# EffectCraft — rules for agents and contributors

These rules apply to every human and AI contributor. `CLAUDE.md` holds the working instructions; this
file holds the rules that must never be broken. When the two disagree, this file wins.

## Never crash

People trust EffectCraft with hours of work. A malformed project, PSD, SVG, Lottie or media file, a bad
expression or script, a broken plug-in, a bad control-channel or MCP argument, a corrupt preferences file
or a full disk must produce an error the user (or agent) can act on, never a crash and never lost work.
**This rule outranks feature work:** don't ship a feature by adding a panic path, and fix a crash before
building on top of it. Full standard: [craftrules `standards/never-crash.md`](https://github.com/storytold/craftrules/blob/main/standards/never-crash.md).

- **Fail with `Result<T, E>`** through the crate's error type and propagate with `?`; add context
  (`map_err`, an error variant) rather than discarding it. Lenient readers fall back and record the repair.
- **No panicking shortcuts in non-test code:** no `unwrap()`, `expect()`, `panic!`, `unreachable!`,
  `todo!` or `unimplemented!`. Use `?`, `ok_or(..)?`, `let … else`, `if let`, or `unwrap_or*` where a
  fallback is genuinely correct (never where it would silently corrupt a document). Unfinished features
  return an "unsupported" error. The only exception is a provably infallible literal, written as
  `#[allow(clippy::expect_used)]` + `.expect("why this cannot fail")`.
- **No `unsafe`** (`unsafe_code = "forbid"` for the workspace).
- **Every input-derived number is hostile.** Use `get()` instead of `[i]`/`[a..b]` when the position
  comes from a file, a user, an agent or arithmetic on those; slice strings only at char boundaries; use
  checked or saturating arithmetic for lengths, offsets and counts; guard division by zero and NaN/inf
  casts; cap allocations sized by input.
- **Bound recursion:** projects, precomps, expressions and SVG/PSD trees can be cyclic or deeply nested;
  walk them with seen-sets or depth limits.
- **Don't cascade:** handle lock poisoning (`lock().unwrap_or_else(PoisonError::into_inner)` or an
  error), and treat worker-thread join results as `Result`s.
- **Last-resort guard:** the app wraps command execution and file import/export in a panic hook /
  `catch_unwind` boundary that turns an escaped panic into an error and keeps the document. It is a
  safety net, not a substitute for the rules above; keep `panic = "unwind"`.
- **Prove it:** every crash fix comes with a small synthetic regression test that panicked before the fix.

Tests, benches, fuzz targets and `xtask` may `unwrap()`; `clippy.toml` allows it in tests. Crates that are
clean carry `#![deny(clippy::unwrap_used, clippy::expect_used, clippy::panic, clippy::unimplemented,
clippy::todo, clippy::unreachable)]`; new crates start with it.

## 1. Assets: no Adobe artwork, every asset licensed and attributed

This rule is absolute. Breaking it is the most serious mistake a contributor can make on this project.

**What counts as an asset:** any image, icon, cursor, logo, illustration, screenshot, font, colour LUT,
preset, template, sound, music, video, 3D model, or other non-code media. This covers files in the
repository, bytes embedded in code (`include_bytes!`, base64, data URIs), and data hard-coded to
reproduce an image (for example, point lists traced from someone else's icon).

1. **Never use Adobe iconography, images or other Adobe assets**, in any form:
   - no icons, cursors, logos, splash screens, UI artwork or screenshots from any Adobe product;
   - no Adobe fonts, LUTs, presets, templates, sound effects, stock media or sample projects;
   - no traced, redrawn, recoloured or "inspired-by" copies of Adobe icons. Our icons may follow generic
     conventions (a play triangle, a razor blade, a stopwatch), but each must be drawn from scratch
     without reference to Adobe's artwork.
2. **Every asset must be open**: open-source licensed (MIT, Apache-2.0, BSD, ISC, zlib, SIL OFL…),
   public domain / CC0, or Creative Commons (CC BY or CC BY-SA; no NC/ND licences), **or** created by a
   contributor who owns it and licenses it to the project under the project licence (MIT OR Apache-2.0).
   If the licence is unknown or unclear, the asset does not go in.
3. **Every asset needs an attribution sidecar.** Next to each asset file `X`, add `X.attribution` with:
   ```text
   asset:        <file name>
   title:        <what it is>
   author:       <creator / copyright holder>
   source:       <URL, or "original work" for contributor-made assets>
   license:      <SPDX id or licence name>
   license-file: <path to the licence text, if the licence requires shipping it>
   added:        <YYYY-MM-DD> by <contributor>
   notes:        <how it was made or modified; for screenshots, what is shown>
   ```
   Also add one line for the asset to [`ATTRIBUTION.md`](ATTRIBUTION.md). `cargo xtask assets` (part of
   `cargo xtask ci`) fails if any asset lacks a sidecar or index entry.
4. **Screenshots** in the repo may show only EffectCraft (or other open projects), with media we generated
   or media that is itself openly licensed. Never commit screenshots of Adobe products.
5. **Local reference material stays local.** After Effects reference screenshots and notes live only in
   `plan/aftereffects/` (gitignored). They must never be committed, bundled, embedded, traced or shipped.
6. **Code-drawn assets** (icons in `crates/ui-egui/src/icons.rs`, procedural demo content in
   `crates/engine/src/demo.rs`, generators in `crates/effects`) are original work under the project licence
   and are listed in `ATTRIBUTION.md`.
7. **When in doubt, leave it out** and draw or generate it yourself.
8. **The one exception: first-party ArtCraft brand marks.** The ArtCraft name and logos in `docs/brand/`
   are trademarks of the ArtCraft Team, not open source, usable only unmodified and only in the context of
   EffectCraft under `docs/brand/LICENSE-brand.txt` (forks and modified versions must remove them). They still
   need a sidecar and an `ATTRIBUTION.md` row (licence `LicenseRef-ArtCraft-Trademark`). No other
   non-open asset is allowed, and this exception never covers third-party marks (Adobe, Discord, GitHub
   and other logos stay out; draw a generic icon instead).

## 2. Clean-room code

- Never read, disassemble or copy anything inside Adobe application bundles; file names and listings only.
  Observe behaviour by using the app; never capture its Home screen, recent projects, account info or
  file browsers.
- Never copy GPL/LGPL/AGPL code (FFmpeg, Natron, Blender, Glaxnimate, Synfig, Friction, Olive, MLT, frei0r, G'MIC…).
- Never read or copy Adobe expression/scripting implementations, `.ffx` presets or effect plug-ins; the public Expression Language Reference and Scripting Guide describe *behaviour* only.
- Implement codecs and formats from public specifications (ITU-T/ISO/IEC standards, IETF RFCs, the VP9
  and AV1 bitstream specs, SMPTE documents, published container specs). Do not read the source of
  reference or third-party decoders/encoders while implementing a format, even permissively licensed
  ones (libvpx, libopus, libaom, dav1d, openh264…); spec text and conformance vectors only. Record the
  spec edition used in the crate README.
- ffmpeg/ffprobe may be used only as external test oracles and fixture generators. They are never
  linked, bundled or shipped.
- Dependencies must use permissive licences: MIT/Apache-2.0/BSD/ISC/Zlib/Unicode/CC0/BSL-1.0, or
  MPL-2.0 used unmodified.

## 3. Engineering rules

See `CLAUDE.md`: pure Rust, dependency layering (`cargo xtask layers`), exact `Tick` time, everything is
a command, everything is agent-drivable, and the quality gates (`cargo xtask ci`) before every commit.

Shared real-file test corpora (Photoshop-authored PSDs, etc.) live in
[`storytold/photocraft-corpus`](https://github.com/storytold/photocraft-corpus), explained in
[craftrules `standards/test-corpora.md`](https://github.com/storytold/craftrules/blob/main/standards/test-corpora.md).
Never commit large binary fixtures to this repo; fetch them pinned by commit and sha256-verified,
as PhotoCraft does with `cargo xtask corpus`.


## See also

- [docs/gaps.md](docs/gaps.md): where EffectCraft falls short of After Effects and the prioritised workstreams (G1–G9); read it before choosing work
- [CONTRIBUTING.md](CONTRIBUTING.md): setup, gates, commits, how to add things
- [docs/architecture.md](docs/architecture.md): layers, data model, commands, pipeline
- [docs/testing.md](docs/testing.md): oracle tests, criteria, benchmarks
- [docs/agents.md](docs/agents.md): driving EffectCraft over MCP / the control channel, and the agent work loop
- [docs/control-protocol.md](docs/control-protocol.md): control-channel method reference
- [docs/contributors.md](docs/contributors.md): the About window's contributor and model credits
- [ATTRIBUTION.md](ATTRIBUTION.md): asset index

## 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).