diff --git a/codex-rs/core/src/codex.rs b/codex-rs/core/src/codex.rs
index c6e11b137..e67779438 100644
--- a/codex-rs/core/src/codex.rs
+++ b/codex-rs/core/src/codex.rs
@@ -525,7 +525,6 @@ impl Session {
             session_configuration.collaboration_mode.model(),
             model_info.slug.as_str(),
         );
-
         let per_turn_config = Arc::new(per_turn_config);
         let client = ModelClient::new(
             per_turn_config.clone(),
diff --git a/codex-rs/core/src/state/turn.rs b/codex-rs/core/src/state/turn.rs
index ddc9efafe..3dfc5132d 100644
--- a/codex-rs/core/src/state/turn.rs
+++ b/codex-rs/core/src/state/turn.rs
@@ -37,7 +37,6 @@ pub(crate) enum TaskKind {
     Compact,
 }
 
-#[derive(Clone)]
 pub(crate) struct RunningTask {
     pub(crate) done: Arc<Notify>,
     pub(crate) kind: TaskKind,
@@ -45,6 +44,8 @@ pub(crate) struct RunningTask {
     pub(crate) cancellation_token: CancellationToken,
     pub(crate) handle: Arc<AbortOnDropHandle<()>>,
     pub(crate) turn_context: Arc<TurnContext>,
+    // Timer recorded when the task drops to capture the full turn duration.
+    pub(crate) _timer: Option<codex_otel::Timer>,
 }
 
 impl ActiveTurn {
diff --git a/codex-rs/core/src/tasks/mod.rs b/codex-rs/core/src/tasks/mod.rs
index d6754c23c..83326b1f0 100644
--- a/codex-rs/core/src/tasks/mod.rs
+++ b/codex-rs/core/src/tasks/mod.rs
@@ -144,6 +144,12 @@ impl Session {
             })
         };
 
+        let timer = turn_context
+            .client
+            .get_otel_manager()
+            .start_timer("codex.turn.e2e_duration_ms", &[])
+            .ok();
+
         let running_task = RunningTask {
             done,
             handle: Arc::new(AbortOnDropHandle::new(handle)),
@@ -151,6 +157,7 @@ impl Session {
             task,
             cancellation_token,
             turn_context: Arc::clone(&turn_context),
+            _timer: timer,
         };
         self.register_new_active_task(running_task).await;
     }
diff --git a/codex-rs/otel/src/lib.rs b/codex-rs/otel/src/lib.rs
index 868a97773..fa7cc93bb 100644
--- a/codex-rs/otel/src/lib.rs
+++ b/codex-rs/otel/src/lib.rs
@@ -9,7 +9,7 @@ use crate::metrics::MetricsClient;
 use crate::metrics::MetricsConfig;
 use crate::metrics::MetricsError;
 use crate::metrics::Result as MetricsResult;
-use crate::metrics::timer::Timer;
+pub use crate::metrics::timer::Timer;
 use crate::metrics::validation::validate_tag_key;
 use crate::metrics::validation::validate_tag_value;
 use crate::otel_provider::OtelProvider;
diff --git a/codex-rs/otel/src/metrics/timer.rs b/codex-rs/otel/src/metrics/timer.rs
index b1624fda1..6c85f413b 100644
--- a/codex-rs/otel/src/metrics/timer.rs
+++ b/codex-rs/otel/src/metrics/timer.rs
@@ -2,6 +2,7 @@ use crate::metrics::MetricsClient;
 use crate::metrics::error::Result;
 use std::time::Instant;
 
+#[derive(Debug)]
 pub struct Timer {
     name: String,
     tags: Vec<(String, String)>,