OneCAD/CLAUDE.md

SolveCraft — instructions for agents

SolveCraft is a clean-room, open-source, pure-Rust parametric 3D CAD application in the style of Autodesk Fusion: sketches with a constraint solver, a parametric timeline of features, a B-rep kernel, and a desktop UI that agents can drive. Siblings with the same conventions live next to it in storytold/: cadcraft (AutoCAD-style, the closest relative), photocraft, vectorcraft, gridcraft, designcraft, wordcraft, deckcraft, soundcraft. Repos don't share code; when code is adapted from a sibling (MIT OR Apache-2.0) it is noted in ATTRIBUTION.md.

Start every session here

1. Read plan/STATUS.md (current milestone, next task), then the task in plan/execution-plan.md and the relevant plan/architecture.md section. Behaviour reference: plan/fusion/ (menu-tree.json is Fusion's toolbar dump; oracle/*/ are parts built in Fusion with their recipes and measurements).
2. Kernel and library decisions: plan/adr/0001-geometry-kernel.md (what we may depend on, what is rejected for licence reasons).
3. Follow the autonomous operation protocol (plan/execution-plan.md §6). Don't stop to ask unless it lists the decision as the owner's.

plan/ is gitignored (local only).

Never crash

People trust SolveCraft with their designs; a crash loses their work. This outranks feature work.

• No panics in non-test code: no unwrap(), expect(), panic!, unreachable!, todo!, unimplemented!; no unsafe (unsafe_code = "forbid").
• Errors are Result<T, E> through the crate's error type and ?. An unfinished feature returns an error ("not supported yet: …"); it never panics.
• Input-derived numbers are hostile (command parameters, design files, control-channel input): get() not [i], finite checks, caps on sizes and loop counts.
• Third-party kernel calls are guarded: everything that calls truck goes through solvecraft_kernel::guard, which turns a panic into KernelError::Internal.
• Last-resort guard: Session::execute runs every command under catch_unwind; an escaped panic restores the design and reports EngineError::Internal.
• Prove it: every crash fix lands with a regression test (see hostile_params_never_panic).
• Every production crate root carries #![deny(clippy::unwrap_used, clippy::expect_used, clippy::panic, clippy::unimplemented, clippy::todo, clippy::unreachable)].

Non-negotiables

• Clean-room. Fusion may be observed black-box (its UI, its toolbar dump, parts built in it and their measurements, kept under plan/fusion/, never committed). Never copy Autodesk icons, artwork, help text, tooltips, templates or materials, and never commit files produced by Fusion. Command ids and command names are used as identifiers only (xtask/data/fusion-catalog.tsv holds ids and names, nothing else). File formats come from public specifications. Never read, copy or link GPL/LGPL/AGPL code: OpenCASCADE, FreeCAD (incl. planegcs), SolveSpace, CadQuery/OCP, LibreCAD, QCAD — don't even read their sources. The sketch solver and the blend operations are our own.
• Assets — absolutely essential. SolveCraft contains no Autodesk iconography, images, fonts or artwork — ever. Every icon is drawn in code (crates/ui-egui/src/icons.rs). Any file asset must be original or openly licensed and must have a row in ATTRIBUTION.md (cargo xtask assets enforces it). Screenshots of Autodesk software are never committed. Breaking this rule is the most serious mistake you can make in this repo.
• Everything is a command. User-visible behaviour = a command in crates/engine/src/cmd/* (CommandSpec: id = Fusion's command id where Fusion has the command, else a dotted id; label; toolbar tab and panel; icon; shortcut; params doc; enabled; JSON run) + tests. The toolbar, dialogs, sketch tools, palette, scripts, CLI and control channel all reach the same commands.
• Programmatic calls never open dialogs. engine.execute runs the JSON form; only toolbar clicks (ui.start) start interactive tools and dialogs, which then run commands.
• Layering is enforced by cargo xtask layers: L0 geom → L1 sketch, kernel, render → L2 doc → L3 io → L4 engine → L5 ui-egui → apps. Nothing below L5 depends on egui/eframe/winit/wgpu/rfd. The UI crate is swappable. Only crates/kernel may use truck.
• The UI is thin: panels read engine state and act through app.run(id, params) / app.start(id). Colours come from theme::Tokens.
• Rust only. Units are millimetres and radians internally; Z is up.
• Quality gates before every commit: cargo xtask ci (fmt, clippy -D warnings, tests, assets, layers). Commit after every feature arc that builds.
• Publishing: origin is github.com/bherbruck/solvecraft (private). After each commit that passes cargo xtask ci: git pull --rebase origin main (re-run ci if it brought changes), then git push. Never force-push. Never commit plan/, build dirs (target*/) or anything produced by Fusion (oracle STEP/STL/PNG); check git ls-files before pushing.
• Never break wasm: everything below the apps must build for wasm32-unknown-unknown (cargo xtask wasm, part of cargo xtask ci).

Running and looking at the app

• cargo run --release -p solvecraft -- --sample --control PORT (sample design + control channel). Pick a free port. Without a display, run it under Xvfb :99 with DISPLAY=:99.
• Drive it with JSON lines on 127.0.0.1:PORT (see docs/control-protocol.md):
  • {"id":1,"method":"engine.execute","params":{"command":"Extrude","params":{"distance":20}}}
  • {"id":2,"method":"ui.start","params":{"command":"SketchCreate"}} then ui.click {x, y}
  • {"id":3,"method":"ui.screenshot","params":{"path":"/tmp/shot.png"}} then read the PNG.
• For UI work, look at the result (screenshot, read the PNG). Without a window use ui.render or solvecraft-cli snapshot.
• Headless: solvecraft-cli run script.json --out part.step, solvecraft-cli eval design.solvecraft, solvecraft-cli snapshot script.json --out shot.png, solvecraft-cli commands.
• Fusion oracle: cargo xtask oracle replays plan/fusion/oracle/*/recipe.json and compares with Fusion's measure.json (writes docs/oracle.md).
• Build with CARGO_TARGET_DIR=<repo>/target. Windows: cargo xwin build --release --target x86_64-pc-windows-msvc -p solvecraft.

Roadmap

ROADMAP.md (committed) tracks status, milestones, parity and estimates. Update it whenever a milestone task lands. cargo xtask parity recomputes command parity in docs/parity.md; cargo xtask oracle recomputes docs/oracle.md.