vmark: Agent for Claude Code

.claude/agents/spec-guardian.md

spec-guardian is an agent for Claude Code from xiaolai/vmark. It costs 18 tokens per session (95 once invoked), scanned A, original, ISC.

A planning check that compares proposed work with project instructions and written specifications. It reviews files such as AGENTS.md, CLAUDE.md, rule files, and development plans.

In plain words
What is it for?
Use it before coding to receive a pass-or-fail checklist, identify conflicts, and learn what must change in the plan.
Why use it?
It helps prevent work from drifting away from agreed requirements or breaking project-specific rules before implementation starts.

Agent for Claude Code

Written for Claude Code: installed under .claude/. Also seen: mentions CLAUDE.md; mentions AGENTS.md.

This is xiaolai/vmark's own configuration. It tells Claude Code how to work on vmark itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything vmark configures →

Reuse

Borrowing it

Nothing to install: this file belongs to xiaolai/vmark. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/xiaolai/vmark/main/.claude/agents/spec-guardian.md
Clone the repo
git clone --depth 1 https://github.com/xiaolai/vmark

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 spec-guardian

README.md
[![agentmods](https://agentmods.dev/badge/agents/xiaolai/vmark/spec-guardian/github.svg)](https://agentmods.dev/agents/xiaolai/vmark/spec-guardian)
Your own site
<a href="https://agentmods.dev/agents/xiaolai/vmark/spec-guardian"><img src="https://agentmods.dev/badge/agents/xiaolai/vmark/spec-guardian/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 spec-guardian

Your own site · 80×15
<a href="https://agentmods.dev/agents/xiaolai/vmark/spec-guardian"><img src="https://agentmods.dev/badge/agents/xiaolai/vmark/spec-guardian.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 18 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 95 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 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 $0.00018 $0.00095
Opus 5.5 $0.00007 $0.00038
Sonnet 5.5 $0.00004 $0.00019
Haiku 4.5 $0.00002 $0.00010

Measured yesterday against content hash 4b6a0d6b1aef, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

spec-guardian 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 yesterday.

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.

.claude/agents/spec-guardian.md · 17 lines

What it actually says

You verify the plan and proposed changes against:

  • AGENTS.md
  • CLAUDE.md
  • .claude/rules/*.md
  • Relevant plans in dev-docs/plans/*.md.

Output:

  • Compatibility checklist (pass/fail).
  • Conflicts and required changes before implementation proceeds.
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. yesterday Changed · -1 lines 4b6a0d6b1aef
  2. 2mo ago First seen · 18 lines · 18 tokens per session scan A f0b152f3ed94

Subscribe to this mod's changes

spec-guardian is an agent published in the GitHub repository xiaolai/vmark (878 stars, last pushed yesterday), licensed ISC. It adds 18 tokens to every session and 95 once invoked, about $0.0001 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 2026-08-30.

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