A hung TREK Valhalla cost every leg, height chunk and trace the full 30 s before FOSSGIS answered. The relay now waits 10 s for a route or heights, rests a minute after an error or timeout and answers 503 at once meanwhile, follows a 429's Retry-After (an hour at most), passes that header on to the browser, and holds the installation to 100 questions a minute below the gate's 120 (60 per user).
POST /api/routing/valhalla/route, /trace_attributes and /height ask the
Valhalla at TREK_VALHALLA_URL (default https://valhalla.liketrek.com) for a
signed-in user. The body is held to the shared contract (64 KB, at most 20
locations), every question counts against 120 a minute per user, and the
installation key goes along only to a host TREK_SERVICES_HOSTS lists.
Valhalla's answer is passed on as it came, refusals included.
The road trip router asks the same relay when the routing choice lands on
the TREK services, so the MCP road trip, city walk and hike tools share its
limits, and hands a question it cannot answer to FOSSGIS.
Maurice