beast

beast is an agent for Claude Code from yelaco/claude-xmen. It costs 33 tokens per session (1,064 once invoked), scanned A, original, no licence file.

An agent that reviews implementation plans for missing details, unclear requirements, edge cases, and unnecessary complexity.

In plain words
What is it for?
Use it before finalising a Cerebro plan to find ambiguity, missing acceptance criteria, edge cases, and over-engineered work.
Why use it?
Plans can appear complete while still leaving important decisions or failure cases unspecified.

Agent for Claude Code

Written for Claude Code: effort in frontmatter. Also seen: model in frontmatter.

Good fit Use it before finalising a Cerebro plan to find ambiguity, missing acceptance…

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/yelaco/claude-xmen/beast
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.

Clone the repo
git clone --depth 1 https://github.com/yelaco/claude-xmen

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 beast

README.md
[![agentmods](https://agentmods.dev/badge/agents/yelaco/claude-xmen/beast.svg)](https://agentmods.dev/agents/yelaco/claude-xmen/beast)
Your own site
<a href="https://agentmods.dev/agents/yelaco/claude-xmen/beast"><img src="https://agentmods.dev/badge/agents/yelaco/claude-xmen/beast.svg" alt="Measured on agentmods" height="20"></a>
Per session 33 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,064 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 $0.00033 $0.01064
Opus 5 $0.00016 $0.00532
Sonnet 5 $0.00007 $0.00213
Haiku 4.5 $0.00003 $0.00106

Measured 6d ago against content hash fc56abf78c18, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

beast 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.

.claude/agents/beast.md · 100 lines

The source is not reproduced here

No licence file

A repository with no LICENSE is all rights reserved by default, so the body is not copied here. The metadata, the measurements and the link are.

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. 6d ago First seen · 100 lines · 33 tokens per session scan A fc56abf78c18

Subscribe to this mod's changes

beast is an agent published in the GitHub repository yelaco/claude-xmen (2 stars, last pushed 3mo ago), with no licence file. It adds 33 tokens to every session and 1,064 once invoked, about $0.0002 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 2026-08-31.