Add /side conversations

codex-rs/tui/src/app_event.rs

@@ -29,6 +29,7 @@ use codex_utils_approval_presets::ApprovalPreset;
 use crate::bottom_pane::ApprovalRequest;
 use crate::bottom_pane::StatusLineItem;
 use crate::bottom_pane::TerminalTitleItem;
+use crate::chatwidget::UserMessage;
 use crate::history_cell::HistoryCell;
 use crate::legacy_core::plugins::PluginCapabilitySummary;
 
@@ -103,6 +104,12 @@ pub(crate) enum AppEvent {
     /// Switch the active thread to the selected agent.
     SelectAgentThread(ThreadId),
 
+    /// Fork the current thread into a transient side conversation.
+    StartSide {
+        parent_thread_id: ThreadId,
+        user_message: Option<UserMessage>,
+    },
+
     /// Submit an op to the specified thread, regardless of current focus.
     SubmitThreadOp {
         thread_id: ThreadId,

codex-rs/tui/src/app_server_session.rs

@@ -36,6 +36,8 @@ use codex_app_server_protocol::ThreadCompactStartParams;
 use codex_app_server_protocol::ThreadCompactStartResponse;
 use codex_app_server_protocol::ThreadForkParams;
 use codex_app_server_protocol::ThreadForkResponse;
+use codex_app_server_protocol::ThreadInjectItemsParams;
+use codex_app_server_protocol::ThreadInjectItemsResponse;
 use codex_app_server_protocol::ThreadListParams;
 use codex_app_server_protocol::ThreadListResponse;
 use codex_app_server_protocol::ThreadLoadedListParams;
@@ -76,6 +78,7 @@ use codex_app_server_protocol::TurnSteerParams;
 use codex_app_server_protocol::TurnSteerResponse;
 use codex_otel::TelemetryAuthMode;
 use codex_protocol::ThreadId;
+use codex_protocol::models::ResponseItem;
 use codex_protocol::openai_models::ModelAvailabilityNux;
 use codex_protocol::openai_models::ModelPreset;
 use codex_protocol::openai_models::ModelUpgrade;
@@ -415,6 +418,29 @@ impl AppServerSession {
         Ok(response.thread)
     }
 
+    pub(crate) async fn thread_inject_items(
+        &mut self,
+        thread_id: ThreadId,
+        items: Vec<ResponseItem>,
+    ) -> Result<ThreadInjectItemsResponse> {
+        let items = items
+            .into_iter()
+            .map(serde_json::to_value)
+            .collect::<std::result::Result<Vec<_>, _>>()
+            .wrap_err("failed to encode thread/inject_items payload")?;
+        let request_id = self.next_request_id();
+        self.client
+            .request_typed(ClientRequest::ThreadInjectItems {
+                request_id,
+                params: ThreadInjectItemsParams {
+                    thread_id: thread_id.to_string(),
+                    items,
+                },
+            })
+            .await
+            .wrap_err("thread/inject_items failed during TUI side conversation setup")
+    }
+
     #[allow(clippy::too_many_arguments)]
     pub(crate) async fn turn_start(
         &mut self,
@@ -967,6 +993,8 @@ fn thread_fork_params_from_config(
         approvals_reviewer: approvals_reviewer_override_from_config(&config),
         sandbox: sandbox_mode_from_policy(config.permissions.sandbox_policy.get().clone()),
         config: config_request_overrides_from_config(&config),
+        base_instructions: config.base_instructions.clone(),
+        developer_instructions: config.developer_instructions.clone(),
         ephemeral: config.ephemeral,
         persist_extended_history: true,
         ..ThreadForkParams::default()
@@ -1329,6 +1357,28 @@ mod tests {
         assert_eq!(fork.model_provider, None);
     }
 
+    #[tokio::test]
+    async fn thread_fork_params_forward_instruction_overrides() {
+        let temp_dir = tempfile::tempdir().expect("tempdir");
+        let mut config = build_config(&temp_dir).await;
+        config.base_instructions = Some("Base override.".to_string());
+        config.developer_instructions = Some("Developer override.".to_string());
+        let thread_id = ThreadId::new();
+
+        let params = thread_fork_params_from_config(
+            config,
+            thread_id,
+            ThreadParamsMode::Embedded,
+            /*remote_cwd_override*/ None,
+        );
+
+        assert_eq!(params.base_instructions.as_deref(), Some("Base override."));
+        assert_eq!(
+            params.developer_instructions.as_deref(),
+            Some("Developer override.")
+        );
+    }
+
     #[tokio::test]
     async fn resume_response_restores_turns_from_thread_items() {
         let temp_dir = tempfile::tempdir().expect("tempdir");

codex-rs/tui/src/bottom_pane/chat_composer.rs

@@ -171,6 +171,7 @@ use super::footer::render_footer_from_props;
 use super::footer::render_footer_hint_items;
 use super::footer::render_footer_line;
 use super::footer::reset_mode_after_activity;
+use super::footer::side_conversation_context_line;
 use super::footer::single_line_footer_layout;
 use super::footer::toggle_shortcut_mode;
 use super::footer::uses_passive_footer_status_layout;
@@ -359,9 +360,11 @@ pub(crate) struct ChatComposer {
     realtime_conversation_enabled: bool,
     audio_device_selection_enabled: bool,
     windows_degraded_sandbox_active: bool,
+    side_conversation_active: bool,
     is_zellij: bool,
     status_line_value: Option<Line<'static>>,
     status_line_enabled: bool,
+    side_conversation_context_label: Option<String>,
     // Agent label injected into the footer's contextual row when multi-agent mode is active.
     active_agent_label: Option<String>,
     history_search: Option<HistorySearchSession>,
@@ -411,6 +414,7 @@ impl ChatComposer {
             realtime_conversation_enabled: self.realtime_conversation_enabled,
             audio_device_selection_enabled: self.audio_device_selection_enabled,
             allow_elevate_sandbox: self.windows_degraded_sandbox_active,
+            side_conversation_active: self.side_conversation_active,
         }
     }
 
@@ -494,12 +498,14 @@ impl ChatComposer {
             realtime_conversation_enabled: false,
             audio_device_selection_enabled: false,
             windows_degraded_sandbox_active: false,
+            side_conversation_active: false,
             is_zellij: matches!(
                 codex_terminal_detection::terminal_info().multiplexer,
                 Some(codex_terminal_detection::Multiplexer::Zellij {})
             ),
             status_line_value: None,
             status_line_enabled: false,
+            side_conversation_context_label: None,
             active_agent_label: None,
             history_search: None,
         };
@@ -594,6 +600,10 @@ impl ChatComposer {
         self.audio_device_selection_enabled = enabled;
     }
 
+    pub fn set_side_conversation_active(&mut self, active: bool) {
+        self.side_conversation_active = active;
+    }
+
     /// Compatibility shim for tests that still toggle the removed steer mode flag.
     #[cfg(test)]
     pub fn set_steer_enabled(&mut self, _enabled: bool) {}
@@ -3258,6 +3268,7 @@ impl ChatComposer {
                         realtime_conversation_enabled,
                         audio_device_selection_enabled,
                         windows_degraded_sandbox_active: self.windows_degraded_sandbox_active,
+                        side_conversation_active: self.side_conversation_active,
                     });
                     command_popup.on_composer_text_change(first_line.to_string());
                     self.active_popup = ActivePopup::Command(command_popup);
@@ -3502,6 +3513,14 @@ impl ChatComposer {
         true
     }
 
+    pub(crate) fn set_side_conversation_context_label(&mut self, label: Option<String>) -> bool {
+        if self.side_conversation_context_label == label {
+            return false;
+        }
+        self.side_conversation_context_label = label;
+        true
+    }
+
     /// Replaces the contextual footer label for the currently viewed agent.
     ///
     /// Returning `false` means the value was unchanged, so callers can skip redraw work. This
@@ -3711,12 +3730,13 @@ impl ChatComposer {
                     } else {
                         self.collaboration_mode_indicator
                     };
+                    let active_footer_hint_override = self.footer_hint_override.as_ref();
                     let mut left_width = if self.footer_flash_visible() {
                         self.footer_flash
                             .as_ref()
                             .map(|flash| flash.line.width() as u16)
                             .unwrap_or(0)
-                    } else if let Some(items) = self.footer_hint_override.as_ref() {
+                    } else if let Some(items) = active_footer_hint_override {
                         footer_hint_items_width(items)
                     } else if status_line_active {
                         truncated_status_line
@@ -3732,7 +3752,11 @@ impl ChatComposer {
                             show_queue_hint,
                         )
                     };
-                    let right_line = if status_line_active {
+                    let right_line = if let Some(label) =
+                        self.side_conversation_context_label.as_ref()
+                    {
+                        Some(side_conversation_context_line(label))
+                    } else if status_line_active {
                         let full =
                             mode_indicator_line(self.collaboration_mode_indicator, show_cycle_hint);
                         let compact = mode_indicator_line(
@@ -3765,7 +3789,7 @@ impl ChatComposer {
                     let can_show_left_and_context =
                         can_show_left_with_context(hint_rect, left_width, right_width);
                     let has_override =
-                        self.footer_flash_visible() || self.footer_hint_override.is_some();
+                        self.footer_flash_visible() || active_footer_hint_override.is_some();
                     let single_line_layout = if has_override || status_line_active {
                         None
                     } else {
@@ -3843,7 +3867,7 @@ impl ChatComposer {
                         if let Some(flash) = self.footer_flash.as_ref() {
                             flash.line.render(inset_footer_hint_area(hint_rect), buf);
                         }
-                    } else if let Some(items) = self.footer_hint_override.as_ref() {
+                    } else if let Some(items) = active_footer_hint_override {
                         render_footer_hint_items(hint_rect, buf, items);
                     } else if status_line_active {
                         if let Some(line) = truncated_status_line {
@@ -3860,7 +3884,6 @@ impl ChatComposer {
                             show_queue_hint,
                         );
                     }
-
                     if show_right && let Some(line) = &right_line {
                         render_context_right(hint_rect, buf, line);
                     }

codex-rs/tui/src/bottom_pane/command_popup.rs

@@ -38,6 +38,7 @@ pub(crate) struct CommandPopupFlags {
     pub(crate) realtime_conversation_enabled: bool,
     pub(crate) audio_device_selection_enabled: bool,
     pub(crate) windows_degraded_sandbox_active: bool,
+    pub(crate) side_conversation_active: bool,
 }
 
 impl From<CommandPopupFlags> for slash_commands::BuiltinCommandFlags {
@@ -51,6 +52,7 @@ impl From<CommandPopupFlags> for slash_commands::BuiltinCommandFlags {
             realtime_conversation_enabled: value.realtime_conversation_enabled,
             audio_device_selection_enabled: value.audio_device_selection_enabled,
             allow_elevate_sandbox: value.windows_degraded_sandbox_active,
+            side_conversation_active: value.side_conversation_active,
         }
     }
 }
@@ -359,6 +361,7 @@ mod tests {
             realtime_conversation_enabled: false,
             audio_device_selection_enabled: false,
             windows_degraded_sandbox_active: false,
+            side_conversation_active: false,
         });
         popup.on_composer_text_change("/collab".to_string());
 
@@ -379,6 +382,7 @@ mod tests {
             realtime_conversation_enabled: false,
             audio_device_selection_enabled: false,
             windows_degraded_sandbox_active: false,
+            side_conversation_active: false,
         });
         popup.on_composer_text_change("/plan".to_string());
 
@@ -399,6 +403,7 @@ mod tests {
             realtime_conversation_enabled: false,
             audio_device_selection_enabled: false,
             windows_degraded_sandbox_active: false,
+            side_conversation_active: false,
         });
         popup.on_composer_text_change("/pers".to_string());
 
@@ -426,6 +431,7 @@ mod tests {
             realtime_conversation_enabled: false,
             audio_device_selection_enabled: false,
             windows_degraded_sandbox_active: false,
+            side_conversation_active: false,
         });
         popup.on_composer_text_change("/personality".to_string());
 
@@ -446,6 +452,7 @@ mod tests {
             realtime_conversation_enabled: true,
             audio_device_selection_enabled: false,
             windows_degraded_sandbox_active: false,
+            side_conversation_active: false,
         });
         popup.on_composer_text_change("/aud".to_string());
 

codex-rs/tui/src/bottom_pane/footer.rs

@@ -16,7 +16,7 @@
 //!   confirmation, shortcut help, or queue hints.
 //! - "contextual footer" means the footer is free to show ambient context instead of an
 //!   instruction. In that state, the footer may render the configured status line, the active
-//!   agent label, or both combined.
+//!   agent label, side-conversation state, or some combination of those.
 //!
 //! Single-line collapse overview:
 //! 1. The composer decides the current `FooterMode` and hint flags, then calls
@@ -483,6 +483,14 @@ pub(crate) fn mode_indicator_line(
     indicator.map(|indicator| Line::from(vec![indicator.styled_span(show_cycle_hint)]))
 }
 
+pub(crate) fn side_conversation_context_line(label: &str) -> Line<'static> {
+    if let Some(rest) = label.strip_prefix("Side ") {
+        Line::from(vec!["Side".magenta().bold(), format!(" {rest}").magenta()])
+    } else {
+        Line::from(label.to_string()).magenta()
+    }
+}
+
 fn right_aligned_x(area: Rect, content_width: u16) -> Option<u16> {
     if area.is_empty() {
         return None;

codex-rs/tui/src/bottom_pane/mod.rs

@@ -345,6 +345,16 @@ impl BottomPane {
         self.request_redraw();
     }
 
+    pub(crate) fn set_side_conversation_active(&mut self, active: bool) {
+        self.composer.set_side_conversation_active(active);
+        self.request_redraw();
+    }
+
+    pub(crate) fn set_placeholder_text(&mut self, placeholder: String) {
+        self.composer.set_placeholder_text(placeholder);
+        self.request_redraw();
+    }
+
     /// Update the key hint shown next to queued messages so it matches the
     /// binding that `ChatWidget` actually listens for.
     pub(crate) fn set_queued_message_edit_binding(&mut self, binding: KeyBinding) {
@@ -1272,6 +1282,12 @@ impl BottomPane {
             self.request_redraw();
         }
     }
+
+    pub(crate) fn set_side_conversation_context_label(&mut self, label: Option<String>) {
+        if self.composer.set_side_conversation_context_label(label) {
+            self.request_redraw();
+        }
+    }
 }
 
 #[cfg(not(target_os = "linux"))]