Port a project

The source is read-only; the port goes into a separate output project. Work in dependency order so every file you write can use the real names of what it depends on.

0. Understand and decide

re_scan {path}                         → engine, version, languages, entry points
re_graph {path}                        → cycles (port those files together), externals (need replacements)
port_map {from, to}                    → conventions (axes, units, lifecycle) and the API map with pitfalls

Tell the user the plan in a few lines: target, what converts automatically (scenes, transforms, assets, project skeleton), what needs real porting work (scripts, shaders, UI, physics tuning), and risks (risky units, cycles, engine features with no equivalent). Ask before starting when the target or scope is unclear.

1. Plan

port_plan {source, to:"unity"|"godot"|"godot-csharp"|"unreal"|"threejs"|<language>, name?, output?, include?, exclude?}

Creates the output project with a scaffold (three.js: Vite + TypeScript + game loop; Unreal: .uproject + module; Godot: project.godot; Godot C#: .csproj; Unity: the scene-builder editor script) and PORT-PLAN.md.

2. Loop

port_copy_assets {planId}                       → textures, audio, models, fonts in one go
port_unit {planId}                              → next unit: source, symbols, apiHints (line numbers), conventions,
                                                   naming rules, dependencies with their ported symbols, checklist
  scenes:  port_scene {planId, unit}            → converted automatically; read its notes
  code:    write the port yourself, then
           port_write {planId, unit, files:[{path, content}], notes?}
           → fix every leftover and missingFromSource it reports before moving on
port_status {planId}                            → progress

Porting code well:

• Translate behaviour, not syntax. Use the target engine's idioms from the map (events instead of signals, serialized references instead of node paths, coroutines/timers instead of awaits…).
• Every position, direction, rotation, speed or distance crosses a coordinate system: use port_convert (Unreal is centimeters and Z-up; Unity mirrors Z; three.js matches Godot).
• Keep public names recognisable (PascalCase/snake_case per target) so port_verify can match them.
• Cannot port something yet? Write a PORT: comment that says what is missing and use status:"partial".
• Large files: port in parts, but write the whole file in one port_write (files can hold up to 8 MiB).

3. Finish

Use the port-verify skill. Then tell the user exactly how to open the result (Unity: copy Assets/ into a project, run Tools ▸ ReversePort ▸ Build prefabs and scenes from specs; Godot: open the folder; three.js: npm install && npm run dev; Unreal: right-click the .uproject → Generate project files, build), and what is left for them.