OneCAD/CLAUDE.md

SolidCraft — instructions for agents

SolidCraft is a clean-room, open-source, pure-Rust parametric 3D CAD application: sketches with a constraint solver, a parametric timeline of features, a B-rep kernel, and a desktop UI that agents can drive. Projects published by storytold can serve as references for implementation conventions. Any code adapted from other projects (MIT OR Apache-2.0) is noted in ATTRIBUTION.md.

Product name

SolidCraft everywhere: crates solidcraft-*, binaries solidcraft and solidcraft-cli, .solidcraft designs, the solidcraft/N format tag, SOLIDCRAFT_* environment variables, settings and recovery folders, the MCP server name, docs, CI and packaging. The old name survives only in the explicit compatibility shims listed in docs/compatibility.md; don't add new uses of it anywhere else. Public docs/web/Flatpak deployments use project Pages /solidcraft/; do not add permanent old-name Pages aliases.

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.
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 SolidCraft 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"). The three exceptions, in the app crate (which denies it instead), have no safe API: two functions in apps/solidcraft/src/open_documents.rs (macOS hands Finder files only to an Objective-C method), the Windows-only apps/solidcraft/src/native_crash.rs (the exception filter that records crashes inside native code such as graphics drivers) and the Windows-only apps/solidcraft/src/native_frame.rs (the window procedure that answers the resize-border hit test of the window without OS decorations).
• 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 solidcraft_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.
• Crash reports: the desktop app writes every panic and every unclean exit to a local crash folder, with the design and the commands that reproduce it (solidcraft_engine::crash, docs/crash-reports.md). When someone says the app crashed, look there first: solidcraft-cli crashes, crashes show <id>, crashes replay <id> (or the diagnostics.crash_reports command / MCP crash_reports tool).
• Prove it: every crash fix lands with a regression test (see hostile_params_never_panic); a crash report's design.solidcraft + replay.json is the test's starting point.
• Every production crate root carries #![deny(clippy::unwrap_used, clippy::expect_used, clippy::panic, clippy::unimplemented, clippy::todo, clippy::unreachable)].

Non-negotiables

• Independent. SolidCraft is independent. Behaviour is designed from public documentation, general CAD conventions and user feedback. Reference tests use analytic values and open-source tools. Never copy another product's code, icons, artwork, help text, tooltips, templates or materials. File formats come from public specifications.
• No commercial CAD products. Agents must not drive, script, automate or extract data from commercial CAD products (Fusion, SolidWorks, Onshape, …) for this project: no test data, measurements, command lists, ids or files produced with them.
• Never read, copy or link GPL/LGPL/AGPL code: OpenCASCADE, FreeCAD (incl. planegcs), SolveSpace, CadQuery/OCP, LibreCAD, QCAD — don't even read their sources. (tools/freecad-oracle/ runs FreeCAD as a separate program through its public scripting API to compute reference values; nothing from FreeCAD is linked, vendored or shipped.) The sketch solver and the blend operations are our own.
• Assets — absolutely essential. SolidCraft contains no iconography, images, fonts or artwork from commercial CAD products — 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 commercial CAD 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 = our own dotted, lower-case id <area>.<thing>[.<variant>] such as solid.extrude or sketch.rectangle.two_point, never another product's command 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. The one exception is JavaScript the browser requires: the service worker apps/solidcraft-web/sw.js (browsers only run service workers as JavaScript) and the small inline scripts in apps/solidcraft-web/index.html. Keep them minimal; cargo xtask web-offline-test covers the service worker.
• 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/solidcraft. Changes land through pull requests: push a branch, open a PR, and let GitHub CI run. Maintainers (and agents working for them) may merge their own PR as soon as CI is green (gh pr merge --squash); a trivial fix (docs, typos) may be merged right away. Keep each PR to one topic, rebase or merge main into it when it conflicts, and never force-push main. Never commit plan/, build dirs (target*/) or generated reference data; 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).

Design file format

A change that saves something new in a design adds ONE file, crates/doc/src/format/pending/<name>.rs (a //! note, and pub fn step if older designs must be rewritten). Never edit FORMAT, JSON_STEPS, the history in format.rs, another change's file or a v<N>/ folder: the build works out the number (the next one while anything is pending), and the release folds pending changes into v<N>/ with scripts/fold-format-pending.sh. See CONTRIBUTING.md.

Application releases

Development pushes are not application releases. Follow docs/releasing.md when asked to prepare or ship a release: choose the version from the actual changes, update Cargo.toml and Cargo.lock, pass the quality gates, advance release without force-pushing, and verify the resulting draft and its artifacts. When shipping is authorized, publish that verified draft and confirm its tag and downstream deployment. Do not auto-release every push to main, infer version bumps solely from commit prefixes, overwrite published versions, or push release tags before the draft is verified.

Running and looking at the app

• cargo run --release -p solidcraft -- --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). The first request on a connection carries the launch's token as "token": read it from ~/.local/share/solidcraft/control/PORT.token, or start the app with SOLIDCRAFT_CONTROL_TOKEN=$(openssl rand -hex 32) and send that.
  • {"id":1,"method":"engine.execute","params":{"command":"solid.extrude","params":{"distance":20}}}
  • {"id":2,"method":"ui.start","params":{"command":"sketch.create"}} 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 solidcraft-cli snapshot.
• Headless: solidcraft-cli run script.json --out part.step, solidcraft-cli eval design.solidcraft, solidcraft-cli snapshot script.json --out shot.png, solidcraft-cli commands.
• Reference tests: cargo xtask oracle replays tests/oracle/*/recipe.json and compares with each case's expected.json (analytic or FreeCAD values; writes docs/oracle.md). Expected values never come from a commercial CAD product.
• Build with CARGO_TARGET_DIR=<repo>/target. Windows: cargo xwin build --release --target x86_64-pc-windows-msvc -p solidcraft.

Roadmap

ROADMAP.md (committed) tracks status, milestones and estimates. Update it whenever a milestone task lands. cargo xtask features regenerates docs/features.md (SolidCraft's commands by area, from the registry) when commands are added or renamed.