Budget-Guarded Autonomy(BGA)

Hard, enforced per-task and per-session budgets on tokens, dollars, wall-clock time, and tool-call count that are checked before each call and pause or terminate execution, rather than after-the-fact cost alerts. Mechanisms include pre-flight budget checks that raise a budget-exceeded stop before the next call reaches the provider, a token-velocity circuit breaker that trips on runaway loops, loop detectors that halt no-progress cycles, and delegated budget ceilings where a parent agent grants a child a spend cap the child cannot exceed. Distinct from `cost-aware-model-selection`, which routes to cheaper models to lower unit cost but does not enforce a ceiling or halt spend.