juno

juno is a skill for Claude Code from AlexWortega/junoclaude. It costs 121 tokens per session (1,614 once invoked), scanned A, original, MIT.

A toolkit for designing, programming, and testing vehicles in Juno: New Origins, also known as SimpleRockets 2. It works with the game's craft files and Vizzy flight programs, where Vizzy is the game's visual programming system.

In plain words
What is it for?
Use it to build or inspect rockets, planes, rovers, or satellites, create Vizzy programs, launch craft in the game, and diagnose results from logs.
Why use it?
It provides a workflow for checking the game state, making backups, editing craft or flight programs, launching the game, and reading test logs.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the junoclaude plugin — 1 skill shipped together

Good fit Use it to build or inspect rockets, planes, rovers, or satellites, create Vizzy programs, launch craft in the game, and diagnose results from logs.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/alexwortega/junoclaude/juno
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.

Any agent
npx skills add AlexWortega/junoclaude --skill juno
Clone the repo
git clone --depth 1 https://github.com/AlexWortega/junoclaude

Made for: Claude Code.

Or install junoclaude, the plugin that ships this one along with the rest of its 1 skill.

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 juno

README.md
[![agentmods](https://agentmods.dev/badge/skills/alexwortega/junoclaude/juno.svg)](https://agentmods.dev/skills/alexwortega/junoclaude/juno)
Your own site
<a href="https://agentmods.dev/skills/alexwortega/junoclaude/juno"><img src="https://agentmods.dev/badge/skills/alexwortega/junoclaude/juno.svg" alt="Measured on agentmods" height="20"></a>
Per session 121 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,614 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 $0.00121 $0.01614
Opus 5 $0.00060 $0.00807
Sonnet 5 $0.00024 $0.00323
Haiku 4.5 $0.00012 $0.00161

Measured 8d ago against content hash 03a2af4d48e3, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

juno 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 8d 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/juno/SKILL.md · 141 lines

How it starts

The opening of the file, as written. The whole thing — 141 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Juno: New Origins

The tools work directly on the game's files. All of its formats are plain XML with no signatures or checksums, so craft and flight programs can be generated programmatically.

Workflow

  1. game_state — confirm the game is not running: you cannot write while it is.
  2. craft_read / part_lookup — understand what you are working with.
  3. vizzy_write — the flight program (start with dry_run: true).
  4. game_launch → check in game → log_read — feedback.
  5. junoclaude_restore — roll back if something went wrong.

Every write takes a snapshot first; junoclaude_restore with no arguments lists them.

Four rules

They prevent almost every failure.

  1. Do not write craft XML by hand. The connection structure is not obvious (see below); use the tools.
  2. Do not request craft_read in xml mode without part_ids. Craft reach 2 MB — the context will run out on the first call. Start with the summary.
  3. Do not edit live what the game writes itselfGameStates/, Settings.xml, Career/. Craft and flight programs can be written while the game is running: the craft list is verified not to be cached, and a new file shows up in the designer immediately.
  4. Do not invent Vizzy property names. The compiler checks them against the catalog and suggests near matches, but it is better to check beforehand.

Coordinate system and geometry

  • +Y is up along the stack. A part's position is its center, in meters, in craft-local coordinates.
  • rotation is Euler angles in degrees.
  • Bounds and mass (price, initialBounds*, localCenterOfMass, <Drag>) are derived: the game recomputes them on load. Approximate values are enough.
  • Most fuselage parts are procedural: Fuselage1 is a fuel tank, an adapter and a nose cone all at once, the difference being only the <Fuselage> modifier (topScale, bottomScale, with offset.y setting the length). Likewise RocketEngine1 covers every rocket engine via nozzleTypeId.

Read the full file on GitHub · 141 lines

Files

What ships with it

3 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 8d ago First seen · 141 lines · 121 tokens per session scan A 03a2af4d48e3

Subscribe to this mod's changes

juno is a skill published in the GitHub repository AlexWortega/junoclaude (8 stars, last pushed 1mo ago), licensed MIT. It adds 121 tokens to every session and 1,614 once invoked, about $0.0006 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.