Remove legacy Guardian approval review paths (#43462)

## What changed

- Remove the `fast_decision` and `full_review` extension hooks and `ApprovalAssessment`, leaving `ApprovalReviewContributor::decide` as the approval decision interface.
- Remove the duplicate Guardian V2 fast-approval implementation and `StrictReviewReason` state.
- Require an explicit `GuardianReviewReason` for synchronous reviews.

## Testing

Migrate Guardian reviewer tests to the production `decide_approval` path and cached-score tests to the registry's decision interface.

GitOrigin-RevId: 1f9092c0ff5bb1eed0c63fa557fb3807e2e71564

codex-rs/core/src/guardian/mod.rs

@@ -46,10 +46,6 @@ pub(crate) use review::is_basic_session_source;
 pub(crate) use review::new_guardian_review_id;
 #[cfg(test)]
 pub(crate) use review::record_guardian_denial_for_test;
-#[cfg(test)]
-pub(crate) use review::review_approval_request;
-#[cfg(test)]
-pub(crate) use review::review_approval_request_with_cancel;
 pub(crate) use review::routes_approval_policy_to_guardian;
 pub(crate) use review::routes_approval_to_guardian;
 pub(crate) use review_session::GuardianReviewSessionManager;

codex-rs/core/src/guardian/review.rs

@@ -6,13 +6,7 @@ use codex_analytics::GuardianReviewFailureReason;
 use codex_analytics::GuardianReviewTerminalStatus;
 use codex_analytics::GuardianReviewTrackContext;
 use codex_analytics::GuardianReviewedAction;
-#[cfg(test)]
-use codex_analytics::GuardianV2Event;
-#[cfg(test)]
-use codex_analytics::GuardianV2EventKind;
 use codex_core_plugins::PluginCommandAttribution;
-#[cfg(test)]
-use codex_extension_api::GuardianV2Enabled;
 use codex_extension_api::ThreadIdleCause;
 use codex_features::Feature;
 use codex_protocol::config_types::ApprovalsReviewer;
@@ -32,8 +26,6 @@ use codex_protocol::protocol::SessionSource;
 use codex_protocol::protocol::SubAgentSource;
 use codex_protocol::protocol::TurnAbortReason;
 use codex_protocol::protocol::WarningEvent;
-#[cfg(test)]
-use futures::future::BoxFuture;
 use std::sync::Arc;
 use std::time::Duration;
 use tokio::time::Instant;
@@ -57,8 +49,6 @@ use super::GuardianAssessmentOutcome;
 use super::GuardianRejectionCircuitBreakerAction;
 use super::GuardianRejectionCircuitBreakerPolicy;
 use super::GuardianReviewContext;
-#[cfg(test)]
-use super::approval_request::format_guardian_action_compact;
 use super::approval_request::format_guardian_action_pretty;
 use super::approval_request::guardian_assessment_action;
 use super::approval_request::guardian_request_target_item_id;
@@ -342,112 +332,10 @@ pub(crate) async fn record_guardian_denial_for_test(
     record_guardian_denial(session, turn, turn_id).await;
 }
 
-/// Runs Guardian unless Full Access or an installed extension resolves the review.
-/// Guardian timeouts, review-session failures, and parse failures all block
-/// execution, with timeouts surfaced separately from explicit denials.
-#[cfg(test)]
-async fn run_guardian_review(
-    session: Arc<Session>,
-    context: GuardianReviewContext,
-    review_id: String,
-    request: GuardianApprovalRequest,
-    reasons: ApprovalRequestReasons,
-    options: GuardianReviewOptions,
-) -> ReviewDecision {
-    let turn = Arc::clone(context.turn());
-    if context.environments().has_full_access(
-        context.approval_policy,
-        &turn.config.permissions.effective_permission_profile(),
-    ) {
-        return if options
-            .external_cancel
-            .as_ref()
-            .is_some_and(CancellationToken::is_cancelled)
-        {
-            ReviewDecision::Abort
-        } else {
-            ReviewDecision::Approved
-        };
-    }
-    let requires_synchronous_review = options.require_synchronous_review
-        || reasons.retry.is_some()
-        || matches!(
-            &request,
-            GuardianApprovalRequest::ExecCommand {
-                sandbox_permissions,
-                ..
-            } if sandbox_permissions.requires_escalated_permissions()
-        );
-    // Guardian V2 may satisfy ordinary reviews, including required-model reviews, but broader
-    // permission requests, retries, and elicitations requiring synchronous review must not use
-    // extension fast approval.
-    if (!turn
-        .config
-        .config_layer_stack
-        .requirements()
-        .auto_review_required_for_model(&turn.model_info().slug)
-        || turn.config.features.enabled(Feature::GuardianV2))
-        && !requires_synchronous_review
-        && options
-            .external_cancel
-            .as_ref()
-            .is_none_or(|cancel| !cancel.is_cancelled())
-        && let Ok(action) = format_guardian_action_compact(&request)
-        && let Some(decision) = session
-            .services
-            .extensions
-            .fast_approval_decision(
-                &session.services.session_extension_data,
-                &session.services.thread_extension_data,
-                &action,
-                Some(crate::session::extension_metrics::from_session_telemetry(
-                    turn.session_telemetry.clone(),
-                )),
-            )
-            .await
-    {
-        if decision == ReviewDecision::Approved {
-            if session
-                .services
-                .thread_extension_data
-                .get::<GuardianV2Enabled>()
-                .is_some()
-            {
-                session
-                    .services
-                    .analytics_events_client
-                    .track_guardian_v2_event(GuardianV2Event {
-                        thread_id: session.thread_id.to_string(),
-                        turn_id: guardian_request_turn_id(&request, &turn.sub_id).to_owned(),
-                        item_id: guardian_request_target_item_id(&request).map(str::to_owned),
-                        model: Some(turn.model_info().slug.clone()),
-                        occurred_at_ms: codex_analytics::now_unix_millis(),
-                        kind: GuardianV2EventKind::FastDecision {
-                            decision: "approved",
-                        },
-                    });
-            }
-            record_guardian_non_denial(&session, guardian_request_turn_id(&request, &turn.sub_id))
-                .await;
-        }
-        return decision;
-    }
-
-    let runtime = super::runtime::ReviewRuntime {
-        session,
-        context,
-        review_id,
-        request: request.into(),
-        reasons,
-        options,
-    };
-    run_synchronous_review(runtime, /*review_reason*/ None).await
-}
-
 /// Runs the existing synchronous reviewer without choosing policy or reusing a score.
 pub(super) async fn run_synchronous_review(
     runtime: super::runtime::ReviewRuntime,
-    review_reason: Option<codex_protocol::approvals::GuardianReviewReason>,
+    review_reason: codex_protocol::approvals::GuardianReviewReason,
 ) -> ReviewDecision {
     let super::runtime::ReviewRuntime {
         session,
@@ -524,7 +412,7 @@ pub(super) async fn run_synchronous_review(
         .send_event(
             turn.as_ref(),
             EventMsg::GuardianAssessment(GuardianAssessmentEvent {
-                review_reason,
+                review_reason: Some(review_reason),
                 id: review_id.clone(),
                 target_item_id: target_item_id.clone(),
                 plugin_id: plugin_id.clone(),
@@ -564,7 +452,7 @@ pub(super) async fn run_synchronous_review(
             .send_event(
                 turn.as_ref(),
                 EventMsg::GuardianAssessment(GuardianAssessmentEvent {
-                    review_reason,
+                    review_reason: Some(review_reason),
                     id: review_id,
                     target_item_id,
                     plugin_id: plugin_id.clone(),
@@ -711,7 +599,7 @@ pub(super) async fn run_synchronous_review(
                     .send_event(
                         turn.as_ref(),
                         EventMsg::GuardianAssessment(GuardianAssessmentEvent {
-                            review_reason,
+                            review_reason: Some(review_reason),
                             id: review_id,
                             target_item_id,
                             plugin_id: plugin_id.clone(),
@@ -749,7 +637,7 @@ pub(super) async fn run_synchronous_review(
                     .send_event(
                         turn.as_ref(),
                         EventMsg::GuardianAssessment(GuardianAssessmentEvent {
-                            review_reason,
+                            review_reason: Some(review_reason),
                             id: review_id,
                             target_item_id,
                             plugin_id: plugin_id.clone(),
@@ -835,7 +723,7 @@ pub(super) async fn run_synchronous_review(
         GuardianAssessmentStatus::Denied
     };
     let assessment_event = GuardianAssessmentEvent {
-        review_reason,
+        review_reason: Some(review_reason),
         id: review_id,
         target_item_id,
         plugin_id: plugin_id.clone(),
@@ -906,56 +794,6 @@ pub(crate) struct GuardianReviewOptions {
     pub(crate) require_synchronous_review: bool,
 }
 
-/// Public entrypoint for approval requests that should be reviewed by guardian.
-#[cfg(test)]
-pub(crate) async fn review_approval_request(
-    session: &Arc<Session>,
-    context: impl Into<GuardianReviewContext>,
-    review_id: String,
-    request: GuardianApprovalRequest,
-    reasons: ApprovalRequestReasons,
-) -> ReviewDecision {
-    // Erase the delegated future to bound its async state and the tool handlers' Send checks.
-    let review: BoxFuture<'_, ReviewDecision> = Box::pin(run_guardian_review(
-        Arc::clone(session),
-        context.into(),
-        review_id,
-        request,
-        reasons,
-        GuardianReviewOptions {
-            require_guardian: false,
-            plugin_attribution_override: None,
-            approval_request_source: GuardianApprovalRequestSource::MainTurn,
-            external_cancel: None,
-            require_synchronous_review: false,
-        },
-    ));
-    review.await
-}
-
-#[cfg(test)]
-pub(crate) async fn review_approval_request_with_cancel(
-    session: &Arc<Session>,
-    context: impl Into<GuardianReviewContext>,
-    review_id: String,
-    request: GuardianApprovalRequest,
-    retry_reason: Option<String>,
-    options: GuardianReviewOptions,
-) -> ReviewDecision {
-    run_guardian_review(
-        Arc::clone(session),
-        context.into(),
-        review_id,
-        request,
-        ApprovalRequestReasons {
-            approval: None,
-            retry: retry_reason,
-        },
-        options,
-    )
-    .await
-}
-
 pub(super) struct GuardianReviewSessionConfig {
     pub(super) spawn_config: crate::config::Config,
     pub(super) node_repl_policy: GuardianNodeReplPolicy,

codex-rs/core/src/guardian/runtime.rs

@@ -89,6 +89,6 @@ impl SynchronousApprovalReviewer for ReviewRuntime {
         &self,
         reason: codex_protocol::approvals::GuardianReviewReason,
     ) -> ExtensionFuture<'_, ReviewDecision> {
-        Box::pin(run_synchronous_review(self.clone(), Some(reason)))
+        Box::pin(run_synchronous_review(self.clone(), reason))
     }
 }

codex-rs/core/src/guardian/tests.rs

@@ -1688,8 +1688,8 @@ async fn cancelled_guardian_review_emits_terminal_abort_without_warning() {
     let cancel_token = CancellationToken::new();
     cancel_token.cancel();
 
-    let decision = review_approval_request_with_cancel(
+    let decision = super::decide_approval(
-        &session,
+        Arc::clone(&session),
         &turn,
         "review-cancelled-guardian".to_string(),
         GuardianApprovalRequest::ApplyPatch {
@@ -1699,9 +1699,12 @@ async fn cancelled_guardian_review_emits_terminal_abort_without_warning() {
             patch: "*** Begin Patch\n*** Update File: guardian.txt\n@@\n+hello\n*** End Patch"
                 .to_string(),
         },
-        /*retry_reason*/ None,
+        ApprovalRequestReasons {
+            approval: None,
+            retry: None,
+        },
         GuardianReviewOptions {
-            require_guardian: false,
+            require_guardian: true,
             plugin_attribution_override: None,
             approval_request_source: GuardianApprovalRequestSource::MainTurn,
             external_cancel: Some(cancel_token),
@@ -1710,7 +1713,7 @@ async fn cancelled_guardian_review_emits_terminal_abort_without_warning() {
     )
     .await;
 
-    assert_eq!(decision, ReviewDecision::Abort);
+    assert_eq!(decision, Some(ReviewDecision::Abort));
 
     let mut guardian_statuses = Vec::new();
     let mut warnings = Vec::new();
@@ -3399,14 +3402,12 @@ async fn escalated_retry_bypasses_extension_approval_and_runs_guardian() -> anyh
     struct AutoApprovingReviewContributor;
 
     impl codex_extension_api::ApprovalReviewContributor for AutoApprovingReviewContributor {
-        fn fast_decision<'a>(
+        fn decide<'a>(
             &'a self,
-            _session_store: &'a codex_extension_api::ExtensionData,
+            _input: &'a codex_extension_api::ApprovalDecisionInput<'_>,
-            _thread_store: &'a codex_extension_api::ExtensionData,
+        ) -> codex_extension_api::ExtensionFuture<'a, Option<codex_extension_api::ApprovalDecision>>
-            _prompt: &'a str,
+        {
-            _extension_metrics: Option<Arc<dyn codex_extension_api::ExtensionMetrics>>,
+            Box::pin(async { Some(codex_extension_api::ApprovalDecision::Allow) })
-        ) -> codex_extension_api::ExtensionFuture<'a, Option<ReviewDecision>> {
-            Box::pin(async move { Some(ReviewDecision::Approved) })
         }
     }
 
@@ -4188,3 +4189,29 @@ async fn guardian_review_session_config_uses_default_guardian_policy_without_req
         ))
     );
 }
+
+// Keep the existing reviewer tests on the production decision path.
+async fn review_approval_request(
+    session: &Arc<Session>,
+    context: impl Into<GuardianReviewContext>,
+    review_id: String,
+    request: GuardianApprovalRequest,
+    reasons: ApprovalRequestReasons,
+) -> ReviewDecision {
+    super::decide_approval(
+        Arc::clone(session),
+        context,
+        review_id,
+        request,
+        reasons,
+        GuardianReviewOptions {
+            require_guardian: true,
+            plugin_attribution_override: None,
+            approval_request_source: GuardianApprovalRequestSource::MainTurn,
+            external_cancel: None,
+            require_synchronous_review: false,
+        },
+    )
+    .await
+    .expect("Guardian should handle the request")
+}

codex-rs/ext/extension-api/src/contributors.rs

@@ -4,7 +4,6 @@ use std::sync::Arc;
 
 use codex_context_fragments::ContextualUserFragment;
 use codex_protocol::items::TurnItem;
-use codex_protocol::protocol::ReviewDecision;
 use codex_protocol::protocol::TokenUsageInfo;
 use codex_tools::ToolCall;
 use codex_tools::ToolExecutor;
@@ -23,7 +22,6 @@ mod turn_input;
 mod turn_lifecycle;
 mod world_state;
 
-pub use approval_review::ApprovalAssessment;
 pub use approval_review::ApprovalDecision;
 pub use approval_review::ApprovalDecisionInput;
 pub use approval_review::ApprovalReviewError;
@@ -349,11 +347,8 @@ pub trait ToolLifecycleContributor: Send + Sync {
     }
 }
 
-/// Extension contribution for fast approval decisions and full action reviews.
+/// Owns the complete approval decision, including whether to consult a reviewer.
-///
+/// Returning `None` leaves the request to the next contributor.
-/// Implementations can provide a fast decision from existing evidence, perform
-/// a full structured review, or support both paths. Returning `None` leaves the
-/// request available to the next contributor or the host's fallback path.
 pub trait ApprovalReviewContributor: Send + Sync {
     /// Claims one request, including a handoff to the user.
     fn decide<'a>(
@@ -362,25 +357,6 @@ pub trait ApprovalReviewContributor: Send + Sync {
     ) -> ExtensionFuture<'a, Option<ApprovalDecision>> {
         Box::pin(std::future::ready(None))
     }
-
-    /// Returns an available approval decision without performing a full review.
-    fn fast_decision<'a>(
-        &'a self,
-        _session_store: &'a ExtensionData,
-        _thread_store: &'a ExtensionData,
-        _prompt: &'a str,
-        _extension_metrics: Option<Arc<dyn ExtensionMetrics>>,
-    ) -> ExtensionFuture<'a, Option<ReviewDecision>> {
-        Box::pin(std::future::ready(None))
-    }
-
-    /// Performs a full review of a structured host-owned approval request.
-    fn full_review<'a>(
-        &'a self,
-        _input: &'a ApprovalReviewInput<'_>,
-    ) -> ExtensionFuture<'a, Option<Result<ApprovalAssessment, ApprovalReviewError>>> {
-        Box::pin(std::future::ready(None))
-    }
 }
 
 /// Ordered post-processing contribution for one parsed turn item.

codex-rs/ext/extension-api/src/contributors/approval_review.rs

@@ -4,9 +4,6 @@ use std::fmt;
 use std::sync::Arc;
 
 use codex_protocol::ThreadId;
-use codex_protocol::approvals::GuardianAssessmentOutcome;
-use codex_protocol::approvals::GuardianRiskLevel;
-use codex_protocol::approvals::GuardianUserAuthorization;
 use serde_json::Value;
 
 use crate::ConversationHistorySnapshot;
@@ -15,19 +12,6 @@ use crate::ExtensionData;
 /// Thread-local state installed only after Guardian V2's async classifier initializes.
 pub struct GuardianV2Enabled;
 
-/// Classification returned by an approval reviewer.
-#[derive(Clone, Debug, Eq, PartialEq)]
-pub struct ApprovalAssessment {
-    /// Final allow-or-deny decision for the requested action.
-    pub outcome: GuardianAssessmentOutcome,
-    /// Risk level assigned to the action by the reviewer.
-    pub risk_level: GuardianRiskLevel,
-    /// Whether the conversation authorizes the requested action.
-    pub user_authorization: GuardianUserAuthorization,
-    /// Human-readable explanation of the assessment.
-    pub rationale: String,
-}
-
 /// Operational failure returned by an approval reviewer.
 #[derive(Clone, Debug, Eq, PartialEq)]
 pub enum ApprovalReviewError {

codex-rs/ext/extension-api/src/lib.rs

@@ -40,7 +40,6 @@ pub use codex_tools::TurnItemEmissionFuture;
 pub use codex_tools::TurnItemEmitter;
 pub use codex_tools::parse_tool_input_schema;
 pub use codex_tools::parse_tool_input_schema_without_compaction;
-pub use contributors::ApprovalAssessment;
 pub use contributors::ApprovalDecision;
 pub use contributors::ApprovalDecisionInput;
 pub use contributors::ApprovalReviewContributor;

codex-rs/ext/extension-api/src/registry.rs

@@ -1,16 +1,9 @@
 use std::sync::Arc;
 
-use codex_protocol::protocol::ReviewDecision;
-
-use crate::ApprovalAssessment;
 use crate::ApprovalReviewContributor;
-use crate::ApprovalReviewError;
-use crate::ApprovalReviewInput;
 use crate::ConfigContributor;
 use crate::ContextContributor;
-use crate::ExtensionData;
 use crate::ExtensionEventSink;
-use crate::ExtensionMetrics;
 use crate::McpServerContributor;
 use crate::NoopExtensionEventSink;
 use crate::SkillInvocationContributor;
@@ -202,45 +195,6 @@ impl<C: Sync> ExtensionRegistry<C> {
                 .any(|contributor| contributor.requires_host_skill_discovery())
     }
 
-    /// Returns the first full approval assessment claimed by a contributor.
-    pub async fn full_approval_review(
-        &self,
-        input: ApprovalReviewInput<'_>,
-    ) -> Option<Result<ApprovalAssessment, ApprovalReviewError>> {
-        for contributor in &self.approval_review_contributors {
-            if let Some(assessment) = contributor.full_review(&input).await {
-                return Some(assessment);
-            }
-        }
-
-        None
-    }
-
-    /// Returns the first fast approval decision claimed by a contributor.
-    pub async fn fast_approval_decision(
-        &self,
-        session_store: &ExtensionData,
-        thread_store: &ExtensionData,
-        prompt: &str,
-        extension_metrics: Option<Arc<dyn ExtensionMetrics>>,
-    ) -> Option<ReviewDecision> {
-        for contributor in &self.approval_review_contributors {
-            if let Some(decision) = contributor
-                .fast_decision(
-                    session_store,
-                    thread_store,
-                    prompt,
-                    extension_metrics.clone(),
-                )
-                .await
-            {
-                return Some(decision);
-            }
-        }
-
-        None
-    }
-
     /// Returns the first claimed decision in registration order.
     pub async fn decide_approval(
         &self,

codex-rs/ext/extension-api/tests/registry.rs

@@ -3,10 +3,7 @@
 use std::sync::Arc;
 use std::sync::Mutex;
 
-use codex_extension_api::ApprovalAssessment;
 use codex_extension_api::ApprovalReviewContributor;
-use codex_extension_api::ApprovalReviewError;
-use codex_extension_api::ApprovalReviewInput;
 use codex_extension_api::ConfigContributor;
 use codex_extension_api::ContentItemKind;
 use codex_extension_api::ContextContributor;
@@ -34,21 +31,14 @@ use codex_extension_api::TurnInputContext;
 use codex_extension_api::TurnInputContributor;
 use codex_extension_api::TurnItemContributor;
 use codex_extension_api::TurnLifecycleContributor;
-use codex_extension_api::empty_extension_registry;
-use codex_protocol::ThreadId;
-use codex_protocol::approvals::GuardianAssessmentOutcome;
-use codex_protocol::approvals::GuardianRiskLevel;
-use codex_protocol::approvals::GuardianUserAuthorization;
 use codex_protocol::items::HookPromptItem;
 use codex_protocol::items::TurnItem;
 use codex_protocol::protocol::Event;
 use codex_protocol::protocol::EventMsg;
-use codex_protocol::protocol::ReviewDecision;
 use codex_protocol::protocol::SessionSource;
 use codex_protocol::protocol::SubAgentSource;
 use codex_protocol::protocol::WarningEvent;
 use pretty_assertions::assert_eq;
-use serde_json::json;
 
 struct AllContributors;
 
@@ -166,33 +156,22 @@ impl TurnItemContributor for AllContributors {
 }
 
 impl ApprovalReviewContributor for AllContributors {
-    fn fast_decision<'a>(
+    fn decide<'a>(
         &'a self,
-        _session_store: &'a ExtensionData,
+        _input: &'a codex_extension_api::ApprovalDecisionInput<'_>,
-        _thread_store: &'a ExtensionData,
+    ) -> ExtensionFuture<'a, Option<codex_extension_api::ApprovalDecision>> {
-        _prompt: &'a str,
+        Box::pin(async { Some(codex_extension_api::ApprovalDecision::AskUser) })
-        _extension_metrics: Option<Arc<dyn ExtensionMetrics>>,
+    }
-    ) -> ExtensionFuture<'a, Option<ReviewDecision>> {
-        Box::pin(async move {
-            let _self = self;
-            Some(ReviewDecision::ApprovedForSession)
-        })
 }
 
-    fn full_review<'a>(
+impl codex_extension_api::SynchronousApprovalReviewer for AllContributors {
-        &'a self,
+    fn review(
-        input: &'a ApprovalReviewInput<'_>,
+        &self,
-    ) -> ExtensionFuture<'a, Option<Result<ApprovalAssessment, ApprovalReviewError>>> {
+        _reason: codex_protocol::approvals::GuardianReviewReason,
-        assert_eq!(
+    ) -> ExtensionFuture<'_, codex_protocol::protocol::ReviewDecision> {
-            (input.approval_reason, input.retry_reason),
+        Box::pin(std::future::ready(
-            (Some("A policy rule requires approval."), None)
+            codex_protocol::protocol::ReviewDecision::Approved,
-        );
+        ))
-        Box::pin(std::future::ready(Some(Ok(ApprovalAssessment {
-            outcome: GuardianAssessmentOutcome::Allow,
-            risk_level: GuardianRiskLevel::Low,
-            user_authorization: GuardianUserAuthorization::High,
-            rationale: "approved".to_string(),
-        }))))
     }
 }
 
@@ -223,16 +202,24 @@ async fn build_round_trips_every_contributor_category() {
     assert_eq!(registry.tool_contributors().len(), 1);
     assert_eq!(registry.tool_lifecycle_contributors().len(), 1);
     assert_eq!(registry.turn_item_contributors().len(), 1);
+    let thread_store = ExtensionData::new("thread");
+    let input = codex_extension_api::ApprovalDecisionInput {
+        approval_id: "approval-1",
+        action: &serde_json::Value::Null,
+        thread_id: codex_protocol::ThreadId::new(),
+        thread_store: &thread_store,
+        category: codex_protocol::openai_models::GuardianScope::Shell,
+        approval_policy: codex_protocol::protocol::AskForApproval::OnRequest,
+        approvals_reviewer: codex_protocol::config_types::ApprovalsReviewer::AutoReview,
+        require_guardian: false,
+        require_fresh_review: false,
+        full_access: false,
+        metrics: None,
+        synchronous_reviewer: &AllContributors,
+    };
     assert_eq!(
-        registry
+        registry.decide_approval(&input).await,
-            .fast_approval_decision(
+        Some(codex_extension_api::ApprovalDecision::AskUser)
-                &ExtensionData::new("session"),
-                &ExtensionData::new("thread"),
-                "review this",
-                /*extension_metrics*/ None,
-            )
-            .await,
-        Some(ReviewDecision::ApprovedForSession)
     );
 }
 
@@ -250,86 +237,6 @@ impl ConversationHistorySnapshot for AllContributors {
     }
 }
 
-#[tokio::test]
-async fn full_approval_review_returns_first_claim_and_short_circuits() {
-    let assessment = ApprovalAssessment {
-        outcome: GuardianAssessmentOutcome::Allow,
-        risk_level: GuardianRiskLevel::Low,
-        user_authorization: GuardianUserAuthorization::High,
-        rationale: "approved".to_string(),
-    };
-    let action = json!({
-        "tool": "exec_command",
-        "command": ["echo", "hello"],
-    });
-    let thread_store = ExtensionData::new("thread");
-    let input = ApprovalReviewInput {
-        action: &action,
-        conversation_history: Arc::new(AllContributors),
-        thread_id: ThreadId::default(),
-        thread_store: &thread_store,
-        turn_id: "turn",
-        approval_reason: Some("A policy rule requires approval."),
-        retry_reason: None,
-    };
-
-    let calls = Arc::new(Mutex::new(Vec::new()));
-    let mut builder = ExtensionRegistryBuilder::<()>::new();
-    for (name, result) in [
-        ("first", None),
-        ("second", Some(Ok(assessment.clone()))),
-        (
-            "third",
-            Some(Err(ApprovalReviewError::Failed(
-                "should not run".to_string(),
-            ))),
-        ),
-    ] {
-        builder.approval_review_contributor(Arc::new(RecordingStructuredApprovalContributor {
-            name,
-            result,
-            calls: Arc::clone(&calls),
-        }));
-    }
-
-    assert_eq!(
-        builder.build().full_approval_review(input).await,
-        Some(Ok(assessment))
-    );
-    assert_eq!(
-        calls.lock().expect("approval calls lock").as_slice(),
-        ["first", "second"]
-    );
-}
-
-struct RecordingStructuredApprovalContributor {
-    name: &'static str,
-    result: Option<Result<ApprovalAssessment, ApprovalReviewError>>,
-    calls: Arc<Mutex<Vec<&'static str>>>,
-}
-
-impl ApprovalReviewContributor for RecordingStructuredApprovalContributor {
-    fn full_review<'a>(
-        &'a self,
-        input: &'a ApprovalReviewInput<'_>,
-    ) -> ExtensionFuture<'a, Option<Result<ApprovalAssessment, ApprovalReviewError>>> {
-        Box::pin(async move {
-            assert_eq!(
-                input.action,
-                &json!({
-                    "tool": "exec_command",
-                    "command": ["echo", "hello"],
-                })
-            );
-            self.calls
-                .lock()
-                .expect("approval calls lock should not be poisoned")
-                .push(self.name);
-            self.result.clone()
-        })
-    }
-}
-
 struct NamedContextContributor(&'static str);
 
 impl ContextContributor for NamedContextContributor {
@@ -465,92 +372,6 @@ async fn contributors_preserve_registration_order() {
     );
 }
 
-#[derive(Debug, PartialEq, Eq)]
-struct ApprovalCall {
-    contributor: &'static str,
-    session_id: String,
-    thread_id: String,
-    prompt: String,
-}
-
-struct RecordingApprovalContributor {
-    name: &'static str,
-    decision: Option<ReviewDecision>,
-    calls: Arc<Mutex<Vec<ApprovalCall>>>,
-}
-
-impl ApprovalReviewContributor for RecordingApprovalContributor {
-    fn fast_decision<'a>(
-        &'a self,
-        session_store: &'a ExtensionData,
-        thread_store: &'a ExtensionData,
-        prompt: &'a str,
-        _extension_metrics: Option<Arc<dyn ExtensionMetrics>>,
-    ) -> ExtensionFuture<'a, Option<ReviewDecision>> {
-        Box::pin(async move {
-            self.calls
-                .lock()
-                .expect("approval calls lock should not be poisoned")
-                .push(ApprovalCall {
-                    contributor: self.name,
-                    session_id: session_store.level_id().to_string(),
-                    thread_id: thread_store.level_id().to_string(),
-                    prompt: prompt.to_string(),
-                });
-            self.decision.clone()
-        })
-    }
-}
-
-#[tokio::test]
-async fn fast_approval_decision_returns_first_claim_and_short_circuits() {
-    let calls = Arc::new(Mutex::new(Vec::new()));
-    let mut builder = ExtensionRegistryBuilder::<()>::new();
-    for (name, decision) in [
-        ("first", None),
-        ("second", Some(ReviewDecision::Approved)),
-        (
-            "third",
-            Some(ReviewDecision::denied("rejected by extension")),
-        ),
-    ] {
-        builder.approval_review_contributor(Arc::new(RecordingApprovalContributor {
-            name,
-            decision,
-            calls: Arc::clone(&calls),
-        }));
-    }
-    let registry = builder.build();
-
-    let decision = registry
-        .fast_approval_decision(
-            &ExtensionData::new("session-1"),
-            &ExtensionData::new("thread-1"),
-            "allow command?",
-            /*extension_metrics*/ None,
-        )
-        .await;
-
-    assert_eq!(decision, Some(ReviewDecision::Approved));
-    assert_eq!(
-        calls.lock().expect("approval calls lock").as_slice(),
-        [
-            ApprovalCall {
-                contributor: "first",
-                session_id: "session-1".to_string(),
-                thread_id: "thread-1".to_string(),
-                prompt: "allow command?".to_string(),
-            },
-            ApprovalCall {
-                contributor: "second",
-                session_id: "session-1".to_string(),
-                thread_id: "thread-1".to_string(),
-                prompt: "allow command?".to_string(),
-            },
-        ]
-    );
-}
-
 #[derive(Default)]
 struct RecordingEventSink {
     events: Mutex<Vec<(String, String)>>,
@@ -606,23 +427,6 @@ fn custom_event_sink_survives_registry_build() {
     );
 }
 
-#[tokio::test]
-async fn empty_registry_does_not_claim_fast_approval_decision() {
-    let registry = empty_extension_registry::<()>();
-
-    assert_eq!(
-        registry
-            .fast_approval_decision(
-                &ExtensionData::new("session"),
-                &ExtensionData::new("thread"),
-                "unclaimed",
-                /*extension_metrics*/ None,
-            )
-            .await,
-        None
-    );
-}
-
 fn warning_event(id: &str, message: &str) -> Event {
     Event {
         id: id.to_string(),

codex-rs/ext/guardian-v2/src/async_scorer/coverage.rs

@@ -150,15 +150,4 @@ impl GuardianPolicy {
                 == Some("require_escalated")
         }))
     }
-
-    pub(super) fn review_scope(action: &serde_json::Value) -> Option<GuardianScope> {
-        match action.get("tool").and_then(serde_json::Value::as_str)? {
-            "mcp_tool_call" => action
-                .get("server")
-                .and_then(serde_json::Value::as_str)
-                .map(GuardianScope::for_mcp_server),
-            "network_access" => Some(GuardianScope::Network),
-            tool => GuardianScope::for_tool(&ToolName::plain(tool)),
-        }
-    }
 }

codex-rs/ext/guardian-v2/src/async_scorer/extension.rs

@@ -15,7 +15,6 @@ use codex_core::config::Config;
 use codex_core::context::GuardianContextMode;
 use codex_core::context::GuardianReviewEvidence;
 use codex_core::context::NodeReplReviewEvidence;
-use codex_extension_api::ApprovalReviewContributor;
 use codex_extension_api::ExtensionData;
 use codex_extension_api::ExtensionEventSink;
 use codex_extension_api::ExtensionFuture;
@@ -40,10 +39,8 @@ use codex_model_provider::create_model_provider;
 use codex_protocol::ThreadId;
 use codex_protocol::config_types::ApprovalsReviewer;
 use codex_protocol::mcp::is_node_repl_backed_server;
-use codex_protocol::openai_models::GuardianReviewMode;
 use codex_protocol::openai_models::GuardianScope;
 use codex_protocol::openai_models::ModelInfo;
-use codex_protocol::protocol::ReviewDecision;
 use codex_protocol::protocol::has_full_access;
 use codex_protocol::security_risk::SecurityRiskScore;
 
@@ -51,13 +48,9 @@ use super::action::GuardianAction;
 use super::action::RenderedAction;
 use super::authorization::ScoreAuthorization;
 use super::config::GuardianV2Config;
-use super::coverage::GuardianPolicy;
 use super::coverage::UnscoredAction;
-use super::metrics::REVIEW_FALLBACK_METRIC;
-use super::metrics::TOOL_CALL_LAG_METRIC;
 use super::metrics::record_classification;
 use super::metrics::record_classification_risk;
-use super::metrics::record_fast_decision;
 use super::metrics::sampler_failure_reason;
 use super::parent_compaction::ParentCompactionError;
 use super::parent_compaction::select_parent_compaction;
@@ -72,14 +65,6 @@ use super::trusted_skills::TrustedSkillInvocations;
 use super::trusted_skills::TrustedSkillRoots;
 use super::trusted_tools::trusted_tool_context;
 
-/// Explains why Guardian v2 requires synchronous approval review.
-#[derive(Debug, Eq, PartialEq)]
-pub enum StrictReviewReason {
-    ElevatedRisk,
-    StaleScore,
-    IncompatibleCompaction,
-}
-
 enum ClassificationOutcome {
     Scored,
     Superseded,
@@ -242,195 +227,6 @@ impl SkillInvocationContributor for GuardianV2Extension {
     }
 }
 
-impl ApprovalReviewContributor for GuardianV2Extension {
-    fn fast_decision<'a>(
-        &'a self,
-        _session_store: &'a ExtensionData,
-        thread_store: &'a ExtensionData,
-        prompt: &'a str,
-        extension_metrics: Option<Arc<dyn ExtensionMetrics>>,
-    ) -> ExtensionFuture<'a, Option<ReviewDecision>> {
-        Box::pin(async move {
-            let model = thread_store.get::<ModelInfo>();
-            let guardian_config = thread_store.get::<GuardianV2Config>()?;
-            let policy = guardian_config.policy_for_model(model.as_deref());
-            let action = serde_json::from_str::<serde_json::Value>(prompt).unwrap_or_default();
-            let scope = GuardianPolicy::review_scope(&action);
-            if scope.map_or(policy.other_tools, |scope| policy.mode(scope))
-                != GuardianReviewMode::Adaptive
-            {
-                record_fast_decision(extension_metrics.as_deref(), "deferred", "out_of_scope");
-                return None;
-            }
-            let guardian_evidence = thread_store.get_or_init(GuardianReviewEvidence::default);
-            let context_mode = guardian_evidence.context_mode();
-            let mut initial_cua_call = false;
-            if scope == Some(GuardianScope::ComputerUse) && policy.initial_cua_call {
-                // Thread-owned context checks checkpoint compatibility before the first CUA allowance.
-                initial_cua_call = action.get("tool_name").and_then(serde_json::Value::as_str)
-                    == Some("js")
-                    && action
-                        .get("connector_id")
-                        .and_then(serde_json::Value::as_str)
-                        == Some("node_repl")
-                    && thread_store
-                        .get::<GuardianV2ScoreProgress>()?
-                        .js_executions
-                        .load(Ordering::Acquire)
-                        == 1;
-                if initial_cua_call && context_mode == GuardianContextMode::Legacy {
-                    record_fast_decision(
-                        extension_metrics.as_deref(),
-                        "approved",
-                        "initial_cua_call",
-                    );
-                    return Some(ReviewDecision::Approved);
-                }
-            } else if thread_store.get::<ModelInfo>().is_some() {
-                let manager = self.thread_manager.upgrade()?;
-                let thread_id = ThreadId::from_string(thread_store.level_id()).ok()?;
-                let Ok(thread) = manager.get_thread(thread_id).await else {
-                    record_fast_decision(
-                        extension_metrics.as_deref(),
-                        "deferred",
-                        "scoring_failure",
-                    );
-                    return None;
-                };
-                let config = thread.config().await;
-                let model = thread_store.get::<ModelInfo>()?;
-                if config
-                    .config_layer_stack
-                    .requirements()
-                    .auto_review_required_for_model(&model.slug)
-                {
-                    record_fast_decision(
-                        extension_metrics.as_deref(),
-                        "deferred",
-                        "required_model",
-                    );
-                    return None;
-                }
-            }
-            let Some(score_progress) = thread_store.get::<GuardianV2ScoreProgress>() else {
-                record_fast_decision(extension_metrics.as_deref(), "deferred", "missing_score");
-                return None;
-            };
-            let manager = self.thread_manager.upgrade()?;
-            let thread_id = ThreadId::from_string(thread_store.level_id()).ok()?;
-            let Ok(thread) = manager.get_thread(thread_id).await else {
-                record_fast_decision(extension_metrics.as_deref(), "deferred", "scoring_failure");
-                return None;
-            };
-            let history = thread.conversation_history_snapshot().await;
-            if context_mode == GuardianContextMode::ThreadOwned {
-                let sampler = thread_store.get::<LunaSampler>()?;
-                if select_parent_compaction(
-                    context_mode,
-                    &guardian_config,
-                    history.as_ref(),
-                    &sampler,
-                    /*legacy_model_hash*/ None,
-                )
-                .is_err()
-                {
-                    thread_store.insert(StrictReviewReason::IncompatibleCompaction);
-                    record_fast_decision(
-                        extension_metrics.as_deref(),
-                        "deferred",
-                        "incompatible_compaction",
-                    );
-                    return None;
-                }
-            }
-            if initial_cua_call {
-                record_fast_decision(extension_metrics.as_deref(), "approved", "initial_cua_call");
-                return Some(ReviewDecision::Approved);
-            }
-            let current_authorization = ScoreAuthorization::current(&thread).await;
-            if !current_authorization.local.retained_context_complete
-                || current_authorization
-                    .root
-                    .is_some_and(|root| !root.retained_context_complete)
-            {
-                record_fast_decision(
-                    extension_metrics.as_deref(),
-                    "deferred",
-                    "incomplete_authorization",
-                );
-                return None;
-            }
-            let scored_authorization = score_progress
-                .authorization
-                .lock()
-                .unwrap_or_else(std::sync::PoisonError::into_inner);
-            let latest_scored_tool_call = score_progress
-                .latest_scored_tool_call
-                .load(Ordering::Acquire);
-            let tool_call_lag = score_progress
-                .latest_tool_call
-                .load(Ordering::Acquire)
-                .saturating_sub(latest_scored_tool_call);
-            if let Some(metrics) = &extension_metrics {
-                metrics.histogram(
-                    TOOL_CALL_LAG_METRIC,
-                    i64::try_from(tool_call_lag).unwrap_or(i64::MAX),
-                    &[],
-                );
-            }
-            if tool_call_lag > guardian_config.max_tool_call_lag {
-                thread_store.insert(StrictReviewReason::StaleScore);
-                if let Some(metrics) = &extension_metrics {
-                    metrics.counter(
-                        REVIEW_FALLBACK_METRIC,
-                        /*inc*/ 1,
-                        &[("fallback_reason", "score_lag")],
-                    );
-                }
-                record_fast_decision(extension_metrics.as_deref(), "deferred", "stale_score");
-                return None;
-            }
-            if score_progress
-                .latest_failed_tool_call
-                .load(Ordering::Acquire)
-                > latest_scored_tool_call
-            {
-                thread_store.insert(StrictReviewReason::ElevatedRisk);
-                record_fast_decision(extension_metrics.as_deref(), "deferred", "scoring_failure");
-                return None;
-            }
-
-            let Some(score) = thread_store
-                .get::<SecurityRiskScore>()
-                .and_then(|score| score.scores.get("action_risk").copied())
-            else {
-                record_fast_decision(extension_metrics.as_deref(), "deferred", "missing_score");
-                return None;
-            };
-            if score < guardian_config.review_threshold {
-                if scored_authorization.as_ref() != Some(&current_authorization) {
-                    thread_store.insert(StrictReviewReason::StaleScore);
-                    record_fast_decision(
-                        extension_metrics.as_deref(),
-                        "deferred",
-                        "authorization_changed",
-                    );
-                    return None;
-                }
-                record_fast_decision(extension_metrics.as_deref(), "approved", "low_risk");
-                return Some(ReviewDecision::Approved);
-            }
-            if score >= guardian_config.review_threshold {
-                thread_store.insert(StrictReviewReason::ElevatedRisk);
-                record_fast_decision(extension_metrics.as_deref(), "deferred", "elevated_risk");
-            } else {
-                record_fast_decision(extension_metrics.as_deref(), "deferred", "invalid_score");
-            }
-            None
-        })
-    }
-}
-
 impl ToolLifecycleContributor for GuardianV2Extension {
     fn on_tool_start<'a>(&'a self, input: ToolStartInput<'a>) -> ToolLifecycleFuture<'a> {
         Box::pin(self.score_tool(input))
@@ -971,13 +767,12 @@ pub fn install(
     let extension = Arc::new(GuardianV2Extension {
         auth_manager,
         event_sink: registry.event_sink(),
-        thread_manager: thread_manager.clone(),
+        thread_manager,
     });
     registry.thread_lifecycle_contributor(extension.clone());
     registry.approval_review_contributor(Arc::new(super::approval::GuardianApprovalReviewer {
-        thread_manager,
+        thread_manager: extension.thread_manager.clone(),
     }));
-    registry.approval_review_contributor(extension.clone());
     registry.skill_invocation_contributor(extension.clone());
     registry.tool_lifecycle_contributor(extension);
 }

codex-rs/ext/guardian-v2/src/async_scorer/extension_tests.rs

@@ -69,7 +69,6 @@ use serde_json::json;
 
 use super::GuardianV2Extension;
 use super::GuardianV2ScoreProgress;
-use super::StrictReviewReason;
 
 use crate::async_scorer::config::CLASSIFICATION_OUTPUT_INSTRUCTIONS;
 use crate::async_scorer::config::DEFAULT_MODEL_CONTEXT_ITEM_TOKENS;
@@ -285,12 +284,11 @@ async fn installed_extension_uses_http_after_warm_socket_auth_expires() -> Resul
         })
         .await?;
         assert_eq!(
-            registry
+            cached_approval(
-                .fast_approval_decision(
+                &registry,
-                    &session_store,
                 thread_store,
                 r#"{"tool":"mcp_tool_call","server":"node_repl"}"#,
-                    /*extension_metrics*/ None,
+                /*metrics*/ None,
             )
             .await,
             Some(ReviewDecision::Approved)
@@ -669,10 +667,8 @@ async fn computer_use_only_scores_cannot_approve_other_actions() -> Result<()> {
     ] {
         let prompt = action.to_string();
         assert_eq!(
-            fixture
+            cached_approval(
-                .registry
+                &fixture.registry,
-                .fast_approval_decision(
-                    &fixture.session_store,
                 thread_store,
                 &prompt,
                 thread_store
@@ -685,10 +681,8 @@ async fn computer_use_only_scores_cannot_approve_other_actions() -> Result<()> {
         );
     }
     assert_eq!(
-        fixture
+        cached_approval(
-            .registry
+            &fixture.registry,
-            .fast_approval_decision(
-                &fixture.session_store,
             thread_store,
             "not valid JSON",
             thread_store
@@ -711,14 +705,11 @@ async fn computer_use_only_scores_cannot_approve_other_actions() -> Result<()> {
     });
     thread_store.insert(changed_model);
     assert_eq!(
-        fixture
+        cached_approval(
-            .registry
+            &fixture.registry,
-            .fast_approval_decision(
-                &fixture.session_store,
             thread_store,
-                &json!({"tool": "mcp_tool_call", "server": "node_repl", "tool_name": "js"})
+            &json!({"tool": "mcp_tool_call", "server": "node_repl", "tool_name": "js"}).to_string(),
-                    .to_string(),
+            /*metrics*/ None,
-                /*extension_metrics*/ None,
         )
         .await,
         None,
@@ -772,13 +763,11 @@ async fn computer_use_only_scores_cannot_approve_other_actions() -> Result<()> {
             sampled_at: None,
         });
         assert_eq!(
-            fixture
+            cached_approval(
-                .registry
+                &fixture.registry,
-                .fast_approval_decision(
-                    &fixture.session_store,
                 thread_store,
                 r#"{"tool":"mcp_tool_call","server":"node_repl","tool_name":"js"}"#,
-                    /*extension_metrics*/ None,
+                /*metrics*/ None,
             )
             .await,
             None,
@@ -909,12 +898,11 @@ async fn sample_configured_conversation_history_with_source(
         thread_store.insert(parent_model);
     }
     assert_eq!(
-        registry
+        cached_approval(
-            .fast_approval_decision(
+            &registry,
-                &session_store,
             thread_store,
             "review action",
-                /*extension_metrics*/ None,
+            /*metrics*/ None,
         )
         .await,
         None
@@ -1123,9 +1111,8 @@ impl GuardianFailureFixture {
         .await?;
         thread_store.insert(RecordingMetrics::default());
         assert_eq!(
-            self.registry
+            cached_approval(
-                .fast_approval_decision(
+                &self.registry,
-                    &self.session_store,
                 thread_store,
                 "review action",
                 thread_store
@@ -1434,7 +1421,6 @@ max_recent_non_user_entries = 8
     let retained_action_bytes = i64::try_from(serde_json::to_string_pretty(&action)?.len())?;
     assert_eq!(action["tool"], "read_file");
 
-    let session_store = ExtensionData::new("session-1");
     let thread_store = test.codex.thread_extension_data();
     let score_progress = thread_store
         .get::<GuardianV2ScoreProgress>()
@@ -1451,7 +1437,6 @@ max_recent_non_user_entries = 8
         }
     })
     .await?;
-    assert_eq!(thread_store.get::<StrictReviewReason>(), None);
     thread_store.insert(SecurityRiskScore {
         scores: BTreeMap::from([("action_risk".to_owned(), 0.65)]),
         call_id: None,
@@ -1459,9 +1444,8 @@ max_recent_non_user_entries = 8
         sampled_at: None,
     });
     assert_eq!(
-        registry
+        cached_approval(
-            .fast_approval_decision(
+            &registry,
-                &session_store,
             thread_store,
             "review action",
             thread_store
@@ -1471,10 +1455,6 @@ max_recent_non_user_entries = 8
         .await,
         None
     );
-    assert_eq!(
-        thread_store.remove::<StrictReviewReason>().as_deref(),
-        Some(&StrictReviewReason::ElevatedRisk)
-    );
     thread_store.insert(SecurityRiskScore {
         scores: BTreeMap::from([("action_risk".to_owned(), 0.55)]),
         call_id: None,
@@ -1482,9 +1462,8 @@ max_recent_non_user_entries = 8
         sampled_at: None,
     });
     assert_eq!(
-        registry
+        cached_approval(
-            .fast_approval_decision(
+            &registry,
-                &session_store,
             thread_store,
             "review action",
             thread_store
@@ -1505,9 +1484,8 @@ max_recent_non_user_entries = 8
         .latest_tool_call
         .store(/*val*/ 3, Ordering::Release);
     assert_eq!(
-        registry
+        cached_approval(
-            .fast_approval_decision(
+            &registry,
-                &session_store,
             thread_store,
             "review action",
             thread_store
@@ -1524,9 +1502,8 @@ max_recent_non_user_entries = 8
         .latest_tool_call
         .store(/*val*/ 4, Ordering::Release);
     assert_eq!(
-        registry
+        cached_approval(
-            .fast_approval_decision(
+            &registry,
-                &session_store,
             thread_store,
             "review action",
             thread_store
@@ -1536,18 +1513,13 @@ max_recent_non_user_entries = 8
         .await,
         None
     );
-    assert_eq!(
-        thread_store.remove::<StrictReviewReason>().as_deref(),
-        Some(&StrictReviewReason::StaleScore)
-    );
 
     score_progress
         .latest_scored_tool_call
         .store(/*val*/ 2, Ordering::Release);
     assert_eq!(
-        registry
+        cached_approval(
-            .fast_approval_decision(
+            &registry,
-                &session_store,
             thread_store,
             "review action",
             thread_store
@@ -1822,7 +1794,6 @@ async fn contributor_uses_model_defaults_and_preserves_local_overrides() -> Resu
         .expect("planned action should be a text item");
     assert!(action.len() <= TruncationPolicy::Tokens(/*limit*/ 128).byte_budget());
 
-    let session_store = ExtensionData::new("session-1");
     let thread_store = test.codex.thread_extension_data();
     let guardian_config = thread_store
         .get::<crate::async_scorer::config::GuardianV2Config>()
@@ -1857,12 +1828,11 @@ async fn contributor_uses_model_defaults_and_preserves_local_overrides() -> Resu
         sampled_at: None,
     });
     assert_eq!(
-        registry
+        cached_approval(
-            .fast_approval_decision(
+            &registry,
-                &session_store,
             thread_store,
             "review action",
-                /*extension_metrics*/ None,
+            /*metrics*/ None,
         )
         .await,
         Some(ReviewDecision::Approved)
@@ -1931,7 +1901,6 @@ async fn assert_luna_pool_context(thread_context_enabled: bool) -> Result<()> {
     )
     .await?;
     let thread_id = test.session_configured.thread_id;
-    let session_store = ExtensionData::new("session-1");
     let thread_store = test.codex.thread_extension_data();
     assert_eq!(request["model"], "gpt-5.6-luna");
     let classifier_thread_id = request["client_metadata"]["thread_id"]
@@ -2043,12 +2012,11 @@ async fn assert_luna_pool_context(thread_context_enabled: bool) -> Result<()> {
         "risk scores should not be persisted unless explicitly enabled"
     );
     assert_eq!(
-        registry
+        cached_approval(
-            .fast_approval_decision(
+            &registry,
-                &session_store,
             thread_store,
             "review action",
-                /*extension_metrics*/ None,
+            /*metrics*/ None,
         )
         .await,
         None
@@ -2060,12 +2028,11 @@ async fn assert_luna_pool_context(thread_context_enabled: bool) -> Result<()> {
         sampled_at: None,
     });
     assert_eq!(
-        registry
+        cached_approval(
-            .fast_approval_decision(
+            &registry,
-                &session_store,
             thread_store,
             "review action",
-                /*extension_metrics*/ None,
+            /*metrics*/ None,
         )
         .await,
         None
@@ -2078,12 +2045,11 @@ async fn assert_luna_pool_context(thread_context_enabled: bool) -> Result<()> {
         sampled_at: None,
     });
     assert_eq!(
-        registry
+        cached_approval(
-            .fast_approval_decision(
+            &registry,
-                &session_store,
             thread_store,
             "review action",
-                /*extension_metrics*/ None,
+            /*metrics*/ None,
         )
         .await,
         Some(ReviewDecision::Approved)
@@ -2097,12 +2063,11 @@ async fn assert_luna_pool_context(thread_context_enabled: bool) -> Result<()> {
         sampled_at: None,
     });
     assert_eq!(
-        registry
+        cached_approval(
-            .fast_approval_decision(
+            &registry,
-                &session_store,
             &disabled_thread_store,
             "review action",
-                /*extension_metrics*/ None
+            /*metrics*/ None
         )
         .await,
         None
@@ -2254,12 +2219,11 @@ async fn contributor_skips_required_models_in_standard_scope() -> Result<()> {
         sampled_at: None,
     });
     assert_eq!(
-        registry
+        cached_approval(
-            .fast_approval_decision(
+            &registry,
-                &session_store,
             thread_store,
             r#"{"tool":"mcp_tool_call","server":"node_repl"}"#,
-                /*extension_metrics*/ None,
+            /*metrics*/ None,
         )
         .await,
         None
@@ -2316,7 +2280,6 @@ async fn cached_score_survives_compaction_and_internal_context_but_not_user_inpu
         /*model_defaults*/ None,
     )
     .await?;
-    let session_store = ExtensionData::new("session-1");
     let thread_store = test.codex.thread_extension_data();
     let progress = thread_store.get::<GuardianV2ScoreProgress>().unwrap();
     tokio::time::timeout(ASYNC_TEST_TIMEOUT, async {
@@ -2346,12 +2309,11 @@ async fn cached_score_survives_compaction_and_internal_context_but_not_user_inpu
     })
     .await;
     assert_eq!(
-        registry
+        cached_approval(
-            .fast_approval_decision(
+            &registry,
-                &session_store,
             thread_store,
             "review action",
-                /*extension_metrics*/ None,
+            /*metrics*/ None,
         )
         .await,
         Some(ReviewDecision::Approved),
@@ -2369,12 +2331,11 @@ async fn cached_score_survives_compaction_and_internal_context_but_not_user_inpu
         }])
         .await?;
     assert_eq!(
-        registry
+        cached_approval(
-            .fast_approval_decision(
+            &registry,
-                &session_store,
             thread_store,
             "review action",
-                /*extension_metrics*/ None
+            /*metrics*/ None
         )
         .await,
         None,
@@ -2408,13 +2369,11 @@ async fn assert_compaction_approval_policy(thread_context_enabled: bool) -> Resu
         sampled_at: None,
     });
     assert_eq!(
-        fixture
+        cached_approval(
-            .registry
+            &fixture.registry,
-            .fast_approval_decision(
-                &fixture.session_store,
             thread_store,
             "review action",
-                /*extension_metrics*/ None
+            /*metrics*/ None
         )
         .await,
         Some(ReviewDecision::Approved)
@@ -2472,21 +2431,15 @@ async fn assert_compaction_approval_policy(thread_context_enabled: bool) -> Resu
             .js_executions
             .store(/*val*/ 1, Ordering::Release);
         assert_eq!(
-            fixture
+            cached_approval(
-                .registry
+                &fixture.registry,
-                .fast_approval_decision(
-                    &fixture.session_store,
                 thread_store,
                 prompt,
-                    /*extension_metrics*/ None
+                /*metrics*/ None
             )
             .await,
             (!thread_context_enabled).then_some(ReviewDecision::Approved)
         );
-        assert_eq!(
-            thread_store.remove::<StrictReviewReason>().as_deref(),
-            thread_context_enabled.then_some(&StrictReviewReason::IncompatibleCompaction)
-        );
     }
     Ok(())
 }
@@ -2525,12 +2478,11 @@ async fn contributor_counts_failed_thread_lookups_toward_score_lag() -> Result<(
         sampled_at: None,
     });
     assert_eq!(
-        registry
+        cached_approval(
-            .fast_approval_decision(
+            &registry,
-                &session_store,
             thread_store,
             "review action",
-                /*extension_metrics*/ None,
+            /*metrics*/ None,
         )
         .await,
         Some(ReviewDecision::Approved)
@@ -2563,12 +2515,11 @@ async fn contributor_counts_failed_thread_lookups_toward_score_lag() -> Result<(
 
     assert_eq!(score_progress.latest_tool_call.load(Ordering::Acquire), 2);
     assert_eq!(
-        registry
+        cached_approval(
-            .fast_approval_decision(
+            &registry,
-                &session_store,
             thread_store,
             "review action",
-                /*extension_metrics*/ None,
+            /*metrics*/ None,
         )
         .await,
         None
@@ -3098,12 +3049,11 @@ async fn assert_parent_compaction_reuse(thread_context_enabled: bool) -> Result<
     // Raw injection did not attach producer provenance to the live checkpoint.
     // The sample's mock snapshot cannot make that live checkpoint safe for approval.
     assert_eq!(
-        registry
+        cached_approval(
-            .fast_approval_decision(
+            &registry,
-                &session_store,
             thread_store,
             "review action",
-                /*extension_metrics*/ None,
+            /*metrics*/ None,
         )
         .await,
         (!thread_context_enabled).then_some(ReviewDecision::Approved),
@@ -3149,12 +3099,11 @@ async fn assert_parent_compaction_reuse(thread_context_enabled: bool) -> Result<
         }
     );
     assert_eq!(
-        registry
+        cached_approval(
-            .fast_approval_decision(
+            &registry,
-                &session_store,
             thread_store,
             "review action",
-                /*extension_metrics*/ None,
+            /*metrics*/ None,
         )
         .await,
         None
@@ -3289,3 +3238,68 @@ async fn contributor_bounds_oversized_actions_and_fairly_truncates_nested_fields
 
     Ok(())
 }
+
+struct CacheMiss;
+impl codex_extension_api::SynchronousApprovalReviewer for CacheMiss {
+    fn review(
+        &self,
+        _reason: codex_protocol::approvals::GuardianReviewReason,
+    ) -> codex_extension_api::ExtensionFuture<'_, ReviewDecision> {
+        Box::pin(async { ReviewDecision::denied("cache miss") })
+    }
+}
+
+/// Exercises decision routing; a fresh review is observed as a cache miss.
+async fn cached_approval(
+    registry: &codex_extension_api::ExtensionRegistry<Config>,
+    store: &ExtensionData,
+    action: &str,
+    metrics: Option<Arc<dyn ExtensionMetrics>>,
+) -> Option<ReviewDecision> {
+    let action = serde_json::from_str(action).unwrap_or(serde_json::Value::Null);
+    let category = match review_scope(&action) {
+        Some(category) => category,
+        None if store.get::<super::GuardianV2Config>()?.policy.other_tools
+            == codex_protocol::openai_models::GuardianReviewMode::Adaptive =>
+        {
+            codex_protocol::openai_models::GuardianScope::Shell
+        }
+        None => {
+            super::super::metrics::record_fast_decision(
+                metrics.as_deref(),
+                "deferred",
+                "out_of_scope",
+            );
+            return None;
+        }
+    };
+    let input = codex_extension_api::ApprovalDecisionInput {
+        approval_id: "cache-probe",
+        action: &action,
+        thread_id: codex_protocol::ThreadId::from_string(store.level_id()).unwrap(),
+        thread_store: store,
+        category,
+        approval_policy: codex_protocol::protocol::AskForApproval::OnRequest,
+        approvals_reviewer: ApprovalsReviewer::AutoReview,
+        require_guardian: false,
+        require_fresh_review: false,
+        full_access: false,
+        metrics,
+        synchronous_reviewer: &CacheMiss,
+    };
+    match registry.decide_approval(&input).await {
+        Some(codex_extension_api::ApprovalDecision::Allow) => Some(ReviewDecision::Approved),
+        _ => None,
+    }
+}
+
+fn review_scope(action: &serde_json::Value) -> Option<GuardianScope> {
+    match action.get("tool").and_then(serde_json::Value::as_str)? {
+        "mcp_tool_call" => action
+            .get("server")
+            .and_then(serde_json::Value::as_str)
+            .map(GuardianScope::for_mcp_server),
+        "network_access" => Some(GuardianScope::Network),
+        tool => GuardianScope::for_tool(&ToolName::plain(tool)),
+    }
+}

codex-rs/ext/guardian-v2/src/async_scorer/mod.rs

@@ -15,7 +15,6 @@ mod trusted_tools;
 
 pub(crate) use config::DEFAULT_MODEL_CONTEXT_ITEM_TOKENS;
 pub(crate) use config::GuardianV2Config;
-pub use extension::StrictReviewReason;
 pub(crate) use extension::install;
 pub(crate) use transcript::MAX_TOOL_ENTRY_TOKENS;
 pub(crate) use transcript::RenderedContext;

codex-rs/ext/guardian-v2/src/lib.rs

@@ -15,7 +15,6 @@ use codex_protocol::ThreadId;
 mod async_scorer;
 mod sync_reviewer;
 
-pub use async_scorer::StrictReviewReason;
 pub use sync_reviewer::GuardianExtension as GuardianReviewerExtension;
 pub use sync_reviewer::GuardianThreadContext as GuardianReviewerThreadContext;