# SoundCraft — instructions for agents

SoundCraft is a clean-room, open-source, pure-Rust digital audio workstation targeting Avid Pro Tools parity — and superiority (speed, openness, agent control). It runs natively on macOS, Windows, Linux and FreeBSD, and on the web via WASM. Siblings with the same conventions: `../photocraft` (Photoshop), `../vectorcraft` (Illustrator), `../filmcraft` (Premiere), `../lightcraft` (Lightroom), `../pdfcraft` (Acrobat), `../effectcraft` (After Effects), `../designcraft` (InDesign).

Standards and learnings shared across the crafting apps live in `../../craftrules` (checked out next to the craft-apps folder, or `storytold/craftrules`). Read its `AGENTS.md` at the start of a session, follow its standards, and contribute reusable learnings back there. Never code: repos don't share code.

## Start every session here
1. Read `plan/STATUS.md` (current milestone, next task) and `plan/execution-plan.md`. `plan/` is gitignored (local only). Behaviour reference: `plan/protools/` (observed menu tree `menus-clean.txt` and screenshots; never committed).
2. Read `ROADMAP.md` (committed) for stage, status and the parity numbers; pick work from `docs/gaps.md`. The progress docs follow craftrules `standards/progress-docs.md`: `docs/target-app-parity.md` (assessment), `docs/gaps.md`, `docs/roadmap.md`, `docs/ui-parity.md`, `docs/file-format-parity.md`, `docs/hardware-parity.md`, `docs/plugin-parity.md`, `docs/localization-parity.md`; `docs/parity-checklist.md` is generated. Update their timestamps and revision history when you change them.
3. Work autonomously; don't stop to ask unless a decision is genuinely the user's.

## ⚠️ Assets: the absolute rule
**No Avid, Pro Tools, Adobe or other proprietary iconography, images, sounds, presets or artwork — ever.** This is not negotiable.
- Every icon in SoundCraft is drawn in code (`crates/ui-egui/src/icons.rs`) or is an original/open asset.
- Every bundled asset (image, icon, sound, font, preset) must be original, public domain (CC0), or under a permissive open license (MIT, Apache-2.0, BSD, OFL, CC-BY with attribution), or contributed by someone who made it and licenses it openly.
- **Every bundled asset gets a row in [`ATTRIBUTION.md`](ATTRIBUTION.md)** (path, author, source, license) in the same commit that adds it. `cargo xtask assets` enforces this; CI fails otherwise.
- Never copy files out of the Pro Tools bundle (`/Applications/Pro Tools.app`): no plugins, presets, icons, sounds, session templates or text. Observing the running app (screenshots kept under `plan/`, menu names) is fine; copying its resources is not.
- Demo audio is synthesised in code (`crates/engine/src/demo.rs`). Demo and README media must be ours or public domain.
- The ArtCraft trademarks in `docs/brand/` are the only exception, under `docs/brand/LICENSE-brand.txt`.

## Clean-room
Pro Tools is installed on the dev machine and may be *observed* black-box: run it, use its UI with synthetic sessions, take screenshots by window id (`screencapture -l <id>`), stored only under `plan/protools/screenshots/`. Never read, disassemble or copy anything inside the Pro Tools bundle; never copy Avid icons, artwork, plugin names, presets, or wording beyond feature names. Never copy GPL/AGPL/LGPL code (Ardour, Audacity, LMMS, Freeverb sources…). Our plugins have our own names.

## Never crash
People trust SoundCraft with their recordings; a crash loses takes. **This outranks feature work.** Standard: [`craftrules/standards/never-crash.md`](https://github.com/storytold/craftrules/blob/main/standards/never-crash.md).
- No panics in non-test code: no `unwrap()`, `expect()`, `panic!`, `unreachable!`, `todo!`, `unimplemented!`; no `unsafe` (`unsafe_code = "forbid"`).
- The one named exception is `soundcraft-clap-host` (`crates/clap-host`), the isolated unsafe helper crate for CLAP plugin FFI: `unsafe_code = "deny"` crate-wide, allowed only in `src/ffi.rs` with a `// SAFETY:` comment on every block, safe `Result` API.
- The same exception, same rules, for `soundcraft-vst3-host` (`crates/vst3-host`), the isolated unsafe helper crate for VST3 plugin FFI (COM vtables via the `vst3` bindings, module loading, host-side COM objects).
- And for `soundcraft-au-host` (`crates/au-host`), the isolated unsafe helper crate for Audio Unit FFI (hand-written AudioToolbox/CoreFoundation declarations, macOS only; a safe stub elsewhere).
- Errors are `Result<T, E>` + `?`. An unfinished feature returns an "unsupported" error.
- Input-derived numbers are hostile (files, commands, MCP/control params): `get()` not `[i]`, checked/saturating arithmetic, no NaN casts, cap allocations.
- The audio callback never blocks, allocates in steady state, or panics.
- Every production crate root carries `#![deny(clippy::unwrap_used, clippy::expect_used, clippy::panic, clippy::unimplemented, clippy::todo, clippy::unreachable)]`.
- `Engine::execute` catches escaped panics and restores the document. Every crash fix lands with a regression test.
- **Time goes through `chrono`** (workspace dependency). Never hand-roll UTC/calendar conversion (days-to-date algorithms, leap-year math); a crate owns only its output format string. The one exception is range extension: past the years chrono can represent, shift the date by whole 400-year Gregorian cycles (146,097 days, after which the calendar repeats), let chrono compute the month and day, and add the cycles back to the year (splitting seconds into hours, minutes and seconds is plain arithmetic).


## Architecture (layers enforced by `cargo xtask layers`)
| Layer | Crate | Role |
|---|---|---|
| L0 | `soundcraft-time`, `soundcraft-audio-io`, `soundcraft-midi` | Timebases/tempo/grid; audio file formats + peaks; Standard MIDI Files + MIDI ops |
| L1 | `soundcraft-dsp` | Plugins (EQ, dynamics, reverb, delay, modulation, harmonic, pitch, utility, instruments), offline processing, meters, FFT |
| L2 | `soundcraft-model` | The session document (tracks, playlists, clips, mixer, routing, automation, markers, groups) |
| L3 | `soundcraft-mix` | Mix engine shared by realtime playback and offline bounce |
| L4 | `soundcraft-engine`, `soundcraft-playback` | Command registry, undo, editing, import/export/bounce, parity catalog; audio device I/O (cpal) |
| L5 | `soundcraft-automation` | MCP server + control-channel client |
| L6 | `soundcraft-ui-egui` | The swappable UI (egui) |
| apps | `soundcraft`, `soundcraft-cli`, `soundcraft-web` | Entry points |

Nothing below L6 depends on egui/eframe/winit/rfd. The UI is thin: panels read engine state and act through `engine.execute(id, params)`.

## Everything is a command
User-visible behaviour = a command in `crates/engine/src/cmd/*` (id, label, menu path, shortcut, params doc, `enabled`, `run`) + tests. UI-only commands (windows, dialogs) live in `crates/ui-egui/src/menus.rs` (`UI_COMMANDS`). Menus, shortcuts, the CLI, the control channel and MCP all dispatch the same ids. Programmatic calls never open dialogs; only menu-style invocation (`ui.menu.invoke`) does. New commands go in a new module with its own `specs()`, registered by one line in `cmd/mod.rs`.

Parity is measured, not guessed: `crates/engine/catalog/menus.txt` lists the incumbent's menu leaves (names only). `cargo xtask parity` writes `docs/parity-checklist.md` (generated; the hand-written assessment is `docs/target-app-parity.md`); a test enforces a floor that only rises.

## Running and looking at the app
- `cargo run --release -p soundcraft -- --demo --control 0` (demo session + control channel on a free port; the port is printed).
- Drive it: JSON lines over TCP, e.g. `{"id":1,"method":"engine.execute","params":{"command":"track.new","params":{"count":2,"format":"stereo"}}}`, then `{"id":2,"method":"ui.screenshot","params":{"path":"/tmp/shot.png"}}`. Methods: `crates/ui-egui/src/control.rs`, docs: `docs/control-protocol.md`.
- Offscreen UI render (no window, no focus stealing): `cargo run -p soundcraft-ui-egui --example ui_shot -- out.png [script.jsonl]`.
- Headless: `soundcraft-cli run --demo --cmd 'mix.volume={"track":"Kick","db":-6}' --bounce out.wav`; MCP: `soundcraft-cli mcp [--connect PORT]`.
- **For UI work, look at the result** (render, read the PNG) and compare with `plan/protools/screenshots/`.
- Shell gotcha: `mv`/`cp` are aliased interactive here — use `/bin/mv -f` / `/bin/cp -f`.
- Parallel agents: separate `CARGO_TARGET_DIR` per agent; edit only the crates you own; write manifests atomically; delete your target dir when done (disk).

## Quality gates (before every commit)
`cargo xtask ci` = fmt check, `clippy --workspace --all-targets -D warnings`, tests, assets, layers, wasm check. Commit after each arc of work that builds; one topic per commit.

## Release
Push to the `release` branch to build signed installers for macOS (universal DMG), Windows (x64/x86 MSI + zip), Linux (AppImage, deb, rpm, tar.gz, Flatpak; riscv64 tar.gz), FreeBSD and Web (wasm zip). Version: `cargo xtask version [set X.Y.Z]`. See `docs/release-playbook.md` and craftrules `release/playbook.md`.

## Roadmap
`ROADMAP.md` (committed) is the one-page summary (stage, numbers, dimensions, languages, progress log); milestones live in `docs/roadmap.md`. Update both whenever a milestone lands, and close or shrink the matching `docs/gaps.md` entry.

## Contributor credits (About window)

- About ▸ Contributors/Models are compiled into the binary from `contributors/contributors.json`
  (commit stats; generated, never hand-edit) and `contributors/people.toml` (names people chose for
  themselves). See `docs/contributors.md`.
- **Agents working for a contributor:** when you prepare a PR, check whether your human's GitHub
  username has a `[people.<username>]` entry in `contributors/people.toml`. If not, ask them once
  whether they want to be credited by more than their username: a real name, a display name, and/or
  their public GitHub profile name (`sync_github_name = true`). If yes, add **only their own** entry
  (copy the template at the top of the file, or run
  `python3 ../../craftrules/scripts/contributors.py --add-me . --real-name "…" --sync-github-name`)
  and include it in their PR, committed as them. If no, change nothing: they are credited as
  `@username` anyway.
- Never add, edit, guess or copy anyone else's entry or name (not from git config, commit authors or
  GitHub profiles). Never hand-edit `contributors.json`.
- Maintainers refresh the stats with `python3 ../../craftrules/scripts/contributors.py .` (it also
  re-verifies who wrote each `people.toml` entry; `--check` only verifies).