Expose semantic prompt state through C APIs

include/ghostty.h

@@ -1134,6 +1134,7 @@ GHOSTTY_API ghostty_app_t ghostty_surface_app(ghostty_surface_t);
 GHOSTTY_API ghostty_surface_config_s ghostty_surface_inherited_config(ghostty_surface_t, ghostty_surface_context_e);
 GHOSTTY_API void ghostty_surface_update_config(ghostty_surface_t, ghostty_config_t);
 GHOSTTY_API bool ghostty_surface_needs_confirm_quit(ghostty_surface_t);
+GHOSTTY_API bool ghostty_surface_is_at_prompt(ghostty_surface_t);
 GHOSTTY_API bool ghostty_surface_process_exited(ghostty_surface_t);
 GHOSTTY_API void ghostty_surface_refresh(ghostty_surface_t);
 GHOSTTY_API void ghostty_surface_draw(ghostty_surface_t);

include/ghostty/vt/terminal.h

@@ -1613,6 +1613,17 @@ typedef enum GHOSTTY_ENUM_TYPED {
    * Output type: bool *
    */
   GHOSTTY_TERMINAL_DATA_VT_GROUND = 38,
+
+  /**
+   * Whether the cursor is currently at a semantic shell prompt or input area.
+   *
+   * This depends on semantic prompt markers such as OSC 133. Returns false
+   * when semantic prompt information is unavailable or the alternate screen
+   * is active.
+   *
+   * Output type: bool *
+   */
+  GHOSTTY_TERMINAL_DATA_CURSOR_AT_PROMPT = 39,
   GHOSTTY_TERMINAL_DATA_MAX_VALUE = GHOSTTY_ENUM_MAX_VALUE,
 } GhosttyTerminalData;
 

src/Surface.zig

@@ -967,6 +967,17 @@ pub fn needsConfirmQuit(self: *Surface) bool {
     };
 }
 
+/// True if the surface cursor is currently at a shell prompt according to
+/// semantic prompt integration. If shell integration is unavailable, this
+/// conservatively returns false.
+pub fn isAtPrompt(self: *Surface) bool {
+    if (self.child_exited) return false;
+
+    self.renderer_state.mutex.lockUncancelable(global.io());
+    defer self.renderer_state.mutex.unlock(global.io());
+    return self.io.terminal.cursorIsAtPrompt();
+}
+
 /// Called from the app thread to handle mailbox messages to our specific
 /// surface.
 pub fn handleMessage(self: *Surface, msg: Message) !void {

src/apprt/embedded.zig

@@ -1606,6 +1606,11 @@ pub const CAPI = struct {
         return surface.core_surface.needsConfirmQuit();
     }
 
+    /// Returns true if the surface cursor is currently at a semantic prompt.
+    export fn ghostty_surface_is_at_prompt(surface: *Surface) bool {
+        return surface.core_surface.isAtPrompt();
+    }
+
     /// Returns true if the surface process has exited.
     export fn ghostty_surface_process_exited(surface: *Surface) bool {
         return surface.core_surface.child_exited;

src/terminal/c/terminal.zig

@@ -1355,6 +1355,7 @@ pub const TerminalData = enum(c_int) {
     continuation_max_bytes = 36,
     mode = 37,
     vt_ground = 38,
+    cursor_at_prompt = 39,
 
     /// Output type expected for querying the data of the given kind.
     pub fn OutType(comptime self: TerminalData) type {
@@ -1367,6 +1368,7 @@ pub const TerminalData = enum(c_int) {
             .viewport_active,
             .vt_processing_error,
             .vt_ground,
+            .cursor_at_prompt,
             => bool,
             .active_screen => TerminalScreen,
             .kitty_keyboard_flags => u8,
@@ -1533,6 +1535,7 @@ fn getTyped(
             const mode = out.toMode() orelse return .invalid_value;
             out.value = t.modes.get(mode);
         },
+        .cursor_at_prompt => out.* = t.cursorIsAtPrompt(),
     }
 
     return .success;
@@ -2864,6 +2867,31 @@ test "get cursor_visible" {
     try testing.expect(!visible);
 }
 
+test "get cursor_at_prompt" {
+    var t: Terminal = null;
+    try testing.expectEqual(Result.success, new(
+        &lib.alloc.test_allocator,
+        &t,
+        80,
+        24,
+    ));
+    defer free(t);
+
+    var at_prompt: bool = undefined;
+    try testing.expectEqual(Result.success, get(t, .cursor_at_prompt, @ptrCast(&at_prompt)));
+    try testing.expect(!at_prompt);
+
+    const prompt_start = "\x1b]133;A\x07";
+    vt_write(t, prompt_start, prompt_start.len);
+    try testing.expectEqual(Result.success, get(t, .cursor_at_prompt, @ptrCast(&at_prompt)));
+    try testing.expect(at_prompt);
+
+    const alternate_screen = "\x1b[?1049h";
+    vt_write(t, alternate_screen, alternate_screen.len);
+    try testing.expectEqual(Result.success, get(t, .cursor_at_prompt, @ptrCast(&at_prompt)));
+    try testing.expect(!at_prompt);
+}
+
 test "get active_screen" {
     var t: Terminal = null;
     try testing.expectEqual(Result.success, new(