diff --git a/codex-rs/app-server/src/codex_message_processor.rs b/codex-rs/app-server/src/codex_message_processor.rs
index ac7e608500..daac6a019d 100644
--- a/codex-rs/app-server/src/codex_message_processor.rs
+++ b/codex-rs/app-server/src/codex_message_processor.rs
@@ -341,8 +341,11 @@ use codex_protocol::dynamic_tools::DynamicToolSpec as CoreDynamicToolSpec;
 use codex_protocol::error::CodexErr;
 use codex_protocol::error::Result as CodexResult;
 use codex_protocol::items::TurnItem;
+use codex_protocol::models::PermissionProfile;
 use codex_protocol::models::ResponseItem;
+use codex_protocol::models::SandboxEnforcement;
 use codex_protocol::permissions::FileSystemSandboxPolicy;
+use codex_protocol::permissions::NetworkSandboxPolicy;
 use codex_protocol::protocol::AgentStatus;
 use codex_protocol::protocol::ConversationAudioParams;
 use codex_protocol::protocol::ConversationStartParams;
@@ -361,6 +364,7 @@ use codex_protocol::protocol::ReviewDelivery as CoreReviewDelivery;
 use codex_protocol::protocol::ReviewRequest;
 use codex_protocol::protocol::ReviewTarget as CoreReviewTarget;
 use codex_protocol::protocol::RolloutItem;
+use codex_protocol::protocol::SandboxPolicy as CoreSandboxPolicy;
 use codex_protocol::protocol::SessionConfiguredEvent;
 use codex_protocol::protocol::SessionMetaLine;
 use codex_protocol::protocol::TurnEnvironmentSelection;
@@ -6666,6 +6670,19 @@ impl CodexMessageProcessor {
                 } else {
                     (None, None)
                 };
+            let permission_profile_for_validation =
+                if permission_profile.is_some() || sandbox_policy.is_none() {
+                    permission_profile.clone()
+                } else {
+                    let snapshot = thread.config_snapshot().await;
+                    sandbox_policy.as_ref().map(|sandbox_policy| {
+                        permission_profile_from_legacy_turn_sandbox_policy(
+                            &snapshot,
+                            sandbox_policy,
+                            cwd.as_deref(),
+                        )
+                    })
+                };
             let model = params.model;
             let effort = params.effort.map(Some);
             let summary = params.summary;
@@ -6681,9 +6698,9 @@ impl CodexMessageProcessor {
                         cwd: cwd.clone(),
                         approval_policy,
                         approvals_reviewer,
-                        sandbox_policy: sandbox_policy.clone(),
-                        permission_profile: permission_profile.clone(),
+                        permission_profile: permission_profile_for_validation,
                         active_permission_profile: active_permission_profile.clone(),
+                        clear_active_permission_profile: sandbox_policy.is_some(),
                         windows_sandbox_level: None,
                         model: model.clone(),
                         effort,
@@ -9568,6 +9585,27 @@ fn apply_permission_profile_selection_to_config_overrides(
         ));
 }
 
+fn permission_profile_from_legacy_turn_sandbox_policy(
+    snapshot: &ThreadConfigSnapshot,
+    sandbox_policy: &CoreSandboxPolicy,
+    cwd: Option<&Path>,
+) -> PermissionProfile {
+    let sandbox_cwd = cwd.unwrap_or(snapshot.cwd.as_path());
+    let configured_file_system_sandbox_policy =
+        snapshot.permission_profile.file_system_sandbox_policy();
+    let file_system_sandbox_policy =
+        FileSystemSandboxPolicy::from_legacy_sandbox_policy_preserving_deny_entries(
+            sandbox_policy,
+            sandbox_cwd,
+            &configured_file_system_sandbox_policy,
+        );
+    PermissionProfile::from_runtime_permissions_with_enforcement(
+        SandboxEnforcement::from_legacy_sandbox_policy(sandbox_policy),
+        &file_system_sandbox_policy,
+        NetworkSandboxPolicy::from(sandbox_policy),
+    )
+}
+
 fn thread_response_sandbox_policy(
     permission_profile: &codex_protocol::models::PermissionProfile,
     cwd: &Path,
diff --git a/codex-rs/core/src/codex_thread.rs b/codex-rs/core/src/codex_thread.rs
index 47092cdeb0..b66f64fcd6 100644
--- a/codex-rs/core/src/codex_thread.rs
+++ b/codex-rs/core/src/codex_thread.rs
@@ -24,7 +24,6 @@ use codex_protocol::openai_models::ReasoningEffort;
 use codex_protocol::protocol::AskForApproval;
 use codex_protocol::protocol::Event;
 use codex_protocol::protocol::Op;
-use codex_protocol::protocol::SandboxPolicy;
 use codex_protocol::protocol::SessionSource;
 use codex_protocol::protocol::Submission;
 use codex_protocol::protocol::ThreadMemoryMode;
@@ -63,9 +62,9 @@ pub struct CodexThreadTurnContextOverrides {
     pub cwd: Option<PathBuf>,
     pub approval_policy: Option<AskForApproval>,
     pub approvals_reviewer: Option<ApprovalsReviewer>,
-    pub sandbox_policy: Option<SandboxPolicy>,
     pub permission_profile: Option<PermissionProfile>,
     pub active_permission_profile: Option<ActivePermissionProfile>,
+    pub clear_active_permission_profile: bool,
     pub windows_sandbox_level: Option<WindowsSandboxLevel>,
     pub model: Option<String>,
     pub effort: Option<Option<ReasoningEffort>>,
@@ -214,9 +213,9 @@ impl CodexThread {
             cwd,
             approval_policy,
             approvals_reviewer,
-            sandbox_policy,
             permission_profile,
             active_permission_profile,
+            clear_active_permission_profile,
             windows_sandbox_level,
             model,
             effort,
@@ -234,19 +233,6 @@ impl CodexThread {
                 .await
                 .with_updates(model, effort, /*developer_instructions*/ None)
         };
-        let clear_active_permission_profile =
-            permission_profile.is_none() && sandbox_policy.is_some();
-        let permission_profile = match (permission_profile, sandbox_policy.as_ref()) {
-            (Some(permission_profile), _) => Some(permission_profile),
-            (None, Some(sandbox_policy)) => Some(
-                self.codex
-                    .session
-                    .permission_profile_from_legacy_sandbox_update(sandbox_policy, cwd.as_deref())
-                    .await,
-            ),
-            (None, None) => None,
-        };
-
         let updates = SessionSettingsUpdate {
             cwd,
             approval_policy,