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.
npx agentmods add instructions/ako/backing-tracks/claude-mdgit clone --depth 1 https://github.com/ako/backing-tracksWhat 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 | $0.03366 | $0.03366 |
| Opus 5 | $0.01683 | $0.01683 |
| Sonnet 5 | $0.00673 | $0.00673 |
| Haiku 4.5 | $0.00337 | $0.00337 |
Grade B, and why
backing-tracks CLAUDE.md scanned grade B with 1 finding 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 3d 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.
Asks for rootmediumPrivilege escalation
A mod that escalates privileges can change anything on the machine, not only the project.
sudo apt install fluidsynth fluid-soundfont-gm How it starts
The opening of the file, as written. The whole thing — 410 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Claude Project Context: Backing Tracks
Project Overview
This is a terminal-based backing track player written in Go that uses YAML-based DSL (Domain-Specific Language) called BTML (Backing Track Markup Language) to define complete backing tracks for guitar practice.
Current Version: v0.7
Purpose: Enable guitarists to create and play full-band backing tracks (chords, bass, drums) from simple YAML files, with real-time visual display showing current chord and beat.
Architecture
┌─────────────────────────────────────────────────────────┐
│ BTML File (.yaml) │
│ - Track metadata (tempo, key, time signature) │
│ - Chord progression (pattern string) │
│ - Bass configuration (style, swing) │
│ - Drums configuration (presets or Euclidean rhythms) │
└─────────────────────────────────────────────────────────┘
↓
┌─────────────────────────────────────────────────────────┐
│ Parser (parser/parser.go) │
│ - Parses YAML into Go structs │
│ - Validates and sets defaults │
└─────────────────────────────────────────────────────────┘
↓
┌─────────────────────────────────────────────────────────┐
│ Display (display/terminal.go) │
│ - Shows track info, chord grid, bass/drum info │
└─────────────────────────────────────────────────────────┘
↓
┌─────────────────────────────────────────────────────────┐
│ MIDI Generation (midi/) │
│ ├─ generator.go: Main MIDI file creation │
│ ├─ bass.go: Bass pattern generation │
│ └─ drums.go: Drum pattern generation (w/ Euclidean) │
│ │
│ Output: 3-track MIDI file │
│ - Track 0: Tempo metadata │
│ - Track 1: Chords (channel 0, piano) │
│ - Track 2: Bass (channel 1, fingered bass) │
│ - Track 3: Drums (channel 9, GM drum map) │
└─────────────────────────────────────────────────────────┘
↓
┌─────────────────────────────────────────────────────────┐
│ Live Display (display/live.go) │
│ - Real-time chord and beat visualization │
│ - Updates 10x/second via goroutine │
│ - Visual metronome, progress bar │
└─────────────────────────────────────────────────────────┘
↓
┌─────────────────────────────────────────────────────────┐
│ Player (player/fluidsynth.go) │
│ - Executes FluidSynth via exec.Command │
│ - Manages live display lifecycle │
│ - Synthesizes MIDI to audio using SoundFont │
└─────────────────────────────────────────────────────────┘
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.
- 3d ago First seen · 410 lines · 3,366 tokens per session scan B 3cdbc6e2286d
backing-tracks CLAUDE.md is an instructions file published in the GitHub repository ako/backing-tracks (20 stars, last pushed 8mo ago), licensed MIT. It adds 3,366 tokens to every session, about $0.0168 per session on Opus 5. A static security scan graded it B with 1 finding (asks for root). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
Other instructions, from other repositories
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AGENTS.md instructions for github/spec-kit, covering agents.md, about spec kit and specify, quickstart — add a new integration in 5 steps, integration architecture and integrationmanifest — file tracking.
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AGENTS.md instructions for openai/codex, covering rust/codex-rs, the codex-core crate, code review rules, crate api surface and model visible context.
langchain AGENTS.md
AGENTS.md instructions for langchain-ai/langchain, covering global development guidelines for the langchain monorepo, corridor security analysis, project architecture and context, monorepo structure and development tools & commands.
vscode oss-third-party-notices.instructions.md
Instructions for microsoft/vscode, covering vs code oss third-party-notices pipeline, architecture, pipeline flow in ci, applying the notice (cutover) and fallback chain (never fail the build).
next.js AGENTS.md
Instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.