security-0day

security-0day is a command for Claude Code from Security-Phoenix-demo/security-skills-claude-code. It costs 24 tokens per session (230 once invoked), scanned A, original, MIT.

A command for checking the current branch’s code changes against a base branch for serious security vulnerabilities. A branch is a separate line of development, and the command does not change the code.

In plain words
What is it for?
Use it before a pull request to review the branch diff and receive severity, file location, evidence, suggested fixes, and remaining risks.
Why use it?
It gives a quick, focused security check for proposed changes without running a full assessment of the entire codebase.

Command for Claude Code

Written for Claude Code: argument-hint in frontmatter.

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.

agentmods
npx agentmods add commands/security-phoenix-demo/security-skills-claude-code/security-0day
Clone the repo
git clone --depth 1 https://github.com/Security-Phoenix-demo/security-skills-claude-code

Made for: Claude Code.

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 security-0day

README.md
[![agentmods](https://agentmods.dev/badge/commands/security-phoenix-demo/security-skills-claude-code/security-0day.svg)](https://agentmods.dev/commands/security-phoenix-demo/security-skills-claude-code/security-0day)
Your own site
<a href="https://agentmods.dev/commands/security-phoenix-demo/security-skills-claude-code/security-0day"><img src="https://agentmods.dev/badge/commands/security-phoenix-demo/security-skills-claude-code/security-0day.svg" alt="Measured on agentmods" height="20"></a>
Per session 24 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 230 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original 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 $0.00024 $0.00230
Opus 5 $0.00012 $0.00115
Sonnet 5 $0.00005 $0.00046
Haiku 4.5 $0.00002 $0.00023

Measured 6d ago against content hash 3389a56a5fd5, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

security-0day 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 6d 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.

skills/Security Assessment/install/commands/security-0day.md · 22 lines

What it actually says

You are running the 0-Day Vulnerability Scanner skill against the current branch's diff.

Instructions

  1. Invoke the 0day-scanner skill (file: skills/Security Assessment/0day-scanner/SKILL.md).
  2. Target = git diff between $ARGUMENTS (default main) and HEAD.
  3. Prefer light mode unless the diff is large (>50 changed files → standard mode).
  4. Report findings inline with severity, file:line, evidence, and suggested fix.
  5. If no vulnerabilities are found, say so explicitly and list residual risks worth follow-up.

Scope guard

  • Do not modify code. This is a read-only review.
  • Do not run the full security-assessment skill — that's a different command.

If you cannot determine a base ref or the working tree has no diff, say so and stop.

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. 6d ago First seen · 22 lines · 24 tokens per session scan A 3389a56a5fd5

Subscribe to this mod's changes

security-0day is a command published in the GitHub repository Security-Phoenix-demo/security-skills-claude-code (69 stars, last pushed 4mo ago), licensed MIT. It adds 24 tokens to every session and 230 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.