Speculative Routing

import { finalizeRoute, prepareRoute } from "@mupt-ai/dari-router/policy-engine";

const prepared = prepareRoute(routeInput);
if (!prepared.selectorPreparation) throw new Error("Selector unavailable");

const incumbent = prepared.previousDecision;
const stillEligible = incumbent !== undefined &&
  prepared.candidateResolution.candidates.some((candidate) =>
    candidate.model === incumbent.model &&
    candidate.reasoningEffort === incumbent.reasoningEffort
  );

const speculative = stillEligible ? startModel(incumbent) : null;
const selectorOutput = await callSelector(prepared.selectorPreparation.selectorRequest);
const next = finalizeRoute(prepared, selectorOutput);
const served = await serveOrRecover({ speculative, selectedRoute: next.decision });
await persistNextDecision({ served, nextDecision: next.decision });