feat(grpc): proper tool result relay via tokio::select

session_chat_via_orchestrator now:
- Spawns generation on a background task
- Reads in_stream for client tool results in foreground
- Forwards results to orchestrator.submit_tool_result()
- Uses tokio::select! to handle both concurrently
- Uses GenerateRequest + Metadata (no transport types in orchestrator)
- Calls grpc::bridge (not orchestrator::grpc_bridge)

src/grpc/service.rs

@@ -5,7 +5,7 @@ use futures::Stream;
 use tokio::sync::mpsc;
 use tokio_stream::wrappers::ReceiverStream;
 use tonic::{Request, Response, Status, Streaming};
-use tracing::{error, info, warn};
+use tracing::{debug, error, info, warn};
 
 use super::auth::Claims;
 use super::proto::code_agent_server::CodeAgent;
@@ -122,19 +122,41 @@ async fn run_session(
     }))
     .await?;
 
+    // Check if orchestrator is available
+    let has_orch = state.orchestrator.is_some();
+    info!(has_orchestrator = has_orch, "Checking orchestrator availability");
+    let orchestrator = state.orchestrator.as_ref().cloned();
+
     // Main message loop
     while let Some(msg) = in_stream.message().await? {
         match msg.payload {
             Some(client_message::Payload::Input(input)) => {
-                if let Err(e) = session.chat(&input.text, tx, in_stream).await {
-                    error!("Chat error: {e}");
-                    tx.send(Ok(ServerMessage {
-                        payload: Some(server_message::Payload::Error(Error {
-                            message: e.to_string(),
-                            fatal: false,
-                        })),
-                    }))
-                    .await?;
+                if let Some(ref orch) = orchestrator {
+                    // Orchestrator path: delegate tool loop, bridge forwards events
+                    if let Err(e) = session_chat_via_orchestrator(
+                        &mut session, &input.text, orch, tx, in_stream,
+                    ).await {
+                        error!("Chat error: {e}");
+                        tx.send(Ok(ServerMessage {
+                            payload: Some(server_message::Payload::Error(Error {
+                                message: e.to_string(),
+                                fatal: false,
+                            })),
+                        }))
+                        .await?;
+                    }
+                } else {
+                    // Fallback: inline tool loop (legacy)
+                    if let Err(e) = session.chat(&input.text, tx, in_stream).await {
+                        error!("Chat error: {e}");
+                        tx.send(Ok(ServerMessage {
+                            payload: Some(server_message::Payload::Error(Error {
+                                message: e.to_string(),
+                                fatal: false,
+                            })),
+                        }))
+                        .await?;
+                    }
                 }
             }
             Some(client_message::Payload::End(_)) => {
@@ -150,10 +172,95 @@ async fn run_session(
             Some(client_message::Payload::Start(_)) => {
                 warn!("Received duplicate StartSession — ignoring");
             }
-            // ToolResult and Approval are handled inside session.chat()
+            // ToolResult and Approval are handled by the orchestrator bridge
             _ => continue,
         }
     }
 
     Ok(())
 }
+
+/// Chat via the orchestrator: session handles conversation creation,
+/// orchestrator handles the tool loop, gRPC bridge forwards events.
+/// Client-side tool results are read from in_stream and forwarded to the orchestrator.
+async fn session_chat_via_orchestrator(
+    session: &mut super::session::CodeSession,
+    text: &str,
+    orchestrator: &Arc<crate::orchestrator::Orchestrator>,
+    tx: &mpsc::Sender<Result<ServerMessage, Status>>,
+    in_stream: &mut Streaming<ClientMessage>,
+) -> anyhow::Result<()> {
+    use crate::orchestrator::event::*;
+
+    let conversation_response = session.create_or_append_conversation(text).await?;
+    session.post_to_matrix(text).await;
+
+    let request_id = RequestId::new();
+    let request = GenerateRequest {
+        request_id: request_id.clone(),
+        text: text.into(),
+        user_id: "dev".into(),
+        display_name: None,
+        conversation_key: session.session_id.clone(),
+        is_direct: true,
+        image: None,
+        metadata: Metadata::new()
+            .with("session_id", session.session_id.as_str())
+            .with("room_id", session.room_id.as_str()),
+    };
+
+    // Subscribe BEFORE starting generation
+    let event_rx = orchestrator.subscribe();
+
+    // Spawn gRPC bridge (lives in grpc module, not orchestrator)
+    let tx_clone = tx.clone();
+    let rid_for_bridge = request_id.clone();
+    let bridge_handle = tokio::spawn(async move {
+        super::bridge::bridge_events_to_grpc(rid_for_bridge, event_rx, tx_clone).await;
+    });
+
+    // Spawn orchestrator generation
+    let orch_for_gen = orchestrator.clone();
+    let mut gen_handle = tokio::spawn(async move {
+        orch_for_gen.generate_from_response(&request, conversation_response).await
+    });
+
+    // Read client tool results while generation runs
+    loop {
+        tokio::select! {
+            result = &mut gen_handle => {
+                let gen_result = result.unwrap_or(None);
+                if let Some(ref response_text) = gen_result {
+                    session.post_response_to_matrix(response_text).await;
+                }
+                break;
+            }
+            msg = in_stream.message() => {
+                match msg {
+                    Ok(Some(msg)) => match msg.payload {
+                        Some(client_message::Payload::ToolResult(result)) => {
+                            debug!(call_id = result.call_id.as_str(), "Forwarding tool result");
+                            let _ = orchestrator.submit_tool_result(
+                                &result.call_id,
+                                ToolResultPayload { text: result.result, is_error: result.is_error },
+                            ).await;
+                        }
+                        Some(client_message::Payload::Approval(a)) if !a.approved => {
+                            let _ = orchestrator.submit_tool_result(
+                                &a.call_id,
+                                ToolResultPayload { text: "Denied by user.".into(), is_error: true },
+                            ).await;
+                        }
+                        _ => {}
+                    },
+                    Ok(None) => break,
+                    Err(e) => { warn!("Client stream error: {e}"); break; }
+                }
+            }
+        }
+    }
+
+    let _ = bridge_handle.await;
+    session.touch();
+    Ok(())
+}

src/grpc/session.rs

@@ -480,6 +480,87 @@ you also have access to server-side tools: search_archive, search_web, research,
         tools
     }
 
+    /// Create or append to the Mistral conversation. Returns the response
+    /// for the orchestrator to run through its tool loop.
+    pub async fn create_or_append_conversation(
+        &mut self,
+        text: &str,
+    ) -> anyhow::Result<mistralai_client::v1::conversations::ConversationResponse> {
+        let context_header = self.build_context_header();
+        let input_text = format!("{context_header}\n{text}");
+
+        if let Some(ref conv_id) = self.conversation_id {
+            let req = AppendConversationRequest {
+                inputs: ConversationInput::Text(input_text),
+                completion_args: None,
+                handoff_execution: None,
+                store: Some(true),
+                tool_confirmations: None,
+                stream: false,
+            };
+            self.state
+                .mistral
+                .append_conversation_async(conv_id, &req)
+                .await
+                .map_err(|e| anyhow::anyhow!("append_conversation failed: {}", e.message))
+        } else {
+            let instructions = self.build_instructions();
+            let req = CreateConversationRequest {
+                inputs: ConversationInput::Text(input_text),
+                model: Some(self.model.clone()),
+                agent_id: None,
+                agent_version: None,
+                name: Some(format!("code-{}", self.project_name)),
+                description: None,
+                instructions: Some(instructions),
+                completion_args: None,
+                tools: Some(self.build_tool_definitions()),
+                handoff_execution: None,
+                metadata: None,
+                store: Some(true),
+                stream: false,
+            };
+            let resp = self.state
+                .mistral
+                .create_conversation_async(&req)
+                .await
+                .map_err(|e| anyhow::anyhow!("create_conversation failed: {}", e.message))?;
+
+            self.conversation_id = Some(resp.conversation_id.clone());
+            self.state.store.set_code_session_conversation(
+                &self.session_id,
+                &resp.conversation_id,
+            );
+
+            info!(
+                conversation_id = resp.conversation_id.as_str(),
+                "Created Mistral conversation for code session"
+            );
+            Ok(resp)
+        }
+    }
+
+    /// Post user message to the Matrix room.
+    pub async fn post_to_matrix(&self, text: &str) {
+        if let Some(ref room) = self.room {
+            let content = RoomMessageEventContent::notice_plain(text);
+            let _ = room.send(content).await;
+        }
+    }
+
+    /// Post assistant response to the Matrix room.
+    pub async fn post_response_to_matrix(&self, text: &str) {
+        if let Some(ref room) = self.room {
+            let content = RoomMessageEventContent::text_markdown(text);
+            let _ = room.send(content).await;
+        }
+    }
+
+    /// Touch the session's last_active timestamp.
+    pub fn touch(&self) {
+        self.state.store.touch_code_session(&self.session_id);
+    }
+
     /// Disconnect from the session (keeps it active for future reconnection).
     pub fn end(&self) {
         self.state.store.touch_code_session(&self.session_id);

src/main.rs

@@ -307,6 +307,13 @@ async fn main() -> anyhow::Result<()> {
     if config.grpc.is_some() {
         let orchestrator_id = state.conversation_registry.get_agent_id().await
             .unwrap_or_default();
+        let orch = Arc::new(orchestrator::Orchestrator::new(
+            config.clone(),
+            state.responder.tools(),
+            state.mistral.clone(),
+            state.conversation_registry.clone(),
+            system_prompt_text.clone(),
+        ));
         let grpc_state = std::sync::Arc::new(grpc::GrpcState {
             config: config.clone(),
             tools: state.responder.tools(),
@@ -315,6 +322,7 @@ async fn main() -> anyhow::Result<()> {
             matrix: matrix_client.clone(),
             system_prompt: system_prompt_text.clone(),
             orchestrator_agent_id: orchestrator_id,
+            orchestrator: Some(orch),
         });
         tokio::spawn(async move {
             if let Err(e) = grpc::start_server(grpc_state).await {