effectcraft/AGENTS.md

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.

• 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 Results.
• 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:

   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. 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, explained in craftrules 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

• ROADMAP.md: stage, headline numbers and what's next
• docs/gaps.md: every known shortfall against After Effects, ranked, and the prioritised workstreams (G1–G9); read it before choosing work
• docs/target-app-parity.md: the parity numbers and how they were measured, with the per-area docs it links (UI, file formats, hardware, localization, effects, scripting); progress docs follow craftrules standards/progress-docs.md
• CONTRIBUTING.md: setup, gates, commits, how to add things
• docs/architecture.md: layers, data model, commands, pipeline
• docs/testing.md: oracle tests, criteria, benchmarks
• docs/agents.md: driving EffectCraft over MCP / the control channel, and the agent work loop
• docs/control-protocol.md: control-channel method reference
• docs/contributors.md: the About window's contributor and model credits
• 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).