crt.sh

crt.sh is a skill for Claude Code, Codex from taracodlabs/aiden. It costs 20 tokens per session (918 once invoked), scanned A, original, AGPL-3.0.

A tool for finding subdomains and checking TLS certificates through certificate-transparency logs, public records of certificates issued for websites.

In plain words
What is it for?
Use it to enumerate subdomains and inspect related TLS certificate records.
Why use it?
It helps reveal which subdomains and certificates are associated with a domain without needing an API key.

Skill for Claude CodeCodex

Which agent this was written for is unclear — body not stored (licence); the path alone says nothing.

Good fit Use it to enumerate subdomains and inspect related TLS certificate records.

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Install with agentmods
npx agentmods add skills/taracodlabs/aiden/crt-sh
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add taracodlabs/aiden --skill crt-sh
Clone the repo
git clone --depth 1 https://github.com/taracodlabs/aiden

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for crt.sh

README.md
[![agentmods](https://agentmods.dev/badge/skills/taracodlabs/aiden/crt-sh/github.svg)](https://agentmods.dev/skills/taracodlabs/aiden/crt-sh)
Your own site
<a href="https://agentmods.dev/skills/taracodlabs/aiden/crt-sh"><img src="https://agentmods.dev/badge/skills/taracodlabs/aiden/crt-sh/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for crt.sh

Your own site · 80×15
<a href="https://agentmods.dev/skills/taracodlabs/aiden/crt-sh"><img src="https://agentmods.dev/badge/skills/taracodlabs/aiden/crt-sh.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 20 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 918 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
Origin unknown No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00020 $0.00918
Opus 5 $0.00010 $0.00459
Sonnet 5 $0.00004 $0.00184
Haiku 4.5 $0.00002 $0.00092

Measured 9d ago against content hash f016ccfc8308, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

crt.sh scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 9d ago.

The scan reads SKILL.md. This mod also ships 1 executable file (index.ts), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/crt-sh/SKILL.md · 103 lines

The source is not reproduced here

Licensed AGPL-3.0

The repository is licensed AGPL-3.0, which this catalogue does not treat as permission to reproduce the file. Read it at the source.

Read it on GitHub

Files

What ships with it

2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 9d ago First seen · 103 lines · 20 tokens per session scan A f016ccfc8308

Subscribe to this mod's changes

crt.sh is a skill published in the GitHub repository taracodlabs/aiden (810 stars, last pushed 15d ago), licensed AGPL-3.0. It adds 20 tokens to every session and 918 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.