diff --git a/src/agent/api/mod.rs b/src/agent/api/mod.rs
index 48f4039..6822dfd 100644
--- a/src/agent/api/mod.rs
+++ b/src/agent/api/mod.rs
@@ -578,6 +578,8 @@ pub(crate) struct StreamResult {
     pub(crate) error: Option<String>,
     /// Remaining display buffer (caller should flush if not in a tool call).
     pub(crate) display_buf: String,
+    /// Accumulated reasoning/thinking content.
+    pub(crate) reasoning: String,
     /// Whether we were mid-tool-call when the stream ended.
     pub(crate) in_tool_call: bool,
 }
@@ -601,6 +603,7 @@ pub(crate) async fn collect_stream(
     let mut error = None;
     let mut first_content = true;
     let mut display_buf = String::new();
+    let mut reasoning_buf = String::new();
     let mut _streaming_guard: Option<super::ActivityGuard> = None;
 
     while let Some(event) = rx.recv().await {
@@ -668,8 +671,7 @@ pub(crate) async fn collect_stream(
                 }
             }
             StreamEvent::Reasoning(text) => {
-                // TODO: reasoning tokens → context entries
-                let _ = text;
+                reasoning_buf.push_str(&text);
             }
             StreamEvent::ToolCallDelta { index, id, call_type, name, arguments } => {
                 while tool_calls.len() <= index {
@@ -696,5 +698,5 @@ pub(crate) async fn collect_stream(
         }
     }
 
-    StreamResult { content, tool_calls, usage, finish_reason, error, display_buf, in_tool_call }
+    StreamResult { content, tool_calls, usage, finish_reason, error, display_buf, in_tool_call, reasoning: reasoning_buf }
 }
diff --git a/src/agent/mod.rs b/src/agent/mod.rs
index 4d8f41c..4a1c86f 100644
--- a/src/agent/mod.rs
+++ b/src/agent/mod.rs
@@ -477,10 +477,16 @@ impl Agent {
             ).await;
             let api::StreamResult {
                 content, tool_calls, usage, finish_reason,
-                error: stream_error, display_buf, in_tool_call,
+                error: stream_error, display_buf, in_tool_call, reasoning,
             } = sr;
             // --- Stream complete ---
 
+            // Push thinking entry if model produced reasoning
+            if !reasoning.is_empty() {
+                let mut me = agent.lock().await;
+                me.push_entry(context::ConversationEntry::Thinking(reasoning));
+            }
+
             // --- Lock 3: process results ---
             let (msg, pending) = {
                 let mut me = agent.lock().await;