What problem does it solve? Running untrusted game logic inside the classic-wgl engine requires a sandboxed, cross-platform execution layer. This Skill documents how the classic-guest crate runs compiled WASM modules from ROMs against a stable host SDK, with fuel, memory, and watchdog limits enforced per backend. ## Core Features & Use Cases - Four runtime backends: Wasmi and Wasmtime on native, browser-native WebAssembly for trusted guests, and a Worker-isolated runtime with a terminate watchdog for untrusted web guests, all behind one GuestRuntime trait. - Host-import ABI: a single install_host_imports! macro defines the full SDK surface (entities, sprites, UI, input, camera, lights, pathfinding, bulk terrain noise, field kernels) shared across backends. - Sandboxing: fuel metering, memory caps via StoreLimits, and a wall-clock Worker watchdog protect the host from untrusted guest code. - Use Case: When adding a new host import (e.g., a new UI element type), follow the documented steps: add the GuestHost method in sdk.rs, register it in the shared macro plus the web and worker OP tables, and add a WAT test that runs against every backend. ## Quick Start Ask the assistant to add a new host import to the classic-guest runtime following the documented SDK workflow.
