Visualization

Every example accepts the same flags — no per-script setup:

python examples/two_robots.py                # pyglet if installed, else headless
python examples/two_robots.py --web-viewer   # browser viewer
python examples/two_robots.py --pyglet       # force the pyglet window
python examples/two_robots.py --headless     # force text-only

Web viewer

WebViewer (coordination_oru/viz/web_viewer.py) serves a Vite/React frontend (starlette + uvicorn, port 8723 by default; --port, --no-browser) and streams coordinator state over a websocket. It shows live paths, swept envelopes, critical-section highlights, current dependencies, footprints, zoom/pan, dark mode — and, when the example provides an on_goal callback, interactive goal posting (click a robot, press-drag-release to set the goal pose).

It is a pure polling observer: it reads public coordinator state and never calls into the core. The server shares the simulation's asyncio loop — no threads. PyPI wheels ship the frontend prebuilt; in a source checkout build it once with npm --prefix frontend install && npm --prefix frontend run build.

Pyglet viewer

PygletViewer (coordination_oru/viz/pyglet_viewer.py) is a zero-dependency (beyond pyglet) local window with the same essentials: footprints, envelopes, critical sections, per-robot progress. The simulation runs on a background thread's event loop; the window closes itself when the fleet goes idle.

Headless

No extra dependencies: per-robot progress lines once a second and a final summary (open critical sections, held precedence decisions). All example runs are bounded by a 120 s idle timeout, so a coordination bug can never hang a terminal or CI job.