Fall back to http when websockets fail (#10139)

I expect not all proxies work with websockets, fall back to http if
websockets fail.

codex-rs/core/src/codex.rs

@@ -30,6 +30,7 @@ use crate::stream_events_utils::HandleOutputCtx;
 use crate::stream_events_utils::handle_non_tool_response_item;
 use crate::stream_events_utils::handle_output_item_done;
 use crate::terminal;
+use crate::transport_manager::TransportManager;
 use crate::truncate::TruncationPolicy;
 use crate::user_notification::UserNotifier;
 use crate::util::error_or_panic;
@@ -624,6 +625,7 @@ impl Session {
         model_info: ModelInfo,
         conversation_id: ThreadId,
         sub_id: String,
+        transport_manager: TransportManager,
     ) -> TurnContext {
         let otel_manager = otel_manager.clone().with_model(
             session_configuration.collaboration_mode.model(),
@@ -640,6 +642,7 @@ impl Session {
             session_configuration.model_reasoning_summary,
             conversation_id,
             session_configuration.session_source.clone(),
+            transport_manager,
         );
 
         let tools_config = ToolsConfig::new(&ToolsConfigParams {
@@ -869,6 +872,7 @@ impl Session {
             skills_manager,
             agent_control,
             state_db: state_db_ctx.clone(),
+            transport_manager: TransportManager::new(),
         };
 
         let sess = Arc::new(Session {
@@ -1188,6 +1192,7 @@ impl Session {
             model_info,
             self.conversation_id,
             sub_id,
+            self.services.transport_manager.clone(),
         );
         if let Some(final_schema) = final_output_json_schema {
             turn_context.final_output_json_schema = final_schema;
@@ -3042,6 +3047,7 @@ async fn spawn_review_thread(
         per_turn_config.model_reasoning_summary,
         sess.conversation_id,
         parent_turn_context.client.get_session_source(),
+        parent_turn_context.client.transport_manager(),
     );
 
     let review_turn_context = TurnContext {
@@ -3537,7 +3543,9 @@ async fn run_sampling_request(
         )
         .await
         {
-            Ok(output) => return Ok(output),
+            Ok(output) => {
+                return Ok(output);
+            }
             Err(CodexErr::ContextWindowExceeded) => {
                 sess.set_total_tokens_full(&turn_context).await;
                 return Err(CodexErr::ContextWindowExceeded);
@@ -3558,6 +3566,17 @@ async fn run_sampling_request(
 
         // Use the configured provider-specific stream retry budget.
         let max_retries = turn_context.client.get_provider().stream_max_retries();
+        if retries >= max_retries && client_session.try_switch_fallback_transport() {
+            sess.send_event(
+                &turn_context,
+                EventMsg::Warning(WarningEvent {
+                    message: format!("Falling back from WebSockets to HTTPS transport. {err:#}"),
+                }),
+            )
+            .await;
+            retries = 0;
+            continue;
+        }
         if retries < max_retries {
             retries += 1;
             let delay = match &err {
@@ -4753,6 +4772,7 @@ mod tests {
             skills_manager,
             agent_control,
             state_db: None,
+            transport_manager: TransportManager::new(),
         };
 
         let turn_context = Session::make_turn_context(
@@ -4764,6 +4784,7 @@ mod tests {
             model_info,
             conversation_id,
             "turn_id".to_string(),
+            services.transport_manager.clone(),
         );
 
         let session = Session {
@@ -4865,6 +4886,7 @@ mod tests {
             skills_manager,
             agent_control,
             state_db: None,
+            transport_manager: TransportManager::new(),
         };
 
         let turn_context = Arc::new(Session::make_turn_context(
@@ -4876,6 +4898,7 @@ mod tests {
             model_info,
             conversation_id,
             "turn_id".to_string(),
+            services.transport_manager.clone(),
         ));
 
         let session = Arc::new(Session {