fix: three PTY input handling gaps reported in issue #145

Bug 1 — DECSCUSR cursor shape silently dropped:
Add ghostty_render_state_get_cursor_style and
ghostty_render_state_get_cursor_blinking WASM exports to the patch.
GhosttyTerminal.getCursor() now reads both from the terminal state
instead of hardcoding style:'block' and blinking:false.

Bug 2 — Ctrl+V not forwarded to PTY:
InputHandler.handleKeyDown emits the encoded \x16 byte to onDataCallback
before returning, so apps that read Ctrl+V natively (e.g. image paste
flows) receive it. The browser paste event still fires afterwards so
handlePaste continues to cover text paste unchanged.

Bug 3 — Mouse wheel sends arrow keys when mouse tracking is active:
Terminal.handleWheel checks hasMouseTracking() in the isAlternateScreen
branch. When active, it emits an SGR scroll sequence
(\x1b[<64/65;col;rowM) via dataEmitter instead of arrow keys, matching
xterm.js behaviour. The arrow-key fallback is preserved for apps without
mouse tracking (less, man, etc.).

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

Author: jesse23

lib/ghostty.ts

@@ -31,9 +31,9 @@ export {
   type GhosttyCell,
   type GhosttyTerminalConfig,
   KeyEncoderOption,
-  type RGB,
   type RenderStateColors,
   type RenderStateCursor,
+  type RGB,
 };
 
 /**
@@ -55,7 +55,7 @@ export class Ghostty {
   createTerminal(
     cols: number = 80,
     rows: number = 24,
-    config?: GhosttyTerminalConfig
+    config?: GhosttyTerminalConfig,
   ): GhosttyTerminal {
     return new GhosttyTerminal(this.exports, this.memory, cols, rows, config);
   }
@@ -145,7 +145,7 @@ export class Ghostty {
           const bytes = new Uint8Array(
             (wasmInstance.exports as GhosttyWasmExports).memory.buffer,
             ptr,
-            len
+            len,
           );
           console.log('[ghostty-vt]', new TextDecoder().decode(bytes));
         },
@@ -215,7 +215,7 @@ export class KeyEncoder {
       eventPtr,
       bufPtr,
       bufferSize,
-      writtenPtr
+      writtenPtr,
     );
 
     if (encodeResult !== 0) {
@@ -273,7 +273,7 @@ export class GhosttyTerminal {
     memory: WebAssembly.Memory,
     cols: number = 80,
     rows: number = 24,
-    config?: GhosttyTerminalConfig
+    config?: GhosttyTerminalConfig,
   ) {
     this.exports = exports;
     this.memory = memory;
@@ -399,8 +399,11 @@ export class GhosttyTerminal {
       viewportX: this.exports.ghostty_render_state_get_cursor_x(this.handle),
       viewportY: this.exports.ghostty_render_state_get_cursor_y(this.handle),
       visible: this.exports.ghostty_render_state_get_cursor_visible(this.handle),
-      blinking: false, // TODO: Add blinking support
-      style: 'block', // TODO: Add style support
+      blinking: this.exports.ghostty_render_state_get_cursor_blinking(this.handle),
+      style:
+        (['block', 'bar', 'underline'] as const)[
+          this.exports.ghostty_render_state_get_cursor_style(this.handle)
+        ] ?? 'block',
     };
   }
 
@@ -460,7 +463,7 @@ export class GhosttyTerminal {
     const count = this.exports.ghostty_render_state_get_viewport(
       this.handle,
       this.viewportBufferPtr,
-      totalCells
+      totalCells,
     );
 
     if (count < 0) return this.cellPool;
@@ -569,7 +572,7 @@ export class GhosttyTerminal {
       this.handle,
       offset,
       this.viewportBufferPtr,
-      this._cols
+      this._cols,
     );
 
     if (count < 0) return null;
@@ -629,7 +632,7 @@ export class GhosttyTerminal {
           row,
           col,
           bufPtr,
-          bufSize
+          bufSize,
         );
 
         // 0 means no hyperlink at this position
@@ -676,7 +679,7 @@ export class GhosttyTerminal {
           offset,
           col,
           bufPtr,
-          bufSize
+          bufSize,
         );
 
         // 0 means no hyperlink at this position
@@ -811,7 +814,7 @@ export class GhosttyTerminal {
       row,
       col,
       this.graphemeBufferPtr,
-      16
+      16,
     );
 
     if (count < 0) return null;
@@ -849,7 +852,7 @@ export class GhosttyTerminal {
       offset,
       col,
       this.graphemeBufferPtr,
-      16
+      16,
     );
 
     if (count < 0) return null;

lib/input-handler.ts

@@ -13,8 +13,7 @@
  * - Captures all keyboard input (preventDefault on everything)
  */
 
-import type { Ghostty } from './ghostty';
-import type { KeyEncoder } from './ghostty';
+import type { Ghostty, KeyEncoder } from './ghostty';
 import type { IKeyEvent } from './interfaces';
 import { Key, KeyAction, KeyEncoderOption, Mods } from './types';
 
@@ -231,7 +230,7 @@ export class InputHandler {
     getMode?: (mode: number) => boolean,
     onCopy?: () => boolean,
     inputElement?: HTMLElement,
-    mouseConfig?: MouseTrackingConfig
+    mouseConfig?: MouseTrackingConfig,
   ) {
     this.encoder = ghostty.createKeyEncoder();
     this.container = container;
@@ -384,9 +383,18 @@ export class InputHandler {
       }
     }
 
-    // Allow Ctrl+V and Cmd+V to trigger paste event (don't preventDefault)
+    // Ctrl+V / Cmd+V: emit \x16 to the PTY so apps that read it natively
+    // (e.g. opencode image paste via osascript) receive the signal, then let
+    // the browser paste event fire so handlePaste covers text content.
     if ((event.ctrlKey || event.metaKey) && event.code === 'KeyV') {
-      // Let the browser's native paste event fire
+      const encoded = this.encoder.encode({
+        key: Key.V,
+        mods: event.ctrlKey ? Mods.CTRL : Mods.SUPER,
+        action: KeyAction.PRESS,
+      });
+      if (encoded.length > 0) {
+        this.onDataCallback(new TextDecoder().decode(encoded));
+      }
       return;
     }
 
@@ -765,7 +773,7 @@ export class InputHandler {
     col: number,
     row: number,
     isRelease: boolean,
-    modifiers: number
+    modifiers: number,
   ): string {
     const btn = button + modifiers;
     const suffix = isRelease ? 'm' : 'M';
@@ -793,7 +801,7 @@ export class InputHandler {
     col: number,
     row: number,
     isRelease: boolean,
-    event: MouseEvent
+    event: MouseEvent,
   ): void {
     const modifiers = this.getMouseModifiers(event);
 

lib/terminal.ts

@@ -477,15 +477,15 @@ export class Terminal implements ITerminalCore {
           return this.copySelection();
         },
         this.textarea,
-        mouseConfig
+        mouseConfig,
       );
 
       // Create selection manager (pass textarea for context menu positioning)
       this.selectionManager = new SelectionManager(
         this,
         this.renderer,
         this.wasmTerm,
-        this.textarea
+        this.textarea,
       );
 
       // Connect selection manager to renderer
@@ -845,7 +845,7 @@ export class Terminal implements ITerminalCore {
    * Returns true to prevent default handling
    */
   public attachCustomKeyEventHandler(
-    customKeyEventHandler: (event: KeyboardEvent) => boolean
+    customKeyEventHandler: (event: KeyboardEvent) => boolean,
   ): void {
     this.customKeyEventHandler = customKeyEventHandler;
     // Update input handler if already created
@@ -859,7 +859,7 @@ export class Terminal implements ITerminalCore {
    * Returns true to prevent default handling
    */
   public attachCustomWheelEventHandler(
-    customWheelEventHandler?: (event: WheelEvent) => boolean
+    customWheelEventHandler?: (event: WheelEvent) => boolean,
   ): void {
     this.customWheelEventHandler = customWheelEventHandler;
   }
@@ -1556,9 +1556,21 @@ export class Terminal implements ITerminalCore {
     const isAltScreen = this.wasmTerm?.isAlternateScreen() ?? false;
 
     if (isAltScreen) {
-      // Alternate screen: send arrow keys to the application
-      // Applications like vim handle scrolling internally
-      // Standard: ~3 arrow presses per wheel "click"
+      if (this.wasmTerm?.hasMouseTracking()) {
+        // App negotiated mouse tracking (e.g. vim `set mouse=a`): send SGR
+        // scroll sequence so the app scrolls its buffer, not the cursor.
+        const metrics = this.renderer?.getMetrics();
+        const canvas = this.canvas;
+        if (metrics && canvas) {
+          const rect = canvas.getBoundingClientRect();
+          const col = Math.max(1, Math.floor((e.clientX - rect.left) / metrics.width) + 1);
+          const row = Math.max(1, Math.floor((e.clientY - rect.top) / metrics.height) + 1);
+          const btn = e.deltaY < 0 ? 64 : 65;
+          this.dataEmitter.fire(`\x1b[<${btn};${col};${row}M`);
+        }
+        return;
+      }
+      // No mouse tracking: arrow-key fallback for apps like `less`.
       const direction = e.deltaY > 0 ? 'down' : 'up';
       const count = Math.min(Math.abs(Math.round(e.deltaY / 33)), 5); // Cap at 5
 

lib/types.ts

@@ -379,7 +379,7 @@ export interface GhosttyWasmExports extends WebAssembly.Exports {
     parser: number,
     paramsPtr: number,
     subsPtr: number,
-    paramsLen: number
+    paramsLen: number,
   ): number;
   ghostty_sgr_next(parser: number, attrPtr: number): boolean;
   ghostty_sgr_attribute_tag(attrPtr: number): number;
@@ -396,7 +396,7 @@ export interface GhosttyWasmExports extends WebAssembly.Exports {
     eventPtr: number,
     bufPtr: number,
     bufLen: number,
-    writtenPtr: number
+    writtenPtr: number,
   ): number;
 
   // Key event
@@ -421,21 +421,24 @@ export interface GhosttyWasmExports extends WebAssembly.Exports {
   ghostty_render_state_get_cursor_x(terminal: TerminalHandle): number;
   ghostty_render_state_get_cursor_y(terminal: TerminalHandle): number;
   ghostty_render_state_get_cursor_visible(terminal: TerminalHandle): boolean;
+  /** Returns 0=block, 1=bar, 2=underline */
+  ghostty_render_state_get_cursor_style(terminal: TerminalHandle): number;
+  ghostty_render_state_get_cursor_blinking(terminal: TerminalHandle): boolean;
   ghostty_render_state_get_bg_color(terminal: TerminalHandle): number; // 0xRRGGBB
   ghostty_render_state_get_fg_color(terminal: TerminalHandle): number; // 0xRRGGBB
   ghostty_render_state_is_row_dirty(terminal: TerminalHandle, row: number): boolean;
   ghostty_render_state_mark_clean(terminal: TerminalHandle): void;
   ghostty_render_state_get_viewport(
     terminal: TerminalHandle,
     bufPtr: number,
-    bufLen: number
+    bufLen: number,
   ): number; // Returns total cells written or -1 on error
   ghostty_render_state_get_grapheme(
     terminal: TerminalHandle,
     row: number,
     col: number,
     bufPtr: number,
-    bufLen: number
+    bufLen: number,
   ): number; // Returns count of codepoints or -1 on error
 
   // Terminal modes
@@ -449,14 +452,14 @@ export interface GhosttyWasmExports extends WebAssembly.Exports {
     terminal: TerminalHandle,
     offset: number,
     bufPtr: number,
-    bufLen: number
+    bufLen: number,
   ): number; // Returns cells written or -1 on error
   ghostty_terminal_get_scrollback_grapheme(
     terminal: TerminalHandle,
     offset: number,
     col: number,
     bufPtr: number,
-    bufLen: number
+    bufLen: number,
   ): number; // Returns codepoint count or -1 on error
   ghostty_terminal_is_row_wrapped(terminal: TerminalHandle, row: number): number;
 
@@ -466,14 +469,14 @@ export interface GhosttyWasmExports extends WebAssembly.Exports {
     row: number,
     col: number,
     bufPtr: number,
-    bufLen: number
+    bufLen: number,
   ): number; // Returns bytes written, 0 if no hyperlink, -1 on error
   ghostty_terminal_get_scrollback_hyperlink_uri(
     terminal: TerminalHandle,
     offset: number,
     col: number,
     bufPtr: number,
-    bufLen: number
+    bufLen: number,
   ): number; // Returns bytes written, 0 if no hyperlink, -1 on error
 
   // Response API (for DSR and other terminal queries)

patches/ghostty-wasm-api.patch

@@ -157,6 +157,10 @@ index 000000000..c467102c3
 +int ghostty_render_state_get_cursor_x(GhosttyTerminal term);
 +int ghostty_render_state_get_cursor_y(GhosttyTerminal term);
 +bool ghostty_render_state_get_cursor_visible(GhosttyTerminal term);
++/** Get cursor style: 0=block, 1=bar, 2=underline */
++int ghostty_render_state_get_cursor_style(GhosttyTerminal term);
++/** Check if cursor is blinking */
++bool ghostty_render_state_get_cursor_blinking(GhosttyTerminal term);
 +
 +/** Get default colors as 0xRRGGBB */
 +uint32_t ghostty_render_state_get_bg_color(GhosttyTerminal term);
@@ -340,6 +344,8 @@ index 03a883e20..1336676d7 100644
 +        @export(&c.render_state_get_cursor_x, .{ .name = "ghostty_render_state_get_cursor_x" });
 +        @export(&c.render_state_get_cursor_y, .{ .name = "ghostty_render_state_get_cursor_y" });
 +        @export(&c.render_state_get_cursor_visible, .{ .name = "ghostty_render_state_get_cursor_visible" });
++        @export(&c.render_state_get_cursor_style, .{ .name = "ghostty_render_state_get_cursor_style" });
++        @export(&c.render_state_get_cursor_blinking, .{ .name = "ghostty_render_state_get_cursor_blinking" });
 +        @export(&c.render_state_get_bg_color, .{ .name = "ghostty_render_state_get_bg_color" });
 +        @export(&c.render_state_get_fg_color, .{ .name = "ghostty_render_state_get_fg_color" });
 +        @export(&c.render_state_is_row_dirty, .{ .name = "ghostty_render_state_is_row_dirty" });
@@ -398,6 +404,8 @@ index bc92597f5..d0ee49c1b 100644
 +pub const render_state_get_cursor_x = terminal.renderStateGetCursorX;
 +pub const render_state_get_cursor_y = terminal.renderStateGetCursorY;
 +pub const render_state_get_cursor_visible = terminal.renderStateGetCursorVisible;
++pub const render_state_get_cursor_style = terminal.renderStateGetCursorStyle;
++pub const render_state_get_cursor_blinking = terminal.renderStateGetCursorBlinking;
 +pub const render_state_get_bg_color = terminal.renderStateGetBgColor;
 +pub const render_state_get_fg_color = terminal.renderStateGetFgColor;
 +pub const render_state_is_row_dirty = terminal.renderStateIsRowDirty;
@@ -991,6 +999,22 @@ index 000000000..73ae2e6fa
 +    return wrapper.render_state.cursor.visible;
 +}
 +
++/// Get cursor style: 0=block, 1=bar, 2=underline
++pub fn renderStateGetCursorStyle(ptr: ?*anyopaque) callconv(.c) c_int {
++    const wrapper: *const TerminalWrapper = @ptrCast(@alignCast(ptr orelse return 0));
++    return switch (wrapper.terminal.screens.active.cursor.cursor_style) {
++        .bar => 1,
++        .underline => 2,
++        else => 0,
++    };
++}
++
++/// Check if cursor is blinking
++pub fn renderStateGetCursorBlinking(ptr: ?*anyopaque) callconv(.c) bool {
++    const wrapper: *const TerminalWrapper = @ptrCast(@alignCast(ptr orelse return false));
++    return wrapper.terminal.modes.get(.cursor_blinking);
++}
++
 +/// Get default background color as 0xRRGGBB
 +pub fn renderStateGetBgColor(ptr: ?*anyopaque) callconv(.c) u32 {
 +    const wrapper: *const TerminalWrapper = @ptrCast(@alignCast(ptr orelse return 0));