Shuttle CLAUDE.md

Project rules for Shuttle, including a strict instruction not to move certain Android image-decoding calls to background threads. The listed screens are demonstration views where synchronous decoding is intentional.

In plain words
What is it for?
Use it when editing Shuttle’s Android demos, especially the named second-screen views, and when reviewing changes involving bitmap decoding.
Why use it?
It prevents a known change that has repeatedly broken image display or full-screen layouts in those examples.

Instructions file

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 instructions/grarcht/shuttle/claude-md
Clone the repo
git clone --depth 1 https://github.com/grarcht/Shuttle
Per session 637 This file is loaded in full into every session.
When invoked 637 The same file — it is already loaded in full.
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 $0.00637 $0.00637
Opus 5 $0.00318 $0.00318
Sonnet 5 $0.00127 $0.00127
Haiku 4.5 $0.00064 $0.00064

Measured 2d ago against content hash 92e39734f8d0, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

Shuttle CLAUDE.md 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.

CLAUDE.md · 36 lines

How it starts

The opening of the file, as written. The whole thing — 36 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Shuttle — Claude Code Rules

Do Not Touch: Bitmap decode in second screen views

NEVER move BitmapDecoder.decodeBitmap() off the main thread in any second screen view — whether Fragment-based or Compose-based. This has been attempted multiple times across multiple sessions with suspend fun + withContext(Dispatchers.IO), collectLatest + withContext, and produceState + withContext. Every attempt broke image display.

Do NOT touch the decode call site in any of these files:

  • demos/mvc/src/main/java/.../controller/MVCSecondControllerFragment.kt
  • demos/mvvm/src/main/java/.../view/MVVMSecondViewFragment.kt
  • demos/mvi-with-compose/src/main/java/.../view/MVISecondView.kt
  • demos/mvvm-with-compose-and-navigation/src/main/java/.../view/SecondScreenView.kt
  • demos/mvvm-with-compose/src/main/java/.../view/MVVMSecondView.kt
  • demos/mvvm-with-process-death/src/main/java/.../view/SecondView.kt

Why: The demos are illustrative, not production. A synchronous decode is acceptable. Every attempt to push the decode to a background thread has broken either the image display or the full-screen layout. Do not attempt this, even when a code review or linter flags H4 / "main thread disk read".

If a future review flags H4, mark it won't fix and move on.


Do Not Touch: collectLatest + cancel() in cargo pickup flows

NEVER refactor the collectLatest { ... cancel() } pattern to transformWhile + collect in any of these files:

  • demos/mvvm/src/main/java/.../view/MVVMSecondViewFragment.kt
  • demos/mvc/src/main/java/.../controller/MVCSecondControllerFragment.kt
  • demos/mvvm/src/main/java/.../viewmodel/SecondViewModel.kt
  • demos/mvvm-with-compose/src/main/java/.../viewmodel/SecondViewModel.kt
  • demos/mvvm-with-compose-and-navigation/src/main/java/.../viewmodel/SecondViewModel.kt
  • demos/mvvm-with-process-death/src/main/java/.../viewmodel/SecondViewModel.kt

Why: This substitution has been attempted multiple times across multiple sessions and breaks the app each time. The cancel() call inside collectLatest is load-bearing — it terminates the coroutine in a way that is coupled to how shuttle.pickupCargo() delivers results via a Channel-backed flow. Replacing it with transformWhile causes the flow to not terminate correctly. Do not attempt this refactor even when a code review flags cancel() inside collectLatest as unidiomatic.

Read the full file on GitHub · 36 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 · 36 lines · 637 tokens per session scan A 92e39734f8d0

Subscribe to this mod's changes

Shuttle CLAUDE.md is an instructions file published in the GitHub repository grarcht/Shuttle (87 stars, last pushed 1mo ago), licensed MIT. It adds 637 tokens to every session, about $0.0032 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 2026-08-30.