helper script, Available commands, When to use this vs built-in… and Platform compatibility, plus 2 more sections
  • Runs Python scripts from its folder; calls python3 and curl
  • Tasks that involve OSINT

What it does

Domain Intel is an agent skill from Tommy-yw/RunbookHermes. Passive domain reconnaissance using Python stdlib. Subdomain discovery, SSL certificate inspection, WHOIS lookups, DNS records, domain availability checks, and bulk multi-domain analysis. No API keys required.

Its SKILL.md is about 1.1k tokens, which your agent loads only when the skill is triggered. The skill folder holds 2 other files, including scripts (for example `scripts/domain_intel.py`).

It sits in Security, covering Cloud networking and OSINT. It works with Python. The repository describes itself as: Hermes-native AIOps agent for evidence-driven incident response, approval-gated remediation, and runbook learning. The licence is MIT.

When your agent uses it

  • Tasks that involve Cloud networking
  • Tasks that involve OSINT

Example prompts

  • “/domain-intel”

Requirements

  • Python 3

What it can do on your machine

Read from SKILL.md and the folder at commit 7fd2b9a. It shows what the files ask for, not the result of running them.

  • Tool permissions

    Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

    From allowed-tools in the SKILL.md frontmatter.

  • Runs code

    Ships 1 file in scripts/ (Python), which the agent can run.

    Shell commands in SKILL.md call:

    • python3
    • curl

    From the folder's file list and the shell code blocks in SKILL.md.

  • Network

    Links to these hosts (documentation or services it may open):

    • github.com

    From URLs in SKILL.md, links to its own repository left out.

  • Credentials

    Names no API keys, tokens, secrets or passwords.

    From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Domain Intel loads about 1.1k tokens when it runs. Until then it costs about 56 tokens; SKILL.md has 435 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it
~56
When it runs · the whole SKILL.md, loaded when a task matches
~1.1k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); the scripts in this folder are not scanned.

SKILL.md

The full file from Tommy-yw/RunbookHermes at commit 7fd2b9a, republished under its MIT licence (© Tommy-yw). 435 words, ~1,121 tokens.

Download SKILL.mdSave it as .claude/skills/domain-intel/SKILL.md (or your agent's skills folder). This skill also uses 1 other file; get the full folder from GitHub.
name
domain-intel
description
Passive domain reconnaissance using Python stdlib. Subdomain discovery, SSL certificate inspection, WHOIS lookups, DNS records, domain availability checks, and bulk multi-domain analysis. No API keys required.

Domain Intelligence — Passive OSINT

Passive domain reconnaissance using only Python stdlib. Zero dependencies. Zero API keys. Works on Linux, macOS, and Windows.

Helper script

This skill includes scripts/domain_intel.py — a complete CLI tool for all domain intelligence operations.

bash
# Subdomain discovery via Certificate Transparency logs
python3 SKILL_DIR/scripts/domain_intel.py subdomains example.com

# SSL certificate inspection (expiry, cipher, SANs, issuer)
python3 SKILL_DIR/scripts/domain_intel.py ssl example.com

# WHOIS lookup (registrar, dates, name servers — 100+ TLDs)
python3 SKILL_DIR/scripts/domain_intel.py whois example.com

# DNS records (A, AAAA, MX, NS, TXT, CNAME)
python3 SKILL_DIR/scripts/domain_intel.py dns example.com

# Domain availability check (passive: DNS + WHOIS + SSL signals)
python3 SKILL_DIR/scripts/domain_intel.py available coolstartup.io

# Bulk analysis — multiple domains, multiple checks in parallel
python3 SKILL_DIR/scripts/domain_intel.py bulk example.com github.com google.com
python3 SKILL_DIR/scripts/domain_intel.py bulk example.com github.com --checks ssl,dns

SKILL_DIR is the directory containing this SKILL.md file. All output is structured JSON.

Available commands

CommandWhat it doesData source
subdomainsFind subdomains from certificate logscrt.sh (HTTPS)
sslInspect TLS certificate detailsDirect TCP:443 to target
whoisRegistration info, registrar, datesWHOIS servers (TCP:43)
dnsA, AAAA, MX, NS, TXT, CNAME recordsSystem DNS + Google DoH
availableCheck if domain is registeredDNS + WHOIS + SSL signals
bulkRun multiple checks on multiple domainsAll of the above

When to use this vs built-in tools

  • Use this skill for infrastructure questions: subdomains, SSL certs, WHOIS, DNS records, availability
  • Use web_search for general research about what a domain/company does
  • Use web_extract to get the actual content of a webpage
  • Use terminal with curl -I for a simple "is this URL reachable" check
TaskBetter toolWhy
"What does example.com do?"web_extractGets page content, not DNS/WHOIS data
"Find info about a company"web_searchGeneral research, not domain-specific
"Is this website safe?"web_searchReputation checks need web context
"Check if a URL is reachable"terminal with curl -ISimple HTTP check
"Find subdomains of X"This skillOnly passive source for this
"When does the SSL cert expire?"This skillBuilt-in tools can't inspect TLS
"Who registered this domain?"This skillWHOIS data not in web search
"Is coolstartup.io available?"This skillPassive availability via DNS+WHOIS+SSL
Show full SKILL.md (173 more words)Show less

Platform compatibility

Pure Python stdlib (socket, ssl, urllib, json, concurrent.futures). Works identically on Linux, macOS, and Windows with no dependencies.

  • crt.sh queries use HTTPS (port 443) — works behind most firewalls
  • WHOIS queries use TCP port 43 — may be blocked on restrictive networks
  • DNS queries use Google DoH (HTTPS) for MX/NS/TXT — firewall-friendly
  • SSL checks connect to the target on port 443 — the only "active" operation

Data sources

All queries are passive — no port scanning, no vulnerability testing:

  • crt.sh — Certificate Transparency logs (subdomain discovery, HTTPS only)
  • WHOIS servers — Direct TCP to 100+ authoritative TLD registrars
  • Google DNS-over-HTTPS — MX, NS, TXT, CNAME resolution (firewall-friendly)
  • System DNS — A/AAAA record resolution
  • SSL check is the only "active" operation (TCP connection to target:443)

Notes

  • WHOIS queries use TCP port 43 — may be blocked on restrictive networks
  • Some WHOIS servers redact registrant info (GDPR) — mention this to the user
  • crt.sh can be slow for very popular domains (thousands of certs) — set reasonable expectations
  • The availability check is heuristic-based (3 passive signals) — not authoritative like a registrar API

Contributed by @FurkanL0

© Tommy-yw, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

SKILL.md and 1 other file (scripts) in optional-skills/research/domain-intel of Tommy-yw/RunbookHermes.

  • SKILL.md
  • scripts/domain_intel.py

Open the folder on GitHubat commit 7fd2b9a

Used in 1 other repository

We found 1 copy of this SKILL.md (exact, near-identical or edited) in other folders, from 1 other GitHub owner. This page covers the copy in Tommy-yw/RunbookHermes, which our catalogue first saw on October 7, 2026.

Compare with similar skills

Domain Intel next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

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Azure Firewallvinayaklatthe/microsoft-security-skills175—~1.7kAutomated safety check: PassMIT
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Implementing Stix Taxii Feed Integrationmukul975/Anthropic-Cybersecurity-Skills34k—~2.7kAutomated safety check: PassApache-2.0
Automating Ioc Enrichmentmukul975/Anthropic-Cybersecurity-Skills34k—~2.2kAutomated safety check: PassApache-2.0
Building Adversary Infrastructure Tracking Systemmukul975/Anthropic-Cybersecurity-Skills34k—~3.7kAutomated safety check: PassApache-2.0

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Works with

Questions about Domain Intel

What does Domain Intel do?

Passive domain reconnaissance using Python stdlib. An agent skill from Tommy-yw/RunbookHermes. Domain Intel is an agent skill from Tommy-yw/RunbookHermes. Passive domain reconnaissance using Python stdlib.

When should I use Domain Intel?

Domain Intel fits situations like: tasks that involve Cloud networking; tasks that involve OSINT.

How do I install Domain Intel in Claude Code?

Run `npx skills add Tommy-yw/RunbookHermes --skill domain-intel -a claude-code`. Or copy the skill folder (optional-skills/research/domain-intel in Tommy-yw/RunbookHermes) into .claude/skills/domain-intel in your project. Claude Code loads it when a task matches its description.

How do I install Domain Intel in Codex?

Run `npx skills add Tommy-yw/RunbookHermes --skill domain-intel -a codex`. Or copy the skill folder (optional-skills/research/domain-intel in Tommy-yw/RunbookHermes) into .agents/skills/domain-intel in your project. Codex loads it when a task matches its description.

Can I use Domain Intel in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add Tommy-yw/RunbookHermes --skill domain-intel -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/domain-intel, .gemini/skills/domain-intel, .github/skills/domain-intel and .opencode/skills/domain-intel in your project.

What does Domain Intel need to run?

Going by SKILL.md and its folder, Domain Intel needs Python for the scripts in its folder and the command-line tools its instructions call (python3 and curl). Our summary lists: Python 3.

Does Domain Intel access the network?

SKILL.md names 1 domain. As links in the text: github.com. This is read from the text; nothing was executed.

Is Domain Intel safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. The check reads SKILL.md only: the scripts in the folder are not scanned, so read them before running anything.

What licence does Domain Intel use?

Domain Intel is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Domain Intel use?

About 1.1k tokens (SKILL.md is roughly 4.5k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.

What are the alternatives to Domain Intel?

Skills that share tags, products or a category with Domain Intel: Azure Firewall (vinayaklatthe/microsoft-security-skills, 175 stars), Osint Investigation (johnson7788/MultiUserClaw, 327 stars), Implementing Stix Taxii Feed Integration (mukul975/Anthropic-Cybersecurity-Skills, 34k stars) and Automating Ioc Enrichment (mukul975/Anthropic-Cybersecurity-Skills, 34k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Domain Intel?

Tommy-yw (a GitHub user) maintains it in Tommy-yw/RunbookHermes, which has 546 GitHub stars. The repository holds 38 skills in this directory. The repository was last updated on May 18, 2026.

Source: Tommy-yw/RunbookHermes on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.