feat: display reasoning tokens (#1139)

1 files changed, 27 insertions, 1 deletions

diff --git a/src/client/openai.rs b/src/client/openai.rs
index ce00de7..6490236 100644
--- a/src/client/openai.rs
+++ b/src/client/openai.rs
@@ -104,6 +104,7 @@ pub async fn openai_chat_completions_streaming(
     let mut function_name = String::new();
     let mut function_arguments = String::new();
     let mut function_id = String::new();
+    let mut reason_state = 0;
     let handle = |message: SseMmessage| -> Result<bool> {
         if message.data == "[DONE]" {
             if !function_name.is_empty() {
@@ -124,6 +125,20 @@ pub async fn openai_chat_completions_streaming(
             .as_str()
             .filter(|v| !v.is_empty())
         {
+            if reason_state == 1 {
+                handler.text("\n</think>\n\n")?;
+                reason_state = 0;
+            }
+            handler.text(text)?;
+        } else if let Some(text) = data["choices"][0]["delta"]["reasoning_content"]
+            .as_str()
+            .or_else(|| data["choices"][0]["delta"]["reasoning"].as_str())
+            .filter(|v| !v.is_empty())
+        {
+            if reason_state == 0 {
+                handler.text("<think>\n")?;
+                reason_state = 1;
+            }
             handler.text(text)?;
         } else if let (Some(function), index, id) = (
             data["choices"][0]["delta"]["tool_calls"][0]["function"].as_object(),
@@ -314,6 +329,12 @@ pub fn openai_extract_chat_completions(data: &Value) -> Result<ChatCompletionsOu
         .as_str()
         .unwrap_or_default();
 
+    let reasoning = data["choices"][0]["message"]["reasoning_content"]
+        .as_str()
+        .or_else(|| data["choices"][0]["message"]["reasoning"].as_str())
+        .unwrap_or_default()
+        .trim();
+
     let mut tool_calls = vec![];
     if let Some(calls) = data["choices"][0]["message"]["tool_calls"].as_array() {
         for call in calls {
@@ -337,8 +358,13 @@ pub fn openai_extract_chat_completions(data: &Value) -> Result<ChatCompletionsOu
     if text.is_empty() && tool_calls.is_empty() {
         bail!("Invalid response data: {data}");
     }
+    let text = if !reasoning.is_empty() {
+        format!("<think>\n{reasoning}\n</think>\n\n{text}")
+    } else {
+        text.to_string()
+    };
     let output = ChatCompletionsOutput {
-        text: text.to_string(),
+        text,
         tool_calls,
         id: data["id"].as_str().map(|v| v.to_string()),
         input_tokens: data["usage"]["prompt_tokens"].as_u64(),