Merge remote-tracking branch 'origin/rcc/thinking' into dev/rust

# Conflicts:
#	rust/crates/commands/src/lib.rs
#	rust/crates/rusty-claude-cli/src/main.rs

rust/crates/runtime/src/compact.rs

@@ -164,7 +164,7 @@ fn summarize_messages(messages: &[ConversationMessage]) -> String {
         .filter_map(|block| match block {
             ContentBlock::ToolUse { name, .. } => Some(name.as_str()),
             ContentBlock::ToolResult { tool_name, .. } => Some(tool_name.as_str()),
-            ContentBlock::Text { .. } => None,
+            ContentBlock::Text { .. } | ContentBlock::Thinking { .. } => None,
         })
         .collect::<Vec<_>>();
     tool_names.sort_unstable();
@@ -234,6 +234,7 @@ fn summarize_messages(messages: &[ConversationMessage]) -> String {
 fn summarize_block(block: &ContentBlock) -> String {
     let raw = match block {
         ContentBlock::Text { text } => text.clone(),
+        ContentBlock::Thinking { text, .. } => format!("thinking: {text}"),
         ContentBlock::ToolUse { name, input, .. } => format!("tool_use {name}({input})"),
         ContentBlock::ToolResult {
             tool_name,
@@ -292,7 +293,7 @@ fn collect_key_files(messages: &[ConversationMessage]) -> Vec<String> {
         .iter()
         .flat_map(|message| message.blocks.iter())
         .map(|block| match block {
-            ContentBlock::Text { text } => text.as_str(),
+            ContentBlock::Text { text } | ContentBlock::Thinking { text, .. } => text.as_str(),
             ContentBlock::ToolUse { input, .. } => input.as_str(),
             ContentBlock::ToolResult { output, .. } => output.as_str(),
         })
@@ -314,10 +315,15 @@ fn infer_current_work(messages: &[ConversationMessage]) -> Option<String> {
 
 fn first_text_block(message: &ConversationMessage) -> Option<&str> {
     message.blocks.iter().find_map(|block| match block {
-        ContentBlock::Text { text } if !text.trim().is_empty() => Some(text.as_str()),
+        ContentBlock::Text { text } | ContentBlock::Thinking { text, .. }
+            if !text.trim().is_empty() =>
+        {
+            Some(text.as_str())
+        }
         ContentBlock::ToolUse { .. }
         | ContentBlock::ToolResult { .. }
-        | ContentBlock::Text { .. } => None,
+        | ContentBlock::Text { .. }
+        | ContentBlock::Thinking { .. } => None,
     })
 }
 
@@ -362,7 +368,7 @@ fn estimate_message_tokens(message: &ConversationMessage) -> usize {
         .blocks
         .iter()
         .map(|block| match block {
-            ContentBlock::Text { text } => text.len() / 4 + 1,
+            ContentBlock::Text { text } | ContentBlock::Thinking { text, .. } => text.len() / 4 + 1,
             ContentBlock::ToolUse { name, input, .. } => (name.len() + input.len()) / 4 + 1,
             ContentBlock::ToolResult {
                 tool_name, output, ..

rust/crates/runtime/src/conversation.rs

@@ -17,6 +17,8 @@ pub struct ApiRequest {
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub enum AssistantEvent {
     TextDelta(String),
+    ThinkingDelta(String),
+    ThinkingSignature(String),
     ToolUse {
         id: String,
         name: String,
@@ -247,15 +249,26 @@ fn build_assistant_message(
     events: Vec<AssistantEvent>,
 ) -> Result<(ConversationMessage, Option<TokenUsage>), RuntimeError> {
     let mut text = String::new();
+    let mut thinking = String::new();
+    let mut thinking_signature: Option<String> = None;
     let mut blocks = Vec::new();
     let mut finished = false;
     let mut usage = None;
 
     for event in events {
         match event {
-            AssistantEvent::TextDelta(delta) => text.push_str(&delta),
+            AssistantEvent::TextDelta(delta) => {
+                flush_thinking_block(&mut thinking, &mut thinking_signature, &mut blocks);
+                text.push_str(&delta);
+            }
+            AssistantEvent::ThinkingDelta(delta) => {
+                flush_text_block(&mut text, &mut blocks);
+                thinking.push_str(&delta);
+            }
+            AssistantEvent::ThinkingSignature(signature) => thinking_signature = Some(signature),
             AssistantEvent::ToolUse { id, name, input } => {
                 flush_text_block(&mut text, &mut blocks);
+                flush_thinking_block(&mut thinking, &mut thinking_signature, &mut blocks);
                 blocks.push(ContentBlock::ToolUse { id, name, input });
             }
             AssistantEvent::Usage(value) => usage = Some(value),
@@ -266,6 +279,7 @@ fn build_assistant_message(
     }
 
     flush_text_block(&mut text, &mut blocks);
+    flush_thinking_block(&mut thinking, &mut thinking_signature, &mut blocks);
 
     if !finished {
         return Err(RuntimeError::new(
@@ -290,6 +304,19 @@ fn flush_text_block(text: &mut String, blocks: &mut Vec<ContentBlock>) {
     }
 }
 
+fn flush_thinking_block(
+    thinking: &mut String,
+    signature: &mut Option<String>,
+    blocks: &mut Vec<ContentBlock>,
+) {
+    if !thinking.is_empty() || signature.is_some() {
+        blocks.push(ContentBlock::Thinking {
+            text: std::mem::take(thinking),
+            signature: signature.take(),
+        });
+    }
+}
+
 type ToolHandler = Box<dyn FnMut(&str) -> Result<String, ToolError>>;
 
 #[derive(Default)]
@@ -325,8 +352,8 @@ impl ToolExecutor for StaticToolExecutor {
 #[cfg(test)]
 mod tests {
     use super::{
-        ApiClient, ApiRequest, AssistantEvent, ConversationRuntime, RuntimeError,
-        StaticToolExecutor,
+        build_assistant_message, ApiClient, ApiRequest, AssistantEvent, ConversationRuntime,
+        RuntimeError, StaticToolExecutor,
     };
     use crate::compact::CompactionConfig;
     use crate::permissions::{
@@ -503,6 +530,29 @@ mod tests {
         ));
     }
 
+    #[test]
+    fn thinking_blocks_are_preserved_separately_from_text() {
+        let (message, usage) = build_assistant_message(vec![
+            AssistantEvent::ThinkingDelta("first ".to_string()),
+            AssistantEvent::ThinkingDelta("second".to_string()),
+            AssistantEvent::ThinkingSignature("sig-1".to_string()),
+            AssistantEvent::TextDelta("final".to_string()),
+            AssistantEvent::MessageStop,
+        ])
+        .expect("assistant message should build");
+
+        assert_eq!(usage, None);
+        assert!(matches!(
+            &message.blocks[0],
+            ContentBlock::Thinking { text, signature }
+                if text == "first second" && signature.as_deref() == Some("sig-1")
+        ));
+        assert!(matches!(
+            &message.blocks[1],
+            ContentBlock::Text { text } if text == "final"
+        ));
+    }
+
     #[test]
     fn reconstructs_usage_tracker_from_restored_session() {
         struct SimpleApi;

rust/crates/runtime/src/session.rs

@@ -19,6 +19,10 @@ pub enum ContentBlock {
     Text {
         text: String,
     },
+    Thinking {
+        text: String,
+        signature: Option<String>,
+    },
     ToolUse {
         id: String,
         name: String,
@@ -313,6 +317,19 @@ impl ContentBlock {
                 object.insert("type".to_string(), JsonValue::String("text".to_string()));
                 object.insert("text".to_string(), JsonValue::String(text.clone()));
             }
+            Self::Thinking { text, signature } => {
+                object.insert(
+                    "type".to_string(),
+                    JsonValue::String("thinking".to_string()),
+                );
+                object.insert("text".to_string(), JsonValue::String(text.clone()));
+                if let Some(signature) = signature {
+                    object.insert(
+                        "signature".to_string(),
+                        JsonValue::String(signature.clone()),
+                    );
+                }
+            }
             Self::ToolUse { id, name, input } => {
                 object.insert(
                     "type".to_string(),
@@ -359,6 +376,13 @@ impl ContentBlock {
             "text" => Ok(Self::Text {
                 text: required_string(object, "text")?,
             }),
+            "thinking" => Ok(Self::Thinking {
+                text: required_string(object, "text")?,
+                signature: object
+                    .get("signature")
+                    .and_then(JsonValue::as_str)
+                    .map(ToOwned::to_owned),
+            }),
             "tool_use" => Ok(Self::ToolUse {
                 id: required_string(object, "id")?,
                 name: required_string(object, "name")?,