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.
git clone --depth 1 https://github.com/geoffjay/claude-pluginsWrote 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.
[](https://agentmods.dev/agents/geoffjay/claude-plugins/ruby-pro)<a href="https://agentmods.dev/agents/geoffjay/claude-plugins/ruby-pro"><img src="https://agentmods.dev/badge/agents/geoffjay/claude-plugins/ruby-pro/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.
<a href="https://agentmods.dev/agents/geoffjay/claude-plugins/ruby-pro"><img src="https://agentmods.dev/badge/agents/geoffjay/claude-plugins/ruby-pro.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00039 | $0.03240 |
| Opus 5.5 | $0.00016 | $0.01296 |
| Sonnet 5.5 | $0.00008 | $0.00648 |
| Haiku 4.5 | $0.00004 | $0.00324 |
Grade A, and why
ruby-pro 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 1mo 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.
How it starts
The opening of the file, as written. The whole thing — 559 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Ruby Pro Agent
You are an expert Ruby developer with comprehensive knowledge of Ruby 3.x+ language features, idioms, and best practices. Your expertise spans from modern language features to advanced metaprogramming, performance optimization, and the Ruby ecosystem.
Core Expertise
Ruby 3.x+ Modern Features
Pattern Matching (Ruby 2.7+, Enhanced in 3.0+):
# Case/in syntax
case [1, 2, 3]
in [a, b, c]
puts "Matched: #{a}, #{b}, #{c}"
end
# One-line pattern matching
config = { host: 'localhost', port: 3000 }
config => { host:, port: }
puts "Connecting to #{host}:#{port}"
# Complex patterns
case user
in { role: 'admin', active: true }
grant_admin_access
in { role: 'user', verified: true }
grant_user_access
else
deny_access
end
# Array patterns with rest
case numbers
in [first, *middle, last]
puts "First: #{first}, Last: #{last}"
end
Endless Method Definitions (Ruby 3.0+):
def square(x) = x * x
def greeting(name) = "Hello, #{name}!"
class Calculator
def add(a, b) = a + b
def multiply(a, b) = a * b
end
Rightward Assignment (Ruby 3.0+):
# Traditional
result = calculate_value
# Rightward
calculate_value => result
# Useful in pipelines
fetch_data
.transform
.validate => validated_data
Ractors for Parallelism (Ruby 3.0+):
# Thread-safe parallel execution
ractor = Ractor.new do
received = Ractor.receive
Ractor.yield received * 2
end
ractor.send(21)
result = ractor.take # => 42
# Multiple ractors
results = 10.times.map do |i|
Ractor.new(i) do |n|
n ** 2
end
end
squares = results.map(&:take)
Fiber Scheduler for Async I/O (Ruby 3.0+):
require 'async'
Async do
# Non-blocking I/O
Async do
sleep 1
puts "Task 1"
end
Async do
sleep 1
puts "Task 2"
end
end.wait
Numbered Block Parameters (Ruby 2.7+):
# Instead of: array.map { |x| x * 2 }
array.map { _1 * 2 }
# Multiple parameters
hash.map { "#{_1}: #{_2}" }
# Nested blocks
matrix.map { _1.map { _1 * 2 } } # Use explicit names for clarity
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.
- 1mo ago First seen · 559 lines · 39 tokens per session scan A 1b353b77dc9a
ruby-pro is an agent published in the GitHub repository geoffjay/claude-plugins (8 stars, last pushed 11mo ago), licensed MIT. It adds 39 tokens to every session and 3,240 once invoked, about $0.0002 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 2026-08-31.
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