Struct BudgetGuard 

pub struct BudgetGuard { /* private fields */ }

The resolved budget for one request: a live guard over the ledger.

Implementations

impl BudgetGuard

pub fn check(&self, now_s: u64) -> BudgetVerdict

Pre-check BEFORE any provider contact: rejected when either window is already exhausted (both windows are checked independently — the done-when requirement). Retry-After is the time to the denying window’s boundary (the later wall when both are exhausted), and the verdict’s kind is the window that set it.

pub fn check_with_estimate( &self, now_s: u64, estimated_tokens: u64, ) -> BudgetVerdict

Pre-check WITH a local token estimate (PERF-01): like check but also rejects when the estimated total tokens for this request would push the minute window OVER its limit. estimated_tokens is the local estimate of the request’s total token cost (prompt estimate + requested max_tokens); the check is spent + estimated_tokens > limit (strictly greater — a request that lands exactly on the limit is allowed, matching the original check-then-spend contract where a holder at the limit can complete one more request).

The estimate is CONSERVATIVE (overcounts), so a rejection here is the honest boundary: the provider call is skipped, the client sees 429 ai_budget_exceeded, and the actual spend is never recorded (no provider contact). The cost window is NOT estimated (cost depends on the provider’s pricing table and the actual token mix, not a pre-call estimate); only the token window benefits from the estimate.

pub fn spend(&self, now_s: u64, usage: Usage, cost_micros: u64) -> bool

Record the provider-reported usage after the call. Returns whether THIS spend crossed the token window (the mid-stream cutoff signal; the spend is recorded either way).

pub fn cutoff_frame(rid: &str) -> String

The SSE event frame for a mid-stream budget cutoff (the documented over-budget event; DW-077’s terminator follows).

pub fn team_key(&self) -> &str

The team key for spend attribution (DW-079): the policy name when the budget is scope: policy (a shared team budget), or an empty string when the budget is consumer-scoped or no budget binds the request.