RUBYN

A registry-based system for handling slash commands in a command-line conversation interface, such as commands beginning with /help.

In plain words
What is it for?
It helps classify commands, register and dispatch them, provide tab completion, pass shared context, and return actions that change session state.
Why use it?
It gives commands a consistent path from user input to execution and keeps shared application dependencies organized.

Command

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/matthewsuttles/rubyn-code/rubyn
Clone the repo
git clone --depth 1 https://github.com/MatthewSuttles/rubyn-code
Per session 0 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,198 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 $0.00000 $0.01198
Opus 5 $0.00000 $0.00599
Sonnet 5 $0.00000 $0.00240
Haiku 4.5 $0.00000 $0.00120

Measured 2d ago against content hash 0686d2596342, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

RUBYN 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 2d 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.

lib/rubyn_code/cli/commands/RUBYN.md · 134 lines

How it starts

The opening of the file, as written. The whole thing — 134 lines — stays where its author put it; the contents beside it link to each section on GitHub.

CLI::Commands — Slash Command System

Registry-based command dispatch for the REPL. Same Base/Registry pattern as the tool system.

Architecture

User types /help
    ↓
InputHandler.classify → :command
    ↓
REPL#handle_command
    ↓
Registry#dispatch('/help', args, context)
    ↓
Help#execute(args, context)
    ↓
(optional) → action hash back to REPL for state changes

Core Infrastructure

File Class Purpose
base.rb Base Abstract command — command_name, description, aliases, execute(args, ctx)
registry.rb Registry Discovers, registers, dispatches commands. Provides tab-completion list
context.rb Context Data.define value object with all deps a command needs

Context Object

Context is a frozen Data.define carrying everything a command might need:

Context = Data.define(
  :renderer, :conversation, :agent_loop, :context_manager,
  :budget_enforcer, :llm_client, :db, :session_id,
  :project_root, :skill_loader, :session_persistence,
  :background_worker, :permission_tier, :plan_mode
)

Commands receive it as the second argument to execute. Never mutate it — use with_message_handler to attach a message callback if the command needs to send prompts back to the agent loop.

Commands

Command File Description
/budget budget.rb Show or set session budget (/budget [amount])
/clear clear.rb Clear the terminal
/compact compact.rb Compress conversation context
/context context_info.rb Show context window usage
/cost cost.rb Show token usage and costs
/diff diff.rb Show git diff (staged, unstaged, or vs branch)
/doctor doctor.rb Environment health check
/help help.rb Show this help message
/model model.rb Show or switch model (/model [name])
/plan plan.rb Toggle plan mode (think before acting)
/quit quit.rb Exit Rubyn Code (aliases: /exit, /q)
/resume resume.rb Resume a session or list recent sessions
/review review.rb Review current branch against best practices
/skill skill.rb Load a skill or list available skills
/spawn spawn.rb Spawn a teammate agent (/spawn <name> [role])
/tasks tasks.rb List all tasks
/tokens tokens.rb Show token usage and context window estimate
/undo undo.rb Remove last exchange
/version version.rb Show version info

Read the full file on GitHub · 134 lines

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. 2d ago First seen · 134 lines · 0 tokens per session scan A 0686d2596342

Subscribe to this mod's changes

RUBYN is a command published in the GitHub repository MatthewSuttles/rubyn-code (63 stars, last pushed 2d ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 1,198 tokens. 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.