# Complete behavior [Back to Luau](https://rustic-game-engine.pages.dev/markdown/scripting/luau.md). Complete the [setup and attachment steps](https://rustic-game-engine.pages.dev/markdown/scripting/luau/setup-and-attachment.md), then paste this behavior into the attached script. ```luau return { on_start = function() rustic.log("info", "Behavior started") end, fixed_update = function(dt) local x, y, z = rustic.get_translation() if rustic.key("KeyW").held then rustic.set_translation(x, y, z + dt) end end, } ``` The SDK is staged automatically beside the source in an engine temporary directory. You do not install a package, copy the SDK into your game, or write a process loop. **Programming > Open Programming Workspace** also writes editor support files under `.rustic/generated/programming`. Regenerate those files after upgrading Rustic. Edit your behavior source, not generated SDK files. Run through Rustic Play so the engine can supply the API and callback state.