Struct ActionBudget 

pub struct ActionBudget<'a> { /* private fields */ }

Budget enforcement bound to a session id and a state store.

Implementations

impl<'a> ActionBudget<'a>

pub fn new( store: &'a dyn StateStore, session: &'a str, spec: &'a BudgetSpec, ) -> Self

Bind a spec to a session.

pub fn session_prefix(session: &str) -> String

Common key prefix for every budget counter of session. Callers use this with StateStore::remove_prefix to drop a finalized session’s counters (per-tool keys are dynamic, so single-key removal cannot enumerate them).

pub fn try_tool_call( &self, tool: &str, payout_usd_micros: u64, ) -> Result<BudgetDecision, StateError>

Check-and-spend one invocation of tool, with an optional payout amount in micro-USD carried by this call.

Dimensions are checked in a fixed order (total calls → per-tool → payout) and committed atomically via try_spend_many: every dimension is validated first and either all spends commit or none do, so a refused call consumes nothing.

pub fn refund_tool_call(&self, tool: &str, payout_usd_micros: u64)

Round-33 F1: compensating refund for a previously-successful Self::try_tool_call. Reverses the spend on exactly the same dimensions that were debited (total_calls, per-tool, payout) so a lost-race path in the caller (concurrent identical MCP request loses execution.claim() after the sandbox gate has already spent) does not double-charge the session budget. Best-effort: any backend error is silently absorbed by the underlying StateStore::refund contract — a Redis blip on the compensation path must never turn a lost-race response into a 5xx.

pub fn try_tokens(&self, tokens: u64) -> Result<BudgetDecision, StateError>

Check-and-spend tokens against max_tokens.