pem-certificate-decoder

pem-certificate-decoder is a skill for Claude Code, Codex from secutils-dev/secutils. It costs 105 tokens per session (956 once invoked), scanned A, original, AGPL-3.0.

A browser tool for decoding and inspecting PEM-encoded X.509 certificate chains. PEM is a text format often used to store certificates, and X.509 certificates identify systems for encrypted connections.

In plain words
What is it for?
Use it to examine a PEM certificate or chain and create a link containing the certificate data.
Why use it?
It makes certificate contents and certificate chains easier to inspect when investigating trust or connection problems.

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 examine a PEM certificate or chain and create a link containing the certificate data.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/secutils-dev/secutils/certificate-decoder
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 secutils-dev/secutils --skill certificate-decoder
Clone the repo
git clone --depth 1 https://github.com/secutils-dev/secutils

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 pem-certificate-decoder

README.md
[![agentmods](https://agentmods.dev/badge/skills/secutils-dev/secutils/certificate-decoder/github.svg)](https://agentmods.dev/skills/secutils-dev/secutils/certificate-decoder)
Your own site
<a href="https://agentmods.dev/skills/secutils-dev/secutils/certificate-decoder"><img src="https://agentmods.dev/badge/skills/secutils-dev/secutils/certificate-decoder/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 pem-certificate-decoder

Your own site · 80×15
<a href="https://agentmods.dev/skills/secutils-dev/secutils/certificate-decoder"><img src="https://agentmods.dev/badge/skills/secutils-dev/secutils/certificate-decoder.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 105 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 956 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.
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 $0.00105 $0.00956
Opus 5.5 $0.00042 $0.00382
Sonnet 5.5 $0.00021 $0.00191
Haiku 4.5 $0.00011 $0.00096

Measured 22d ago against content hash b72d006ff794, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

pem-certificate-decoder 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 22d ago.

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.

dev/tools/certificate-decoder.skill.md · 92 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

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. 22d ago First seen · 92 lines · 105 tokens per session scan A b72d006ff794

Subscribe to this mod's changes

pem-certificate-decoder is a skill published in the GitHub repository secutils-dev/secutils (100 stars, last pushed 3d ago), licensed AGPL-3.0. It adds 105 tokens to every session and 956 once invoked, about $0.0004 per session on Opus 5.5. 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 2026-09-24.