Struct PolicyEngine 

pub struct PolicyEngine { /* private fields */ }

The policy engine evaluates actions against configured rules

Implementations

impl PolicyEngine

pub fn new(tool_allowlist: ToolAllowlist, default_budget: Budget) -> Self

pub fn evaluate_tool_call(&self, tool_name: &str) -> PolicyDecision

Evaluate whether a tool call is allowed.

Now gathers every matching verdict from the allowlist and runs them through crate::precedence::resolve_conflicts, so two disagreeing policies produce a deterministic winner plus a full explanation trace surfaced on PolicyDecision::trace. Behaviour matches the legacy short-circuit (Deny > RequiresApproval > Allow > default-deny) — back-compat is covered by existing tests.

pub fn evaluate_tool_call_with( &self, allowlist: &ToolAllowlist, tool_name: &str, ) -> PolicyDecision

Evaluate a tool call against a caller-supplied allowlist instead of the engine’s process-global default.

The gateway uses this to hold each run to its own agent’s configured tools (deny / approval-required / allowed tiers), so deny-by-default is keyed on the agent — not on a single empty default shared across every run. Self::evaluate_tool_call is the special case where the allowlist is the engine’s own default.

pub fn check_budget( &self, usage: &BudgetUsage, budget: Option<&Budget>, ) -> PolicyDecision

Check if budget allows continuing. The returned decision carries a trace whose single matched verdict (if any) is the offending budget axis.

pub fn default_budget(&self) -> &Budget

Get the default budget

pub fn evaluate_bench_gated_decision( &self, policy: &BenchAuditPolicy, claim: &BenchGatedClaim, summary: &BenchTrustSummary, ) -> PolicyDecision

Evaluate a routing / model-swap decision that cites an external benchmark delta. Reuses resolve_conflicts so the bench-audit gate shares precedence semantics with the allowlist + budget tiers — this is a new rule source, not a parallel engine. Deny-by-default still applies: if the BenchAuditPolicy emits no verdicts (no signal from the eval plane), the decision is denied with an empty trace.

Trait Implementations

impl Default for PolicyEngine

fn default() -> PolicyEngine

Returns the “default value” for a type.