ukulele-companion: Instructions file for Claude Code

AGENTS.md

ukulele-companion AGENTS.md is an instructions file for Claude Code, Codex, OpenCode from baijum/ukulele-companion. It costs 3,296 tokens per session, scanned A, original, MIT.

Repository instructions for coding agents working on Ukulele Companion, an app for learning and playing the ukulele across Android and iOS.

In plain words
What is it for?
Use them to locate features, understand shared and platform-specific code, choose the right tests, and follow the project's documented development rules.
Why use it?
They point agents to the project architecture, relevant coding rules, testing guidance, and known mistakes before changes are made.

Instructions file for Claude CodeCodexOpenCode

Written for Claude Code and Codex and OpenCode: PreToolUse hook event, but also the file is AGENTS.md. Also seen: reads .claude/ paths; mentions CLAUDE.md; mentions subagents.

This is baijum/ukulele-companion's own configuration. It tells Claude Code, Codex and OpenCode how to work on ukulele-companion itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything ukulele-companion configures →

Reuse

Borrowing it

Nothing to install: this file belongs to baijum/ukulele-companion. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/baijum/ukulele-companion/main/AGENTS.md
Clone the repo
git clone --depth 1 https://github.com/baijum/ukulele-companion

Made for: Claude Code, Codex, OpenCode.

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Per session 3,296 This file is loaded in full into every session.
When invoked 3,296 The same file — it is already loaded in full.
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 $0.03296 $0.03296
Opus 5 $0.01648 $0.01648
Sonnet 5 $0.00659 $0.00659
Haiku 4.5 $0.00330 $0.00330

Measured 6d ago against content hash 4e9193298f79, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

ukulele-companion AGENTS.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 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.

AGENTS.md · 195 lines

How it starts

The opening of the file, as written. The whole thing — 195 lines — stays where its author put it; the contents beside it link to each section on GitHub.

AGENTS.md -- AI Agent Instructions for Ukulele Companion

Mandatory instructions for AI coding agents (Cursor, Copilot, Codex, etc.) working on this codebase.

See also: CODEBASE_AREAS_SUBAREAS.md — exhaustive table of feature areas (Play/Create/Practice/Reference + all NavSections), packages, UI/Views, domain logic, and cross-cutting code.

Session context: MEMORY.md — persistent agent memory (read at session start, append when you learn something non-obvious). docs/known-failures.md — recurring agent mistakes to avoid.

Harness docs: docs/architecture-map.md — screen/ViewModel/navigation mapping for both platforms. docs/testing-guide.md — which test pattern for which component. docs/check-registry.md — every automated check, its command, and runtime.

Detailed coding rules live in .cursor/rules/*.mdcthe canonical source. They auto-attach in Cursor; Claude Code picks them up via directory-scoped CLAUDE.md pointer files (e.g. shared/src/commonMain/, app/src/main/.../ui/, iosApp/UkuleleCompanion/); other agents should open the relevant rule from the Coding Rules Reference table below. This document provides project-level context and constraints.

Project Overview

Ukulele Companion is a free, fully offline multiplatform app (Android + iOS) for learning and playing ukulele. A core user base includes blind and visually impaired musicians who rely on TalkBack (Android) and VoiceOver (iOS). Every code change must preserve accessibility. Breaking accessibility is treated as seriously as breaking functionality.

Hard constraints -- never violate these:

  • No network dependencies -- every app feature must work with the radio off
  • No analytics, tracking, or telemetry
  • No ads or monetization code without prior discussion
  • No third-party SDKs without prior discussion
  • Never commit keystore.properties, API keys, or secrets

Read the full file on GitHub · 195 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. 6d ago Changed · +7 tokens per session 4e9193298f79
  2. 10d ago First seen · 195 lines · 3,289 tokens per session scan A 0e2fff8f0719

Subscribe to this mod's changes

ukulele-companion AGENTS.md is an instructions file published in the GitHub repository baijum/ukulele-companion (14 stars, last pushed 6d ago), licensed MIT. It adds 3,296 tokens to every session, about $0.0165 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.

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