Integration Risk: The Main Loop Collision

The critical integration question is whether Wargame Engine’s main loop can accommodate LangGraph’s invoke-driven state model:

• Wargame’s loop: controller.run('scene') — continuous frame loop, reads input, renders
• LangGraph’s loop: graph.invoke() / graph.stream() — discrete super-steps, returns when graph halts or interrupts

Observed resolution paths: 1. Interrupt-driven: LangGraph calls interrupt() → engine shows prompt → human clicks → Command(resume=...) → LangGraph continues → engine re-renders. This maps naturally — the engine’s event loop IS the interrupt handler. 2. Polling: LangGraph state is queried each frame. Engine renders whatever state exists. On click, invoke() runs synchronously (blocking). For turn-based with 10 units, the blocking time is negligible. 3. Frame-skip: If invoke() is slow (LLM call inside node), engine shows a “processing…” overlay or loading screen via Wargame’s GUI system.

The messaging system is the bridge: engine sends “input event” messages → LangGraph node receives → LangGraph returns state update → engine rebuilds view from new state. This is the cleanest decoupling pattern and Wargame Engine was designed for it.