diff --git a/codex-rs/analytics/src/client.rs b/codex-rs/analytics/src/client.rs
index f957a665a0..96ace49fc9 100644
--- a/codex-rs/analytics/src/client.rs
+++ b/codex-rs/analytics/src/client.rs
@@ -548,7 +548,7 @@ impl AnalyticsEventsClient {
 async fn send_track_events(
     auth_manager: &AuthManager,
     destination: &AnalyticsEventsDestination,
-    events: Vec<TrackEventRequest>,
+    mut events: Vec<TrackEventRequest>,
 ) {
     if events.is_empty() {
         return;
@@ -557,7 +557,12 @@ async fn send_track_events(
     let Some(auth) = auth_manager.auth().await else {
         return;
     };
-    if !auth.uses_codex_backend() {
+    if auth.is_api_key_auth() {
+        events.retain(TrackEventRequest::can_send_with_api_key_auth);
+    } else if !auth.uses_codex_backend() {
+        return;
+    }
+    if events.is_empty() {
         return;
     }
 
diff --git a/codex-rs/analytics/src/client_tests.rs b/codex-rs/analytics/src/client_tests.rs
index ac50d6ebc7..62240c703a 100644
--- a/codex-rs/analytics/src/client_tests.rs
+++ b/codex-rs/analytics/src/client_tests.rs
@@ -4,10 +4,18 @@ use super::AnalyticsEventsQueue;
 #[cfg(debug_assertions)]
 use super::capture_track_events_request;
 #[cfg(debug_assertions)]
+use super::send_track_events;
+#[cfg(debug_assertions)]
 use super::send_track_events_request;
 use super::track_event_request_batches;
 use crate::events::CodexAcceptedLineFingerprintsEventParams;
 use crate::events::CodexAcceptedLineFingerprintsEventRequest;
+#[cfg(debug_assertions)]
+use crate::events::CodexPluginMetadata;
+#[cfg(debug_assertions)]
+use crate::events::CodexPluginUsedEventRequest;
+#[cfg(debug_assertions)]
+use crate::events::CodexPluginUsedMetadata;
 use crate::events::SkillInvocationEventParams;
 use crate::events::SkillInvocationEventRequest;
 use crate::events::TrackEventRequest;
@@ -85,6 +93,29 @@ fn sample_regular_track_event(thread_id: &str) -> TrackEventRequest {
     })
 }
 
+#[cfg(debug_assertions)]
+fn sample_plugin_used_track_event(thread_id: &str, plugin_id: Option<&str>) -> TrackEventRequest {
+    TrackEventRequest::PluginUsed(CodexPluginUsedEventRequest {
+        event_type: "codex_plugin_used",
+        event_params: CodexPluginUsedMetadata {
+            plugin: CodexPluginMetadata {
+                plugin_id: plugin_id.map(str::to_string),
+                remote_plugin_id: None,
+                plugin_name: Some("sample".to_string()),
+                marketplace_name: Some("test".to_string()),
+                has_skills: Some(true),
+                mcp_server_count: Some(1),
+                connector_ids: Some(vec!["calendar".to_string()]),
+                product_client_id: Some("codex_desktop".to_string()),
+            },
+            mcp_server_names: Some(vec!["mcp-1".to_string()]),
+            thread_id: Some(thread_id.to_string()),
+            turn_id: Some("turn-1".to_string()),
+            model_slug: Some("gpt-5.1-codex".to_string()),
+        },
+    })
+}
+
 #[cfg(debug_assertions)]
 fn unique_capture_path(name: &str) -> PathBuf {
     let nonce = SystemTime::now()
@@ -227,6 +258,68 @@ async fn capture_file_writes_final_batches_as_separate_lines() {
     fs::remove_file(capture_path).expect("remove capture file");
 }
 
+#[tokio::test]
+#[cfg(debug_assertions)]
+async fn api_key_auth_sends_only_plugin_used_events_to_codex_backend() {
+    let capture_path = unique_capture_path("api-key-plugin-used-events");
+    let destination = AnalyticsEventsDestination::CaptureFile {
+        path: capture_path.clone(),
+    };
+    let auth_manager = codex_login::AuthManager::from_auth_for_testing(
+        codex_login::CodexAuth::from_api_key("sk-test"),
+    );
+
+    send_track_events(
+        &auth_manager,
+        &destination,
+        vec![
+            sample_regular_track_event("non-plugin-skill"),
+            sample_plugin_used_track_event("non-plugin-used", /*plugin_id*/ None),
+            sample_accepted_line_fingerprint_event("other-event"),
+            sample_plugin_used_track_event("plugin-used", Some("sample@test")),
+        ],
+    )
+    .await;
+
+    let contents = fs::read_to_string(&capture_path).expect("read capture file");
+    let lines = contents.lines().collect::<Vec<_>>();
+    assert_eq!(lines.len(), 1);
+    let payload: serde_json::Value =
+        serde_json::from_str(lines[0]).expect("parse captured payload");
+    let events = payload["events"].as_array().expect("events array");
+    for event in events {
+        let event_params = event["event_params"].as_object().expect("event params");
+        for server_owned_field in [
+            "auth_mode",
+            "api_organization_id",
+            "api_project_id",
+            "api_key_tracking_id",
+        ] {
+            assert!(!event_params.contains_key(server_owned_field));
+        }
+    }
+    let delivered_events = events
+        .iter()
+        .map(|event| {
+            serde_json::json!({
+                "event_type": event["event_type"],
+                "plugin_id": event["event_params"]["plugin_id"],
+                "thread_id": event["event_params"]["thread_id"],
+            })
+        })
+        .collect::<Vec<_>>();
+    assert_eq!(
+        delivered_events,
+        vec![serde_json::json!({
+            "event_type": "codex_plugin_used",
+            "plugin_id": "sample@test",
+            "thread_id": "plugin-used",
+        })]
+    );
+
+    fs::remove_file(capture_path).expect("remove capture file");
+}
+
 #[test]
 #[cfg(debug_assertions)]
 fn capture_write_failure_still_consumes_delivery() {
diff --git a/codex-rs/analytics/src/events.rs b/codex-rs/analytics/src/events.rs
index ad8adf14cb..4c58b5b37e 100644
--- a/codex-rs/analytics/src/events.rs
+++ b/codex-rs/analytics/src/events.rs
@@ -95,6 +95,13 @@ impl TrackEventRequest {
     pub(crate) fn should_send_in_isolated_request(&self) -> bool {
         matches!(self, Self::AcceptedLineFingerprints(_))
     }
+
+    pub(crate) fn can_send_with_api_key_auth(&self) -> bool {
+        match self {
+            Self::PluginUsed(event) => event.event_params.plugin.plugin_id.is_some(),
+            _ => false,
+        }
+    }
 }
 
 #[derive(Serialize)]