Borrowing it
Nothing to install: this file belongs to os-tack/fcp-midi. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/os-tack/fcp-midi/main/CLAUDE.mdgit clone --depth 1 https://github.com/os-tack/fcp-midiWrote 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.
[](https://agentmods.dev/instructions/os-tack/fcp-midi/claude-md)<a href="https://agentmods.dev/instructions/os-tack/fcp-midi/claude-md"><img src="https://agentmods.dev/badge/instructions/os-tack/fcp-midi/claude-md/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/instructions/os-tack/fcp-midi/claude-md"><img src="https://agentmods.dev/badge/instructions/os-tack/fcp-midi/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00457 | $0.00457 |
| Opus 5.5 | $0.00183 | $0.00183 |
| Sonnet 5.5 | $0.00091 | $0.00091 |
| Haiku 4.5 | $0.00046 | $0.00046 |
Grade A, and why
fcp-midi 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 2mo 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.
What it actually says
fcp-midi
Project Overview
MCP server that lets LLMs compose MIDI music through semantic operation strings.
See docs/ for design documents and specifications.
Architecture
Mido-native — a mido.MidiFile is the source of truth throughout, with no
parallel semantic model between the op handlers and the file format:
- MCP Server -
src/fcp_midi/server/- Parses op strings, resolves refs, dispatches, viafcp_core.create_fcp_server()+MidiAdapter(src/fcp_midi/adapter.py) - MidiModel -
src/fcp_midi/model/midi_model.py- Wrapsmido.MidiFile; op handlers read/write mido messages directly on the tracks. ANoteIndexgives fast selector lookups (by track/pitch/channel/velocity). Undo/redo and batch atomicity are byte snapshots of the file (MidiModel.snapshot()/.restore()), not event replay.
Key Directories
src/fcp_midi/model/- MidiModel (mido-backed), NoteIndex, timing conversionssrc/fcp_midi/parser/- Operation string parser, pitch/duration/position/chord grammarsrc/fcp_midi/server/- MCP server wiring, op handlers, queries, verb registrysrc/fcp_midi/adapter.py-MidiAdapter, theFcpDomainAdapter[MidiModel, SnapshotEvent]bridging fcp-core to MidiModelsrc/fcp_midi/lib/- GM instrument/drum tables, chord library, soundfont loading
Commands
uv run pytest- Run tests (620;-m "not slow"for the fast ~604-test subset)uv run python -m fcp_midi- Start the MCP server
Conventions
- Python 3.11+
- uv for package management
- Tests co-located in
tests/ - pytest for testing
- mido for MIDI I/O (
MidiModel.save()/.load())
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.
- 2mo ago First seen · 38 lines · 457 tokens per session scan A a4d711cc5a24
fcp-midi CLAUDE.md is an instructions file published in the GitHub repository os-tack/fcp-midi (7 stars, last pushed 4mo ago), licensed MIT. It adds 457 tokens to every session, about $0.0018 per session on Opus 5.5. 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.
fcp-midi CLAUDE.md compared with instructions from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| fcp-midi CLAUDE.mdos-tack/fcp-midi | Instructions file | 7 | 4mo ago | MIT | A | 457 | Claude Code |
| vscode buildNext.instructions.mdmicrosoft/vscode | Instructions file | 195k | yesterday | MIT | A | 9,719 | GitHub Copilot |
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| vscode oss-third-party-notices.instructions.mdmicrosoft/vscode | Instructions file | 195k | yesterday | MIT | A | 5,516 | GitHub Copilot |
| vscode copilot-instructions.mdmicrosoft/vscode | Instructions file | 195k | yesterday | MIT | A | 3,093 | GitHub Copilot |
| deepseek-harness AGENTS.mddeepseek-ai/deepseek-harness | Instructions file | 274k | 2d ago | MIT | A | 4,313 | Codex, OpenCode |