diff --git a/crates/cli/src/lib.rs b/crates/cli/src/lib.rs
index 9f98eebf..db6e8c4a 100644
--- a/crates/cli/src/lib.rs
+++ b/crates/cli/src/lib.rs
@@ -2958,11 +2958,15 @@ mod tests {
     }
 
     #[test]
-    fn parses_top_level_prompt_flag_for_canonical_one_shot() {
+    fn parses_top_level_prompt_flag_for_interactive_startup_prompt() {
         let cli = parse_ok(&["deepseek", "-p", "Reply with exactly OK."]);
 
         assert_eq!(cli.prompt_flag.as_deref(), Some("Reply with exactly OK."));
         assert!(cli.prompt.is_empty());
+        assert_eq!(
+            root_tui_passthrough(&cli).unwrap(),
+            vec!["--prompt".to_string(), "Reply with exactly OK.".to_string()]
+        );
     }
 
     #[test]
@@ -2976,7 +2980,7 @@ mod tests {
     }
 
     #[test]
-    fn top_level_continue_rejects_one_shot_prompt() {
+    fn top_level_continue_rejects_startup_prompt() {
         let cli = parse_ok(&["codewhale", "--continue", "-p", "follow up"]);
 
         let err = root_tui_passthrough(&cli).expect_err("prompted continue should be rejected");
@@ -2992,6 +2996,10 @@ mod tests {
 
         assert_eq!(cli.prompt, vec!["hello", "world"]);
         assert!(cli.command.is_none());
+        assert_eq!(
+            root_tui_passthrough(&cli).unwrap(),
+            vec!["--prompt".to_string(), "hello world".to_string()]
+        );
     }
 
     #[test]
@@ -3000,6 +3008,10 @@ mod tests {
 
         assert_eq!(cli.prompt_flag.as_deref(), Some("hello"));
         assert_eq!(cli.prompt, vec!["world"]);
+        assert_eq!(
+            root_tui_passthrough(&cli).unwrap(),
+            vec!["--prompt".to_string(), "hello world".to_string()]
+        );
     }
 
     #[test]
diff --git a/crates/tui/src/main.rs b/crates/tui/src/main.rs
index 4e5e35ae..476124ce 100644
--- a/crates/tui/src/main.rs
+++ b/crates/tui/src/main.rs
@@ -121,7 +121,7 @@ struct Cli {
     #[command(flatten)]
     feature_toggles: FeatureToggles,
 
-    /// Send a one-shot prompt (non-interactive)
+    /// Initial prompt to submit in the interactive TUI. Use `exec` for non-interactive runs.
     #[arg(short, long, value_name = "PROMPT", num_args = 1..)]
     prompt: Vec<String>,
 
@@ -427,6 +427,10 @@ fn join_prompt_parts(parts: &[String]) -> String {
     parts.join(" ")
 }
 
+fn top_level_prompt_initial_input(parts: &[String]) -> Option<tui::InitialInput> {
+    (!parts.is_empty()).then(|| tui::InitialInput::Submit(join_prompt_parts(parts)))
+}
+
 fn resolve_exec_resume_session_id(args: &ExecArgs, workspace: &Path) -> Result<Option<String>> {
     if let Some(id) = args.resume.as_ref().or(args.session_id.as_ref()) {
         return Ok(Some(id.clone()));
@@ -975,12 +979,12 @@ async fn main() -> Result<()> {
         };
     }
 
-    // One-shot prompt mode
+    // Top-level prompt mode: submit the initial prompt, then keep the TUI alive
+    // for follow-up messages. Use `codewhale exec` for explicit non-interactive
+    // one-shot behavior (#2370).
     let config = load_config_from_cli(&cli)?;
-    if !cli.prompt.is_empty() {
-        let prompt = join_prompt_parts(&cli.prompt);
-        let model = config.default_model();
-        return run_one_shot(&config, &model, &prompt).await;
+    if let Some(initial_input) = top_level_prompt_initial_input(&cli.prompt) {
+        return run_interactive(&cli, &config, None, Some(initial_input)).await;
     }
 
     // Handle session resume. Plain `codewhale` starts fresh: interrupted
@@ -3783,7 +3787,13 @@ async fn run_pr(
     } else {
         cli.resume.clone()
     };
-    run_interactive(cli, config, resume_session_id, Some(prompt)).await
+    run_interactive(
+        cli,
+        config,
+        resume_session_id,
+        Some(tui::InitialInput::Prefill(prompt)),
+    )
+    .await
 }
 
 /// Return true if `name` resolves to an executable on the current `PATH`.
@@ -4795,7 +4805,7 @@ async fn run_interactive(
     cli: &Cli,
     config: &Config,
     resume_session_id: Option<String>,
-    initial_input: Option<String>,
+    initial_input: Option<tui::InitialInput>,
 ) -> Result<()> {
     let workspace = cli
         .workspace
@@ -5838,6 +5848,16 @@ mod terminal_mode_tests {
         assert_eq!(cli.prompt, vec!["hello", "world"]);
     }
 
+    #[test]
+    fn prompt_flag_starts_interactive_submit_input() {
+        let cli = parse_cli(&["codewhale", "-p", "read", "the", "project"]);
+
+        assert_eq!(
+            top_level_prompt_initial_input(&cli.prompt),
+            Some(tui::InitialInput::Submit("read the project".to_string()))
+        );
+    }
+
     #[test]
     fn companion_binary_reports_its_own_name() {
         assert_eq!(Cli::command().get_name(), "codewhale-tui");
diff --git a/crates/tui/src/tui/app.rs b/crates/tui/src/tui/app.rs
index 0bf82425..94a5c1f5 100644
--- a/crates/tui/src/tui/app.rs
+++ b/crates/tui/src/tui/app.rs
@@ -814,7 +814,19 @@ pub struct TuiOptions {
     /// Used by `deepseek pr <N>` (#451) to drop the model into a
     /// session with the PR context already typed — the user can edit
     /// before sending or hit Enter to fire as-is.
-    pub initial_input: Option<String>,
+    pub initial_input: Option<InitialInput>,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum InitialInput {
+    /// Pre-populate the composer and wait for the user to press Enter.
+    ///
+    /// Used by `codewhale pr <N>` (#451) to drop the model into a session
+    /// with the PR context already typed so the user can edit before sending.
+    Prefill(String),
+    /// Pre-populate the composer, submit it once startup is ready, then keep
+    /// the interactive session open for follow-up messages (#2370).
+    Submit(String),
 }
 
 #[derive(Debug, Clone, Copy)]
@@ -1444,6 +1456,8 @@ pub struct App {
     /// Most recent user prompt accepted for an active engine turn. Ctrl+C can
     /// restore this into an empty composer after cancelling that turn.
     pub last_submitted_prompt: Option<String>,
+    /// Startup prompt should be submitted automatically after the engine is ready.
+    pub auto_submit_initial_input: bool,
     /// Two-tap quit confirmation. When set, a prior Ctrl+C in idle state has
     /// armed the quit shortcut; a second Ctrl+C before this `Instant` exits
     /// the app, while expiry silently re-arms the prompt for next time.
@@ -1803,17 +1817,22 @@ impl App {
         let cached_skills = Self::discover_cached_skills(&workspace, &skills_dir);
 
         let input_history = crate::composer_history::load_history();
-        let (initial_input_text, initial_input_cursor) = match initial_input {
-            // #451: pre-populate the composer when invoked via
-            // `deepseek pr <N>` (or any future caller that wants to
-            // drop the model into a session with context already
-            // typed). Cursor lands at the end so Enter sends as-is.
-            Some(text) if !text.is_empty() => {
-                let cursor = text.len();
-                (text, cursor)
-            }
-            _ => (String::new(), 0),
-        };
+        let (initial_input_text, initial_input_cursor, auto_submit_initial_input) =
+            match initial_input {
+                // #451: pre-populate the composer when invoked via
+                // `deepseek pr <N>` (or any future caller that wants to
+                // drop the model into a session with context already
+                // typed). Cursor lands at the end so Enter sends as-is.
+                Some(InitialInput::Prefill(text)) if !text.is_empty() => {
+                    let cursor = text.len();
+                    (text, cursor, false)
+                }
+                Some(InitialInput::Submit(text)) if !text.is_empty() => {
+                    let cursor = text.len();
+                    (text, cursor, true)
+                }
+                _ => (String::new(), 0, false),
+            };
         Self {
             mode: initial_mode,
             composer: ComposerState {
@@ -2004,6 +2023,7 @@ impl App {
             coherence_state: CoherenceState::default(),
             last_send_at: None,
             last_submitted_prompt: None,
+            auto_submit_initial_input,
             quit_armed_until: None,
             cycle_count: 0,
             cycle_briefings: Vec::new(),
@@ -4855,6 +4875,35 @@ mod tests {
         }
     }
 
+    #[test]
+    fn initial_input_prefill_waits_for_manual_submit() {
+        let mut options = test_options(false);
+        options.initial_input = Some(InitialInput::Prefill("review this PR".to_string()));
+
+        let app = App::new(options, &Config::default());
+
+        assert_eq!(app.input, "review this PR");
+        assert_eq!(app.cursor_position, "review this PR".chars().count());
+        assert!(!app.auto_submit_initial_input);
+    }
+
+    #[test]
+    fn initial_input_submit_marks_startup_dispatch() {
+        let mut options = test_options(false);
+        options.initial_input = Some(InitialInput::Submit(
+            "Read the project and wait for instructions".to_string(),
+        ));
+
+        let app = App::new(options, &Config::default());
+
+        assert_eq!(app.input, "Read the project and wait for instructions");
+        assert_eq!(
+            app.cursor_position,
+            "Read the project and wait for instructions".chars().count()
+        );
+        assert!(app.auto_submit_initial_input);
+    }
+
     #[test]
     fn composer_arrows_scroll_default_is_true_without_mouse_capture() {
         assert!(default_composer_arrows_scroll_for_platform(false, false));
diff --git a/crates/tui/src/tui/mod.rs b/crates/tui/src/tui/mod.rs
index bfb2e477..3b20455f 100644
--- a/crates/tui/src/tui/mod.rs
+++ b/crates/tui/src/tui/mod.rs
@@ -76,5 +76,5 @@ pub mod workspace_context;
 
 // === Re-exports ===
 
-pub use app::TuiOptions;
+pub use app::{InitialInput, TuiOptions};
 pub use ui::run_tui;
diff --git a/crates/tui/src/tui/ui.rs b/crates/tui/src/tui/ui.rs
index efbae714..e1a040a5 100644
--- a/crates/tui/src/tui/ui.rs
+++ b/crates/tui/src/tui/ui.rs
@@ -530,6 +530,19 @@ pub async fn run_tui(config: &Config, options: TuiOptions) -> Result<()> {
         persistence_actor::init_actor(handle);
     }
 
+    if app.auto_submit_initial_input {
+        app.auto_submit_initial_input = false;
+        if app.onboarding == OnboardingState::None {
+            if let Some(input) = app.submit_input() {
+                let queued = build_queued_message(&mut app, input);
+                dispatch_user_message(&mut app, config, &engine_handle, queued).await?;
+            }
+        } else if app.status_message.is_none() && !app.input.trim().is_empty() {
+            app.status_message =
+                Some("Initial prompt ready; complete setup, then press Enter".to_string());
+        }
+    }
+
     let result = run_event_loop(
         &mut terminal,
         &mut app,