figcraft/AGENTS.md

FigCraft — instructions for agents

FigCraft is a clean-room, open-source, pure-Rust (egui) reimplementation of the Figma design workflow: interface design, auto layout, components and variants, styles and variables, prototyping and inspection. It runs natively on macOS, Windows, Linux and FreeBSD, and in the browser via WASM. Siblings: ../vectorcraft (Illustrator-class), ../photocraft (Photoshop-class), ../designcraft (InDesign-class) and the other Crafting Apps; same conventions.

Standards and learnings shared across the crafting apps live in ../../craftrules (checked out next to craft-apps/, 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 ROADMAP.md (stage, headline numbers, estimates) and docs/gaps.md (the ranked work list). Unless the user gives you a task, pick work from the top of docs/gaps.md.
2. Read plan/STATUS.md and plan/execution-plan.md (local, gitignored) if present; behaviour reference notes are in plan/figma/*.md.
3. Orient → plan → implement + test → verify (screenshot) → record (ROADMAP, devlog) → commit.

plan/ is gitignored (local only).

Non-negotiables

Clean-room

• Behaviour comes from public documentation and black-box observation of the running incumbent app with synthetic documents only. Never read, disassemble or copy anything inside the incumbent's application bundle, web bundle or network traffic (names and public listings only).
• Never copy GPL/AGPL code.
• Reference screenshots of the incumbent stay local under the gitignored plan/figma/screenshots/ and are never committed, published or used as assets.

Assets: no third-party product iconography or images — ever (absolute rule from the project owner)

• Never add, copy, trace, redraw-from, embed or ship any icon, image, illustration, cursor, logo, template, UI kit, preset library, font file or screenshot from Figma, Adobe, Avid, Autodesk or any other product, or from any source whose licence doesn't allow it. This includes "lookalike" redraws of their icons. Breaking this rule is the worst thing you can do in this repo.
• Every image, icon, font or other asset must be one of:
  • original work created for FigCraft by a contributor (licensed MIT OR Apache-2.0);
  • OSI open source;
  • public domain / CC0;
  • Creative Commons with redistribution allowed.
• Every asset file must have a row in ATTRIBUTION.md (path, author, source, licence, notes). cargo xtask assets (part of cargo xtask ci) fails on any unlisted file under assets/, docs/brand/ or docs/images/.
• FigCraft's UI icons are drawn in code (crates/ui-egui/src/icons.rs) from simple primitives and are original. Keep it that way: new icons are new code, designed from scratch.
• The app icon is the owner's chameleon drawing, vectorised (assets/app-icon/README.md); cargo xtask icon renders the PNGs and .ico from assets/app-icon/figcraft.svg.
• Fonts live in storytold/craft-fonts, never in this repo. The app uses it only through the optional CRAFT_FONTS_DIR build input (.cargo/config.toml points it at ../craft-fonts for local builds; crates/text/build.rs embeds it). Everything must build, test and run without it (system fonts are scanned at runtime).
• Demo and test content is synthetic or public domain; never personal photos or data.
• Code and original assets are MIT OR Apache-2.0 (LICENSE-MIT, LICENSE-APACHE, NOTICE). The ArtCraft logos in docs/brand/ are trademarks, not open source, under docs/brand/LICENSE-brand.txt: never modify them or use them outside FigCraft.
• If the provenance of an asset is unclear, don't add it.

Never crash

• No unwrap(), expect(), panic!, unreachable!, todo!, unimplemented! in shipped code (workspace clippy lints deny them; tests may use them). Return Result/Option; use .get() for data-derived indexes; slice strings only at char boundaries; check floats are finite; cap sizes.
• figcraft_engine::guard turns a panicking command into EngineError::Internal and the document is rolled back; the desktop app also guards each UI frame and writes recovery copies. These are safety nets, not substitutes for Result.
• unsafe_code = "forbid" workspace-wide.
• Every crash fix comes with a regression test. The engine has a junk-parameter sweep over every command (crates/engine/src/tests.rs): extend fuzz/sweep tests when you add parsers or commands.

Architecture

• Everything is a command. User-visible behaviour = a command in crates/engine/src/cmd/* (spec!(id, label, params doc, undoable, run)) + tests. The menus, shortcuts, Actions palette, CLI, control channel and MCP server all dispatch the same command ids. Command ids follow the incumbent's menu catalog in crates/engine/src/catalog.rs (the parity metric: cargo xtask parity).
• Programmatic calls never open dialogs. Commands only request UI (Session::request_ui); the control channel drops dialog requests.
• Layering is enforced by cargo xtask layers: geom/color (L0) → doc (L1) → layout/text/pathops/plugin/collab (L2) → render/format (L3) → svg/pdf (L4) → engine (L5) → ui-egui/mcp (L6) → apps. Nothing below L6 depends on egui/eframe/rfd/winit. The UI crate is swappable.
• The UI is thin: panels read engine state and act through app.run(id, params) / app.set_props(ids, props). Colours come from theme::Tokens.
• Rust only (no handwritten JS/TS). Never break wasm (cargo xtask wasm).

Quality gates (before every commit)

cargo xtask ci (fmt, clippy -D warnings, tests, layers, assets, wasm). One task per commit with a milestone id in the message (M2.1: auto layout wrap). Commit after every landed arc of work; push to main.

Running and looking at the app

• cargo run -p figcraft -- --control <port> [file.figcraft|file.svg|image]. Pick a free port (python3 -c 'import socket;s=socket.socket();s.bind(("127.0.0.1",0));print(s.getsockname()[1])'); sibling apps use the control channel too.
• Drive it with JSON lines, e.g. {"id":1,"method":"engine.execute","params":{"command":"shape.rectangle","params":{"x":10,"y":10,"width":100,"height":50}}} then {"id":2,"method":"ui.screenshot","params":{"path":"/tmp/shot.png"}}. Methods are documented in crates/ui-egui/src/control.rs and docs/control-protocol.md.
• For UI work, look at the result (take a screenshot and read the PNG). Compare with the incumbent side by side where the owner allows (plan/figma/).
• Headless: figcraft-cli (info, export, run, commands, mcp). MCP: figcraft-cli mcp (see docs/mcp.md).
• Shell gotcha on the owner's machine: mv/cp may be aliased interactive — use /bin/mv -f.
• Parallel agents: separate CARGO_TARGET_DIR per agent, edit only the crates/files you own, write manifests atomically, delete your target dir when done (disk is limited).

Roadmap

Progress docs follow craftrules standards/progress-docs.md: ROADMAP.md (one-page summary and stage), docs/target-app-parity.md (the authoritative assessment), docs/gaps.md (ranked work list), docs/roadmap.md (milestones), docs/architecture.md, the per-area docs/*-parity.md files and the generated docs/parity-checklist.md (cargo xtask parity). When a task lands, update the affected rows and the status line and revision history in the same commit. Grade by behaviour against the incumbent, not by whether a menu item exists; err low.

Contributor credits (About window)

• About ▸ Contributors 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 craftrules standards/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).