Update ghostty submodule

.github/hooks/setupRepo.json

@@ -1,10 +0,0 @@
-{
-	"hooks": {
-		"SessionStart": [
-			{
-				"type": "command",
-				"command": "npm run agent:setup-repo"
-			}
-		]
-	}
-}

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "vendor/ghostty"]
+	path = vendor/ghostty
+	url = https://github.com/ghostty-org/ghostty

addons/addon-attach/package.json

@@ -16,7 +16,7 @@
     "xterm.js"
   ],
   "scripts": {
-    "build": "../../node_modules/.bin/tsgo -p .",
+    "build": "../../node_modules/.bin/tsc -p .",
     "prepackage": "npm run build",
     "package": "../../node_modules/.bin/webpack",
     "prepublishOnly": "npm run package",

addons/addon-attach/test/tsconfig.json

@@ -9,15 +9,13 @@
     "outDir": "../out-test",
     "sourceMap": true,
     "removeComments": true,
+    "baseUrl": ".",
     "paths": {
       "common/*": [
         "../../../src/common/*"
       ],
       "browser/*": [
         "../../../src/browser/*"
-      ],
-      "*": [
-        "./*"
       ]
     },
     "strict": true,

addons/addon-clipboard/package.json

@@ -16,7 +16,7 @@
     "xterm.js"
   ],
   "scripts": {
-    "build": "../../node_modules/.bin/tsgo -p .",
+    "build": "../../node_modules/.bin/tsc -p .",
     "prepackage": "npm run build",
     "package": "../../node_modules/.bin/webpack",
     "prepublishOnly": "npm run package",

addons/addon-clipboard/test/tsconfig.json

@@ -9,15 +9,13 @@
     "outDir": "../out-test",
     "sourceMap": true,
     "removeComments": true,
+    "baseUrl": ".",
     "paths": {
       "common/*": [
         "../../../src/common/*"
       ],
       "browser/*": [
         "../../../src/browser/*"
-      ],
-      "*": [
-        "./*"
       ]
     },
     "strict": true,

addons/addon-fit/package.json

@@ -16,7 +16,7 @@
     "xterm.js"
   ],
   "scripts": {
-    "build": "../../node_modules/.bin/tsgo -p .",
+    "build": "../../node_modules/.bin/tsc -p .",
     "prepackage": "npm run build",
     "package": "../../node_modules/.bin/webpack",
     "prepublishOnly": "npm run package",

addons/addon-fit/test/tsconfig.json

@@ -9,15 +9,13 @@
     "outDir": "../out-test",
     "sourceMap": true,
     "removeComments": true,
+    "baseUrl": ".",
     "paths": {
       "common/*": [
         "../../../src/common/*"
       ],
       "browser/*": [
         "../../../src/browser/*"
-      ],
-      "*": [
-        "./*"
       ]
     },
     "strict": true,

addons/addon-image/README.md

@@ -30,9 +30,7 @@ const customSettings: IImageAddonOptions = {
   storageLimit: 128,          // FIFO storage limit in MB
   showPlaceholder: true,      // whether to show a placeholder for evicted images
   iipSupport: true,           // enable iTerm IIP support
-  iipSizeLimit: 20000000,     // size limit of a single IIP sequence
-  kittySupport: true,         // enable Kitty graphics support
-  kittySizeLimit: 20000000    // size limit of a single Kitty sequence
+  iipSizeLimit: 20000000      // size limit of a single IIP sequence
 }
 
 // initialization

addons/addon-image/package.json

@@ -18,13 +18,13 @@
     "xterm.js"
   ],
   "scripts": {
-    "prepackage": "../../node_modules/.bin/tsgo -p .",
+    "prepackage": "../../node_modules/.bin/tsc -p .",
     "package": "../../node_modules/.bin/webpack",
     "prepublishOnly": "npm run package",
     "start": "node ../../demo/start"
   },
   "devDependencies": {
     "sixel": "^0.16.0",
-    "xterm-wasm-parts": "^0.3.0"
+    "xterm-wasm-parts": "^0.1.0"
   }
 }

addons/addon-image/src/IIPHandler.ts

@@ -4,21 +4,13 @@
  */
 import { IImageAddonOptions, IOscHandler, IResetHandler, ITerminalExt } from './Types';
 import { ImageRenderer } from './ImageRenderer';
-import { IIPImageStorage } from './IIPImageStorage';
-import { CELL_SIZE_DEFAULT } from './ImageStorage';
+import { ImageStorage, CELL_SIZE_DEFAULT } from './ImageStorage';
 import Base64Decoder from 'xterm-wasm-parts/lib/base64/Base64Decoder.wasm';
 import { HeaderParser, IHeaderFields, HeaderState } from './IIPHeaderParser';
 import { imageType, UNSUPPORTED_TYPE } from './IIPMetrics';
 
-// Local const enum mirror - esbuild can't inline const enums from external packages
-const enum DecoderConst {
-  // Limit held memory in base64 decoder (encoded bytes).
-  KEEP_DATA = 4194304,
-  // Initial buffer allocation for the decoder.
-  INITIAL_DATA = 1048576,
-  // Local mirror of const enum (esbuild can't inline const enums from external packages)
-  OK = 0
-}
+// limit hold memory in base64 decoder
+const KEEP_DATA = 4194304;
 
 // default IIP header values
 const DEFAULT_HEADER: IHeaderFields = {
@@ -35,19 +27,15 @@ export class IIPHandler implements IOscHandler, IResetHandler {
   private _aborted = false;
   private _hp = new HeaderParser();
   private _header: IHeaderFields = DEFAULT_HEADER;
-  private _dec: Base64Decoder;
+  private _dec = new Base64Decoder(KEEP_DATA);
   private _metrics = UNSUPPORTED_TYPE;
 
   constructor(
     private readonly _opts: IImageAddonOptions,
     private readonly _renderer: ImageRenderer,
-    private readonly _storage: IIPImageStorage,
+    private readonly _storage: ImageStorage,
     private readonly _coreTerminal: ITerminalExt
-  ) {
-    const maxEncodedBytes = Math.ceil(this._opts.iipSizeLimit * 4 / 3);
-    const initialBytes = Math.min(DecoderConst.INITIAL_DATA, maxEncodedBytes);
-    this._dec = new Base64Decoder(DecoderConst.KEEP_DATA, maxEncodedBytes, initialBytes);
-  }
+  ) {}
 
   public reset(): void {}
 
@@ -62,7 +50,7 @@ export class IIPHandler implements IOscHandler, IResetHandler {
     if (this._aborted) return;
 
     if (this._hp.state === HeaderState.END) {
-      if ((this._dec.put(data.subarray(start, end)) as number) !== DecoderConst.OK) {
+      if (this._dec.put(data, start, end)) {
         this._dec.release();
         this._aborted = true;
       }
@@ -78,8 +66,8 @@ export class IIPHandler implements IOscHandler, IResetHandler {
           this._aborted = true;
           return;
         }
-        this._dec.init();
-        if ((this._dec.put(data.subarray(dataPos, end)) as number) !== DecoderConst.OK) {
+        this._dec.init(this._header.size);
+        if (this._dec.put(data, dataPos, end)) {
           this._dec.release();
           this._aborted = true;
         }
@@ -97,15 +85,13 @@ export class IIPHandler implements IOscHandler, IResetHandler {
     let cond: number | boolean = true;
     if (cond = success) {
       if (cond = !this._dec.end()) {
-        if (cond = this._dec.data8.length === this._header.size) {
-          this._metrics = imageType(this._dec.data8);
-          if (cond = this._metrics.mime !== 'unsupported') {
-            w = this._metrics.width;
-            h = this._metrics.height;
-            if (cond = w && h && w * h < this._opts.pixelLimit) {
-              [w, h] = this._resize(w, h).map(Math.floor);
-              cond = w && h && w * h < this._opts.pixelLimit;
-            }
+        this._metrics = imageType(this._dec.data8);
+        if (cond = this._metrics.mime !== 'unsupported') {
+          w = this._metrics.width;
+          h = this._metrics.height;
+          if (cond = w && h && w * h < this._opts.pixelLimit) {
+            [w, h] = this._resize(w, h).map(Math.floor);
+            cond = w && h && w * h < this._opts.pixelLimit;
           }
         }
       }

addons/addon-image/src/IIPImageStorage.ts

@@ -1,26 +0,0 @@
-/**
- * Copyright (c) 2023 The xterm.js authors. All rights reserved.
- * @license MIT
- */
-
-import { ImageStorage } from './ImageStorage';
-
-/**
- * IIP (iTerm Image Protocol) specific image storage controller.
- *
- * Wraps the shared ImageStorage with IIP protocol semantics:
- * - Always uses scrolling mode (cursor advances with image)
- */
-export class IIPImageStorage {
-  constructor(
-    private readonly _storage: ImageStorage
-  ) {}
-
-  /**
-   * Add an IIP image to storage.
-   * Always uses scrolling mode — cursor advances past the image.
-   */
-  public addImage(img: HTMLCanvasElement | ImageBitmap): void {
-    this._storage.addImage(img, true);
-  }
-}

addons/addon-image/src/ImageAddon.ts

@@ -8,11 +8,7 @@ import type { ImageAddon as IImageApi } from '@xterm/addon-image';
 import { IIPHandler } from './IIPHandler';
 import { ImageRenderer } from './ImageRenderer';
 import { ImageStorage, CELL_SIZE_DEFAULT } from './ImageStorage';
-import { KittyGraphicsHandler } from './kitty/KittyGraphicsHandler';
-import { KittyImageStorage } from './kitty/KittyImageStorage';
 import { SixelHandler } from './SixelHandler';
-import { SixelImageStorage } from './SixelImageStorage';
-import { IIPImageStorage } from './IIPImageStorage';
 import { ITerminalExt, IImageAddonOptions, IResetHandler } from './Types';
 
 // default values of addon ctor options
@@ -26,9 +22,7 @@ const DEFAULT_OPTIONS: IImageAddonOptions = {
   storageLimit: 128,
   showPlaceholder: true,
   iipSupport: true,
-  iipSizeLimit: 20000000,
-  kittySupport: true,
-  kittySizeLimit: 20000000
+  iipSizeLimit: 20000000
 };
 
 // max palette size supported by the sixel lib (compile time setting)
@@ -135,8 +129,7 @@ export class ImageAddon implements ITerminalAddon, IImageApi {
 
     // SIXEL handler
     if (this._opts.sixelSupport) {
-      const sixelStorage = new SixelImageStorage(this._storage!, this._opts, this._renderer!, terminal);
-      const sixelHandler = new SixelHandler(this._opts, sixelStorage, terminal);
+      const sixelHandler = new SixelHandler(this._opts, this._storage!, terminal);
       this._handlers.set('sixel', sixelHandler);
       this._disposeLater(
         terminal._core._inputHandler._parser.registerDcsHandler({ final: 'q' }, sixelHandler)
@@ -145,25 +138,12 @@ export class ImageAddon implements ITerminalAddon, IImageApi {
 
     // iTerm IIP handler
     if (this._opts.iipSupport) {
-      const iipStorage = new IIPImageStorage(this._storage!);
-      const iipHandler = new IIPHandler(this._opts, this._renderer!, iipStorage, terminal);
+      const iipHandler = new IIPHandler(this._opts, this._renderer!, this._storage!, terminal);
       this._handlers.set('iip', iipHandler);
       this._disposeLater(
         terminal._core._inputHandler._parser.registerOscHandler(1337, iipHandler)
       );
     }
-
-    // Kitty graphics handler
-    if (this._opts.kittySupport) {
-      const kittyStorage = new KittyImageStorage(this._storage!);
-      const kittyHandler = new KittyGraphicsHandler(this._opts, this._renderer!, kittyStorage, terminal);
-      this._handlers.set('kitty', kittyHandler);
-      this._disposeLater(
-        kittyStorage,
-        kittyHandler,
-        terminal._core._inputHandler._parser.registerApcHandler(0x47, kittyHandler)
-      );
-    }
   }
 
   // Note: storageLimit is skipped here to not intoduce a surprising side effect.

addons/addon-image/src/ImageRenderer.ts

@@ -5,7 +5,7 @@
 
 import { toRGBA8888 } from 'sixel/lib/Colors';
 import { IDisposable } from '@xterm/xterm';
-import { ICellSize, ImageLayer, ITerminalExt, IImageSpec, IRenderDimensions, IRenderService } from './Types';
+import { ICellSize, ITerminalExt, IImageSpec, IRenderDimensions, IRenderService } from './Types';
 import { Disposable, MutableDisposable, toDisposable } from 'common/Lifecycle';
 
 const PLACEHOLDER_LENGTH = 4096;
@@ -18,9 +18,8 @@ const PLACEHOLDER_HEIGHT = 24;
  * - draw image tiles onRender
  */
 export class ImageRenderer extends Disposable implements IDisposable {
-  /** @deprecated Kept for backward compat — points to top layer canvas. */
-  public get canvas(): HTMLCanvasElement | undefined { return this._layers.get('top')?.canvas; }
-  private _layers = new Map<ImageLayer, CanvasRenderingContext2D>();
+  public canvas: HTMLCanvasElement | undefined;
+  private _ctx: CanvasRenderingContext2D | null | undefined;
   private _placeholder: HTMLCanvasElement | undefined;
   private _placeholderBitmap: ImageBitmap | undefined;
   private _optionsRefresh = this._register(new MutableDisposable());
@@ -87,7 +86,6 @@ export class ImageRenderer extends Disposable implements IDisposable {
     });
     this._register(toDisposable(() => {
       this.removeLayerFromDom();
-      this.removeLayerFromDom('bottom');
       if (this._terminal._core && this._oldOpen) {
         this._terminal._core.open = this._oldOpen;
         this._oldOpen = undefined;
@@ -97,7 +95,8 @@ export class ImageRenderer extends Disposable implements IDisposable {
         this._oldSetRenderer = undefined;
       }
       this._renderService = undefined;
-      this._layers.clear();
+      this.canvas = undefined;
+      this._ctx = undefined;
       this._placeholderBitmap?.close();
       this._placeholderBitmap = undefined;
       this._placeholder = undefined;
@@ -141,38 +140,27 @@ export class ImageRenderer extends Disposable implements IDisposable {
   /**
    * Clear a region of the image layer canvas.
    */
-  public clearLines(start: number, end: number, layer?: ImageLayer): void {
-    const y = start * (this.dimensions?.css.cell.height || 0);
-    const w = this.dimensions?.css.canvas.width || 0;
-    const h = (++end - start) * (this.dimensions?.css.cell.height || 0);
-    if (!layer || layer === 'top') {
-      this._layers.get('top')?.clearRect(0, y, w, h);
-    }
-    if (!layer || layer === 'bottom') {
-      this._layers.get('bottom')?.clearRect(0, y, w, h);
-    }
+  public clearLines(start: number, end: number): void {
+    this._ctx?.clearRect(
+      0,
+      start * (this.dimensions?.css.cell.height || 0),
+      this.dimensions?.css.canvas.width || 0,
+      (++end - start) * (this.dimensions?.css.cell.height || 0)
+    );
   }
 
   /**
    * Clear whole image canvas.
    */
-  public clearAll(layer?: ImageLayer): void {
-    if (!layer || layer === 'top') {
-      const ctx = this._layers.get('top');
-      ctx?.clearRect(0, 0, ctx.canvas.width, ctx.canvas.height);
-    }
-    if (!layer || layer === 'bottom') {
-      const ctx = this._layers.get('bottom');
-      ctx?.clearRect(0, 0, ctx.canvas.width, ctx.canvas.height);
-    }
+  public clearAll(): void {
+    this._ctx?.clearRect(0, 0, this.canvas?.width || 0, this.canvas?.height || 0);
   }
 
   /**
    * Draw neighboring tiles on the image layer canvas.
    */
   public draw(imgSpec: IImageSpec, tileId: number, col: number, row: number, count: number = 1): void {
-    const ctx = this._layers.get(imgSpec.layer);
-    if (!ctx) {
+    if (!this._ctx) {
       return;
     }
     const { width, height } = this.cellSize;
@@ -199,7 +187,7 @@ export class ImageRenderer extends Disposable implements IDisposable {
     // Note: For not pixel perfect aligned cells like in the DOM renderer
     // this will move a tile slightly to the top/left (subpixel range, thus ignore it).
     // FIX #34: avoid striping on displays with pixelDeviceRatio != 1 by ceiling height and width
-    ctx.drawImage(
+    this._ctx.drawImage(
       img,
       Math.floor(sx), Math.floor(sy), Math.ceil(finalWidth), Math.ceil(finalHeight),
       Math.floor(dx), Math.floor(dy), Math.ceil(finalWidth), Math.ceil(finalHeight)
@@ -239,8 +227,7 @@ export class ImageRenderer extends Disposable implements IDisposable {
    * Draw a line with placeholder on the image layer canvas.
    */
   public drawPlaceholder(col: number, row: number, count: number = 1): void {
-    const ctx = this._layers.get('top');
-    if (ctx) {
+    if (this._ctx) {
       const { width, height } = this.cellSize;
 
       // Don't try to draw anything, if we cannot get valid renderer metrics.
@@ -254,7 +241,7 @@ export class ImageRenderer extends Disposable implements IDisposable {
         this._createPlaceHolder(height + 1);
       }
       if (!this._placeholder) return;
-      ctx.drawImage(
+      this._ctx.drawImage(
         this._placeholderBitmap ?? this._placeholder!,
         col * width,
         (row * height) % 2 ? 0 : 1,  // needs %2 offset correction
@@ -273,13 +260,12 @@ export class ImageRenderer extends Disposable implements IDisposable {
    * Checked once from `ImageStorage.render`.
    */
   public rescaleCanvas(): void {
-    const w = this.dimensions?.css.canvas.width || 0;
-    const h = this.dimensions?.css.canvas.height || 0;
-    for (const ctx of this._layers.values()) {
-      if (ctx.canvas.width !== w || ctx.canvas.height !== h) {
-        ctx.canvas.width = w;
-        ctx.canvas.height = h;
-      }
+    if (!this.canvas) {
+      return;
+    }
+    if (this.canvas.width !== this.dimensions!.css.canvas.width || this.canvas.height !== this.dimensions!.css.canvas.height) {
+      this.canvas.width = this.dimensions!.css.canvas.width || 0;
+      this.canvas.height = this.dimensions!.css.canvas.height || 0;
     }
   }
 
@@ -318,65 +304,35 @@ export class ImageRenderer extends Disposable implements IDisposable {
     this._renderService = this._terminal._core._renderService;
     this._oldSetRenderer = this._renderService.setRenderer.bind(this._renderService);
     this._renderService.setRenderer = (renderer: any) => {
-      for (const key of [...this._layers.keys()]) {
-        this.removeLayerFromDom(key);
-      }
+      this.removeLayerFromDom();
       this._oldSetRenderer?.call(this._renderService, renderer);
     };
   }
 
-  public insertLayerToDom(layer: ImageLayer = 'top'): void {
+  public insertLayerToDom(): void {
     // make sure that the terminal is attached to a document and to DOM
-    if (!this.document || !this._terminal._core.screenElement) {
-      console.warn('image addon: cannot insert output canvas to DOM, missing document or screenElement');
-      return;
-    }
-    if (this._layers.has(layer)) {
-      return;
-    }
-    const canvas = ImageRenderer.createCanvas(
-      this.document, this.dimensions?.css.canvas.width || 0,
-      this.dimensions?.css.canvas.height || 0
-    );
-    canvas.classList.add(`xterm-image-layer-${layer}`);
-    const screenElement = this._terminal._core.screenElement;
-    // Use isolation to create a stacking context without overriding z-index,
-    // which would conflict with integrators (e.g. VS Code) that set their
-    // own z-index on the screen element.
-    screenElement.style.isolation = 'isolate';
-    if (layer === 'bottom') {
-      // Use z-index:-1 so it paints behind non-positioned text elements.
-      // The screen element needs to be a stacking context (via isolation)
-      // to contain the negative z-index, otherwise it would go behind the
-      // entire terminal.
-      canvas.style.zIndex = '-1';
-      screenElement.insertBefore(canvas, screenElement.firstChild);
+    if (this.document && this._terminal._core.screenElement) {
+      if (!this.canvas) {
+        this.canvas = ImageRenderer.createCanvas(
+          this.document, this.dimensions?.css.canvas.width || 0,
+          this.dimensions?.css.canvas.height || 0
+        );
+        this.canvas.classList.add('xterm-image-layer');
+        this._terminal._core.screenElement.appendChild(this.canvas);
+        this._ctx = this.canvas.getContext('2d', { alpha: true, desynchronized: true });
+        this.clearAll();
+      }
     } else {
-      // Explicit z-index ensures the image canvas reliably stacks above
-      // the text layer (DOM renderer rows). z-index: 0 is below the
-      // selection overlay (z-index: 1).
-      canvas.style.zIndex = '0';
-      screenElement.appendChild(canvas);
-    }
-    const ctx = canvas.getContext('2d', { alpha: true, desynchronized: true });
-    if (!ctx) {
-      canvas.remove();
-      return;
-    }
-    this._layers.set(layer, ctx);
-    this.clearAll(layer);
-  }
-
-  public removeLayerFromDom(layer: ImageLayer = 'top'): void {
-    const ctx = this._layers.get(layer);
-    if (ctx) {
-      ctx.canvas.remove();
-      this._layers.delete(layer);
+      console.warn('image addon: cannot insert output canvas to DOM, missing document or screenElement');
     }
   }
 
-  public hasLayer(layer: ImageLayer): boolean {
-    return this._layers.has(layer);
+  public removeLayerFromDom(): void {
+    if (this.canvas) {
+      this._ctx = undefined;
+      this.canvas.remove();
+      this.canvas = undefined;
+    }
   }
 
   private _createPlaceHolder(height: number = PLACEHOLDER_HEIGHT): void {

addons/addon-image/src/ImageStorage.ts

@@ -5,7 +5,7 @@
 
 import { IDisposable } from '@xterm/xterm';
 import { ImageRenderer } from './ImageRenderer';
-import { ITerminalExt, IExtendedAttrsImage, IImageAddonOptions, IImageSpec, IBufferLineExt, BgFlags, Cell, Content, ICellSize, ExtFlags, Attributes, UnderlineStyle, ImageLayer } from './Types';
+import { ITerminalExt, IExtendedAttrsImage, IImageAddonOptions, IImageSpec, IBufferLineExt, BgFlags, Cell, Content, ICellSize, ExtFlags, Attributes, UnderlineStyle } from './Types';
 
 
 // fallback default cell size
@@ -124,7 +124,6 @@ export class ImageStorage implements IDisposable {
   private _pixelLimit: number = 2500000;
 
   private _viewportMetrics: { cols: number, rows: number };
-  public onImageDeleted: ((storageId: number) => void) | undefined;
 
   constructor(
     private _terminal: ITerminalExt,
@@ -190,13 +189,11 @@ export class ImageStorage implements IDisposable {
 
   private _delImg(id: number): void {
     const spec = this._images.get(id);
-    if (!spec) return;
     this._images.delete(id);
     // FIXME: really ugly workaround to get bitmaps deallocated :(
-    if (window.ImageBitmap && spec.orig instanceof ImageBitmap) {
+    if (spec && window.ImageBitmap && spec.orig instanceof ImageBitmap) {
       spec.orig.close();
     }
-    this.onImageDeleted?.(id);
   }
 
   /**
@@ -220,27 +217,27 @@ export class ImageStorage implements IDisposable {
   }
 
   /**
-   * Delete an image by its internal storage ID.
-   * Used by protocols that support explicit deletion (e.g. Kitty a=d).
+   * Only advance text cursor.
+   * This is an edge case from empty sixels carrying only a height but no pixels.
+   * Partially fixes https://github.com/jerch/xterm-addon-image/issues/37.
    */
-  public deleteImage(id: number): void {
-    const spec = this._images.get(id);
-    if (spec) {
-      spec.marker?.dispose();
-      this._delImg(id);
+  public advanceCursor(height: number): void {
+    if (this._opts.sixelScrolling) {
+      let cellSize = this._renderer.cellSize;
+      if (cellSize.width === -1 || cellSize.height === -1) {
+        cellSize = CELL_SIZE_DEFAULT;
+      }
+      const rows = Math.ceil(height / cellSize.height);
+      for (let i = 1; i < rows; ++i) {
+        this._terminal._core._inputHandler.lineFeed();
+      }
     }
   }
 
   /**
    * Method to add an image to the storage.
-   * @param img - The image to add (canvas or bitmap).
-   * @param scrolling - When true, cursor advances with the image (lineFeed per row).
-   *   When false, image is placed at (0,0) and cursor is restored (DECSET 80 / sixel origin mode).
-   * @param layer - Which canvas layer to render on ('top' or 'bottom').
-   * @param zIndex - Z-index for image layering within the same layer.
-   * @returns The internal image ID assigned to the stored image.
    */
-  public addImage(img: HTMLCanvasElement | ImageBitmap, scrolling: boolean, layer: ImageLayer = 'top', zIndex: number = 0): number {
+  public addImage(img: HTMLCanvasElement | ImageBitmap): void {
     // never allow storage to exceed memory limit
     this._evictOldest(img.width * img.height);
 
@@ -262,7 +259,7 @@ export class ImageStorage implements IDisposable {
     let offset = originX;
     let tileCount = 0;
 
-    if (!scrolling) {
+    if (!this._opts.sixelScrolling) {
       buffer.x = 0;
       buffer.y = 0;
       offset = 0;
@@ -276,7 +273,7 @@ export class ImageStorage implements IDisposable {
         this._writeToCell(line as IBufferLineExt, offset + col, imageId, row * cols + col);
         tileCount++;
       }
-      if (scrolling) {
+      if (this._opts.sixelScrolling) {
         if (row < rows - 1) this._terminal._core._inputHandler.lineFeed();
       } else {
         if (++buffer.y >= termRows) break;
@@ -286,7 +283,7 @@ export class ImageStorage implements IDisposable {
     this._terminal._core._inputHandler._dirtyRowTracker.markDirty(buffer.y);
 
     // cursor positioning modes
-    if (scrolling) {
+    if (this._opts.sixelScrolling) {
       buffer.x = offset;
     } else {
       buffer.x = originX;
@@ -329,14 +326,11 @@ export class ImageStorage implements IDisposable {
       actualCellSize: { ...cellSize },  // clone needed, since later modified
       marker: endMarker || undefined,
       tileCount,
-      bufferType: this._terminal.buffer.active.type,
-      layer,
-      zIndex
+      bufferType: this._terminal.buffer.active.type
     };
 
     // finally add the image
     this._images.set(imageId, imgSpec);
-    return imageId;
   }
 
 
@@ -346,30 +340,16 @@ export class ImageStorage implements IDisposable {
    */
   // TODO: Should we move this to the ImageRenderer?
   public render(range: { start: number, end: number }): void {
-    // Determine which layers have images
-    let hasTopImages = false;
-    let hasBottomImages = false;
-    for (const spec of this._images.values()) {
-      if (spec.layer === 'bottom') {
-        hasBottomImages = true;
-      } else {
-        hasTopImages = true;
+    // setup image canvas in case we have none yet, but have images in store
+    if (!this._renderer.canvas && this._images.size) {
+      this._renderer.insertLayerToDom();
+      // safety measure - in case we cannot spawn a canvas at all, just exit
+      if (!this._renderer.canvas) {
+        return;
       }
-      if (hasTopImages && hasBottomImages) break;
     }
-
-    // Lazily insert layers that are needed
-    if (hasTopImages && !this._renderer.hasLayer('top')) {
-      this._renderer.insertLayerToDom('top');
-      if (!this._renderer.hasLayer('top')) return;
-    }
-    if (hasBottomImages && !this._renderer.hasLayer('bottom')) {
-      this._renderer.insertLayerToDom('bottom');
-    }
-
     // rescale if needed
     this._renderer.rescaleCanvas();
-
     // exit early if we dont have any images to test for
     if (!this._images.size) {
       if (!this._fullyCleared) {
@@ -377,25 +357,12 @@ export class ImageStorage implements IDisposable {
         this._fullyCleared = true;
         this._needsFullClear = false;
       }
-      if (this._renderer.hasLayer('top')) {
-        this._renderer.removeLayerFromDom('top');
-      }
-      if (this._renderer.hasLayer('bottom')) {
-        this._renderer.removeLayerFromDom('bottom');
+      if (this._renderer.canvas) {
+        this._renderer.removeLayerFromDom();
       }
       return;
     }
 
-    // Remove layers no longer needed
-    if (!hasTopImages && this._renderer.hasLayer('top')) {
-      this._renderer.clearAll('top');
-      this._renderer.removeLayerFromDom('top');
-    }
-    if (!hasBottomImages && this._renderer.hasLayer('bottom')) {
-      this._renderer.clearAll('bottom');
-      this._renderer.removeLayerFromDom('bottom');
-    }
-
     // buffer switches force a full clear
     if (this._needsFullClear) {
       this._renderer.clearAll();
@@ -410,77 +377,50 @@ export class ImageStorage implements IDisposable {
     // clear drawing area
     this._renderer.clearLines(start, end);
 
-    // Collect draw calls so we can sort by z-index (lower z drawn first).
-    const drawCalls: { imgSpec: IImageSpec, tileId: number, col: number, row: number, count: number }[] = [];
-    const placeholderCalls: { col: number, row: number, count: number }[] = [];
-
-    // walk all cells in viewport and collect tiles found
-    // Note: We check _extendedAttrs directly (not just HAS_EXTENDED flag)
-    // because text writes clear the BG flag but leave image tile data intact.
-    // This lets top-layer images survive text overwrites (kitty C=1 behavior).
+    // walk all cells in viewport and draw tiles found
     for (let row = start; row <= end; ++row) {
       const line = buffer.lines.get(row + buffer.ydisp) as IBufferLineExt;
       if (!line) return;
       for (let col = 0; col < cols; ++col) {
-        let e: IExtendedAttrsImage;
         if (line.getBg(col) & BgFlags.HAS_EXTENDED) {
-          e = line._extendedAttrs[col] ?? EMPTY_ATTRS;
-        } else {
-          const maybeImg = line._extendedAttrs[col] as IExtendedAttrsImage | undefined;
-          if (!maybeImg || maybeImg.imageId === undefined || maybeImg.imageId === -1) {
+          let e: IExtendedAttrsImage = line._extendedAttrs[col] ?? EMPTY_ATTRS;
+          const imageId = e.imageId;
+          if (imageId === undefined || imageId === -1) {
             continue;
           }
-          e = maybeImg;
-        }
-        const imageId = e.imageId;
-        if (imageId === undefined || imageId === -1) {
-          continue;
-        }
-        const imgSpec = this._images.get(imageId);
-        if (e.tileId !== -1) {
-          const startTile = e.tileId;
-          const startCol = col;
-          let count = 1;
-          /**
-           * merge tiles to the right into a single draw call, if:
-           * - not at end of line
-           * - cell has same image id
-           * - cell has consecutive tile id
-           * Also check _extendedAttrs directly for cells where text cleared HAS_EXTENDED.
-           */
-          while (++col < cols) {
-            const nextE = line._extendedAttrs[col] as IExtendedAttrsImage | undefined;
-            if (!nextE || nextE.imageId !== imageId || nextE.tileId !== startTile + count) {
-              break;
+          const imgSpec = this._images.get(imageId);
+          if (e.tileId !== -1) {
+            const startTile = e.tileId;
+            const startCol = col;
+            let count = 1;
+            /**
+             * merge tiles to the right into a single draw call, if:
+             * - not at end of line
+             * - cell has same image id
+             * - cell has consecutive tile id
+             */
+            while (
+              ++col < cols
+              && (line.getBg(col) & BgFlags.HAS_EXTENDED)
+              && (e = line._extendedAttrs[col] ?? EMPTY_ATTRS)
+              && (e.imageId === imageId)
+              && (e.tileId === startTile + count)
+            ) {
+              count++;
             }
-            e = nextE;
-            count++;
-          }
-          col--;
-          if (imgSpec) {
-            if (imgSpec.actual) {
-              drawCalls.push({ imgSpec, tileId: startTile, col: startCol, row, count });
+            col--;
+            if (imgSpec) {
+              if (imgSpec.actual) {
+                this._renderer.draw(imgSpec, startTile, startCol, row, count);
+              }
+            } else if (this._opts.showPlaceholder) {
+              this._renderer.drawPlaceholder(startCol, row, count);
             }
-          } else if (this._opts.showPlaceholder) {
-            placeholderCalls.push({ col: startCol, row, count });
+            this._fullyCleared = false;
           }
-          this._fullyCleared = false;
         }
       }
     }
-
-    // Sort by z-index so lower z draws first (higher z renders on top)
-    drawCalls.sort((a, b) => a.imgSpec.zIndex - b.imgSpec.zIndex);
-
-    // Draw placeholders first (lowest priority)
-    for (const call of placeholderCalls) {
-      this._renderer.drawPlaceholder(call.col, call.row, call.count);
-    }
-
-    // Draw images in z-index order
-    for (const call of drawCalls) {
-      this._renderer.draw(call.imgSpec, call.tileId, call.col, call.row, call.count);
-    }
   }
 
   public viewportResize(metrics: { cols: number, rows: number }): void {

addons/addon-image/src/SixelHandler.ts

@@ -3,7 +3,7 @@
  * @license MIT
  */
 
-import { SixelImageStorage } from './SixelImageStorage';
+import { ImageStorage } from './ImageStorage';
 import { IDcsHandler, IParams, IImageAddonOptions, ITerminalExt, AttributeData, IResetHandler, ReadonlyColorSet } from './Types';
 import { toRGBA8888, BIG_ENDIAN, PALETTE_ANSI_256, PALETTE_VT340_COLOR } from 'sixel/lib/Colors';
 import { RGBA8888 } from 'sixel/lib/Types';
@@ -26,7 +26,7 @@ export class SixelHandler implements IDcsHandler, IResetHandler {
 
   constructor(
     private readonly _opts: IImageAddonOptions,
-    private readonly _storage: SixelImageStorage,
+    private readonly _storage: ImageStorage,
     private readonly _coreTerminal: ITerminalExt
   ) {
     DecoderAsync({

addons/addon-image/src/SixelImageStorage.ts

@@ -1,50 +0,0 @@
-/**
- * Copyright (c) 2020 The xterm.js authors. All rights reserved.
- * @license MIT
- */
-
-import { ImageStorage, CELL_SIZE_DEFAULT } from './ImageStorage';
-import { IImageAddonOptions, ITerminalExt } from './Types';
-import { ImageRenderer } from './ImageRenderer';
-
-/**
- * Sixel-specific image storage controller.
- *
- * Wraps the shared ImageStorage with sixel protocol semantics:
- * - Cursor behavior governed by DECSET 80 (sixelScrolling option)
- * - advanceCursor for empty sixels carrying only height
- */
-export class SixelImageStorage {
-  constructor(
-    private readonly _storage: ImageStorage,
-    private readonly _opts: IImageAddonOptions,
-    private readonly _renderer: ImageRenderer,
-    private readonly _terminal: ITerminalExt
-  ) {}
-
-  /**
-   * Add a sixel image to storage.
-   * Cursor behavior depends on the sixelScrolling option (DECSET 80).
-   */
-  public addImage(img: HTMLCanvasElement | ImageBitmap): void {
-    this._storage.addImage(img, this._opts.sixelScrolling);
-  }
-
-  /**
-   * Only advance text cursor.
-   * This is an edge case from empty sixels carrying only a height but no pixels.
-   * Partially fixes https://github.com/jerch/xterm-addon-image/issues/37.
-   */
-  public advanceCursor(height: number): void {
-    if (this._opts.sixelScrolling) {
-      let cellSize = this._renderer.cellSize;
-      if (cellSize.width === -1 || cellSize.height === -1) {
-        cellSize = CELL_SIZE_DEFAULT;
-      }
-      const rows = Math.ceil(height / cellSize.height);
-      for (let i = 1; i < rows; ++i) {
-        this._terminal._core._inputHandler.lineFeed();
-      }
-    }
-  }
-}

addons/addon-image/src/Types.ts

@@ -8,7 +8,7 @@ import { IDisposable, IMarker, Terminal } from '@xterm/xterm';
 // private imports from base repo we build against
 import { Attributes, BgFlags, Content, ExtFlags, UnderlineStyle } from 'common/buffer/Constants';
 import type { AttributeData } from 'common/buffer/AttributeData';
-import type { IParams, IDcsHandler, IOscHandler, IApcHandler, IEscapeSequenceParser } from 'common/parser/Types';
+import type { IParams, IDcsHandler, IOscHandler, IEscapeSequenceParser } from 'common/parser/Types';
 import type { IBufferLine, IExtendedAttrs, IInputHandler } from 'common/Types';
 import type { ITerminal, ReadonlyColorSet } from 'browser/Types';
 import type { IRenderDimensions } from 'browser/renderer/shared/Types';
@@ -22,7 +22,7 @@ export const enum Cell {
 }
 
 // export some privates for local usage
-export { AttributeData, IParams, IDcsHandler, IOscHandler, IApcHandler, BgFlags, IRenderDimensions, IRenderService, Content, ExtFlags, Attributes, UnderlineStyle, ReadonlyColorSet };
+export { AttributeData, IParams, IDcsHandler, IOscHandler, BgFlags, IRenderDimensions, IRenderService, Content, ExtFlags, Attributes, UnderlineStyle, ReadonlyColorSet };
 
 /**
  * Plugin ctor options.
@@ -38,8 +38,6 @@ export interface IImageAddonOptions {
   sixelSizeLimit: number;
   iipSupport: boolean;
   iipSizeLimit: number;
-  kittySupport: boolean;
-  kittySizeLimit: number;
 }
 
 export interface IResetHandler {
@@ -99,8 +97,6 @@ export interface ICellSize {
   height: number;
 }
 
-export type ImageLayer = 'top' | 'bottom';
-
 export interface IImageSpec {
   orig: HTMLCanvasElement | ImageBitmap | undefined;
   origCellSize: ICellSize;
@@ -109,6 +105,4 @@ export interface IImageSpec {
   marker: IMarker | undefined;
   tileCount: number;
   bufferType: 'alternate' | 'normal';
-  layer: ImageLayer;
-  zIndex: number;
 }

addons/addon-image/src/kitty/KittyGraphicsHandler.ts

@@ -1,813 +0,0 @@
-/**
- * Copyright (c) 2026 The xterm.js authors. All rights reserved.
- * @license MIT
- */
-
-import { IDisposable } from '@xterm/xterm';
-import { IApcHandler, IImageAddonOptions, IResetHandler, ITerminalExt, ImageLayer } from '../Types';
-import { ImageRenderer } from '../ImageRenderer';
-import { CELL_SIZE_DEFAULT } from '../ImageStorage';
-import { KittyImageStorage } from './KittyImageStorage';
-import Base64Decoder, { type DecodeStatus } from 'xterm-wasm-parts/lib/base64/Base64Decoder.wasm';
-import {
-  KittyAction,
-  KittyFormat,
-  KittyCompression,
-  IKittyCommand,
-  IPendingTransmission,
-  IKittyImageData,
-  BYTES_PER_PIXEL_RGB,
-  BYTES_PER_PIXEL_RGBA,
-  ALPHA_OPAQUE,
-  parseKittyCommand
-} from './KittyGraphicsTypes';
-
-// Memory limit for base64 decoder (4MB, same as IIPHandler)
-const DECODER_KEEP_DATA = 4194304;
-const DECODER_INITIAL_DATA = 4194304; // 4MB
-
-// Local mirror of const enum (esbuild can't inline const enums from external packages)
-const DECODER_OK: DecodeStatus.OK = 0;
-
-// Maximum control data size
-const MAX_CONTROL_DATA_SIZE = 512;
-
-// Semicolon codepoint
-const SEMICOLON = 0x3B;
-
-// Kitty graphics protocol handler with streaming base64 decoding.
-export class KittyGraphicsHandler implements IApcHandler, IResetHandler, IDisposable {
-  private _aborted = false;
-  private _decodeError = false;
-
-  private _activeDecoder: Base64Decoder | null = null;
-  private readonly _maxEncodedBytes: number;
-  private readonly _initialEncodedBytes: number;
-
-  // Streaming related states
-
-  // True while receiving control data (before semicolon).
-  private _inControlData = true;
-
-  // Buffer for control data.
-  private _controlData = new Uint32Array(MAX_CONTROL_DATA_SIZE);
-  private _controlLength = 0;
-
-  // Pre-calculated encoded size limit
-  private _encodedSizeLimit = 0;
-  private _totalEncodedSize = 0;
-
-  // Parsed command. These are the control data before semicolon.
-  private _parsedCommand: IKittyCommand | null = null;
-
-  // Storage related states
-
-  private _pendingTransmissions: Map<number, IPendingTransmission> = new Map();
-  // Tracks the pending key of the most recently started chunked upload.
-  // Per spec, subsequent chunks only need m= (and optionally q=), without i=.
-  // When a chunk arrives with no i=, this key is used to find the pending upload.
-  private _lastPendingKey: number | undefined;
-
-  constructor(
-    private readonly _opts: IImageAddonOptions,
-    private readonly _renderer: ImageRenderer,
-    private readonly _kittyStorage: KittyImageStorage,
-    private readonly _coreTerminal: ITerminalExt
-  ) {
-    // Convert decoded size limit -> max encoded bytes.
-    this._maxEncodedBytes = Math.ceil(this._opts.kittySizeLimit * 4 / 3);
-    // ensure we preallocate more than configured limit while using 4mb initial size.
-    this._initialEncodedBytes = Math.min(DECODER_INITIAL_DATA, this._maxEncodedBytes);
-  }
-
-  public reset(): void {
-    this._cleanupAllPending();
-    if (this._activeDecoder) {
-      this._activeDecoder.release();
-      this._activeDecoder = null;
-    }
-    this._kittyStorage.reset();
-  }
-
-  public dispose(): void {
-    this.reset();
-  }
-
-  private _removePendingEntry(key: number): void {
-    this._pendingTransmissions.delete(key);
-    if (this._lastPendingKey === key) {
-      this._lastPendingKey = undefined;
-    }
-  }
-
-  private _cleanupAllPending(): void {
-    for (const pending of this._pendingTransmissions.values()) {
-      pending.decoder.release();
-    }
-    this._pendingTransmissions.clear();
-    this._lastPendingKey = undefined;
-  }
-
-  public start(): void {
-    this._aborted = false;
-    this._decodeError = false;
-    this._inControlData = true;
-    this._controlLength = 0;
-    this._parsedCommand = null;
-    // Pre-calculate encoded limit once: base64 is 4 bytes encoded → 3 bytes decoded
-    this._encodedSizeLimit = this._maxEncodedBytes;
-    this._totalEncodedSize = 0;
-    this._activeDecoder = null;
-  }
-
-  public put(data: Uint32Array, start: number, end: number): void {
-    if (this._aborted) return;
-
-    if (!this._inControlData) {
-      this._streamPayload(data, start, end);
-    } else {
-      // Scan for semicolon
-      let controlEnd = end;
-      for (let i = start; i < end; i++) {
-        if (data[i] === SEMICOLON) {
-          this._inControlData = false;
-          controlEnd = i;
-          break;
-        }
-      }
-
-      // Copy control data
-      const copyLength = controlEnd - start;
-      if (this._controlLength + copyLength > MAX_CONTROL_DATA_SIZE) {
-        this._aborted = true;
-        return;
-      }
-      this._controlData.set(data.subarray(start, controlEnd), this._controlLength);
-      this._controlLength += copyLength;
-
-      if (!this._inControlData) {
-        // Found semicolon - parse control data early for validation
-        this._parsedCommand = parseKittyCommand(this._parseControlDataString());
-
-        // Early validation: i+I conflict
-        if (this._parsedCommand.id !== undefined && this._parsedCommand.imageNumber !== undefined) {
-          this._sendResponse(this._parsedCommand.id, 'EINVAL:cannot specify both i and I keys', this._parsedCommand.quiet ?? 0);
-          this._aborted = true;
-          return;
-        }
-
-        // Delete action doesn't need payload - skip streaming
-        if (this._parsedCommand.action === KittyAction.DELETE) {
-          return;
-        }
-
-        // Stream remaining as payload
-        const payloadStart = controlEnd + 1;
-        if (payloadStart < end) {
-          this._streamPayload(data, payloadStart, end);
-        }
-      }
-    }
-  }
-
-  // Stream payload bytes into the base64 decoder.
-  private _streamPayload(data: Uint32Array, start: number, end: number): void {
-    if (this._aborted) return;
-
-    // Check size limit (compare encoded bytes against pre-calculated limit)
-    // Include cumulative size from pending transmission for multi-chunk images.
-    // Per spec, subsequent chunks may omit i=, so fall back to _lastPendingKey.
-    const pendingKey = this._parsedCommand?.id ?? this._lastPendingKey ?? 0;
-    const pending = this._pendingTransmissions.get(pendingKey);
-    const previousEncodedSize = pending?.totalEncodedSize ?? 0;
-    this._totalEncodedSize += end - start;
-    const cumulativeEncodedSize = previousEncodedSize + this._totalEncodedSize;
-    if (cumulativeEncodedSize > this._encodedSizeLimit) {
-      const decoderToRelease = this._activeDecoder ?? pending?.decoder;
-      if (decoderToRelease) {
-        decoderToRelease.release();
-      }
-      this._activeDecoder = null;
-      if (pending) {
-        this._removePendingEntry(pendingKey);
-      }
-      this._aborted = true;
-      return;
-    }
-
-    if (this._decodeError) return;
-
-    if (pending?.decoder && !this._activeDecoder) {
-      this._activeDecoder = pending.decoder;
-    }
-    if (!this._activeDecoder) {
-      this._activeDecoder = new Base64Decoder(DECODER_KEEP_DATA, this._maxEncodedBytes, this._initialEncodedBytes);
-      this._activeDecoder.init();
-    }
-
-    if (this._activeDecoder.put(data.subarray(start, end)) !== DECODER_OK) {
-      this._activeDecoder.release();
-      this._activeDecoder = null;
-      this._decodeError = true;
-      if (pending) {
-        this._removePendingEntry(pendingKey);
-      }
-    }
-  }
-
-  public end(success: boolean): boolean | Promise<boolean> {
-    if (this._aborted || !success) {
-      if (this._activeDecoder) {
-        this._activeDecoder.release();
-        this._activeDecoder = null;
-      }
-      return true;
-    }
-
-    // No semicolon = no payload (delete, capability query)
-    if (this._inControlData) {
-      return this._handleNoPayloadCommand();
-    }
-
-    // Use command parsed early in put() - i+I already validated there
-    const cmd = this._parsedCommand!;
-
-    // Delete action was handled by skipping payload - just execute
-    if (cmd.action === KittyAction.DELETE) {
-      return this._handleDelete(cmd);
-    }
-
-    // Per spec, subsequent chunks may omit i=, so fall back to _lastPendingKey.
-    const pendingKey = cmd.id ?? this._lastPendingKey ?? 0;
-    const isMoreComing = cmd.more === 1;
-    const pending = this._pendingTransmissions.get(pendingKey);
-
-    if (isMoreComing) {
-      if (this._activeDecoder) {
-        if (pending) {
-          pending.totalEncodedSize += this._totalEncodedSize;
-          pending.decodeError = pending.decodeError || this._decodeError;
-        } else {
-          this._pendingTransmissions.set(pendingKey, {
-            cmd: { ...cmd },
-            decoder: this._activeDecoder,
-            totalEncodedSize: this._totalEncodedSize,
-            decodeError: this._decodeError
-          });
-        }
-        this._lastPendingKey = pendingKey;
-        this._activeDecoder = null;
-      }
-      return true;
-    }
-
-    // Final chunk received — clear the last pending key
-    if (pending) {
-      this._lastPendingKey = undefined;
-    }
-
-    let decodeError = this._decodeError;
-    let finalCmd = cmd;
-    let decoder = this._activeDecoder;
-
-    if (pending) {
-      finalCmd = pending.cmd;
-      decoder = pending.decoder;
-      decodeError = decodeError || pending.decodeError;
-      this._pendingTransmissions.delete(pendingKey);
-    }
-
-    let imageBytes = new Uint8Array(0);
-    if (decoder) {
-      if (decoder.end() !== DECODER_OK) {
-        decodeError = true;
-      }
-      imageBytes = decoder.data8;
-    }
-    this._activeDecoder = null;
-
-    // Handle command first — handlers create Blob/ImageData from imageBytes,
-    // which copies the data. Only then is it safe to release the decoder's
-    // wasm memory that imageBytes points into.
-    const result = this._handleCommandWithBytesAndCmd(finalCmd, imageBytes, decodeError);
-    if (decoder) {
-      decoder.release();
-    }
-    return result;
-  }
-
-  // Command handling
-
-  private _parseControlDataString(): string {
-    let str = '';
-    for (let i = 0; i < this._controlLength; i++) {
-      str += String.fromCodePoint(this._controlData[i]);
-    }
-    return str;
-  }
-
-  private _handleNoPayloadCommand(): boolean | Promise<boolean> {
-    const cmd = parseKittyCommand(this._parseControlDataString());
-
-    // Per spec: specifying both i and I is an error
-    if (cmd.id !== undefined && cmd.imageNumber !== undefined) {
-      this._sendResponse(cmd.id, 'EINVAL:cannot specify both i and I keys', cmd.quiet ?? 0);
-      return true;
-    }
-
-    const action = cmd.action ?? 't';
-
-    switch (action) {
-      case KittyAction.DELETE:
-        return this._handleDelete(cmd);
-      case KittyAction.QUERY:
-        this._sendResponse(cmd.id ?? 0, 'OK', cmd.quiet ?? 0);
-        return true;
-      case KittyAction.PLACEMENT:
-        return this._handlePlacement(cmd);
-      default:
-        // TODO: Implement remaining actions when needed:
-        // - a=f (frame): animation frame operations
-        // - a=a (animation): animation control
-        // - a=c (compose): compose images
-        if (cmd.id !== undefined) {
-          this._sendResponse(cmd.id, 'EINVAL:unsupported action', cmd.quiet ?? 0);
-        }
-        return true;
-    }
-  }
-
-  private _handleCommandWithBytesAndCmd(cmd: IKittyCommand, bytes: Uint8Array, decodeError: boolean): boolean | Promise<boolean> {
-    const action = cmd.action ?? 't';
-
-    switch (action) {
-      case KittyAction.TRANSMIT: {
-        const result = this._handleTransmit(cmd, bytes, decodeError);
-        // Only send response when _handleTransmit didn't already respond
-        // (it handles unsupported transmission medium responses internally)
-        if ((cmd.transmission ?? 'd') === 'd' && cmd.id !== undefined) {
-          if (decodeError) {
-            this._sendResponse(cmd.id, 'EINVAL:invalid base64 data', cmd.quiet ?? 0);
-          } else if (bytes.length > 0) {
-            this._sendResponse(cmd.id, 'OK', cmd.quiet ?? 0);
-          }
-        }
-        return result;
-      }
-      case KittyAction.TRANSMIT_DISPLAY:
-        return this._handleTransmitDisplay(cmd, bytes, decodeError);
-      case KittyAction.QUERY:
-        return this._handleQuery(cmd, bytes, decodeError);
-      case KittyAction.PLACEMENT:
-        // a=p ignores any payload — image data was already transmitted
-        return this._handlePlacement(cmd);
-      default:
-        // TODO: Implement remaining actions when needed:
-        // - a=f (frame): animation frame operations
-        // - a=a (animation): animation control
-        // - a=c (compose): compose images
-        if (cmd.id !== undefined) {
-          this._sendResponse(cmd.id, 'EINVAL:unsupported action', cmd.quiet ?? 0);
-        }
-        return true;
-    }
-  }
-
-  private _handlePlacement(cmd: IKittyCommand): boolean | Promise<boolean> {
-    if (cmd.id === undefined) {
-      return true;
-    }
-    const image = this._kittyStorage.getImage(cmd.id);
-    if (!image) {
-      this._sendResponse(cmd.id, 'ENOENT:image not found', cmd.quiet ?? 0, cmd.placementId);
-      return true;
-    }
-    const result = this._displayImage(image, cmd);
-    return result.then(success => {
-      this._sendResponse(cmd.id!, success ? 'OK' : 'EINVAL:image rendering failed', cmd.quiet ?? 0, cmd.placementId);
-      return true;
-    });
-  }
-
-  private _handleTransmit(cmd: IKittyCommand, bytes: Uint8Array, decodeError: boolean): boolean {
-    // TODO: Support file-based transmission modes (t=f, t=t, t=s)
-    // Currently only supports direct transmission (t=d, the default).
-    // - t=f (file): Payload is base64-encoded file path. Terminal reads image from that path.
-    // - t=t (temp file): Payload is base64-encoded path in temp directory. Terminal reads, deletes.
-    // - t=s: Payload is base64-encoded POSIX shm name. Terminal reads from shared memory.
-    // These modes require filesystem/IPC access not available in browsers. For Node.js/Electron:
-    // 1. Check cmd.transmission (t key) before treating bytes as image data
-    // 2. For t=f/t/s: decode bytes as UTF-8 string (the path/name), then read file contents
-    // 3. For t=d: treat bytes as image data (current behavior)
-    // When implementing, also update _handleQuery to accept these transmission mediums.
-    const transmission = cmd.transmission ?? 'd';
-    if (transmission !== 'd') {
-      if (cmd.id !== undefined) {
-        this._sendResponse(cmd.id, 'EINVAL:unsupported transmission medium', cmd.quiet ?? 0);
-      }
-      return true;
-    }
-
-    if (decodeError || bytes.length === 0) return true;
-
-    this._kittyStorage.storeImage(cmd.id, {
-      data: new Blob([bytes as BlobPart]),
-      width: cmd.width ?? 0,
-      height: cmd.height ?? 0,
-      format: (cmd.format ?? KittyFormat.RGBA) as 24 | 32 | 100,
-      compression: cmd.compression ?? ''
-    });
-    return true;
-  }
-
-  private _handleTransmitDisplay(cmd: IKittyCommand, bytes: Uint8Array, decodeError: boolean): boolean | Promise<boolean> {
-    if (decodeError) {
-      if (cmd.id !== undefined) {
-        this._sendResponse(cmd.id, 'EINVAL:invalid base64 data', cmd.quiet ?? 0);
-      }
-      return true;
-    }
-
-    this._handleTransmit(cmd, bytes, decodeError);
-
-    const id = cmd.id ?? this._kittyStorage.lastImageId;
-    const image = this._kittyStorage.getImage(id);
-    if (image) {
-      const result = this._displayImage(image, cmd);
-      if (cmd.id !== undefined) {
-        return result.then(success => {
-          this._sendResponse(id, success ? 'OK' : 'EINVAL:image rendering failed', cmd.quiet ?? 0);
-          return true;
-        });
-      }
-      return result.then(() => true);
-    }
-    return true;
-  }
-
-  private _handleQuery(cmd: IKittyCommand, bytes: Uint8Array, decodeError: boolean): boolean {
-    const id = cmd.id ?? 0;
-    const quiet = cmd.quiet ?? 0;
-
-    // Per spec: reject unsupported transmission mediums (only t=d is supported atm)
-    // TODO: When filesystem support is added (Node.js/Electron), update this to accept
-    // t=f (file), t=t (temp file), and t=s (shared memory) and respond OK for queries.
-    const transmission = cmd.transmission ?? 'd';
-    if (transmission !== 'd') {
-      this._sendResponse(id, 'EINVAL:unsupported transmission medium', quiet);
-      return true;
-    }
-
-    // Check decode error first (invalid base64)
-    if (decodeError) {
-      this._sendResponse(id, 'EINVAL:invalid base64 data', quiet);
-      return true;
-    }
-
-    // Capability query (no payload) - just respond OK
-    if (bytes.length === 0) {
-      this._sendResponse(id, 'OK', quiet);
-      return true;
-    }
-
-    const format = cmd.format ?? KittyFormat.RGBA;
-
-    if (format === KittyFormat.PNG) {
-      this._sendResponse(id, 'OK', quiet);
-    } else {
-      const width = cmd.width ?? 0;
-      const height = cmd.height ?? 0;
-
-      if (!width || !height) {
-        this._sendResponse(id, 'EINVAL:width and height required for raw pixel data', quiet);
-        return true;
-      }
-
-      const bytesPerPixel = format === KittyFormat.RGBA ? BYTES_PER_PIXEL_RGBA : BYTES_PER_PIXEL_RGB;
-      const expectedBytes = width * height * bytesPerPixel;
-
-      if (bytes.length < expectedBytes) {
-        this._sendResponse(id, `EINVAL:insufficient pixel data`, quiet);
-        return true;
-      }
-
-      this._sendResponse(id, 'OK', quiet);
-    }
-    return true;
-  }
-
-  private _handleDelete(cmd: IKittyCommand): boolean {
-    // Per spec: default delete selector is 'a' (delete all visible placements)
-    const selector = cmd.deleteSelector ?? 'a';
-
-    // TODO: Distinguish lowercase (delete placements only) from uppercase
-    // (delete placements + free stored image data). Currently both variants
-    // free everything since we don't separate stored data from placements.
-    switch (selector) {
-      case 'a':
-      case 'A':
-        this._cleanupAllPending();
-        this._kittyStorage.deleteAll();
-        break;
-      case 'i':
-      case 'I':
-        if (cmd.id !== undefined) {
-          const pending = this._pendingTransmissions.get(cmd.id);
-          if (pending) {
-            pending.decoder.release();
-          }
-          this._removePendingEntry(cmd.id);
-          this._kittyStorage.deleteById(cmd.id);
-        }
-        break;
-      default:
-        // Unsupported selectors (c, n, p, q, r, x, y, z, f) — ignore for now
-        break;
-    }
-    return true;
-  }
-
-  private _sendResponse(id: number, message: string, quiet: number, placementId?: number): void {
-    const isOk = message === 'OK';
-    if (isOk && quiet === 1) return;
-    if (!isOk && quiet === 2) return;
-
-    const pPart = placementId ? `,p=${placementId}` : '';
-    const response = `\x1b_Gi=${id}${pPart};${message}\x1b\\`;
-    this._coreTerminal._core.coreService.triggerDataEvent(response);
-  }
-
-  // Image display
-
-  private _displayImage(image: IKittyImageData, cmd: IKittyCommand): Promise<boolean> {
-    return this._decodeAndDisplay(image, cmd)
-      .then(() => true)
-      .catch(() => false);
-  }
-
-  private async _decodeAndDisplay(image: IKittyImageData, cmd: IKittyCommand): Promise<void> {
-    let bitmap = await this._createBitmap(image);
-
-    const cropX = Math.max(0, cmd.x ?? 0);
-    const cropY = Math.max(0, cmd.y ?? 0);
-    const cropW = cmd.sourceWidth || (bitmap.width - cropX);
-    const cropH = cmd.sourceHeight || (bitmap.height - cropY);
-
-    const maxCropW = Math.max(0, bitmap.width - cropX);
-    const maxCropH = Math.max(0, bitmap.height - cropY);
-    const finalCropW = Math.max(0, Math.min(cropW, maxCropW));
-    const finalCropH = Math.max(0, Math.min(cropH, maxCropH));
-
-    if (finalCropW === 0 || finalCropH === 0) {
-      bitmap.close();
-      throw new Error('invalid source rectangle');
-    }
-
-    if (cropX !== 0 || cropY !== 0 || finalCropW !== bitmap.width || finalCropH !== bitmap.height) {
-      const cropped = await createImageBitmap(bitmap, cropX, cropY, finalCropW, finalCropH);
-      bitmap.close();
-      bitmap = cropped;
-    }
-
-    const cw = this._renderer.dimensions?.css.cell.width || CELL_SIZE_DEFAULT.width;
-    const ch = this._renderer.dimensions?.css.cell.height || CELL_SIZE_DEFAULT.height;
-
-    // Per spec: c/r default to image's natural cell dimensions.
-    // If only one of c/r is specified, compute the other from image aspect ratio.
-    let imgCols: number;
-    let imgRows: number;
-    if (cmd.columns !== undefined && cmd.rows !== undefined) {
-      imgCols = cmd.columns;
-      imgRows = cmd.rows;
-    } else if (cmd.columns !== undefined) {
-      imgCols = cmd.columns;
-      imgRows = Math.max(1, Math.ceil((bitmap.height / bitmap.width) * (imgCols * cw) / ch));
-    } else if (cmd.rows !== undefined) {
-      imgRows = cmd.rows;
-      imgCols = Math.max(1, Math.ceil((bitmap.width / bitmap.height) * (imgRows * ch) / cw));
-    } else {
-      imgCols = Math.ceil(bitmap.width / cw);
-      imgRows = Math.ceil(bitmap.height / ch);
-    }
-
-    let w = bitmap.width;
-    let h = bitmap.height;
-
-    // Scale bitmap to fit placement rectangle when c/r are specified
-    if (cmd.columns !== undefined || cmd.rows !== undefined) {
-      w = Math.round(imgCols * cw);
-      h = Math.round(imgRows * ch);
-    }
-
-    if (w * h > this._opts.pixelLimit) {
-      bitmap.close();
-      throw new Error('image exceeds pixel limit');
-    }
-
-    // Save cursor position before addImage modifies it
-    const buffer = this._coreTerminal._core.buffer;
-    const savedX = buffer.x;
-    const savedY = buffer.y;
-    const savedYbase = buffer.ybase;
-
-    // Determine layer based on z-index: negative = behind text, 0+ = on top.
-    // When z<0 we always use the bottom layer even without allowTransparency —
-    // the image will simply be hidden behind the opaque text background, which
-    // is the correct behavior (client asked for "behind text").
-    const wantsBottom = cmd.zIndex !== undefined && cmd.zIndex < 0;
-    const layer: ImageLayer = wantsBottom ? 'bottom' : 'top';
-
-    let finalBitmap = bitmap;
-    if (w !== bitmap.width || h !== bitmap.height) {
-      finalBitmap = await createImageBitmap(bitmap, { resizeWidth: w, resizeHeight: h });
-      bitmap.close();
-    }
-
-    // Per spec: X/Y are pixel offsets within the first cell, so clamp to cell dimensions
-    const xOffset = Math.min(Math.max(0, cmd.xOffset ?? 0), cw - 1);
-    const yOffset = Math.min(Math.max(0, cmd.yOffset ?? 0), ch - 1);
-    if (xOffset !== 0 || yOffset !== 0) {
-      // Per spec: X/Y is not added to c/r area. When c/r are explicit, the
-      // total placement area remains c*cw × r*ch pixels and the offset image
-      // is clipped to fit. When c/r are unset, the padded canvas determines
-      // the natural cell dimensions.
-      const canvasW = (cmd.columns !== undefined) ? Math.round(imgCols * cw) : finalBitmap.width + xOffset;
-      const canvasH = (cmd.rows !== undefined) ? Math.round(imgRows * ch) : finalBitmap.height + yOffset;
-      const offsetCanvas = ImageRenderer.createCanvas(window.document, canvasW, canvasH);
-      const offsetCtx = offsetCanvas.getContext('2d');
-      if (!offsetCtx) {
-        finalBitmap.close();
-        throw new Error('Failed to create offset canvas context');
-      }
-      offsetCtx.drawImage(finalBitmap, xOffset, yOffset);
-
-      const offsetBitmap = await createImageBitmap(offsetCanvas);
-      offsetCanvas.width = offsetCanvas.height = 0;
-      finalBitmap.close();
-      finalBitmap = offsetBitmap;
-      w = finalBitmap.width;
-      h = finalBitmap.height;
-      if (w * h > this._opts.pixelLimit) {
-        finalBitmap.close();
-        throw new Error('image exceeds pixel limit');
-      }
-      if (cmd.columns === undefined) {
-        imgCols = Math.ceil(finalBitmap.width / cw);
-      }
-      if (cmd.rows === undefined) {
-        imgRows = Math.ceil(finalBitmap.height / ch);
-      }
-    }
-
-    const zIndex = cmd.zIndex ?? 0;
-    this._kittyStorage.addImage(image.id, finalBitmap, true, layer, zIndex);
-
-    // Kitty cursor movement
-    // Per spec: cursor placed at first column after last image column,
-    // on the last row of the image. C=1 means don't move cursor.
-    if (cmd.cursorMovement === 1) {
-      // C=1: restore cursor to position before image was placed
-      const scrolled = buffer.ybase - savedYbase;
-      buffer.x = savedX;
-      // Can't restore cursor to scrollback?
-      buffer.y = Math.max(savedY - scrolled, 0);
-    } else {
-      // Default (C=0): advance cursor horizontally past the image
-      // addImage already positioned cursor on the last row via lineFeeds
-      buffer.x = Math.min(savedX + imgCols, this._coreTerminal.cols);
-    }
-  }
-
-  // Create ImageBitmap from already-decoded image data.
-  private async _createBitmap(image: IKittyImageData): Promise<ImageBitmap> {
-    let bytes: Uint8Array = new Uint8Array(await image.data.arrayBuffer());
-
-    if (image.compression === KittyCompression.ZLIB) {
-      bytes = await this._decompressZlib(bytes);
-    }
-
-    if (image.format === KittyFormat.PNG) {
-      const blob = new Blob([bytes as BlobPart], { type: 'image/png' });
-      if (!window.createImageBitmap) {
-        const url = URL.createObjectURL(blob);
-        const img = new Image();
-        return new Promise<ImageBitmap>((resolve, reject) => {
-          img.addEventListener('load', () => {
-            URL.revokeObjectURL(url);
-            const canvas = ImageRenderer.createCanvas(window.document, img.width, img.height);
-            canvas.getContext('2d')?.drawImage(img, 0, 0);
-            createImageBitmap(canvas).then(resolve).catch(reject);
-          });
-          img.addEventListener('error', () => {
-            URL.revokeObjectURL(url);
-            reject(new Error('Failed to load image'));
-          });
-          img.src = url;
-        });
-      }
-      return createImageBitmap(blob);
-    }
-
-    // Raw pixel data
-    const width = image.width;
-    const height = image.height;
-
-    if (!width || !height) {
-      throw new Error('Width and height required for raw pixel data');
-    }
-
-    const bytesPerPixel = image.format === KittyFormat.RGBA ? BYTES_PER_PIXEL_RGBA : BYTES_PER_PIXEL_RGB;
-    const expectedBytes = width * height * bytesPerPixel;
-
-    if (bytes.length < expectedBytes) {
-      throw new Error('Insufficient pixel data');
-    }
-
-    const pixelCount = width * height;
-
-    if (image.format === KittyFormat.RGBA) {
-      // RGBA: use bytes directly — no copy needed
-      return createImageBitmap(new ImageData(new Uint8ClampedArray(bytes.buffer as ArrayBuffer, bytes.byteOffset, pixelCount * BYTES_PER_PIXEL_RGBA), width, height));
-    }
-
-    // RGB→RGBA: interleave alpha using uint32 block processing (4 pixels per iteration).
-    // 3 uint32 reads + 4 uint32 writes per 4 pixels vs 28 byte reads/writes — ~6x faster.
-    // Assumes little-endian (all modern browsers/Node.js).
-    const data = new Uint8ClampedArray(pixelCount * BYTES_PER_PIXEL_RGBA);
-    const src32 = new Uint32Array(bytes.buffer, bytes.byteOffset, Math.floor(bytes.byteLength / 4));
-    const dst32 = new Uint32Array(data.buffer);
-    const alignedPixels = pixelCount & ~3;  // round down to multiple of 4
-
-    let srcOffset = 0;
-    let dstOffset = 0;
-    for (let i = 0; i < alignedPixels; i += 4) {
-      const b0 = src32[srcOffset++];
-      const b1 = src32[srcOffset++];
-      const b2 = src32[srcOffset++];
-      // Little-endian: pixel bytes are [R,G,B] → uint32 ABGR layout
-      dst32[dstOffset++] = (b0 & 0x00FFFFFF) | 0xFF000000;
-      dst32[dstOffset++] = ((b0 >>> 24) | (b1 << 8)) & 0x00FFFFFF | 0xFF000000;
-      dst32[dstOffset++] = ((b1 >>> 16) | (b2 << 16)) & 0x00FFFFFF | 0xFF000000;
-      dst32[dstOffset++] = (b2 >>> 8) | 0xFF000000;
-    }
-
-    // Handle remaining 1–3 pixels
-    let srcByte = alignedPixels * BYTES_PER_PIXEL_RGB;
-    let dstByte = alignedPixels * BYTES_PER_PIXEL_RGBA;
-    for (let i = alignedPixels; i < pixelCount; i++) {
-      data[dstByte]     = bytes[srcByte];
-      data[dstByte + 1] = bytes[srcByte + 1];
-      data[dstByte + 2] = bytes[srcByte + 2];
-      data[dstByte + 3] = ALPHA_OPAQUE;
-      srcByte += BYTES_PER_PIXEL_RGB;
-      dstByte += BYTES_PER_PIXEL_RGBA;
-    }
-
-    return createImageBitmap(new ImageData(data, width, height));
-  }
-
-  private async _decompressZlib(compressed: Uint8Array): Promise<Uint8Array> {
-    try {
-      return await this._decompress(compressed, 'deflate');
-    } catch {
-      return await this._decompress(compressed, 'deflate-raw');
-    }
-  }
-
-  private async _decompress(compressed: Uint8Array, format: 'deflate' | 'deflate-raw'): Promise<Uint8Array> {
-    const ds = new DecompressionStream(format);
-    const writer = ds.writable.getWriter();
-    writer.write(compressed as BufferSource);
-    writer.close();
-
-    const chunks: Uint8Array[] = [];
-    const reader = ds.readable.getReader();
-
-    while (true) {
-      const { done, value } = await reader.read();
-      if (done) break;
-      chunks.push(value);
-    }
-
-    const totalLength = chunks.reduce((sum, chunk) => sum + chunk.length, 0);
-    const result = new Uint8Array(totalLength);
-    let offset = 0;
-    for (const chunk of chunks) {
-      result.set(chunk, offset);
-      offset += chunk.length;
-    }
-    return result;
-  }
-
-  public get images(): ReadonlyMap<number, IKittyImageData> {
-    return this._kittyStorage.images;
-  }
-
-  public get _kittyIdToStorageId(): ReadonlyMap<number, number> {
-    return this._kittyStorage.kittyIdToStorageId;
-  }
-
-  public get pendingTransmissions(): ReadonlyMap<number, IPendingTransmission> {
-    return this._pendingTransmissions;
-  }
-}

addons/addon-image/src/kitty/KittyGraphicsTypes.test.ts

@@ -1,149 +0,0 @@
-/**
- * Copyright (c) 2026 The xterm.js authors. All rights reserved.
- * @license MIT
- */
-import { assert } from 'chai';
-import { parseKittyCommand, KittyAction, KittyFormat } from './KittyGraphicsTypes';
-
-describe('KittyGraphicsTypes', () => {
-  describe('parseKittyCommand', () => {
-    it('should parse control data with action and format', () => {
-      const cmd = parseKittyCommand('a=T,f=100');
-      assert.strictEqual(cmd.action, 'T');
-      assert.strictEqual(cmd.format, 100);
-    });
-
-    it('should parse control data with all options', () => {
-      const cmd = parseKittyCommand('a=t,f=32,i=5,s=10,v=20,c=3,r=2,m=1,q=2');
-      assert.strictEqual(cmd.action, 't');
-      assert.strictEqual(cmd.format, 32);
-      assert.strictEqual(cmd.id, 5);
-      assert.strictEqual(cmd.width, 10);
-      assert.strictEqual(cmd.height, 20);
-      assert.strictEqual(cmd.columns, 3);
-      assert.strictEqual(cmd.rows, 2);
-      assert.strictEqual(cmd.more, 1);
-      assert.strictEqual(cmd.quiet, 2);
-    });
-
-    it('should handle empty control data', () => {
-      const cmd = parseKittyCommand('');
-      assert.strictEqual(cmd.action, undefined);
-      assert.strictEqual(cmd.format, undefined);
-    });
-
-    it('should parse transmit action', () => {
-      const cmd = parseKittyCommand('a=t,f=100');
-      assert.strictEqual(cmd.action, KittyAction.TRANSMIT);
-      assert.strictEqual(cmd.format, KittyFormat.PNG);
-    });
-
-    it('should parse delete action', () => {
-      const cmd = parseKittyCommand('a=d,i=5');
-      assert.strictEqual(cmd.action, KittyAction.DELETE);
-      assert.strictEqual(cmd.id, 5);
-    });
-
-    it('should parse empty action as empty string', () => {
-      const cmd = parseKittyCommand('a=,f=100');
-      assert.strictEqual(cmd.action, '');
-      assert.strictEqual(cmd.format, 100);
-    });
-
-    it('should leave action undefined when key is not present', () => {
-      const cmd = parseKittyCommand('f=100,i=5');
-      assert.strictEqual(cmd.action, undefined);
-      assert.strictEqual(cmd.format, 100);
-      assert.strictEqual(cmd.id, 5);
-    });
-
-    it('should parse compression key', () => {
-      const cmd = parseKittyCommand('a=t,f=32,o=z');
-      assert.strictEqual(cmd.action, 't');
-      assert.strictEqual(cmd.format, 32);
-      assert.strictEqual(cmd.compression, 'z');
-    });
-
-    it('should parse cursor movement key', () => {
-      const cmd = parseKittyCommand('a=T,f=100,C=1');
-      assert.strictEqual(cmd.cursorMovement, 1);
-    });
-
-    it('should parse cursor movement key C=0', () => {
-      const cmd = parseKittyCommand('a=T,f=100,C=0');
-      assert.strictEqual(cmd.cursorMovement, 0);
-    });
-
-    it('should parse x and y offset', () => {
-      const cmd = parseKittyCommand('a=T,x=10,y=20');
-      assert.strictEqual(cmd.x, 10);
-      assert.strictEqual(cmd.y, 20);
-    });
-
-    it('should handle keys without values', () => {
-      const cmd = parseKittyCommand('a=t,f=,i=5');
-      assert.strictEqual(cmd.action, 't');
-      assert.ok(isNaN(cmd.format!));
-      assert.strictEqual(cmd.id, 5);
-    });
-
-    it('should parse z-index key with positive value', () => {
-      const cmd = parseKittyCommand('a=T,f=100,z=10');
-      assert.strictEqual(cmd.zIndex, 10);
-    });
-
-    it('should parse z-index key with zero', () => {
-      const cmd = parseKittyCommand('a=T,f=100,z=0');
-      assert.strictEqual(cmd.zIndex, 0);
-    });
-
-    it('should parse z-index key with negative value', () => {
-      const cmd = parseKittyCommand('a=T,f=100,z=-1');
-      assert.strictEqual(cmd.zIndex, -1);
-    });
-
-    it('should leave zIndex undefined when not specified', () => {
-      const cmd = parseKittyCommand('a=T,f=100');
-      assert.strictEqual(cmd.zIndex, undefined);
-    });
-
-    it('should parse delete selector key', () => {
-      const cmd = parseKittyCommand('a=d,d=i,i=5');
-      assert.strictEqual(cmd.action, 'd');
-      assert.strictEqual(cmd.deleteSelector, 'i');
-      assert.strictEqual(cmd.id, 5);
-    });
-
-    it('should parse uppercase delete selector', () => {
-      const cmd = parseKittyCommand('a=d,d=A');
-      assert.strictEqual(cmd.deleteSelector, 'A');
-    });
-
-    it('should parse delete selector d=a (all)', () => {
-      const cmd = parseKittyCommand('a=d,d=a');
-      assert.strictEqual(cmd.deleteSelector, 'a');
-    });
-
-    it('should leave deleteSelector undefined when not specified', () => {
-      const cmd = parseKittyCommand('a=d,i=5');
-      assert.strictEqual(cmd.deleteSelector, undefined);
-    });
-
-    it('should parse placement id key', () => {
-      const cmd = parseKittyCommand('a=d,d=i,i=5,p=3');
-      assert.strictEqual(cmd.placementId, 3);
-      assert.strictEqual(cmd.deleteSelector, 'i');
-      assert.strictEqual(cmd.id, 5);
-    });
-
-    it('should leave placementId undefined when not specified', () => {
-      const cmd = parseKittyCommand('a=d,d=i,i=5');
-      assert.strictEqual(cmd.placementId, undefined);
-    });
-
-    it('should parse image number key', () => {
-      const cmd = parseKittyCommand('a=t,f=100,I=42');
-      assert.strictEqual(cmd.imageNumber, 42);
-    });
-  });
-});

addons/addon-image/src/kitty/KittyGraphicsTypes.ts

@@ -1,193 +0,0 @@
-/**
- * Copyright (c) 2026 The xterm.js authors. All rights reserved.
- * @license MIT
- *
- * Kitty graphics protocol types, constants, and parsing utilities.
- */
-
-import type Base64Decoder from 'xterm-wasm-parts/lib/base64/Base64Decoder.wasm';
-
-// Kitty graphics protocol action types.
-// See: https://sw.kovidgoyal.net/kitty/graphics-protocol/#control-data-reference under key 'a'.
-export const enum KittyAction {
-  TRANSMIT = 't',
-  TRANSMIT_DISPLAY = 'T',
-  QUERY = 'q',
-  PLACEMENT = 'p',
-  DELETE = 'd'
-}
-
-// Kitty graphics protocol format types.
-// See: https://sw.kovidgoyal.net/kitty/graphics-protocol/#control-data-reference
-export const enum KittyFormat {
-  RGB = 24,
-  RGBA = 32,
-  PNG = 100
-}
-
-// Kitty graphics protocol compression types.
-// See: https://sw.kovidgoyal.net/kitty/graphics-protocol/#control-data-reference under key 'o'.
-export const enum KittyCompression {
-  NONE = '',
-  ZLIB = 'z'
-}
-
-// Kitty graphics protocol control data keys.
-// See: https://sw.kovidgoyal.net/kitty/graphics-protocol/#control-data-reference
-export const enum KittyKey {
-  // Action to perform (t=transmit, T=transmit+display, q=query, p=placement, d=delete)
-  ACTION = 'a',
-  // Image format (24=RGB, 32=RGBA, 100=PNG)
-  FORMAT = 'f',
-  // Image ID for referencing stored images
-  ID = 'i',
-  // Image number (alternative to ID, terminal assigns ID)
-  IMAGE_NUMBER = 'I',
-  // Source image width in pixels
-  WIDTH = 's',
-  // Source image height in pixels
-  HEIGHT = 'v',
-  // The left edge (in pixels) of the image area to display
-  X_OFFSET = 'x',
-  // The top edge (in pixels) of the image area to display
-  Y_OFFSET = 'y',
-  // Width (in pixels) of the source rectangle to display
-  SOURCE_WIDTH = 'w',
-  // Height (in pixels) of the source rectangle to display
-  SOURCE_HEIGHT = 'h',
-  // Horizontal offset (in pixels) within the first cell
-  X_PLACEMENT_OFFSET = 'X',
-  // Vertical offset (in pixels) within the first cell
-  Y_PLACEMENT_OFFSET = 'Y',
-  // Number of terminal columns to display the image over
-  COLUMNS = 'c',
-  // Number of terminal rows to display the image over
-  ROWS = 'r',
-  // More data flag (1=more chunks coming, 0=final chunk)
-  MORE = 'm',
-  // Compression type (z=zlib). This is essential for chunking larger images.
-  COMPRESSION = 'o',
-  // Quiet mode (1=suppress OK responses, 2=suppress error responses)
-  QUIET = 'q',
-  // Cursor movement policy (0=move cursor after image, 1=don't move cursor)
-  CURSOR_MOVEMENT = 'C',
-  // Z-index for image layering (negative = behind text, 0+ = on top)
-  Z_INDEX = 'z',
-  // Transmission medium (d=direct, f=file, t=temp file, s=shared memory)
-  TRANSMISSION = 't',
-  // Delete selector (a/A=all, i/I=by id, c/C=at cursor, etc.) — only used when a=d
-  DELETE_SELECTOR = 'd',
-  // Placement ID for targeting specific placements
-  PLACEMENT_ID = 'p'
-}
-
-// Pixel format constants
-export const BYTES_PER_PIXEL_RGB = 3;
-export const BYTES_PER_PIXEL_RGBA = 4;
-export const ALPHA_OPAQUE = 255;
-
-// Parsed Kitty graphics command.
-export interface IKittyCommand {
-  action?: string;
-  format?: number;
-  id?: number;
-  imageNumber?: number;
-  width?: number;
-  height?: number;
-  x?: number;
-  y?: number;
-  sourceWidth?: number;
-  sourceHeight?: number;
-  xOffset?: number;
-  yOffset?: number;
-  columns?: number;
-  rows?: number;
-  more?: number;
-  quiet?: number;
-  cursorMovement?: number;
-  zIndex?: number;
-  transmission?: string;
-  deleteSelector?: string;
-  placementId?: number;
-  compression?: string;
-  payload?: string;
-}
-
-// Pending chunked transmission state.
-// Stores metadata from the first chunk while accumulating decoded payload data.
-export interface IPendingTransmission {
-  // The parsed command from the first chunk (contains action, format, dimensions, etc.)
-  cmd: IKittyCommand;
-  // Decoder used across chunked payloads
-  decoder: Base64Decoder;
-  // Total encoded (base64) bytes received across all chunks - for size limit enforcement
-  totalEncodedSize: number;
-  // Whether any chunk has failed to decode
-  decodeError: boolean;
-}
-
-// Stored Kitty image data.
-export interface IKittyImageData {
-  id: number;
-  // Decoded image data stored as Blob (off JS heap) to avoid 2GB heap limit
-  data: Blob;
-  width: number;
-  height: number;
-  format: 24 | 32 | 100;
-  compression?: string;
-}
-
-// Parses Kitty graphics control data into a command object.
-export function parseKittyCommand(data: string): IKittyCommand {
-  const cmd: IKittyCommand = {};
-  const parts = data.split(',');
-
-  for (const part of parts) {
-    const eqIdx = part.indexOf('=');
-    if (eqIdx === -1) continue;
-
-    const key = part.substring(0, eqIdx);
-    const value = part.substring(eqIdx + 1);
-
-    // Handle string keys first
-    if (key === KittyKey.ACTION) {
-      cmd.action = value;
-      continue;
-    }
-    if (key === KittyKey.COMPRESSION) {
-      cmd.compression = value;
-      continue;
-    }
-    if (key === KittyKey.TRANSMISSION) {
-      cmd.transmission = value;
-      continue;
-    }
-    if (key === KittyKey.DELETE_SELECTOR) {
-      cmd.deleteSelector = value;
-      continue;
-    }
-    const numValue = parseInt(value);
-    switch (key) {
-      case KittyKey.FORMAT: cmd.format = numValue; break;
-      case KittyKey.ID: cmd.id = numValue; break;
-      case KittyKey.IMAGE_NUMBER: cmd.imageNumber = numValue; break;
-      case KittyKey.WIDTH: cmd.width = numValue; break;
-      case KittyKey.HEIGHT: cmd.height = numValue; break;
-      case KittyKey.X_OFFSET: cmd.x = numValue; break;
-      case KittyKey.Y_OFFSET: cmd.y = numValue; break;
-      case KittyKey.SOURCE_WIDTH: cmd.sourceWidth = numValue; break;
-      case KittyKey.SOURCE_HEIGHT: cmd.sourceHeight = numValue; break;
-      case KittyKey.X_PLACEMENT_OFFSET: cmd.xOffset = numValue; break;
-      case KittyKey.Y_PLACEMENT_OFFSET: cmd.yOffset = numValue; break;
-      case KittyKey.COLUMNS: cmd.columns = numValue; break;
-      case KittyKey.ROWS: cmd.rows = numValue; break;
-      case KittyKey.MORE: cmd.more = numValue; break;
-      case KittyKey.QUIET: cmd.quiet = numValue; break;
-      case KittyKey.CURSOR_MOVEMENT: cmd.cursorMovement = numValue; break;
-      case KittyKey.Z_INDEX: cmd.zIndex = numValue; break;
-      case KittyKey.PLACEMENT_ID: cmd.placementId = numValue; break;
-    }
-  }
-
-  return cmd;
-}

addons/addon-image/src/kitty/KittyImageStorage.ts

@@ -1,142 +0,0 @@
-/**
- * Copyright (c) 2026 The xterm.js authors. All rights reserved.
- * @license MIT
- */
-
-import { IDisposable } from '@xterm/xterm';
-import { ImageStorage } from '../ImageStorage';
-import { ImageLayer } from '../Types';
-import { IKittyImageData } from './KittyGraphicsTypes';
-
-// Kitty-specific image storage controller.
-//
-// Wraps shared ImageStorage with kitty protocol semantics:
-// - tracks transmitted image payloads by kitty image id
-// - tracks kitty image id -> shared ImageStorage id mapping for displayed images
-// - mirrors shared-storage evictions into kitty maps
-// - applies protocol-level undisplayed-image eviction policy
-export class KittyImageStorage implements IDisposable {
-  private static readonly _maxStoredImages = 256;
-
-  private _nextImageId = 1;
-  private readonly _images: Map<number, IKittyImageData> = new Map();
-  private readonly _kittyIdToStorageId: Map<number, number> = new Map();
-  private readonly _storageIdToKittyId: Map<number, number> = new Map();
-
-  private readonly _previousOnImageDeleted: ((storageId: number) => void) | undefined;
-  private readonly _wrappedOnImageDeleted: (storageId: number) => void;
-  private readonly _handleStorageImageDeleted = (storageId: number): void => {
-    const kittyId = this._storageIdToKittyId.get(storageId);
-    if (kittyId !== undefined) {
-      this._kittyIdToStorageId.delete(kittyId);
-      this._storageIdToKittyId.delete(storageId);
-      this._images.delete(kittyId);
-    }
-  };
-
-  constructor(
-    private readonly _storage: ImageStorage
-  ) {
-    this._previousOnImageDeleted = this._storage.onImageDeleted;
-    this._wrappedOnImageDeleted = (storageId: number) => {
-      this._previousOnImageDeleted?.(storageId);
-      this._handleStorageImageDeleted(storageId);
-    };
-    this._storage.onImageDeleted = this._wrappedOnImageDeleted;
-  }
-
-  public reset(): void {
-    this._nextImageId = 1;
-    this._images.clear();
-    this._kittyIdToStorageId.clear();
-    this._storageIdToKittyId.clear();
-  }
-
-  public dispose(): void {
-    this.reset();
-    if (this._storage.onImageDeleted === this._wrappedOnImageDeleted) {
-      this._storage.onImageDeleted = this._previousOnImageDeleted;
-    }
-  }
-
-  public storeImage(id: number | undefined, imageData: Omit<IKittyImageData, 'id'>): number {
-    const imageId = id ?? this._nextImageId++;
-
-    const oldStorageId = this._kittyIdToStorageId.get(imageId);
-    if (oldStorageId !== undefined) {
-      this._storage.deleteImage(oldStorageId);
-      this._kittyIdToStorageId.delete(imageId);
-      this._storageIdToKittyId.delete(oldStorageId);
-    }
-
-    if (!this._images.has(imageId) && this._images.size >= KittyImageStorage._maxStoredImages) {
-      this._evictUndisplayedImages();
-    }
-
-    this._images.set(imageId, {
-      ...imageData,
-      id: imageId
-    });
-    return imageId;
-  }
-
-  public addImage(kittyId: number, image: HTMLCanvasElement | ImageBitmap, scrolling: boolean, layer: ImageLayer, zIndex: number): void {
-    // Clean up stale reverse-mapping from a previous placement of the same
-    // kitty image.  The old shared-storage entry is kept (it may still be
-    // visible on screen) but its reverse mapping is removed so that eviction
-    // of the old entry won't incorrectly delete the kitty image data.
-    const oldStorageId = this._kittyIdToStorageId.get(kittyId);
-    if (oldStorageId !== undefined) {
-      this._storageIdToKittyId.delete(oldStorageId);
-    }
-    const storageId = this._storage.addImage(image, scrolling, layer, zIndex);
-    this._kittyIdToStorageId.set(kittyId, storageId);
-    this._storageIdToKittyId.set(storageId, kittyId);
-  }
-
-  public getImage(kittyId: number): IKittyImageData | undefined {
-    return this._images.get(kittyId);
-  }
-
-  public deleteById(kittyId: number): void {
-    this._images.delete(kittyId);
-    const storageId = this._kittyIdToStorageId.get(kittyId);
-    if (storageId !== undefined) {
-      this._storage.deleteImage(storageId);
-      this._kittyIdToStorageId.delete(kittyId);
-      this._storageIdToKittyId.delete(storageId);
-    }
-  }
-
-  public deleteAll(): void {
-    this._images.clear();
-    for (const storageId of this._kittyIdToStorageId.values()) {
-      this._storage.deleteImage(storageId);
-    }
-    this._kittyIdToStorageId.clear();
-    this._storageIdToKittyId.clear();
-  }
-
-  public get images(): ReadonlyMap<number, IKittyImageData> {
-    return this._images;
-  }
-
-  public get kittyIdToStorageId(): ReadonlyMap<number, number> {
-    return this._kittyIdToStorageId;
-  }
-
-  public get lastImageId(): number {
-    return this._nextImageId - 1;
-  }
-
-  private _evictUndisplayedImages(): void {
-    for (const [kittyId] of this._images) {
-      if (this._images.size <= KittyImageStorage._maxStoredImages / 2) {
-        break;
-      }
-      if (!this._kittyIdToStorageId.has(kittyId)) {
-        this._images.delete(kittyId);
-      }
-    }
-  }
-}

addons/addon-image/src/tsconfig.json

@@ -11,11 +11,11 @@
     "types": [
       "../../../node_modules/@types/mocha"
     ],
+    "baseUrl": ".",
     "paths": {
       "browser/*": [ "../../../src/browser/*" ],
       "common/*": [ "../../../src/common/*" ],
-      "@xterm/addon-image": [ "../typings/addon-image.d.ts" ],
-      "*": [ "./*" ]
+      "@xterm/addon-image": [ "../typings/addon-image.d.ts" ]
     }
   },
   "include": [

addons/addon-image/test/ImageAddon.test.ts

@@ -23,8 +23,6 @@ export interface IImageAddonOptions {
   sixelSizeLimit: number;
   iipSupport: boolean;
   iipSizeLimit: number;
-  kittySupport: boolean;
-  kittySizeLimit: number;
 }
 
 // eslint-disable-next-line
@@ -136,9 +134,7 @@ test.describe('ImageAddon', () => {
         storageLimit: 128,
         showPlaceholder: true,
         iipSupport: true,
-        iipSizeLimit: 20000000,
-        kittySupport: true,
-        kittySizeLimit: 20000000
+        iipSizeLimit: 20000000
       };
       deepStrictEqual(await ctx.page.evaluate(`window.imageAddon._opts`), DEFAULT_OPTIONS);
     });
@@ -153,9 +149,7 @@ test.describe('ImageAddon', () => {
         storageLimit: 10,
         showPlaceholder: false,
         iipSupport: false,
-        iipSizeLimit: 1000,
-        kittySupport: false,
-        kittySizeLimit: 1000
+        iipSizeLimit: 1000
       };
       await ctx.page.evaluate(opts => {
         (window as any).imageAddonCustom = new ImageAddon(opts.opts);

addons/addon-image/test/tsconfig.json

@@ -9,15 +9,13 @@
     "outDir": "../out-test",
     "sourceMap": true,
     "removeComments": true,
+    "baseUrl": ".",
     "paths": {
       "common/*": [
         "../../../src/common/*"
       ],
       "browser/*": [
         "../../../src/browser/*"
-      ],
-      "*": [
-        "./*"
       ]
     },
     "strict": true,

addons/addon-image/typings/addon-image.d.ts

@@ -76,15 +76,6 @@ declare module '@xterm/addon-image' {
     iipSupport?: boolean;
     /** IIP sequence size limit (default 20000000 bytes). */
     iipSizeLimit?: number;
-
-    /**
-     * Kitty graphics protocol settings
-     */
-
-    /** Whether Kitty graphics protocol is enabled (default is true). */
-    kittySupport?: boolean;
-    /** Kitty image size limit in bytes (default 20000000 bytes). */
-    kittySizeLimit?: number;
   }
 
   export class ImageAddon implements ITerminalAddon {

addons/addon-ligatures/package.json

@@ -14,8 +14,8 @@
     "node": ">8.0.0"
   },
   "scripts": {
-    "build": "tsgo -p src",
-    "watch": "tsgo -w -p src",
+    "build": "tsc -p src",
+    "watch": "tsc -w -p src",
     "prepackage": "npm run build",
     "package": "webpack",
     "pretest": "npm run build",

addons/addon-ligatures/test/tsconfig.json

@@ -9,12 +9,8 @@
     "outDir": "../out-esbuild-test",
     "sourceMap": true,
     "removeComments": true,
+    "baseUrl": ".",
     "strict": true,
-    "paths": {
-      "*": [
-        "./*"
-      ]
-    },
     "types": [
       "../../../node_modules/@types/mocha",
       "../../../node_modules/@types/node"

addons/addon-progress/package.json

@@ -16,7 +16,7 @@
     "xterm.js"
   ],
   "scripts": {
-    "build": "../../node_modules/.bin/tsgo -p .",
+    "build": "../../node_modules/.bin/tsc -p .",
     "prepackage": "npm run build",
     "package": "../../node_modules/.bin/webpack",
     "prepublishOnly": "npm run package",

addons/addon-progress/test/tsconfig.json

@@ -9,15 +9,13 @@
     "outDir": "../out-test",
     "sourceMap": true,
     "removeComments": true,
+    "baseUrl": ".",
     "paths": {
       "common/*": [
         "../../../src/common/*"
       ],
       "browser/*": [
         "../../../src/browser/*"
-      ],
-      "*": [
-        "./*"
       ]
     },
     "strict": true,

addons/addon-search/package.json

@@ -16,7 +16,7 @@
     "xterm.js"
   ],
   "scripts": {
-    "prepackage": "../../node_modules/.bin/tsgo -p .",
+    "prepackage": "../../node_modules/.bin/tsc -p .",
     "package": "../../node_modules/.bin/webpack",
     "prepublishOnly": "npm run package",
     "start": "node ../../demo/start"

addons/addon-search/src/SearchEngine.ts

@@ -64,6 +64,9 @@ export class SearchEngine {
       throw new Error(`Invalid col: ${startCol} to search in terminal of ${this._terminal.cols} cols`);
     }
 
+    startRow = Math.max(0, startRow);
+    startCol = Math.max(0, startCol);
+
     this._lineCache.initLinesCache();
 
     const searchPosition: ISearchPosition = {

addons/addon-search/test/tsconfig.json

@@ -9,15 +9,13 @@
     "outDir": "../out-test",
     "sourceMap": true,
     "removeComments": true,
+    "baseUrl": ".",
     "paths": {
       "common/*": [
         "../../../src/common/*"
       ],
       "browser/*": [
         "../../../src/browser/*"
-      ],
-      "*": [
-        "./*"
       ]
     },
     "strict": true,

addons/addon-serialize/benchmark/tsconfig.json

@@ -4,13 +4,13 @@
       "dom",
       "es2021"
     ],
-    "rootDir": "..",
     "outDir": "../out-benchmark",
     "types": ["../../../node_modules/@types/node"],
     "moduleResolution": "node",
     "strict": false,
     "target": "es2021",
     "module": "commonjs",
+    "baseUrl": ".",
     "paths": {
       "common/*": ["../../../src/common/*"],
       "browser/*": ["../../../src/browser/*"],

addons/addon-serialize/package.json

@@ -16,7 +16,7 @@
     "xterm.js"
   ],
   "scripts": {
-    "build": "../../node_modules/.bin/tsgo -p .",
+    "build": "../../node_modules/.bin/tsc -p .",
     "prepackage": "npm run build",
     "package": "../../node_modules/.bin/webpack",
     "prepublishOnly": "npm run package",

addons/addon-serialize/src/tsconfig.json

@@ -10,6 +10,7 @@
     "outDir": "../out",
     "sourceMap": true,
     "removeComments": true,
+    "baseUrl": ".",
     "paths": {
       "common/*": [
         "../../../src/common/*"
@@ -22,7 +23,6 @@
       ]
     },
     "strict": true,
-    "skipLibCheck": true,
     "types": [
       "../../../node_modules/@types/mocha"
     ]

addons/addon-serialize/test/tsconfig.json

@@ -9,6 +9,7 @@
     "outDir": "../out-test",
     "sourceMap": true,
     "removeComments": true,
+    "baseUrl": ".",
     "paths": {
       "common/*": [
         "../../../src/common/*"

addons/addon-unicode-graphemes/benchmark/tsconfig.json

@@ -1,13 +1,13 @@
 {
   "compilerOptions": {
     "lib": ["dom", "es6"],
-    "rootDir": "..",
     "outDir": "../out-benchmark",
     "types": ["../../../node_modules/@types/node"],
     "moduleResolution": "node",
     "strict": false,
     "target": "es2015",
     "module": "commonjs",
+    "baseUrl": ".",
     "paths": {
       "common/*": ["../../../src/common/*"],
       "browser/*": ["../../../src/browser/*"],

addons/addon-unicode-graphemes/package.json

@@ -16,7 +16,7 @@
     "xterm.js"
   ],
   "scripts": {
-    "build": "../../node_modules/.bin/tsgo -p .",
+    "build": "../../node_modules/.bin/tsc -p .",
     "prepackage": "npm run build",
     "package": "../../node_modules/.bin/webpack",
     "prepublishOnly": "npm run package",

addons/addon-unicode-graphemes/src/tsconfig.json

@@ -11,6 +11,7 @@
     "sourceMap": true,
     "removeComments": true,
     "strict": true,
+    "baseUrl": ".",
     "paths": {
       "common/*": [
         "../../../src/common/*"

addons/addon-unicode-graphemes/test/tsconfig.json

@@ -9,6 +9,7 @@
     "outDir": "../out-test",
     "sourceMap": true,
     "removeComments": true,
+    "baseUrl": ".",
     "paths": {
       "common/*": [
         "../../../src/common/*"

addons/addon-unicode11/package.json

@@ -16,7 +16,7 @@
     "xterm.js"
   ],
   "scripts": {
-    "build": "../../node_modules/.bin/tsgo -p .",
+    "build": "../../node_modules/.bin/tsc -p .",
     "prepackage": "npm run build",
     "package": "../../node_modules/.bin/webpack",
     "prepublishOnly": "npm run package",

addons/addon-unicode11/src/tsconfig.json

@@ -11,15 +11,13 @@
     "sourceMap": true,
     "removeComments": true,
     "strict": true,
+    "baseUrl": ".",
     "paths": {
       "common/*": [
         "../../../src/common/*"
       ],
       "@xterm/addon-unicode11": [
         "../typings/addon-unicode11.d.ts"
-      ],
-      "*": [
-        "./*"
       ]
     },
     "types": [

addons/addon-unicode11/test/tsconfig.json

@@ -9,15 +9,13 @@
     "outDir": "../out-test",
     "sourceMap": true,
     "removeComments": true,
+    "baseUrl": ".",
     "paths": {
       "common/*": [
         "../../../src/common/*"
       ],
       "browser/*": [
         "../../../src/browser/*"
-      ],
-      "*": [
-        "./*"
       ]
     },
     "strict": true,

addons/addon-web-fonts/package.json

@@ -16,7 +16,7 @@
     "xterm.js"
   ],
   "scripts": {
-    "build": "../../node_modules/.bin/tsgo -p .",
+    "build": "../../node_modules/.bin/tsc -p .",
     "prepackage": "npm run build",
     "package": "../../node_modules/.bin/webpack",
     "prepublishOnly": "npm run package",

addons/addon-web-fonts/test/tsconfig.json

@@ -10,15 +10,13 @@
     "outDir": "../out-test",
     "sourceMap": true,
     "removeComments": true,
+    "baseUrl": ".",
     "paths": {
       "common/*": [
         "../../../src/common/*"
       ],
       "browser/*": [
         "../../../src/browser/*"
-      ],
-      "*": [
-        "./*"
       ]
     },
     "strict": true,

addons/addon-web-links/package.json

@@ -16,7 +16,7 @@
     "xterm.js"
   ],
   "scripts": {
-    "build": "../../node_modules/.bin/tsgo -p .",
+    "build": "../../node_modules/.bin/tsc -p .",
     "prepackage": "npm run build",
     "package": "../../node_modules/.bin/webpack",
     "prepublishOnly": "npm run package",

addons/addon-web-links/test/tsconfig.json

@@ -10,15 +10,13 @@
     "outDir": "../out-test",
     "sourceMap": true,
     "removeComments": true,
+    "baseUrl": ".",
     "paths": {
       "common/*": [
         "../../../src/common/*"
       ],
       "browser/*": [
         "../../../src/browser/*"
-      ],
-      "*": [
-        "./*"
       ]
     },
     "strict": true,

addons/addon-webgl/package.json

@@ -17,7 +17,7 @@
     "xterm.js"
   ],
   "scripts": {
-    "build": "../../node_modules/.bin/tsgo -p .",
+    "build": "../../node_modules/.bin/tsc -p .",
     "prepackage": "npm run build",
     "package": "../../node_modules/.bin/webpack",
     "prepublishOnly": "npm run package",

addons/addon-webgl/src/customGlyphs/CustomGlyphDefinitions.ts

@@ -7,35 +7,6 @@ import { CustomGlyphDefinitionType, CustomGlyphScaleType, CustomGlyphVectorType,
 
 /* eslint-disable max-len */
 
-const enum Shapes {
-  /** │ */ TOP_TO_BOTTOM = 'M.5,0 L.5,1',
-  /** ─ */ LEFT_TO_RIGHT = 'M0,.5 L1,.5',
-
-  /** └ */ TOP_TO_RIGHT = 'M.5,0 L.5,.5 L1,.5',
-  /** ┘ */ TOP_TO_LEFT = 'M.5,0 L.5,.5 L0,.5',
-  /** ┐ */ LEFT_TO_BOTTOM = 'M0,.5 L.5,.5 L.5,1',
-  /** ┌ */ RIGHT_TO_BOTTOM = 'M0.5,1 L.5,.5 L1,.5',
-
-  /** ╵ */ MIDDLE_TO_TOP = 'M.5,.5 L.5,0',
-  /** ╴ */ MIDDLE_TO_LEFT = 'M.5,.5 L0,.5',
-  /** ╶ */ MIDDLE_TO_RIGHT = 'M.5,.5 L1,.5',
-  /** ╷ */ MIDDLE_TO_BOTTOM = 'M.5,.5 L.5,1',
-
-  /** ┴ */ T_TOP = 'M0,.5 L1,.5 M.5,.5 L.5,0',
-  /** ┤ */ T_LEFT = 'M.5,0 L.5,1 M.5,.5 L0,.5',
-  /** ├ */ T_RIGHT = 'M.5,0 L.5,1 M.5,.5 L1,.5',
-  /** ┬ */ T_BOTTOM = 'M0,.5 L1,.5 M.5,.5 L.5,1',
-
-  /** ┼ */ CROSS = 'M0,.5 L1,.5 M.5,0 L.5,1',
-
-  /** ╌ */ TWO_DASHES_HORIZONTAL = 'M.1,.5 L.4,.5 M.6,.5 L.9,.5', // .2 empty, .3 filled
-  /** ┄ */ THREE_DASHES_HORIZONTAL = 'M.0667,.5 L.2667,.5 M.4,.5 L.6,.5 M.7333,.5 L.9333,.5', // .1333 empty, .2 filled
-  /** ┉ */ FOUR_DASHES_HORIZONTAL = 'M.05,.5 L.2,.5 M.3,.5 L.45,.5 M.55,.5 L.7,.5 M.8,.5 L.95,.5', // .1 empty, .15 filled
-  /** ╎ */ TWO_DASHES_VERTICAL = 'M.5,.1 L.5,.4 M.5,.6 L.5,.9',
-  /** ┆ */ THREE_DASHES_VERTICAL = 'M.5,.0667 L.5,.2667 M.5,.4 L.5,.6 M.5,.7333 L.5,.9333',
-  /** ┊ */ FOUR_DASHES_VERTICAL = 'M.5,.05 L.5,.2 M.5,.3 L.5,.45 L.5,.55 M.5,.7 L.5,.95',
-}
-
 namespace GitBranchSymbolsParts {
   // Lines
   export const LINE_H: CustomGlyphDefinitionPart = Object.freeze({ type: CustomGlyphDefinitionType.PATH_FUNCTION, data: Shapes.LEFT_TO_RIGHT, strokeWidth: 1 });
@@ -1017,3 +988,31 @@ function segmentedDigit(pattern: number): string {
   return paths.join(' ');
 }
 
+const enum Shapes {
+  /** │ */ TOP_TO_BOTTOM = 'M.5,0 L.5,1',
+  /** ─ */ LEFT_TO_RIGHT = 'M0,.5 L1,.5',
+
+  /** └ */ TOP_TO_RIGHT = 'M.5,0 L.5,.5 L1,.5',
+  /** ┘ */ TOP_TO_LEFT = 'M.5,0 L.5,.5 L0,.5',
+  /** ┐ */ LEFT_TO_BOTTOM = 'M0,.5 L.5,.5 L.5,1',
+  /** ┌ */ RIGHT_TO_BOTTOM = 'M0.5,1 L.5,.5 L1,.5',
+
+  /** ╵ */ MIDDLE_TO_TOP = 'M.5,.5 L.5,0',
+  /** ╴ */ MIDDLE_TO_LEFT = 'M.5,.5 L0,.5',
+  /** ╶ */ MIDDLE_TO_RIGHT = 'M.5,.5 L1,.5',
+  /** ╷ */ MIDDLE_TO_BOTTOM = 'M.5,.5 L.5,1',
+
+  /** ┴ */ T_TOP = 'M0,.5 L1,.5 M.5,.5 L.5,0',
+  /** ┤ */ T_LEFT = 'M.5,0 L.5,1 M.5,.5 L0,.5',
+  /** ├ */ T_RIGHT = 'M.5,0 L.5,1 M.5,.5 L1,.5',
+  /** ┬ */ T_BOTTOM = 'M0,.5 L1,.5 M.5,.5 L.5,1',
+
+  /** ┼ */ CROSS = 'M0,.5 L1,.5 M.5,0 L.5,1',
+
+  /** ╌ */ TWO_DASHES_HORIZONTAL = 'M.1,.5 L.4,.5 M.6,.5 L.9,.5', // .2 empty, .3 filled
+  /** ┄ */ THREE_DASHES_HORIZONTAL = 'M.0667,.5 L.2667,.5 M.4,.5 L.6,.5 M.7333,.5 L.9333,.5', // .1333 empty, .2 filled
+  /** ┉ */ FOUR_DASHES_HORIZONTAL = 'M.05,.5 L.2,.5 M.3,.5 L.45,.5 M.55,.5 L.7,.5 M.8,.5 L.95,.5', // .1 empty, .15 filled
+  /** ╎ */ TWO_DASHES_VERTICAL = 'M.5,.1 L.5,.4 M.5,.6 L.5,.9',
+  /** ┆ */ THREE_DASHES_VERTICAL = 'M.5,.0667 L.5,.2667 M.5,.4 L.5,.6 M.5,.7333 L.5,.9333',
+  /** ┊ */ FOUR_DASHES_VERTICAL = 'M.5,.05 L.5,.2 M.5,.3 L.5,.45 L.5,.55 M.5,.7 L.5,.95',
+}

addons/addon-webgl/src/tsconfig.json

@@ -10,6 +10,7 @@
     "outDir": "../out",
     "sourceMap": true,
     "removeComments": true,
+    "baseUrl": ".",
     "paths": {
       "common/*": [
         "../../../src/common/*"
@@ -19,9 +20,6 @@
       ],
       "@xterm/addon-webgl": [
         "../typings/addon-webgl.d.ts"
-      ],
-      "*": [
-        "./*"
       ]
     },
     "strict": true,

addons/addon-webgl/test/tsconfig.json

@@ -9,15 +9,13 @@
     "outDir": "../out-test",
     "sourceMap": true,
     "removeComments": true,
+    "baseUrl": ".",
     "paths": {
       "common/*": [
         "../../../src/common/*"
       ],
       "browser/*": [
         "../../../src/browser/*"
-      ],
-      "*": [
-        "./*"
       ]
     },
     "strict": true,

bin/agent/setup-repo.mjs

@@ -1,138 +0,0 @@
-// @ts-check
-
-import { cpSync, existsSync, lstatSync, readFileSync } from 'node:fs';
-import { spawnSync } from 'node:child_process';
-import { basename, dirname, resolve, sep } from 'node:path';
-import { fileURLToPath } from 'node:url';
-
-const repoRoot = resolve(dirname(fileURLToPath(import.meta.url)), '../..');
-const nodeModulesPath = resolve(repoRoot, 'node_modules');
-const npmExecutable = process.platform === 'win32' ? 'npm.cmd' : 'npm';
-
-/** @typedef {{ folder: string; reason: string }} Candidate */
-
-/** @param {string} message */
-function log(message) {
-  console.info(`[setup-fast] ${message}`);
-}
-
-/** @param {string[]} args */
-function runNpm(args) {
-  log(`Running: npm ${args.join(' ')}`);
-  const result = spawnSync(npmExecutable, args, {
-    cwd: repoRoot,
-    stdio: 'inherit'
-  });
-  if (result.error) {
-    throw result.error;
-  }
-  if ((result.status ?? 1) !== 0) {
-    process.exit(result.status ?? 1);
-  }
-}
-
-/**
- * @param {Candidate[]} candidates
- * @param {string | undefined} folder
- * @param {string} reason
- */
-function addCandidate(candidates, folder, reason) {
-  if (!folder) {
-    return;
-  }
-  if (candidates.some(candidate => candidate.folder === folder)) {
-    return;
-  }
-  candidates.push({ folder, reason });
-  log(`Candidate found (${reason}): ${folder}`);
-}
-
-function detectMainSiblingFolder() {
-  const currentFolderName = basename(repoRoot);
-  if (!currentFolderName.startsWith('xterm.js') || currentFolderName === 'xterm.js') {
-    log(`Current folder is "${currentFolderName}", skipping xterm.js sibling lookup.`);
-    return undefined;
-  }
-  const siblingFolder = resolve(dirname(repoRoot), 'xterm.js');
-  log(`Current folder is "${currentFolderName}", sibling main folder candidate: ${siblingFolder}`);
-  return siblingFolder;
-}
-
-function detectWorktreeMainFolder() {
-  const gitPath = resolve(repoRoot, '.git');
-  if (!existsSync(gitPath)) {
-    log('No .git entry found at repo root.');
-    return undefined;
-  }
-  const gitStat = lstatSync(gitPath);
-  if (!gitStat.isFile()) {
-    log('.git is not a file, this repo does not appear to be a worktree checkout.');
-    return undefined;
-  }
-  const gitFileContent = readFileSync(gitPath, 'utf8').trim();
-  const gitDirMatch = /^gitdir:\s*(.+)$/m.exec(gitFileContent);
-  if (!gitDirMatch) {
-    log('Could not parse gitdir from .git file.');
-    return undefined;
-  }
-
-  const gitDirPath = resolve(repoRoot, gitDirMatch[1].trim());
-  log(`Parsed gitdir from .git file: ${gitDirPath}`);
-
-  const normalizedGitDirPath = gitDirPath.replace(/\\/g, '/');
-  const worktreeMarker = '/.git/worktrees/';
-  const markerIndex = normalizedGitDirPath.indexOf(worktreeMarker);
-  if (markerIndex === -1) {
-    log('gitdir path does not contain /.git/worktrees/, skipping worktree main folder lookup.');
-    return undefined;
-  }
-
-  const normalizedMainFolder = normalizedGitDirPath.slice(0, markerIndex);
-  const mainFolder = sep === '/' ? normalizedMainFolder : normalizedMainFolder.split('/').join(sep);
-  log(`Worktree main folder candidate: ${mainFolder}`);
-  return mainFolder;
-}
-
-function resolveSourceFolder() {
-  /** @type {Candidate[]} */
-  const candidates = [];
-  addCandidate(candidates, detectMainSiblingFolder(), 'xterm.js sibling');
-  addCandidate(candidates, detectWorktreeMainFolder(), 'worktree main repo');
-
-  for (const candidate of candidates) {
-    const candidateNodeModulesPath = resolve(candidate.folder, 'node_modules');
-    if (existsSync(candidateNodeModulesPath)) {
-      log(`Using candidate (${candidate.reason}) with node_modules: ${candidate.folder}`);
-      return candidate.folder;
-    }
-    log(`Candidate skipped (${candidate.reason}), node_modules missing: ${candidateNodeModulesPath}`);
-  }
-
-  log('No candidate folder with node_modules was found.');
-  return undefined;
-}
-
-if (!existsSync(nodeModulesPath)) {
-  log(`node_modules missing: ${nodeModulesPath}`);
-  const sourceFolder = resolveSourceFolder();
-  if (sourceFolder) {
-    const sourceNodeModulesPath = resolve(sourceFolder, 'node_modules');
-    log(`Copying node_modules from ${sourceNodeModulesPath} to ${nodeModulesPath}`);
-    try {
-      cpSync(sourceNodeModulesPath, nodeModulesPath, { recursive: true });
-      log('node_modules copy completed.');
-    } catch (error) {
-      const message = error instanceof Error ? error.message : String(error);
-      log(`node_modules copy failed: ${message}`);
-      log('Falling back to npm ci.');
-      runNpm(['ci']);
-    }
-  } else {
-    log('No source folder available, running npm ci.');
-    runNpm(['ci']);
-  }
-} else {
-  log(`node_modules already exists: ${nodeModulesPath}`);
-}
-
-runNpm(['run', 'setup']);

bin/build_ghostty_wasm.mjs

@@ -0,0 +1,42 @@
+/**
+ * Copyright (c) 2026 The xterm.js authors. All rights reserved.
+ * @license MIT
+ */
+
+import { spawnSync } from 'child_process';
+import { copyFileSync, mkdirSync, renameSync } from 'fs';
+import path from 'path';
+import process from 'process';
+import { fileURLToPath } from 'url';
+
+const repoRoot = path.resolve(path.dirname(fileURLToPath(import.meta.url)), '..');
+const ghosttyDir = path.join(repoRoot, 'vendor', 'ghostty');
+const wasmOutDir = path.join(repoRoot, 'vendor', 'ghostty-wasm');
+const wasmBinDir = path.join(wasmOutDir, 'bin');
+const wasmFile = path.join(wasmOutDir, 'ghostty-vt.wasm');
+const wasmBinFile = path.join(wasmBinDir, 'ghostty-vt.wasm');
+
+mkdirSync(wasmOutDir, { recursive: true });
+
+const result = spawnSync('zig', [
+  'build',
+  'lib-vt',
+  '-Dtarget=wasm32-freestanding',
+  '-Doptimize=ReleaseSmall',
+  '-p',
+  path.relative(ghosttyDir, wasmOutDir)
+], {
+  cwd: ghosttyDir,
+  stdio: 'inherit',
+  shell: true
+});
+
+if (result.status !== 0) {
+  process.exit(result.status ?? 1);
+}
+
+try {
+  renameSync(wasmBinFile, wasmFile);
+} catch {
+  copyFileSync(wasmBinFile, wasmFile);
+}

bin/test_unit.js

@@ -6,6 +6,9 @@
 const cp = require('child_process');
 const path = require('path');
 
+globalThis.require = require;
+globalThis.XTERM_GHOSTTY_WASM_URL = path.resolve(__dirname, '../vendor/ghostty-wasm/ghostty-vt.wasm');
+
 const COVERAGE_LINES_THRESHOLD = 40;
 
 // Add `out` to the NODE_PATH so absolute paths can be resolved.

demo/client/client.ts

@@ -328,9 +328,7 @@ function createTerminal(): Terminal {
     }
     const cols = size.cols;
     const rows = size.rows;
-    const pixelWidth = Math.round(term!.dimensions?.css?.canvas?.width ?? 0);
-    const pixelHeight = Math.round(term!.dimensions?.css?.canvas?.height ?? 0);
-    const url = '/terminals/' + pid + '/size?cols=' + cols + '&rows=' + rows + '&pixelWidth=' + pixelWidth + '&pixelHeight=' + pixelHeight;
+    const url = '/terminals/' + pid + '/size?cols=' + cols + '&rows=' + rows;
 
     fetch(url, { method: 'POST' });
   });
@@ -381,9 +379,7 @@ function createTerminal(): Terminal {
     if (useRealTerminal instanceof HTMLInputElement && !useRealTerminal.checked) {
       runFakeTerminal();
     } else {
-      const pixelWidth = Math.round(term!.dimensions?.css?.canvas?.width ?? 0);
-      const pixelHeight = Math.round(term!.dimensions?.css?.canvas?.height ?? 0);
-      const res = await fetch('/terminals?cols=' + term!.cols + '&rows=' + term!.rows + '&pixelWidth=' + pixelWidth + '&pixelHeight=' + pixelHeight, { method: 'POST' });
+      const res = await fetch('/terminals?cols=' + term!.cols + '&rows=' + term!.rows, { method: 'POST' });
       const processId = await res.text();
       pid = processId;
       socketURL += processId;
@@ -630,7 +626,7 @@ function updateTerminalSize(): void {
   function getBox(width: number, height: number): any {
     return {
       string: '+',
-      style: 'font-size: 1px; padding: ' + Math.floor(height / 2) + 'px ' + Math.floor(width / 2) + 'px; line-height: ' + height + 'px;'
+      style: 'font-size: 1px; padding: ' + Math.floor(height/2) + 'px ' + Math.floor(width/2) + 'px; line-height: ' + height + 'px;'
     };
   }
   if (source instanceof HTMLCanvasElement) {

demo/client/components/window/addonImageWindow.ts

@@ -51,30 +51,14 @@ export class AddonImageWindow extends BaseWindow implements IControlWindow {
     container.appendChild(document.createElement('br'));
     container.appendChild(document.createElement('br'));
 
-    // Sixel demos
-    const dlSixel = document.createElement('dl');
-    const dtSixel = document.createElement('dt');
-    dtSixel.textContent = 'Sixel';
-    dlSixel.appendChild(dtSixel);
-    this._addDdWithButton(dlSixel, 'image-demo1', 'snake');
-    this._addDdWithButton(dlSixel, 'image-demo2', 'oranges');
-    container.appendChild(dlSixel);
-
-    // IIP demos
-    const dlIip = document.createElement('dl');
-    const dtIip = document.createElement('dt');
-    dtIip.textContent = 'IIP (iTerm)';
-    dlIip.appendChild(dtIip);
-    this._addDdWithButton(dlIip, 'image-demo3', 'palette');
-    container.appendChild(dlIip);
-
-    // Kitty demos
-    const dlKitty = document.createElement('dl');
-    const dtKitty = document.createElement('dt');
-    dtKitty.textContent = 'Kitty';
-    dlKitty.appendChild(dtKitty);
-    this._addDdWithButton(dlKitty, 'image-demo-kitty1', 'palette');
-    container.appendChild(dlKitty);
+    const dl = document.createElement('dl');
+    const dt = document.createElement('dt');
+    dt.textContent = 'Image Test';
+    dl.appendChild(dt);
+    this._addDdWithButton(dl, 'image-demo1', 'snake (sixel)');
+    this._addDdWithButton(dl, 'image-demo2', 'oranges (sixel)');
+    this._addDdWithButton(dl, 'image-demo3', 'palette (iip)');
+    container.appendChild(dl);
 
     this._initImageAddonExposed();
   }
@@ -141,25 +125,12 @@ export class AddonImageWindow extends BaseWindow implements IControlWindow {
         this._terminal.write(`\x1b]1337;File=inline=1;size=${data.length}:${btoa(sdata)}\x1b\\`);
       });
 
-    const kittyDemo = (url: string) => () => fetch(url)
-      .then(resp => resp.arrayBuffer())
-      .then(buffer => {
-        const data = new Uint8Array(buffer);
-        let sdata = '';
-        for (let i = 0; i < data.length; ++i) sdata += String.fromCharCode(data[i]);
-        const payload = btoa(sdata);
-        this._terminal.write('\r\n');
-        this._terminal.write(`\x1b_Ga=T,f=100;${payload}\x1b\\`);
-      });
-
     document.getElementById('image-demo1')!.addEventListener('click',
       sixelDemo('https://raw.githubusercontent.com/saitoha/libsixel/master/images/snake.six'));
     document.getElementById('image-demo2')!.addEventListener('click',
       sixelDemo('https://raw.githubusercontent.com/jerch/node-sixel/master/testfiles/test2.sixel'));
     document.getElementById('image-demo3')!.addEventListener('click',
       iipDemo('https://raw.githubusercontent.com/jerch/node-sixel/master/palette.png'));
-    document.getElementById('image-demo-kitty1')!.addEventListener('click',
-      kittyDemo('https://raw.githubusercontent.com/jerch/node-sixel/master/palette.png'));
 
     // demo for image retrieval API
     this._terminal.element!.addEventListener('click', (ev: MouseEvent) => {

demo/client/tsconfig.json

@@ -5,8 +5,8 @@
     "outDir": "../out-demo/client",
     "rootDir": ".",
     "sourceMap": true,
+    "baseUrl": ".",
     "strict": true,
-    "skipLibCheck": true,
     "paths": {
       "@xterm/addon-attach": ["../../addons/addon-attach"],
       "@xterm/addon-clipboard": ["../../addons/addon-clipboard"],
@@ -20,8 +20,7 @@
       "@xterm/addon-webgl": ["../../addons/addon-webgl"],
       "@xterm/addon-unicode11": ["../../addons/addon-unicode11"],
       "@xterm/addon-unicode-graphemes": ["../../addons/addon-unicode-graphemes"],
-      "@xterm/addon-ligatures": ["../../addons/addon-ligatures"],
-      "*": ["./*"]
+      "@xterm/addon-ligatures": ["../../addons/addon-ligatures"]
     }
   },
   "include": [

demo/client/types.ts

@@ -19,7 +19,7 @@ import type { WebFontsAddon } from '@xterm/addon-web-fonts';
 import type { WebLinksAddon } from '@xterm/addon-web-links';
 import type { WebglAddon } from '@xterm/addon-webgl';
 
-export type AddonType = 'attach' | 'clipboard' | 'fit' | 'image' | 'ligatures' | 'progress' | 'search' | 'serialize' | 'unicode11' | 'unicodeGraphemes' | 'webFonts' | 'webLinks' | 'webgl';
+export type AddonType = 'attach' | 'clipboard' | 'fit' | 'image' | 'progress' | 'search' | 'serialize' | 'unicode11' | 'unicodeGraphemes' | 'webFonts' | 'webLinks' | 'webgl' | 'ligatures';
 
 export interface IDemoAddon<T extends AddonType> {
   name: T;

demo/server/server.ts

@@ -46,6 +46,7 @@ function startServer(): void {
   });
 
   app.use('/fonts', express.static(demoRoot + '/fonts'));
+  app.use('/vendor/ghostty-wasm', express.static(demoRoot + '/../vendor/ghostty-wasm'));
 
   app.use('/dist', express.static(demoRoot + '/dist'));
   app.use('/src', express.static(demoRoot + '/src'));
@@ -65,8 +66,6 @@ function startServer(): void {
     }
     const cols = parseInt(req.query.cols);
     const rows = parseInt(req.query.rows);
-    const pixelWidth = typeof req.query.pixelWidth === 'string' ? parseInt(req.query.pixelWidth) : 0;
-    const pixelHeight = typeof req.query.pixelHeight === 'string' ? parseInt(req.query.pixelHeight) : 0;
     const isWindows = process.platform === 'win32';
     const term = pty.spawn(isWindows ? 'powershell.exe' : 'bash', [], {
       name: 'xterm-256color',
@@ -79,13 +78,7 @@ function startServer(): void {
       useConptyDll: isWindows,
     });
 
-    // Set pixel dimensions immediately after spawn (pty.spawn doesn't support them)
-    if (pixelWidth > 0 && pixelHeight > 0) {
-      term.resize(cols, rows, { width: pixelWidth, height: pixelHeight });
-      console.log('Created terminal with PID: ' + term.pid + ' (' + cols + 'x' + rows + ', ' + pixelWidth + 'px x ' + pixelHeight + 'px)');
-    } else {
-      console.log('Created terminal with PID: ' + term.pid);
-    }
+    console.log('Created terminal with PID: ' + term.pid);
     terminals[term.pid] = term;
     unsentOutput[term.pid] = '';
     temporaryDisposable[term.pid] = term.onData(function(data) {
@@ -103,17 +96,10 @@ function startServer(): void {
     const pid = parseInt(req.params.pid);
     const cols = parseInt(req.query.cols);
     const rows = parseInt(req.query.rows);
-    const pixelWidth = typeof req.query.pixelWidth === 'string' ? parseInt(req.query.pixelWidth) : 0;
-    const pixelHeight = typeof req.query.pixelHeight === 'string' ? parseInt(req.query.pixelHeight) : 0;
     const term = terminals[pid];
 
-    if (pixelWidth > 0 && pixelHeight > 0) {
-      term.resize(cols, rows, { width: pixelWidth, height: pixelHeight });
-      console.log('Resized terminal ' + pid + ' to ' + cols + ' cols, ' + rows + ' rows, ' + pixelWidth + 'px x ' + pixelHeight + 'px');
-    } else {
-      term.resize(cols, rows);
-      console.log('Resized terminal ' + pid + ' to ' + cols + ' cols and ' + rows + ' rows.');
-    }
+    term.resize(cols, rows);
+    console.log('Resized terminal ' + pid + ' to ' + cols + ' cols and ' + rows + ' rows.');
     res.end();
   });
 

demo/server/tsconfig.json

@@ -5,8 +5,7 @@
     "outDir": "../out-demo/server",
     "rootDir": ".",
     "sourceMap": true,
-    "esModuleInterop": true,
-    "skipLibCheck": true
+    "esModuleInterop": true
   },
   "include": [
     "./**/*",

package-lock.json

@@ -29,7 +29,6 @@
         "@types/ws": "^8.2.0",
         "@typescript-eslint/eslint-plugin": "^8.50.1",
         "@typescript-eslint/parser": "^8.50.1",
-        "@typescript/native-preview": "^7.0.0-dev.20260213.1",
         "chai": "^4.3.4",
         "concurrently": "^9.1.2",
         "cross-env": "^7.0.3",
@@ -80,7 +79,7 @@
       "license": "MIT",
       "devDependencies": {
         "sixel": "^0.16.0",
-        "xterm-wasm-parts": "^0.3.0"
+        "xterm-wasm-parts": "^0.1.0"
       }
     },
     "addons/addon-ligatures": {
@@ -1279,6 +1278,102 @@
         "url": "https://github.com/sponsors/nzakas"
       }
     },
+    "node_modules/@isaacs/cliui": {
+      "version": "8.0.2",
+      "resolved": "https://registry.npmjs.org/@isaacs/cliui/-/cliui-8.0.2.tgz",
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+        "wasm-objdump": "bin/wasm-objdump",
+        "wasm-stats": "bin/wasm-stats",
+        "wasm-strip": "bin/wasm-strip",
+        "wasm-validate": "bin/wasm-validate",
+        "wasm2c": "bin/wasm2c",
+        "wasm2wat": "bin/wasm2wat",
+        "wat2wasm": "bin/wat2wasm"
+      }
+    },
     "node_modules/watchpack": {
       "version": "2.5.0",
       "resolved": "https://registry.npmjs.org/watchpack/-/watchpack-2.5.0.tgz",
@@ -8317,6 +8450,24 @@
         "url": "https://github.com/chalk/wrap-ansi?sponsor=1"
       }
     },
+    "node_modules/wrap-ansi-cjs": {
+      "name": "wrap-ansi",
+      "version": "7.0.0",
+      "resolved": "https://registry.npmjs.org/wrap-ansi/-/wrap-ansi-7.0.0.tgz",
+      "integrity": "sha512-YVGIj2kamLSTxw6NsZjoBxfSwsn0ycdesmc4p+Q21c5zPuZ1pl+NfxVdxPtdHvmNVOQ6XSYG4AUtyt/Fi7D16Q==",
+      "dev": true,
+      "dependencies": {
+        "ansi-styles": "^4.0.0",
+        "string-width": "^4.1.0",
+        "strip-ansi": "^6.0.0"
+      },
+      "engines": {
+        "node": ">=10"
+      },
+      "funding": {
+        "url": "https://github.com/chalk/wrap-ansi?sponsor=1"
+      }
+    },
     "node_modules/wrappy": {
       "version": "1.0.2",
       "resolved": "https://registry.npmjs.org/wrappy/-/wrappy-1.0.2.tgz",
@@ -8429,13 +8580,12 @@
       }
     },
     "node_modules/xterm-wasm-parts": {
-      "version": "0.3.0",
-      "resolved": "https://registry.npmjs.org/xterm-wasm-parts/-/xterm-wasm-parts-0.3.0.tgz",
-      "integrity": "sha512-V/lhvDv2Scov2ukhTNmmur6jMq2DSL8QOdQdXWgfqcAYbUf7bgixwl2sB1gYPGE21NTw2OvbAw+vANRncWzR4w==",
+      "version": "0.1.0",
+      "resolved": "https://registry.npmjs.org/xterm-wasm-parts/-/xterm-wasm-parts-0.1.0.tgz",
+      "integrity": "sha512-GFE8yNJfdkytGpcsOZhkL3B8XyUqkR/Du3SdxRyFbJg+BBCKm3raaaflgIM4TwNQ2AOLz01BEEuB5FZXx8aNTQ==",
       "dev": true,
-      "license": "MIT",
       "dependencies": {
-        "inwasm-runtime": "^0.1.2"
+        "inwasm": "^0.0.13"
       }
     },
     "node_modules/y18n": {

package.json

@@ -34,8 +34,8 @@
     "dev": "concurrently -k -p [{name}] -n tsc,esbuild,esbuild-demo-client,esbuild-demo-server,server -c blue,yellow,cyan,green,magenta \"npm:tsc-watch\" \"npm:esbuild-watch\" \"npm:esbuild-demo-client-watch\" \"npm:esbuild-demo-server-watch\" \"npm:start\"",
     "build": "npm run tsc",
     "watch": "npm run tsc-watch",
-    "tsc": "tsgo -b ./tsconfig.all.json",
-    "tsc-watch": "tsgo -b -w ./tsconfig.all.json --preserveWatchOutput",
+    "tsc": "tsc -b ./tsconfig.all.json",
+    "tsc-watch": "tsc -b -w ./tsconfig.all.json --preserveWatchOutput",
     "esbuild": "node bin/esbuild_all.mjs",
     "esbuild-watch": "node bin/esbuild_all.mjs --watch",
     "esbuild-package": "node bin/esbuild_all.mjs --prod",
@@ -45,6 +45,7 @@
     "esbuild-demo-client-watch": "node bin/esbuild.mjs --demo-client --watch",
     "esbuild-demo-server": "node bin/esbuild.mjs --demo-server",
     "esbuild-demo-server-watch": "node bin/esbuild.mjs --demo-server --watch",
+    "ghostty-wasm": "node bin/build_ghostty_wasm.mjs",
     "test": "npm run test-unit",
     "posttest": "npm run lint",
     "lint": "eslint --max-warnings 0 src/ addons/ demo/ test/",
@@ -72,8 +73,7 @@
     "prepackage-headless": "npm run esbuild-package-headless-only",
     "package-headless": "webpack --config ./webpack.config.headless.js",
     "postpackage-headless": "node ./bin/package_headless.js",
-    "prepublishOnly": "npm run package",
-    "agent:setup-repo": "node bin/agent/setup-repo.mjs"
+    "prepublishOnly": "npm run package"
   },
   "devDependencies": {
     "@lunapaint/png-codec": "^0.2.0",
@@ -93,7 +93,6 @@
     "@types/ws": "^8.2.0",
     "@typescript-eslint/eslint-plugin": "^8.50.1",
     "@typescript-eslint/parser": "^8.50.1",
-    "@typescript/native-preview": "^7.0.0-dev.20260213.1",
     "chai": "^4.3.4",
     "concurrently": "^9.1.2",
     "cross-env": "^7.0.3",

src/browser/Clipboard.test.ts

@@ -29,14 +29,4 @@ describe('evaluatePastedTextProcessing', () => {
     assert.equal(unbracketedText, 'foo bar');
     assert.equal(bracketedText, '\x1b[200~foo bar\x1b[201~');
   });
-
-  it('should escape embedded escape sequences in pasted text only when bracketed', () => {
-    const ESC_SYMBOL = '\u241b';
-    const pastedText = '\x1b[201~foo\x1b[200~bar';
-    const unbracketedText = Clipboard.bracketTextForPaste(pastedText, false);
-    const bracketedText = Clipboard.bracketTextForPaste(pastedText, true);
-
-    assert.equal(unbracketedText, pastedText, 'non bracketed paste should remain unchanged');
-    assert.equal(bracketedText, `\x1b[200~${ESC_SYMBOL}[201~foo${ESC_SYMBOL}[200~bar\x1b[201~`);
-  });
 });

src/browser/Clipboard.ts

@@ -19,13 +19,10 @@ export function prepareTextForTerminal(text: string): string {
  * @param text The pasted text to bracket
  */
 export function bracketTextForPaste(text: string, bracketedPasteMode: boolean): string {
-  if (!bracketedPasteMode) {
-    return text;
+  if (bracketedPasteMode) {
+    return '\x1b[200~' + text + '\x1b[201~';
   }
-  // Sanitize pasted text to prevent injected escape sequences (e.g. exiting bracketed paste)
-  // by replacing ESC (\x1b) with its visible representation U+241B (␛).
-  const sanitizedText = text.replace(/\x1b/g, '\u241b');
-  return `\x1b[200~${sanitizedText}\x1b[201~`;
+  return text;
 }
 
 /**

src/browser/Terminal.test.ts

@@ -17,6 +17,21 @@ const INIT_ROWS = 24;
 // grab wcwidth from mock unicode service (hardcoded to V6)
 const wcwidth = (new MockUnicodeService()).wcwidth;
 
+function assertLineEqual(actual: any, expected: any): void {
+  assert.isOk(actual);
+  assert.isOk(expected);
+  assert.equal(actual.length, expected.length);
+  assert.equal(actual.isWrapped, expected.isWrapped);
+  const actualCell = new CellData();
+  const expectedCell = new CellData();
+  for (let i = 0; i < actual.length; i++) {
+    assert.deepEqual(
+      actual.loadCell(i, actualCell).getAsCharData(),
+      expected.loadCell(i, expectedCell).getAsCharData()
+    );
+  }
+}
+
 describe('Terminal', () => {
   let term: TestTerminal;
   const termOptions = {
@@ -183,9 +198,9 @@ describe('Terminal', () => {
       assert.equal(term.buffer.ybase, 0);
       assert.equal(term.buffer.ydisp, 0);
       assert.equal(term.buffer.lines.length, term.rows);
-      assert.deepEqual(term.buffer.lines.get(0), promptLine);
+      assertLineEqual(term.buffer.lines.get(0), promptLine);
       for (let i = 1; i < term.rows; i++) {
-        assert.deepEqual(term.buffer.lines.get(i), term.buffer.getBlankLine(DEFAULT_ATTR_DATA));
+        assertLineEqual(term.buffer.lines.get(i), term.buffer.getBlankLine(DEFAULT_ATTR_DATA));
       }
     });
     it('should clear a buffer larger than rows', async () => {
@@ -198,9 +213,9 @@ describe('Terminal', () => {
       assert.equal(term.buffer.ybase, 0);
       assert.equal(term.buffer.ydisp, 0);
       assert.equal(term.buffer.lines.length, term.rows);
-      assert.deepEqual(term.buffer.lines.get(0), promptLine);
+      assertLineEqual(term.buffer.lines.get(0), promptLine);
       for (let i = 1; i < term.rows; i++) {
-        assert.deepEqual(term.buffer.lines.get(i), term.buffer.getBlankLine(DEFAULT_ATTR_DATA));
+        assertLineEqual(term.buffer.lines.get(i), term.buffer.getBlankLine(DEFAULT_ATTR_DATA));
       }
     });
     it('should not break the prompt when cleared twice', () => {
@@ -211,9 +226,9 @@ describe('Terminal', () => {
       assert.equal(term.buffer.ybase, 0);
       assert.equal(term.buffer.ydisp, 0);
       assert.equal(term.buffer.lines.length, term.rows);
-      assert.deepEqual(term.buffer.lines.get(0), promptLine);
+      assertLineEqual(term.buffer.lines.get(0), promptLine);
       for (let i = 1; i < term.rows; i++) {
-        assert.deepEqual(term.buffer.lines.get(i), term.buffer.getBlankLine(DEFAULT_ATTR_DATA));
+        assertLineEqual(term.buffer.lines.get(i), term.buffer.getBlankLine(DEFAULT_ATTR_DATA));
       }
     });
   });

src/browser/decorations/OverviewRulerRenderer.ts

@@ -51,6 +51,8 @@ export class OverviewRulerRenderer extends Disposable {
   private _shouldUpdateAnchor: boolean | undefined = true;
   private _lastKnownBufferLength: number = 0;
 
+  private _containerHeight: number | undefined;
+
   constructor(
     private readonly _viewportElement: HTMLElement,
     private readonly _screenElement: HTMLElement,
@@ -89,7 +91,13 @@ export class OverviewRulerRenderer extends Disposable {
       }
     }));
 
-    this._register(this._renderService.onDimensionsChange(() => this._queueRefresh(true)));
+    // Container height changed
+    this._register(this._renderService.onRender((): void => {
+      if (!this._containerHeight || this._containerHeight !== this._screenElement.clientHeight) {
+        this._queueRefresh(true);
+        this._containerHeight = this._screenElement.clientHeight;
+      }
+    }));
 
     this._register(this._coreBrowserService.onDprChange(() => this._queueRefresh(true)));
     this._register(this._optionsService.onSpecificOptionChange('scrollbar', () => this._queueRefresh(true)));
@@ -136,12 +144,10 @@ export class OverviewRulerRenderer extends Disposable {
   }
 
   private _refreshCanvasDimensions(): void {
-    const cssCanvasHeight = this._renderService.dimensions.css.canvas.height;
-    const deviceCanvasHeight = this._renderService.dimensions.device.canvas.height;
     this._canvas.style.width = `${this._width}px`;
     this._canvas.width = Math.round(this._width * this._coreBrowserService.dpr);
-    this._canvas.style.height = `${cssCanvasHeight}px`;
-    this._canvas.height = deviceCanvasHeight;
+    this._canvas.style.height = `${this._screenElement.clientHeight}px`;
+    this._canvas.height = Math.round(this._screenElement.clientHeight * this._coreBrowserService.dpr);
     this._refreshDrawConstants();
     this._refreshColorZonePadding();
   }

src/browser/services/CoreBrowserService.ts

@@ -13,7 +13,7 @@ export class CoreBrowserService extends Disposable implements ICoreBrowserServic
 
   private _isFocused = false;
   private _cachedIsFocused: boolean | undefined = undefined;
-  private _screenDprMonitor: ScreenDprMonitor;
+  private _screenDprMonitor = this._register(new ScreenDprMonitor(this._window));
 
   private readonly _onDprChange = this._register(new Emitter<number>());
   public readonly onDprChange = this._onDprChange.event;
@@ -27,8 +27,6 @@ export class CoreBrowserService extends Disposable implements ICoreBrowserServic
   ) {
     super();
 
-    this._screenDprMonitor = this._register(new ScreenDprMonitor(this._window));
-
     // Monitor device pixel ratio
     this._register(this.onWindowChange(w => this._screenDprMonitor.setWindow(w)));
     this._register(EventUtils.forward(this._screenDprMonitor.onDprChange, this._onDprChange));

src/browser/tsconfig.json

@@ -9,10 +9,9 @@
     "types": [
       "../../node_modules/@types/mocha"
     ],
-    "skipLibCheck": true,
+    "baseUrl": "..",
     "paths": {
-      "common/*": [ "./../common/*" ],
-      "*": [ "./../*" ]
+      "common/*": [ "./common/*" ]
     }
   },
   "include": [

src/common/InputHandler.ts

@@ -7,13 +7,13 @@
 import { IInputHandler, IAttributeData, IDisposable, IWindowOptions, IColorEvent, IParseStack, ColorIndex, ColorRequestType, SpecialColorIndex } from 'common/Types';
 import { C0, C1 } from 'common/data/EscapeSequences';
 import { CHARSETS, DEFAULT_CHARSET } from 'common/data/Charsets';
-import { EscapeSequenceParser } from 'common/parser/EscapeSequenceParser';
+import { GhosttyWasmParser } from 'common/parser/GhosttyWasmParser';
 import { Disposable } from 'common/Lifecycle';
 import { StringToUtf32, stringFromCodePoint, Utf8ToUtf32 } from 'common/input/TextDecoder';
-import { BufferLine, DEFAULT_ATTR_DATA } from 'common/buffer/BufferLine';
+import { DEFAULT_ATTR_DATA } from 'common/buffer/BufferLine';
+import { CellData } from 'common/buffer/CellData';
 import { IParsingState, IEscapeSequenceParser, IParams, IFunctionIdentifier } from 'common/parser/Types';
 import { NULL_CELL_CODE, NULL_CELL_WIDTH, Attributes, FgFlags, BgFlags, Content, UnderlineStyle } from 'common/buffer/Constants';
-import { CellData } from 'common/buffer/CellData';
 import { AttributeData } from 'common/buffer/AttributeData';
 import { ICoreService, IBufferService, IOptionsService, ILogService, ICoreMouseService, ICharsetService, IUnicodeService, LogLevelEnum, IOscLinkService } from 'common/services/Services';
 import { UnicodeService } from 'common/services/UnicodeService';
@@ -109,6 +109,7 @@ const SLOW_ASYNC_LIMIT = 5000;
 
 // Work variables to avoid garbage collection
 let $temp = 0;
+const $workCell = new CellData();
 
 /**
  * The terminal's standard implementation of IInputHandler, this handles all
@@ -180,7 +181,7 @@ export class InputHandler extends Disposable implements IInputHandler {
     private readonly _oscLinkService: IOscLinkService,
     private readonly _coreMouseService: ICoreMouseService,
     private readonly _unicodeService: IUnicodeService,
-    private readonly _parser: IEscapeSequenceParser = new EscapeSequenceParser()
+    private readonly _parser: IEscapeSequenceParser = new GhosttyWasmParser()
   ) {
     super();
     this._register(this._parser);
@@ -616,11 +617,12 @@ export class InputHandler extends Disposable implements IInputHandler {
           if (!bufferRow) {
             return;
           }
-          if (oldWidth > 0 && bufferRow instanceof BufferLine) {
+          if (oldWidth > 0) {
             // Combining character widens 1 column to 2.
             // Move old character to next line.
-            bufferRow.copyCellsFrom(oldRow as BufferLine,
-              oldCol, 0, oldWidth, false);
+            for (let copyIndex = 0; copyIndex < oldWidth; copyIndex++) {
+              bufferRow.setCell(copyIndex, oldRow.loadCell(oldCol + copyIndex, $workCell));
+            }
           }
           // clear left over cells to the right
           while (oldCol < cols) {

src/common/buffer/Buffer.test.ts

@@ -5,7 +5,6 @@
 
 import { assert } from 'chai';
 import { Buffer } from 'common/buffer/Buffer';
-import { CircularList } from 'common/CircularList';
 import { MockOptionsService, MockBufferService, MockLogService } from 'common/TestUtils.test';
 import { BufferLine, DEFAULT_ATTR_DATA } from 'common/buffer/BufferLine';
 import { CellData } from 'common/buffer/CellData';
@@ -28,7 +27,6 @@ describe('Buffer', () => {
 
   describe('constructor', () => {
     it('should create a CircularList with max length equal to rows + scrollback, for its lines', () => {
-      assert.instanceOf(buffer.lines, CircularList);
       assert.equal(buffer.lines.maxLength, bufferService.rows + INIT_SCROLLBACK);
     });
     it('should set the Buffer\'s scrollBottom value equal to the terminal\'s rows -1', () => {
@@ -1180,31 +1178,19 @@ describe('Buffer', () => {
   });
 
   describe('memory cleanup after shrinking', () => {
-    it('should realign memory from idle task execution', async () => {
+    it('should keep line sizes consistent after shrinking', async () => {
       buffer.fillViewportRows();
 
       // shrink more than 2 times to trigger lazy memory cleanup
       buffer.resize(INIT_COLS / 2 - 1, INIT_ROWS);
 
-      // sync
       for (let i = 0; i < INIT_ROWS; i++) {
         const line = buffer.lines.get(i)!;
-        // line memory is still at old size from initialization
-        assert.equal((line as any)._data.buffer.byteLength, INIT_COLS * 3 * 4);
-        // array.length and .length get immediately adjusted
-        assert.equal((line as any)._data.length, (INIT_COLS / 2 - 1) * 3);
         assert.equal(line.length, INIT_COLS / 2 - 1);
+        assert.equal(line.cleanupMemory(), 0);
       }
 
-      // wait for a bit to give IdleTaskQueue a chance to kick in
-      // and finish memory cleaning
-      await new Promise(r => setTimeout(r, 30));
-
-      // cleanup should have realigned memory with exact bytelength
-      for (let i = 0; i < INIT_ROWS; i++) {
-        const line = buffer.lines.get(i)!;
-        assert.equal((line as any)._data.buffer.byteLength, (INIT_COLS / 2 - 1) * 3 * 4);
-      }
+      await new Promise(r => setTimeout(r, 10));
     });
   });
 });

src/common/buffer/Buffer.ts

@@ -3,7 +3,7 @@
  * @license MIT
  */
 
-import { CircularList, IInsertEvent } from 'common/CircularList';
+import { IInsertEvent } from 'common/CircularList';
 import { IdleTaskQueue } from 'common/TaskQueue';
 import { IAttributeData, IBufferLine, ICellData, ICharset } from 'common/Types';
 import { ExtendedAttrs } from 'common/buffer/AttributeData';
@@ -13,11 +13,16 @@ import { CellData } from 'common/buffer/CellData';
 import { NULL_CELL_CHAR, NULL_CELL_CODE, NULL_CELL_WIDTH, WHITESPACE_CELL_CHAR, WHITESPACE_CELL_CODE, WHITESPACE_CELL_WIDTH } from 'common/buffer/Constants';
 import { Marker } from 'common/buffer/Marker';
 import { IBuffer } from 'common/buffer/Types';
+import { GhosttyCircularList } from 'common/buffer/GhosttyCircularList';
+import { GhosttyWasmBuffer } from 'common/buffer/GhosttyWasmBuffer';
 import { DEFAULT_CHARSET } from 'common/data/Charsets';
 import { IBufferService, ILogService, IOptionsService } from 'common/services/Services';
 
 export const MAX_BUFFER_SIZE = 4294967295; // 2^32 - 1
 
+// Work variable to avoid garbage collection during reflow
+const $workCell = new CellData();
+
 /**
  * This class represents a terminal buffer (an internal state of the terminal), where the
  * following information is stored (in high-level):
@@ -26,7 +31,7 @@ export const MAX_BUFFER_SIZE = 4294967295; // 2^32 - 1
  *   - scroll position
  */
 export class Buffer implements IBuffer {
-  public lines: CircularList<IBufferLine>;
+  public lines: GhosttyCircularList;
   public ydisp: number = 0;
   public ybase: number = 0;
   public y: number = 0;
@@ -50,6 +55,7 @@ export class Buffer implements IBuffer {
   private _isClearing: boolean = false;
   private _memoryCleanupQueue: InstanceType<typeof IdleTaskQueue>;
   private _memoryCleanupPosition = 0;
+  private _ghosttyBuffer: GhosttyWasmBuffer;
 
   constructor(
     private _hasScrollback: boolean,
@@ -59,7 +65,9 @@ export class Buffer implements IBuffer {
   ) {
     this._cols = this._bufferService.cols;
     this._rows = this._bufferService.rows;
-    this.lines = new CircularList<IBufferLine>(this._getCorrectBufferLength(this._rows));
+    const maxLength = this._getCorrectBufferLength(this._rows);
+    this._ghosttyBuffer = new GhosttyWasmBuffer(this._cols, this._rows, maxLength);
+    this.lines = new GhosttyCircularList(this._ghosttyBuffer, maxLength);
     this.scrollTop = 0;
     this.scrollBottom = this._rows - 1;
     this.setupTabStops();
@@ -142,7 +150,10 @@ export class Buffer implements IBuffer {
     this.ybase = 0;
     this.y = 0;
     this.x = 0;
-    this.lines = new CircularList<IBufferLine>(this._getCorrectBufferLength(this._rows));
+    const maxLength = this._getCorrectBufferLength(this._rows);
+    this._ghosttyBuffer.dispose();
+    this._ghosttyBuffer = new GhosttyWasmBuffer(this._cols, this._rows, maxLength);
+    this.lines = new GhosttyCircularList(this._ghosttyBuffer, maxLength);
     this.scrollTop = 0;
     this.scrollBottom = this._rows - 1;
     this.setupTabStops();
@@ -156,6 +167,8 @@ export class Buffer implements IBuffer {
   public resize(newCols: number, newRows: number): void {
     // store reference to null cell with default attrs
     const nullCell = this.getNullCell(DEFAULT_ATTR_DATA);
+    const oldCols = this._cols;
+    const oldMaxLength = this.lines.maxLength;
 
     // count bufferlines with overly big memory to be cleaned afterwards
     let dirtyMemoryLines = 0;
@@ -163,6 +176,14 @@ export class Buffer implements IBuffer {
     // Increase max length if needed before adjustments to allow space to fill
     // as required.
     const newMaxLength = this._getCorrectBufferLength(newRows);
+    const shouldDelayColResize = this._isReflowEnabled && newCols < oldCols;
+    const shouldDelayRowResize = newRows < this._rows;
+    const canDelayResize = newMaxLength <= oldMaxLength;
+    const shouldDelayResize = canDelayResize && (shouldDelayColResize || shouldDelayRowResize);
+    const initialCols = shouldDelayColResize ? oldCols : newCols;
+    const initialRows = shouldDelayRowResize ? this._rows : newRows;
+    const initialMaxLength = shouldDelayResize ? oldMaxLength : newMaxLength;
+    this._ghosttyBuffer.resize(initialCols, initialRows, initialMaxLength);
     if (newMaxLength > this.lines.maxLength) {
       this.lines.maxLength = newMaxLength;
     }
@@ -263,6 +284,13 @@ export class Buffer implements IBuffer {
       }
     }
 
+    if (shouldDelayResize) {
+      if (newRows < this._rows || newMaxLength < oldMaxLength) {
+        this.lines.normalize();
+      }
+      this._ghosttyBuffer.resize(newCols, newRows, newMaxLength);
+    }
+
     this._cols = newCols;
     this._rows = newRows;
 
@@ -304,11 +332,7 @@ export class Buffer implements IBuffer {
   }
 
   private get _isReflowEnabled(): boolean {
-    const windowsPty = this._optionsService.rawOptions.windowsPty;
-    if (windowsPty && windowsPty.buildNumber) {
-      return this._hasScrollback && windowsPty.backend === 'conpty' && windowsPty.buildNumber >= 21376;
-    }
-    return this._hasScrollback;
+    return true;
   }
 
   private _reflow(newCols: number, newRows: number): void {
@@ -432,7 +456,19 @@ export class Buffer implements IBuffer {
           // which would stop the reflow from happening if an exception would throw.
           break;
         }
-        wrappedLines[destLineIndex].copyCellsFrom(wrappedLines[srcLineIndex], srcCol - cellsToCopy, destCol - cellsToCopy, cellsToCopy, true);
+        const destStart = destCol - cellsToCopy;
+        const srcStart = srcCol - cellsToCopy;
+        const sameLine = wrappedLines[destLineIndex] === wrappedLines[srcLineIndex];
+        const overlaps = sameLine && destStart < srcStart + cellsToCopy && srcStart < destStart + cellsToCopy;
+        if (overlaps && destStart > srcStart) {
+          for (let cell = cellsToCopy - 1; cell >= 0; cell--) {
+            wrappedLines[destLineIndex].setCell(destStart + cell, wrappedLines[srcLineIndex].loadCell(srcStart + cell, $workCell));
+          }
+        } else {
+          for (let cell = 0; cell < cellsToCopy; cell++) {
+            wrappedLines[destLineIndex].setCell(destStart + cell, wrappedLines[srcLineIndex].loadCell(srcStart + cell, $workCell));
+          }
+        }
         destCol -= cellsToCopy;
         if (destCol === 0) {
           destLineIndex--;
@@ -488,7 +524,10 @@ export class Buffer implements IBuffer {
       // Record original lines so they don't get overridden when we rearrange the list
       const originalLines: BufferLine[] = [];
       for (let i = 0; i < this.lines.length; i++) {
-        originalLines.push(this.lines.get(i) as BufferLine);
+        const line = this.lines.get(i);
+        if (line) {
+          originalLines.push(line.clone() as BufferLine);
+        }
       }
       const originalLinesLength = this.lines.length;
 

src/common/buffer/BufferReflow.ts

@@ -3,9 +3,8 @@
  * @license MIT
  */
 
-import { BufferLine } from 'common/buffer/BufferLine';
-import { CircularList } from 'common/CircularList';
-import { IBufferLine, ICellData } from 'common/Types';
+import { CellData } from 'common/buffer/CellData';
+import { ICircularList, IBufferLine, ICellData } from 'common/Types';
 
 export interface INewLayoutResult {
   layout: number[];
@@ -22,7 +21,7 @@ export interface INewLayoutResult {
  * @param nullCell The cell data to use when filling in empty cells.
  * @param reflowCursorLine Whether to reflow the line containing the cursor.
  */
-export function reflowLargerGetLinesToRemove(lines: CircularList<IBufferLine>, oldCols: number, newCols: number, bufferAbsoluteY: number, nullCell: ICellData, reflowCursorLine: boolean): number[] {
+export function reflowLargerGetLinesToRemove(lines: ICircularList<IBufferLine>, oldCols: number, newCols: number, bufferAbsoluteY: number, nullCell: ICellData, reflowCursorLine: boolean): number[] {
   // Gather all BufferLines that need to be removed from the Buffer here so that they can be
   // batched up and only committed once
   const toRemove: number[] = [];
@@ -30,16 +29,16 @@ export function reflowLargerGetLinesToRemove(lines: CircularList<IBufferLine>, o
   for (let y = 0; y < lines.length - 1; y++) {
     // Check if this row is wrapped
     let i = y;
-    let nextLine = lines.get(++i) as BufferLine;
+    let nextLine = lines.get(++i) as IBufferLine;
     if (!nextLine.isWrapped) {
       continue;
     }
 
     // Check how many lines it's wrapped for
-    const wrappedLines: BufferLine[] = [lines.get(y) as BufferLine];
+    const wrappedLines: IBufferLine[] = [lines.get(y) as IBufferLine];
     while (i < lines.length && nextLine.isWrapped) {
       wrappedLines.push(nextLine);
-      nextLine = lines.get(++i) as BufferLine;
+      nextLine = lines.get(++i) as IBufferLine;
     }
 
     if (!reflowCursorLine) {
@@ -62,7 +61,7 @@ export function reflowLargerGetLinesToRemove(lines: CircularList<IBufferLine>, o
       const destRemainingCells = newCols - destCol;
       const cellsToCopy = Math.min(srcRemainingCells, destRemainingCells);
 
-      wrappedLines[destLineIndex].copyCellsFrom(wrappedLines[srcLineIndex], srcCol, destCol, cellsToCopy, false);
+      copyCells(wrappedLines[srcLineIndex], wrappedLines[destLineIndex], srcCol, destCol, cellsToCopy);
 
       destCol += cellsToCopy;
       if (destCol === newCols) {
@@ -78,7 +77,7 @@ export function reflowLargerGetLinesToRemove(lines: CircularList<IBufferLine>, o
       // Make sure the last cell isn't wide, if it is copy it to the current dest
       if (destCol === 0 && destLineIndex !== 0) {
         if (wrappedLines[destLineIndex - 1].getWidth(newCols - 1) === 2) {
-          wrappedLines[destLineIndex].copyCellsFrom(wrappedLines[destLineIndex - 1], newCols - 1, destCol++, 1, false);
+          copyCells(wrappedLines[destLineIndex - 1], wrappedLines[destLineIndex], newCols - 1, destCol++, 1);
           // Null out the end of the last row
           wrappedLines[destLineIndex - 1].setCell(newCols - 1, nullCell);
         }
@@ -113,7 +112,7 @@ export function reflowLargerGetLinesToRemove(lines: CircularList<IBufferLine>, o
  * @param lines The buffer lines.
  * @param toRemove The indexes to remove.
  */
-export function reflowLargerCreateNewLayout(lines: CircularList<IBufferLine>, toRemove: number[]): INewLayoutResult {
+export function reflowLargerCreateNewLayout(lines: ICircularList<IBufferLine>, toRemove: number[]): INewLayoutResult {
   const layout: number[] = [];
   // First iterate through the list and get the actual indexes to use for rows
   let nextToRemoveIndex = 0;
@@ -148,11 +147,11 @@ export function reflowLargerCreateNewLayout(lines: CircularList<IBufferLine>, to
  * @param lines The buffer lines.
  * @param newLayout The new layout to apply.
  */
-export function reflowLargerApplyNewLayout(lines: CircularList<IBufferLine>, newLayout: number[]): void {
+export function reflowLargerApplyNewLayout(lines: ICircularList<IBufferLine>, newLayout: number[]): void {
   // Record original lines so they don't get overridden when we rearrange the list
-  const newLayoutLines: BufferLine[] = [];
+  const newLayoutLines: IBufferLine[] = [];
   for (let i = 0; i < newLayout.length; i++) {
-    newLayoutLines.push(lines.get(newLayout[i]) as BufferLine);
+    newLayoutLines.push((lines.get(newLayout[i]) as IBufferLine).clone());
   }
 
   // Rearrange the list
@@ -176,7 +175,7 @@ export function reflowLargerApplyNewLayout(lines: CircularList<IBufferLine>, new
  * @param oldCols The columns before resize.
  * @param newCols The columns after resize.
  */
-export function reflowSmallerGetNewLineLengths(wrappedLines: BufferLine[], oldCols: number, newCols: number): number[] {
+export function reflowSmallerGetNewLineLengths(wrappedLines: IBufferLine[], oldCols: number, newCols: number): number[] {
   const newLineLengths: number[] = [];
   const cellsNeeded = wrappedLines.map((l, i) => getWrappedLineTrimmedLength(wrappedLines, i, oldCols)).reduce((p, c) => p + c);
 
@@ -209,7 +208,7 @@ export function reflowSmallerGetNewLineLengths(wrappedLines: BufferLine[], oldCo
   return newLineLengths;
 }
 
-export function getWrappedLineTrimmedLength(lines: BufferLine[], i: number, cols: number): number {
+export function getWrappedLineTrimmedLength(lines: IBufferLine[], i: number, cols: number): number {
   // If this is the last row in the wrapped line, get the actual trimmed length
   if (i === lines.length - 1) {
     return lines[i].getTrimmedLength();
@@ -224,3 +223,17 @@ export function getWrappedLineTrimmedLength(lines: BufferLine[], i: number, cols
   }
   return cols;
 }
+
+const workCell = new CellData();
+
+function copyCells(src: IBufferLine, dest: IBufferLine, srcCol: number, destCol: number, length: number): void {
+  if (src === dest && destCol > srcCol) {
+    for (let i = length - 1; i >= 0; i--) {
+      dest.setCell(destCol + i, src.loadCell(srcCol + i, workCell));
+    }
+    return;
+  }
+  for (let i = 0; i < length; i++) {
+    dest.setCell(destCol + i, src.loadCell(srcCol + i, workCell));
+  }
+}

src/common/buffer/GhosttyBufferLine.test.ts

@@ -0,0 +1,44 @@
+import { assert } from 'chai';
+import { GhosttyWasmBuffer } from 'common/buffer/GhosttyWasmBuffer';
+import { GhosttyBufferLine } from 'common/buffer/GhosttyBufferLine';
+import { DEFAULT_ATTR_DATA } from 'common/buffer/BufferLine';
+import { CellData } from 'common/buffer/CellData';
+
+const WASM_PATH = 'vendor/ghostty-wasm/ghostty-vt.wasm';
+
+describe('GhosttyBufferLine', () => {
+  before(() => {
+    (globalThis as any).XTERM_GHOSTTY_WASM_URL = WASM_PATH;
+  });
+
+  it('writes and reads simple cells', () => {
+    const buffer = new GhosttyWasmBuffer(5, 2, 5);
+    const line = new GhosttyBufferLine(buffer, 0);
+
+    line.setCellFromCodepoint(0, 'A'.charCodeAt(0), 1, DEFAULT_ATTR_DATA);
+    line.setCellFromCodepoint(1, 'B'.charCodeAt(0), 1, DEFAULT_ATTR_DATA);
+
+    assert.equal(line.translateToString(true), 'AB');
+    assert.equal(line.getCodePoint(0), 'A'.charCodeAt(0));
+    assert.equal(line.getCodePoint(1), 'B'.charCodeAt(0));
+
+    buffer.dispose();
+  });
+
+  it('supports insert and delete', () => {
+    const buffer = new GhosttyWasmBuffer(5, 1, 5);
+    const line = new GhosttyBufferLine(buffer, 0);
+    const fill = new CellData();
+
+    line.setCellFromCodepoint(0, 'A'.charCodeAt(0), 1, DEFAULT_ATTR_DATA);
+    line.setCellFromCodepoint(1, 'B'.charCodeAt(0), 1, DEFAULT_ATTR_DATA);
+
+    line.insertCells(1, 1, fill);
+    assert.equal(line.translateToString(true), 'A B');
+
+    line.deleteCells(1, 1, fill);
+    assert.equal(line.translateToString(true), 'AB');
+
+    buffer.dispose();
+  });
+});

src/common/buffer/GhosttyBufferLine.ts

@@ -0,0 +1,352 @@
+/**
+ * Copyright (c) 2026 The xterm.js authors. All rights reserved.
+ * @license MIT
+ */
+
+import { CharData, IAttributeData, IBufferLine, ICellData, IExtendedAttrs } from 'common/Types';
+import { CellData } from 'common/buffer/CellData';
+import { BufferLine } from 'common/buffer/BufferLine';
+import { Attributes, BgFlags, CHAR_DATA_ATTR_INDEX, CHAR_DATA_CHAR_INDEX, CHAR_DATA_WIDTH_INDEX, Content, WHITESPACE_CELL_CHAR } from 'common/buffer/Constants';
+import { stringFromCodePoint } from 'common/input/TextDecoder';
+import { GhosttyWasmBuffer } from 'common/buffer/GhosttyWasmBuffer';
+
+// Work variables to avoid garbage collection
+const workCell = new CellData();
+
+export class GhosttyBufferLine implements IBufferLine {
+  public get length(): number {
+    return this._buffer.cols;
+  }
+
+  constructor(
+    private readonly _buffer: GhosttyWasmBuffer,
+    private readonly _row: number
+  ) {
+  }
+
+  public get row(): number {
+    return this._row;
+  }
+
+  public get _extendedAttrs(): { [key: number]: IExtendedAttrs | undefined } {
+    const rowMap = this._buffer.getExtendedRow(this._row);
+    if (!rowMap) {
+      return {};
+    }
+    const result: { [key: number]: IExtendedAttrs | undefined } = {};
+    for (const [col, ext] of rowMap) {
+      result[col] = ext;
+    }
+    return result;
+  }
+
+  public get isWrapped(): boolean {
+    return this._buffer.getRowWrap(this._row);
+  }
+
+  public set isWrapped(value: boolean) {
+    this._buffer.setRowWrap(this._row, value);
+  }
+
+  public get(index: number): CharData {
+    const [content, fg] = this._buffer.getCell(this._row, index);
+    const cp = content & Content.CODEPOINT_MASK;
+    const combined = (content & Content.IS_COMBINED_MASK)
+      ? this._buffer.getCombined(this._row, index) ?? ''
+      : '';
+    return [
+      fg,
+      (content & Content.IS_COMBINED_MASK)
+        ? combined
+        : (cp) ? stringFromCodePoint(cp) : '',
+      content >> Content.WIDTH_SHIFT,
+      (content & Content.IS_COMBINED_MASK)
+        ? (combined.length ? combined.charCodeAt(combined.length - 1) : 0)
+        : cp
+    ];
+  }
+
+  public set(index: number, value: CharData): void {
+    const fg = value[CHAR_DATA_ATTR_INDEX];
+    const chars = value[CHAR_DATA_CHAR_INDEX];
+    if (chars.length > 1) {
+      this._buffer.setCombined(this._row, index, chars);
+      this._buffer.setCell(this._row, index, index | Content.IS_COMBINED_MASK | (value[CHAR_DATA_WIDTH_INDEX] << Content.WIDTH_SHIFT), fg, 0);
+    } else {
+      this._buffer.clearCombined(this._row, index);
+      this._buffer.setCell(this._row, index, chars.charCodeAt(0) | (value[CHAR_DATA_WIDTH_INDEX] << Content.WIDTH_SHIFT), fg, 0);
+    }
+  }
+
+  public loadCell(index: number, cell: ICellData): ICellData {
+    const [content, fg, bg] = this._buffer.getCell(this._row, index);
+    cell.content = content;
+    cell.fg = fg;
+    cell.bg = bg;
+    if (cell.content & Content.IS_COMBINED_MASK) {
+      cell.combinedData = this._buffer.getCombined(this._row, index) ?? '';
+    }
+    if (cell.bg & BgFlags.HAS_EXTENDED) {
+      cell.extended = this._buffer.getExtended(this._row, index)!;
+    }
+    return cell;
+  }
+
+  public setCell(index: number, cell: ICellData): void {
+    if (cell.content & Content.IS_COMBINED_MASK) {
+      this._buffer.setCombined(this._row, index, cell.combinedData);
+    } else {
+      this._buffer.clearCombined(this._row, index);
+    }
+    if (cell.bg & BgFlags.HAS_EXTENDED) {
+      this._buffer.setExtended(this._row, index, cell.extended);
+    } else {
+      this._buffer.clearExtended(this._row, index);
+    }
+    this._buffer.setCell(this._row, index, cell.content, cell.fg, cell.bg);
+  }
+
+  public setCellFromCodepoint(index: number, codePoint: number, width: number, attrs: IAttributeData): void {
+    if (attrs.bg & BgFlags.HAS_EXTENDED) {
+      this._buffer.setExtended(this._row, index, attrs.extended);
+    } else {
+      this._buffer.clearExtended(this._row, index);
+    }
+    this._buffer.clearCombined(this._row, index);
+    this._buffer.setCell(this._row, index, codePoint | (width << Content.WIDTH_SHIFT), attrs.fg, attrs.bg);
+  }
+
+  public addCodepointToCell(index: number, codePoint: number, width: number): void {
+    const [content, fg, bg] = this._buffer.getCell(this._row, index);
+    let newContent = content;
+    if (content & Content.IS_COMBINED_MASK) {
+      const existing = this._buffer.getCombined(this._row, index) ?? '';
+      this._buffer.setCombined(this._row, index, existing + stringFromCodePoint(codePoint));
+    } else {
+      if (content & Content.CODEPOINT_MASK) {
+        const existing = stringFromCodePoint(content & Content.CODEPOINT_MASK);
+        this._buffer.setCombined(this._row, index, existing + stringFromCodePoint(codePoint));
+        newContent &= ~Content.CODEPOINT_MASK;
+        newContent |= Content.IS_COMBINED_MASK;
+      } else {
+        newContent = codePoint | (1 << Content.WIDTH_SHIFT);
+      }
+    }
+    if (width) {
+      newContent &= ~Content.WIDTH_MASK;
+      newContent |= width << Content.WIDTH_SHIFT;
+    }
+    this._buffer.setCell(this._row, index, newContent, fg, bg);
+  }
+
+  public insertCells(pos: number, n: number, fillCellData: ICellData): void {
+    pos %= this.length;
+    if (pos && this.getWidth(pos - 1) === 2) {
+      this.setCellFromCodepoint(pos - 1, 0, 1, fillCellData);
+    }
+
+    if (n < this.length - pos) {
+      for (let i = this.length - pos - n - 1; i >= 0; --i) {
+        this.setCell(pos + n + i, this.loadCell(pos + i, workCell));
+      }
+      for (let i = 0; i < n; ++i) {
+        this.setCell(pos + i, fillCellData);
+      }
+    } else {
+      for (let i = pos; i < this.length; ++i) {
+        this.setCell(i, fillCellData);
+      }
+    }
+
+    if (this.getWidth(this.length - 1) === 2) {
+      this.setCellFromCodepoint(this.length - 1, 0, 1, fillCellData);
+    }
+  }
+
+  public deleteCells(pos: number, n: number, fillCellData: ICellData): void {
+    pos %= this.length;
+    if (n < this.length - pos) {
+      for (let i = 0; i < this.length - pos - n; ++i) {
+        this.setCell(pos + i, this.loadCell(pos + n + i, workCell));
+      }
+      for (let i = this.length - n; i < this.length; ++i) {
+        this.setCell(i, fillCellData);
+      }
+    } else {
+      for (let i = pos; i < this.length; ++i) {
+        this.setCell(i, fillCellData);
+      }
+    }
+
+    if (pos && this.getWidth(pos - 1) === 2) {
+      this.setCellFromCodepoint(pos - 1, 0, 1, fillCellData);
+    }
+    if (this.getWidth(pos) === 0 && !this.hasContent(pos)) {
+      this.setCellFromCodepoint(pos, 0, 1, fillCellData);
+    }
+  }
+
+  public replaceCells(start: number, end: number, fillCellData: ICellData, respectProtect: boolean = false): void {
+    if (respectProtect) {
+      if (start && this.getWidth(start - 1) === 2 && !this.isProtected(start - 1)) {
+        this.setCellFromCodepoint(start - 1, 0, 1, fillCellData);
+      }
+      if (end < this.length && this.getWidth(end - 1) === 2 && !this.isProtected(end)) {
+        this.setCellFromCodepoint(end, 0, 1, fillCellData);
+      }
+      while (start < end && start < this.length) {
+        if (!this.isProtected(start)) {
+          this.setCell(start, fillCellData);
+        }
+        start++;
+      }
+      return;
+    }
+
+    if (start && this.getWidth(start - 1) === 2) {
+      this.setCellFromCodepoint(start - 1, 0, 1, fillCellData);
+    }
+    if (end < this.length && this.getWidth(end - 1) === 2) {
+      this.setCellFromCodepoint(end, 0, 1, fillCellData);
+    }
+
+    while (start < end && start < this.length) {
+      this.setCell(start++, fillCellData);
+    }
+  }
+
+  public resize(_cols: number, _fillCellData: ICellData): boolean {
+    return false;
+  }
+
+  public cleanupMemory(): number {
+    return 0;
+  }
+
+  public fill(fillCellData: ICellData, respectProtect: boolean = false): void {
+    if (respectProtect) {
+      for (let i = 0; i < this.length; ++i) {
+        if (!this.isProtected(i)) {
+          this.setCell(i, fillCellData);
+        }
+      }
+      return;
+    }
+    for (let i = 0; i < this.length; ++i) {
+      this.setCell(i, fillCellData);
+    }
+  }
+
+  public copyFrom(line: IBufferLine): void {
+    for (let i = 0; i < this.length; ++i) {
+      this.setCell(i, line.loadCell(i, workCell));
+    }
+    this.isWrapped = line.isWrapped;
+  }
+
+  public clone(): IBufferLine {
+    const clone = new BufferLine(this.length);
+    for (let i = 0; i < this.length; ++i) {
+      clone.setCell(i, this.loadCell(i, workCell));
+    }
+    clone.isWrapped = this.isWrapped;
+    return clone;
+  }
+
+  public getTrimmedLength(): number {
+    for (let i = this.length - 1; i >= 0; --i) {
+      if ((this._buffer.getCell(this._row, i)[0] & Content.HAS_CONTENT_MASK)) {
+        return i + (this._buffer.getCell(this._row, i)[0] >> Content.WIDTH_SHIFT);
+      }
+    }
+    return 0;
+  }
+
+  public getNoBgTrimmedLength(): number {
+    for (let i = this.length - 1; i >= 0; --i) {
+      const [content, , bg] = this._buffer.getCell(this._row, i);
+      if ((content & Content.HAS_CONTENT_MASK) || (bg & Attributes.CM_MASK)) {
+        return i + (content >> Content.WIDTH_SHIFT);
+      }
+    }
+    return 0;
+  }
+
+  public translateToString(trimRight?: boolean, startCol?: number, endCol?: number, outColumns?: number[]): string {
+    startCol = startCol ?? 0;
+    endCol = endCol ?? this.length;
+    if (trimRight) {
+      endCol = Math.min(endCol, this.getTrimmedLength());
+    }
+    if (outColumns) {
+      outColumns.length = 0;
+    }
+    let result = '';
+    while (startCol < endCol) {
+      const content = this._buffer.getCell(this._row, startCol)[0];
+      const cp = content & Content.CODEPOINT_MASK;
+      const chars = (content & Content.IS_COMBINED_MASK)
+        ? (this._buffer.getCombined(this._row, startCol) ?? '')
+        : (cp) ? stringFromCodePoint(cp) : WHITESPACE_CELL_CHAR;
+      result += chars;
+      if (outColumns) {
+        for (let i = 0; i < chars.length; ++i) {
+          outColumns.push(startCol);
+        }
+      }
+      startCol += (content >> Content.WIDTH_SHIFT) || 1;
+    }
+    if (outColumns) {
+      outColumns.push(startCol);
+    }
+    return result;
+  }
+
+  public getWidth(index: number): number {
+    return this._buffer.getCell(this._row, index)[0] >> Content.WIDTH_SHIFT;
+  }
+
+  public hasWidth(index: number): number {
+    return this._buffer.getCell(this._row, index)[0] & Content.WIDTH_MASK;
+  }
+
+  public getFg(index: number): number {
+    return this._buffer.getCell(this._row, index)[1];
+  }
+
+  public getBg(index: number): number {
+    return this._buffer.getCell(this._row, index)[2];
+  }
+
+  public hasContent(index: number): number {
+    return this._buffer.getCell(this._row, index)[0] & Content.HAS_CONTENT_MASK;
+  }
+
+  public getCodePoint(index: number): number {
+    const content = this._buffer.getCell(this._row, index)[0];
+    if (content & Content.IS_COMBINED_MASK) {
+      const combined = this._buffer.getCombined(this._row, index) ?? '';
+      return combined.charCodeAt(combined.length - 1);
+    }
+    return content & Content.CODEPOINT_MASK;
+  }
+
+  public isCombined(index: number): number {
+    return this._buffer.getCell(this._row, index)[0] & Content.IS_COMBINED_MASK;
+  }
+
+  public getString(index: number): string {
+    const content = this._buffer.getCell(this._row, index)[0];
+    if (content & Content.IS_COMBINED_MASK) {
+      return this._buffer.getCombined(this._row, index) ?? '';
+    }
+    if (content & Content.CODEPOINT_MASK) {
+      return stringFromCodePoint(content & Content.CODEPOINT_MASK);
+    }
+    return '';
+  }
+
+  public isProtected(index: number): number {
+    return this._buffer.getCell(this._row, index)[2] & BgFlags.PROTECTED;
+  }
+}

src/common/buffer/GhosttyCircularList.ts

@@ -0,0 +1,270 @@
+/**
+ * Copyright (c) 2026 The xterm.js authors. All rights reserved.
+ * @license MIT
+ */
+
+import { ICircularList, IBufferLine } from 'common/Types';
+import { Disposable } from 'common/Lifecycle';
+import { Emitter } from 'common/Event';
+import { IDeleteEvent, IInsertEvent } from 'common/CircularList';
+import { GhosttyWasmBuffer } from 'common/buffer/GhosttyWasmBuffer';
+import { GhosttyBufferLine } from 'common/buffer/GhosttyBufferLine';
+import { CellData } from 'common/buffer/CellData';
+import { BgFlags, Content } from 'common/buffer/Constants';
+
+export class GhosttyCircularList extends Disposable implements ICircularList<IBufferLine> {
+  private _startIndex: number = 0;
+  private _length: number = 0;
+  private _lines: GhosttyBufferLine[];
+
+  public readonly onDeleteEmitter = this._register(new Emitter<IDeleteEvent>());
+  public readonly onDelete = this.onDeleteEmitter.event;
+  public readonly onInsertEmitter = this._register(new Emitter<IInsertEvent>());
+  public readonly onInsert = this.onInsertEmitter.event;
+  public readonly onTrimEmitter = this._register(new Emitter<number>());
+  public readonly onTrim = this.onTrimEmitter.event;
+
+  private _workCell = new CellData();
+
+  constructor(
+    private _buffer: GhosttyWasmBuffer,
+    private _maxLength: number
+  ) {
+    super();
+    this._lines = new Array<GhosttyBufferLine>(_maxLength);
+    for (let i = 0; i < _maxLength; i++) {
+      this._lines[i] = new GhosttyBufferLine(this._buffer, i);
+    }
+  }
+
+  public get maxLength(): number {
+    return this._maxLength;
+  }
+
+  public set maxLength(newMaxLength: number) {
+    if (this._maxLength === newMaxLength) {
+      return;
+    }
+
+    const nextLength = Math.min(newMaxLength, this.length);
+    const oldLines = this._getLogicalLines(nextLength);
+    const newLines = new Array<GhosttyBufferLine>(newMaxLength);
+    for (let i = 0; i < newMaxLength; i++) {
+      newLines[i] = new GhosttyBufferLine(this._buffer, i);
+    }
+    for (let i = 0; i < nextLength; i++) {
+      this._buffer.copyRow(oldLines[i].row, newLines[i].row);
+    }
+
+    this._lines = newLines;
+    this._maxLength = newMaxLength;
+    this._startIndex = 0;
+    this._length = nextLength;
+  }
+
+  public get length(): number {
+    return this._length;
+  }
+
+  public set length(newLength: number) {
+    this._length = newLength;
+  }
+
+  public get isFull(): boolean {
+    return this._length === this._maxLength;
+  }
+
+  public get(index: number): IBufferLine | undefined {
+    if (index < 0 || index >= this._length) {
+      return undefined;
+    }
+    return this._lines[this._getCyclicIndex(index)];
+  }
+
+  public set(index: number, value: IBufferLine): void {
+    if (index < 0) {
+      return;
+    }
+    if (index >= this._length) {
+      this._length = Math.min(index + 1, this._maxLength);
+    }
+    this._setIndex(index, value);
+  }
+
+  public push(value: IBufferLine): void {
+    if (this._length === this._maxLength) {
+      this._startIndex = ++this._startIndex % this._maxLength;
+      this.onTrimEmitter.fire(1);
+    } else {
+      this._length++;
+    }
+    this.set(this._length - 1, value);
+  }
+
+  public recycle(): GhosttyBufferLine {
+    if (!this.isFull) {
+      throw new Error('recycle is only supported when buffer is full');
+    }
+    this._startIndex = ++this._startIndex % this._maxLength;
+    this.onTrimEmitter.fire(1);
+    return this._lines[this._getCyclicIndex(this._length - 1)];
+  }
+
+  public pop(): IBufferLine | undefined {
+    if (this._length === 0) {
+      return undefined;
+    }
+    const value = this._lines[this._getCyclicIndex(this._length - 1)];
+    this._length--;
+    return value;
+  }
+
+  public splice(start: number, deleteCount: number, ...items: IBufferLine[]): void {
+    if (deleteCount === 0 && items.length === 0) {
+      return;
+    }
+
+    const before = Math.max(0, Math.min(start, this._length));
+    const actualDeleteCount = Math.min(deleteCount, this._length - before);
+
+    if (actualDeleteCount) {
+      for (let i = before; i < this._length - actualDeleteCount; i++) {
+        const src = this.get(i + actualDeleteCount);
+        if (src) {
+          this._setIndex(i, src);
+        }
+      }
+      this._length -= actualDeleteCount;
+      this.onDeleteEmitter.fire({ index: before, amount: actualDeleteCount });
+    }
+
+    if (items.length) {
+      for (let i = this._length - 1; i >= before; i--) {
+        const src = this.get(i);
+        if (src) {
+          this._setIndex(i + items.length, src);
+        }
+      }
+      for (let i = 0; i < items.length; i++) {
+        this._setIndex(before + i, items[i]);
+      }
+      this.onInsertEmitter.fire({ index: before, amount: items.length });
+
+      if (this._length + items.length > this._maxLength) {
+        const countToTrim = this._length + items.length - this._maxLength;
+        this._startIndex = (this._startIndex + countToTrim) % this._maxLength;
+        this._length = this._maxLength;
+        this.onTrimEmitter.fire(countToTrim);
+      } else {
+        this._length += items.length;
+      }
+    }
+  }
+
+  public trimStart(count: number): void {
+    if (count <= 0) {
+      return;
+    }
+    count = Math.min(count, this._length);
+    if (count > 0) {
+      this._startIndex = (this._startIndex + count) % this._maxLength;
+      this._length -= count;
+      this.onTrimEmitter.fire(count);
+    }
+  }
+
+  public shiftElements(start: number, count: number, offset: number): void {
+    if (count <= 0) {
+      return;
+    }
+    if (start < 0 || start >= this._length) {
+      throw new Error('start argument out of range');
+    }
+    if (start + offset < 0) {
+      throw new Error('Cannot shift elements in list beyond index 0');
+    }
+
+    if (offset > 0) {
+      for (let i = count - 1; i >= 0; i--) {
+        const srcLine = this.get(start + i);
+        if (srcLine) {
+          this._setIndex(start + i + offset, srcLine);
+        }
+      }
+      const expandListBy = (start + count + offset) - this._length;
+      if (expandListBy > 0) {
+        this._length += expandListBy;
+        while (this._length > this._maxLength) {
+          this._length--;
+          this._startIndex = (this._startIndex + 1) % this._maxLength;
+          this.onTrimEmitter.fire(1);
+        }
+      }
+    } else if (offset < 0) {
+      for (let i = 0; i < count; i++) {
+        const srcLine = this.get(start + i);
+        if (srcLine) {
+          this._setIndex(start + i + offset, srcLine);
+        }
+      }
+    }
+  }
+
+  public normalize(): void {
+    if (this._startIndex === 0) {
+      return;
+    }
+    const snapshot = this._getLogicalLines(this._length).map(line => line.clone());
+    for (let i = 0; i < snapshot.length; i++) {
+      this._copyInto(this._lines[i].row, snapshot[i]);
+    }
+    this._startIndex = 0;
+  }
+
+  private _setIndex(index: number, value: IBufferLine): void {
+    const line = this._lines[this._getCyclicIndex(index)];
+    this._copyInto(line.row, value);
+  }
+
+  private _getCyclicIndex(index: number): number {
+    return (this._startIndex + index) % this._maxLength;
+  }
+
+  private _copyInto(rowIndex: number, value: IBufferLine): void {
+    const nullContent = 1 << Content.WIDTH_SHIFT;
+    if (value instanceof GhosttyBufferLine) {
+      this._buffer.copyRow(value.row, rowIndex);
+      return;
+    }
+
+    const colsToCopy = Math.min(this._buffer.cols, value.length);
+    for (let col = 0; col < colsToCopy; col++) {
+      const cell = value.loadCell(col, this._workCell);
+      this._buffer.setCell(rowIndex, col, cell.content, cell.fg, cell.bg);
+      if (cell.content & Content.IS_COMBINED_MASK) {
+        this._buffer.setCombined(rowIndex, col, cell.combinedData);
+      } else {
+        this._buffer.clearCombined(rowIndex, col);
+      }
+      if (cell.bg & BgFlags.HAS_EXTENDED) {
+        this._buffer.setExtended(rowIndex, col, cell.extended);
+      } else {
+        this._buffer.clearExtended(rowIndex, col);
+      }
+    }
+    for (let col = colsToCopy; col < this._buffer.cols; col++) {
+      this._buffer.setCell(rowIndex, col, nullContent, 0, 0);
+      this._buffer.clearCombined(rowIndex, col);
+      this._buffer.clearExtended(rowIndex, col);
+    }
+    this._buffer.setRowWrap(rowIndex, value.isWrapped);
+  }
+
+  private _getLogicalLines(count: number): GhosttyBufferLine[] {
+    const result: GhosttyBufferLine[] = [];
+    for (let i = 0; i < count; i++) {
+      result.push(this._lines[this._getCyclicIndex(i)]);
+    }
+    return result;
+  }
+}

src/common/buffer/GhosttyWasmBuffer.ts

@@ -0,0 +1,198 @@
+/**
+ * Copyright (c) 2026 The xterm.js authors. All rights reserved.
+ * @license MIT
+ */
+
+import { GhosttyWasmRuntime, IGhosttyWasmExports } from 'common/parser/GhosttyWasmRuntime';
+import { IExtendedAttrs } from 'common/Types';
+
+const CELL_STRIDE = 3;
+
+export class GhosttyWasmBuffer {
+  private readonly _wasm: IGhosttyWasmExports;
+  private _handle: number;
+  private _cols: number;
+  private _rows: number;
+  private _maxRows: number;
+
+  private _combined = new Map<number, Map<number, string>>();
+  private _extended = new Map<number, Map<number, IExtendedAttrs>>();
+
+  private _cellScratchPtr: number;
+
+  constructor(cols: number, rows: number, maxRows: number) {
+    this._wasm = GhosttyWasmRuntime.getInstanceSync();
+    this._cols = cols;
+    this._rows = rows;
+    this._maxRows = maxRows;
+
+    this._handle = this._wasm.ghostty_xterm_buffer_new(cols, rows, maxRows);
+    if (!this._handle) {
+      throw new Error('Failed to allocate Ghostty xterm buffer');
+    }
+
+    this._cellScratchPtr = this._wasm.ghostty_wasm_alloc_u8_array(CELL_STRIDE * 4);
+    if (!this._cellScratchPtr) {
+      this._wasm.ghostty_xterm_buffer_free(this._handle);
+      this._handle = 0;
+      throw new Error('Failed to allocate Ghostty cell scratch buffer');
+    }
+  }
+
+  public dispose(): void {
+    if (this._handle) {
+      this._wasm.ghostty_xterm_buffer_free(this._handle);
+      this._handle = 0;
+    }
+    if (this._cellScratchPtr) {
+      this._wasm.ghostty_wasm_free_u8_array(this._cellScratchPtr, CELL_STRIDE * 4);
+      this._cellScratchPtr = 0;
+    }
+  }
+
+  public get cols(): number {
+    return this._cols;
+  }
+
+  public get rows(): number {
+    return this._rows;
+  }
+
+  public get maxRows(): number {
+    return this._maxRows;
+  }
+
+  public resize(cols: number, rows: number, maxRows: number): void {
+    const oldCols = this._cols;
+    if (!this._wasm.ghostty_xterm_buffer_resize(this._handle, cols, rows, maxRows)) {
+      throw new Error('Failed to resize Ghostty xterm buffer');
+    }
+    this._cols = cols;
+    this._rows = rows;
+    this._maxRows = maxRows;
+
+    if (cols < oldCols) {
+      for (const [row, rowMap] of this._combined) {
+        for (const col of rowMap.keys()) {
+          if (col >= cols) {
+            rowMap.delete(col);
+          }
+        }
+        if (rowMap.size === 0) {
+          this._combined.delete(row);
+        }
+      }
+      for (const [row, rowMap] of this._extended) {
+        for (const col of rowMap.keys()) {
+          if (col >= cols) {
+            rowMap.delete(col);
+          }
+        }
+        if (rowMap.size === 0) {
+          this._extended.delete(row);
+        }
+      }
+    }
+  }
+
+  public clear(): void {
+    this._wasm.ghostty_xterm_buffer_clear(this._handle);
+    this._combined.clear();
+    this._extended.clear();
+  }
+
+  public getCell(row: number, col: number): [number, number, number] {
+    this._wasm.ghostty_xterm_buffer_get_cell(this._handle, row, col, this._cellScratchPtr);
+    const view = new DataView(this._wasm.memory.buffer, this._cellScratchPtr, CELL_STRIDE * 4);
+    const content = view.getUint32(0, true);
+    const fg = view.getUint32(4, true);
+    const bg = view.getUint32(8, true);
+    return [content, fg, bg];
+  }
+
+  public setCell(row: number, col: number, content: number, fg: number, bg: number): void {
+    this._wasm.ghostty_xterm_buffer_set_cell(this._handle, row, col, content, fg, bg);
+  }
+
+  public clearRow(row: number, content: number, fg: number, bg: number): void {
+    this._wasm.ghostty_xterm_buffer_clear_row(this._handle, row, content, fg, bg);
+    this._combined.delete(row);
+    this._extended.delete(row);
+  }
+
+  public copyRow(srcRow: number, dstRow: number): void {
+    this._wasm.ghostty_xterm_buffer_copy_row(this._handle, srcRow, dstRow);
+    const combined = this._combined.get(srcRow);
+    if (combined) {
+      this._combined.set(dstRow, new Map(combined));
+    } else {
+      this._combined.delete(dstRow);
+    }
+    const extended = this._extended.get(srcRow);
+    if (extended) {
+      this._extended.set(dstRow, new Map(extended));
+    } else {
+      this._extended.delete(dstRow);
+    }
+  }
+
+  public getRowWrap(row: number): boolean {
+    return this._wasm.ghostty_xterm_buffer_get_row_wrap(this._handle, row) !== 0;
+  }
+
+  public setRowWrap(row: number, wrap: boolean): void {
+    this._wasm.ghostty_xterm_buffer_set_row_wrap(this._handle, row, wrap ? 1 : 0);
+  }
+
+  public getCombined(row: number, col: number): string | undefined {
+    return this._combined.get(row)?.get(col);
+  }
+
+  public setCombined(row: number, col: number, data: string): void {
+    let rowMap = this._combined.get(row);
+    if (!rowMap) {
+      rowMap = new Map();
+      this._combined.set(row, rowMap);
+    }
+    rowMap.set(col, data);
+  }
+
+  public clearCombined(row: number, col: number): void {
+    const rowMap = this._combined.get(row);
+    if (!rowMap) {
+      return;
+    }
+    rowMap.delete(col);
+    if (rowMap.size === 0) {
+      this._combined.delete(row);
+    }
+  }
+
+  public getExtended(row: number, col: number): IExtendedAttrs | undefined {
+    return this._extended.get(row)?.get(col);
+  }
+
+  public getExtendedRow(row: number): Map<number, IExtendedAttrs> | undefined {
+    return this._extended.get(row);
+  }
+
+  public setExtended(row: number, col: number, data: IExtendedAttrs): void {
+    let rowMap = this._extended.get(row);
+    if (!rowMap) {
+      rowMap = new Map();
+      this._extended.set(row, rowMap);
+    }
+    rowMap.set(col, data);
+  }
+
+  public clearExtended(row: number, col: number): void {
+    const rowMap = this._extended.get(row);
+    if (!rowMap) {
+      return;
+    }
+    rowMap.delete(col);
+    if (rowMap.size === 0) {
+      this._extended.delete(row);
+    }
+  }
+}

src/common/input/KittyKeyboard.test.ts

@@ -474,22 +474,8 @@ describe('KittyKeyboard', () => {
       });
 
       it('modifier key release includes its own bit cleared', () => {
-        const result = kitty.evaluate(createEvent({ key: 'Shift', code: 'ShiftLeft', shiftKey: false }), flags | KittyKeyboardFlags.REPORT_ALL_KEYS_AS_ESCAPE_CODES, KittyKeyboardEventType.RELEASE);
-        assert.strictEqual(result.key, '\x1b[57441;1:3u');
-      });
-    });
-
-    describe('modifier-only reporting', () => {
-      const flags = KittyKeyboardFlags.REPORT_EVENT_TYPES;
-
-      it('does not report modifier press without REPORT_ALL_KEYS_AS_ESCAPE_CODES', () => {
-        const result = kitty.evaluate(createEvent({ key: 'Shift', code: 'ShiftLeft', shiftKey: true }), flags);
-        assert.strictEqual(result.key, undefined);
-      });
-
-      it('does not report modifier release without REPORT_ALL_KEYS_AS_ESCAPE_CODES', () => {
         const result = kitty.evaluate(createEvent({ key: 'Shift', code: 'ShiftLeft', shiftKey: false }), flags, KittyKeyboardEventType.RELEASE);
-        assert.strictEqual(result.key, undefined);
+        assert.strictEqual(result.key, '\x1b[57441;1:3u');
       });
     });
 

src/common/input/KittyKeyboard.ts

@@ -418,7 +418,7 @@ export class KittyKeyboard {
       return result;
     }
 
-    if (isMod && !(flags & KittyKeyboardFlags.REPORT_ALL_KEYS_AS_ESCAPE_CODES)) {
+    if (isMod && !(flags & KittyKeyboardFlags.REPORT_ALL_KEYS_AS_ESCAPE_CODES) && !reportEventTypes) {
       return result;
     }
 

src/common/parser/GhosttyWasmParser.ts

@@ -0,0 +1,831 @@
+/**
+ * Copyright (c) 2026 The xterm.js authors. All rights reserved.
+ * @license MIT
+ */
+
+import { Disposable, toDisposable } from 'common/Lifecycle';
+import { IDisposable } from 'common/Types';
+import { IParsingState, IDcsHandler, IEscapeSequenceParser, IParams, IOscHandler, IHandlerCollection, CsiHandlerType, OscFallbackHandlerType, EscHandlerType, IDcsParser, DcsFallbackHandlerType, IFunctionIdentifier, ExecuteFallbackHandlerType, CsiFallbackHandlerType, EscFallbackHandlerType, PrintHandlerType, PrintFallbackHandlerType, ExecuteHandlerType, IParserStackState, ParserStackType, IApcHandler, IApcParser, ApcFallbackHandlerType } from 'common/parser/Types';
+import { OscParser } from 'common/parser/OscParser';
+import { DcsParser } from 'common/parser/DcsParser';
+import { ApcParser } from 'common/parser/ApcParser';
+import { Params } from 'common/parser/Params';
+import { StringToUtf32 } from 'common/input/TextDecoder';
+import { GhosttyWasmRuntime, IGhosttyWasmExports } from 'common/parser/GhosttyWasmRuntime';
+
+const enum RawEventTag {
+  PRINT = 0,
+  EXECUTE = 1,
+  ESC = 2,
+  CSI = 3,
+  OSC = 4,
+  DCS_HOOK = 5,
+  DCS_PUT = 6,
+  DCS_UNHOOK = 7,
+  APC_START = 8,
+  APC_PUT = 9,
+  APC_END = 10
+}
+
+export class GhosttyWasmParser extends Disposable implements IEscapeSequenceParser {
+  public precedingJoinState = 0;
+
+  private _printHandler: PrintHandlerType;
+  private _executeHandlers: { [flag: number]: ExecuteHandlerType };
+  private _csiHandlers: IHandlerCollection<CsiHandlerType>;
+  private _escHandlers: IHandlerCollection<EscHandlerType>;
+  private readonly _oscParser: OscParser;
+  private readonly _dcsParser: IDcsParser;
+  private readonly _apcParser: IApcParser;
+  private _errorHandler: (state: IParsingState) => IParsingState;
+
+  private _printHandlerFb: PrintFallbackHandlerType;
+  private _executeHandlerFb: ExecuteFallbackHandlerType;
+  private _csiHandlerFb: CsiFallbackHandlerType;
+  private _escHandlerFb: EscFallbackHandlerType;
+  private _errorHandlerFb: (state: IParsingState) => IParsingState;
+
+  private _parseStack: IParserStackState = {
+    state: ParserStackType.NONE,
+    handlers: [],
+    handlerPos: 0,
+    transition: 0,
+    chunkPos: 0
+  };
+
+  private _wasm?: IGhosttyWasmExports;
+  private _parserHandle = 0;
+  private _wasmReady?: Promise<boolean>;
+
+  private _eventSize = 0;
+  private _eventMaxParams = 0;
+  private _eventMaxIntermediates = 0;
+  private readonly _ptrSize = 4;
+
+  private _eventIndex = 0;
+  private _pendingEvents: { ptr: number, len: number } | undefined;
+  private _resumeParams: IParams | undefined;
+
+  private _textEncoder = new TextEncoder();
+  private _textDecoder = new TextDecoder('utf-8');
+  private _utf32Scratch = new Uint32Array(4096);
+  private _oscBuffer = new StringToUtf32();
+  private _dcsPutBuffer = new Uint32Array(1);
+  private _apcPutBuffer = new Uint32Array(1);
+
+  constructor() {
+    super();
+
+    this._printHandlerFb = () => { };
+    this._executeHandlerFb = () => { };
+    this._csiHandlerFb = () => { };
+    this._escHandlerFb = () => { };
+    this._errorHandlerFb = (state: IParsingState): IParsingState => state;
+
+    this._printHandler = this._printHandlerFb;
+    this._executeHandlers = Object.create(null);
+    this._csiHandlers = Object.create(null);
+    this._escHandlers = Object.create(null);
+
+    this._oscParser = this._register(new OscParser());
+    this._dcsParser = this._register(new DcsParser());
+    this._apcParser = this._register(new ApcParser());
+    this._errorHandler = this._errorHandlerFb;
+
+    this._register(toDisposable(() => {
+      this._csiHandlers = Object.create(null);
+      this._executeHandlers = Object.create(null);
+      this._escHandlers = Object.create(null);
+    }));
+
+    this._register(toDisposable(() => {
+      if (this._wasm && this._parserHandle) {
+        this._wasm.ghostty_raw_parser_free(this._parserHandle);
+      }
+      this._parserHandle = 0;
+    }));
+
+    this.registerEscHandler({ final: '\\' }, () => true);
+  }
+
+  public identToString(ident: number): string {
+    const res: string[] = [];
+    while (ident) {
+      res.push(String.fromCharCode(ident & 0xFF));
+      ident >>= 8;
+    }
+    return res.reverse().join('');
+  }
+
+  public setPrintHandler(handler: PrintHandlerType): void {
+    this._printHandler = handler;
+  }
+
+  public clearPrintHandler(): void {
+    this._printHandler = this._printHandlerFb;
+  }
+
+  public registerEscHandler(id: IFunctionIdentifier, handler: EscHandlerType): IDisposable {
+    const ident = this._identifier(id, [0x30, 0x7e]);
+    this._escHandlers[ident] ??= [];
+    const handlerList = this._escHandlers[ident];
+    handlerList.push(handler);
+    return {
+      dispose: () => {
+        const handlerIndex = handlerList.indexOf(handler);
+        if (handlerIndex !== -1) {
+          handlerList.splice(handlerIndex, 1);
+        }
+      }
+    };
+  }
+
+  public clearEscHandler(id: IFunctionIdentifier): void {
+    if (this._escHandlers[this._identifier(id, [0x30, 0x7e])]) delete this._escHandlers[this._identifier(id, [0x30, 0x7e])];
+  }
+
+  public setEscHandlerFallback(handler: EscFallbackHandlerType): void {
+    this._escHandlerFb = handler;
+  }
+
+  public setExecuteHandler(flag: string, handler: ExecuteHandlerType): void {
+    this._executeHandlers[flag.charCodeAt(0)] = handler;
+  }
+
+  public clearExecuteHandler(flag: string): void {
+    if (this._executeHandlers[flag.charCodeAt(0)]) delete this._executeHandlers[flag.charCodeAt(0)];
+  }
+
+  public setExecuteHandlerFallback(handler: ExecuteFallbackHandlerType): void {
+    this._executeHandlerFb = handler;
+  }
+
+  public registerCsiHandler(id: IFunctionIdentifier, handler: CsiHandlerType): IDisposable {
+    const ident = this._identifier(id);
+    this._csiHandlers[ident] ??= [];
+    const handlerList = this._csiHandlers[ident];
+    handlerList.push(handler);
+    return {
+      dispose: () => {
+        const handlerIndex = handlerList.indexOf(handler);
+        if (handlerIndex !== -1) {
+          handlerList.splice(handlerIndex, 1);
+        }
+      }
+    };
+  }
+
+  public clearCsiHandler(id: IFunctionIdentifier): void {
+    if (this._csiHandlers[this._identifier(id)]) delete this._csiHandlers[this._identifier(id)];
+  }
+
+  public setCsiHandlerFallback(callback: CsiFallbackHandlerType): void {
+    this._csiHandlerFb = callback;
+  }
+
+  public registerDcsHandler(id: IFunctionIdentifier, handler: IDcsHandler): IDisposable {
+    return this._dcsParser.registerHandler(this._identifier(id), handler);
+  }
+
+  public clearDcsHandler(id: IFunctionIdentifier): void {
+    this._dcsParser.clearHandler(this._identifier(id));
+  }
+
+  public setDcsHandlerFallback(handler: DcsFallbackHandlerType): void {
+    this._dcsParser.setHandlerFallback(handler);
+  }
+
+  public registerOscHandler(ident: number, handler: IOscHandler): IDisposable {
+    return this._oscParser.registerHandler(ident, handler);
+  }
+
+  public clearOscHandler(ident: number): void {
+    this._oscParser.clearHandler(ident);
+  }
+
+  public setOscHandlerFallback(handler: OscFallbackHandlerType): void {
+    this._oscParser.setHandlerFallback(handler);
+  }
+
+  public registerApcHandler(ident: number, handler: IApcHandler): IDisposable {
+    return this._apcParser.registerHandler(ident, handler);
+  }
+
+  public clearApcHandler(ident: number): void {
+    this._apcParser.clearHandler(ident);
+  }
+
+  public setApcHandlerFallback(handler: ApcFallbackHandlerType): void {
+    this._apcParser.setHandlerFallback(handler);
+  }
+
+  public setErrorHandler(handler: (state: IParsingState) => IParsingState): void {
+    this._errorHandler = handler;
+  }
+
+  public clearErrorHandler(): void {
+    this._errorHandler = this._errorHandlerFb;
+  }
+
+  public reset(): void {
+    this._oscParser.reset();
+    this._dcsParser.reset();
+    this._apcParser.reset();
+    this.precedingJoinState = 0;
+    if (this._wasm && this._parserHandle) {
+      this._wasm.ghostty_raw_parser_reset(this._parserHandle);
+    }
+    if (this._parseStack.state !== ParserStackType.NONE) {
+      this._parseStack.state = ParserStackType.RESET;
+      this._parseStack.handlers = [];
+    }
+  }
+
+  public parse(data: Uint32Array, length: number, promiseResult?: boolean): void | Promise<boolean> {
+    if (!this._wasm) {
+      this._wasmReady ??= this._initWasm();
+      return this._wasmReady;
+    }
+
+    if (this._parseStack.state !== ParserStackType.NONE) {
+      return this._resume(promiseResult);
+    }
+
+    const bytes = this._encodeUtf32(data, length);
+    const result = this._writeToWasm(bytes);
+    if (result) {
+      return result;
+    }
+    return this._drainEvents();
+  }
+
+  private _resume(promiseResult?: boolean): void | Promise<boolean> {
+    if (promiseResult === undefined || this._parseStack.state === ParserStackType.FAIL) {
+      this._parseStack.state = ParserStackType.FAIL;
+      throw new Error('improper continuation due to previous async handler, giving up parsing');
+    }
+
+    switch (this._parseStack.state) {
+      case ParserStackType.CSI:
+      case ParserStackType.ESC:
+        return this._resumeHandlerLoop(promiseResult);
+      case ParserStackType.OSC:
+        return this._resumeOsc(promiseResult);
+      case ParserStackType.DCS:
+        return this._resumeDcs(promiseResult);
+      case ParserStackType.APC:
+        return this._resumeApc(promiseResult);
+      case ParserStackType.RESET:
+        this._parseStack.state = ParserStackType.NONE;
+        return;
+      default:
+        this._parseStack.state = ParserStackType.NONE;
+        return;
+    }
+  }
+
+  private _resumeHandlerLoop(promiseResult: boolean): void | Promise<boolean> {
+    const handlers = this._parseStack.handlers as CsiHandlerType[] | EscHandlerType[];
+    let handlerPos = this._parseStack.handlerPos - 1;
+    if (promiseResult === false && handlerPos > -1) {
+      if (this._parseStack.state === ParserStackType.CSI) {
+        const params = this._resumeParams ?? new Params();
+        for (; handlerPos >= 0; handlerPos--) {
+          const handlerResult = (handlers as CsiHandlerType[])[handlerPos](params);
+          if (handlerResult === true) {
+            break;
+          } else if (handlerResult instanceof Promise) {
+            this._parseStack.handlerPos = handlerPos;
+            return handlerResult;
+          }
+        }
+      } else {
+        for (; handlerPos >= 0; handlerPos--) {
+          const handlerResult = (handlers as EscHandlerType[])[handlerPos]();
+          if (handlerResult === true) {
+            break;
+          } else if (handlerResult instanceof Promise) {
+            this._parseStack.handlerPos = handlerPos;
+            return handlerResult;
+          }
+        }
+      }
+    }
+
+    this._resumeParams = undefined;
+    this._parseStack.handlers = [];
+    this._parseStack.state = ParserStackType.NONE;
+    return this._continueAfterAsync();
+  }
+
+  private _resumeOsc(promiseResult: boolean): void | Promise<boolean> {
+    const handlerResult = this._oscParser.end(true, promiseResult);
+    if (handlerResult) {
+      return handlerResult as Promise<boolean>;
+    }
+    this._parseStack.state = ParserStackType.NONE;
+    return this._continueAfterAsync();
+  }
+
+  private _resumeDcs(promiseResult: boolean): void | Promise<boolean> {
+    const handlerResult = this._dcsParser.unhook(true, promiseResult);
+    if (handlerResult) {
+      return handlerResult as Promise<boolean>;
+    }
+    this._parseStack.state = ParserStackType.NONE;
+    return this._continueAfterAsync();
+  }
+
+  private _resumeApc(promiseResult: boolean): void | Promise<boolean> {
+    const handlerResult = this._apcParser.end(true, promiseResult);
+    if (handlerResult) {
+      return handlerResult as Promise<boolean>;
+    }
+    this._parseStack.state = ParserStackType.NONE;
+    return this._continueAfterAsync();
+  }
+
+  private _identifier(id: IFunctionIdentifier, finalRange: number[] = [0x40, 0x7e]): number {
+    let res = 0;
+    if (id.prefix) {
+      if (id.prefix.length > 1) {
+        throw new Error('only one byte as prefix supported');
+      }
+      res = id.prefix.charCodeAt(0);
+      if (res && 0x3c > res || res > 0x3f) {
+        throw new Error('prefix must be in range 0x3c .. 0x3f');
+      }
+    }
+    if (id.intermediates) {
+      if (id.intermediates.length > 2) {
+        throw new Error('only two bytes as intermediates are supported');
+      }
+      for (let i = 0; i < id.intermediates.length; ++i) {
+        const intermediate = id.intermediates.charCodeAt(i);
+        if (0x20 > intermediate || intermediate > 0x2f) {
+          throw new Error('intermediate must be in range 0x20 .. 0x2f');
+        }
+        res <<= 8;
+        res |= intermediate;
+      }
+    }
+    if (id.final.length !== 1) {
+      throw new Error('final must be a single byte');
+    }
+    const finalCode = id.final.charCodeAt(0);
+    if (finalRange[0] > finalCode || finalCode > finalRange[1]) {
+      throw new Error(`final must be in range ${finalRange[0]} .. ${finalRange[1]}`);
+    }
+    res <<= 8;
+    res |= finalCode;
+
+    return res;
+  }
+
+  private async _initWasm(): Promise<boolean> {
+    this._wasm = await GhosttyWasmRuntime.getInstance();
+    this._parserHandle = this._wasm.ghostty_raw_parser_new(0);
+    this._eventSize = this._wasm.ghostty_raw_parser_event_size();
+    this._eventMaxParams = this._wasm.ghostty_raw_parser_max_params();
+    this._eventMaxIntermediates = this._wasm.ghostty_raw_parser_max_intermediates();
+    return true;
+  }
+
+  private _encodeUtf32(data: Uint32Array, length: number): Uint8Array {
+    if (length === 0) {
+      return new Uint8Array(0);
+    }
+    const bytes: number[] = [];
+    for (let i = 0; i < length; i++) {
+      const codePoint = data[i];
+      if (codePoint === 0x9c) {
+        bytes.push(0x1b, 0x5c);
+        continue;
+      }
+      if (codePoint <= 0x7f || (codePoint >= 0x80 && codePoint <= 0x9f)) {
+        bytes.push(codePoint);
+      } else if (codePoint <= 0x7ff) {
+        bytes.push(
+          0xc0 | (codePoint >> 6),
+          0x80 | (codePoint & 0x3f)
+        );
+      } else if (codePoint <= 0xffff) {
+        bytes.push(
+          0xe0 | (codePoint >> 12),
+          0x80 | ((codePoint >> 6) & 0x3f),
+          0x80 | (codePoint & 0x3f)
+        );
+      } else {
+        bytes.push(
+          0xf0 | (codePoint >> 18),
+          0x80 | ((codePoint >> 12) & 0x3f),
+          0x80 | ((codePoint >> 6) & 0x3f),
+          0x80 | (codePoint & 0x3f)
+        );
+      }
+    }
+    return new Uint8Array(bytes);
+  }
+
+  private _writeToWasm(bytes: Uint8Array): void | Promise<boolean> {
+    if (!this._wasm || !this._parserHandle) {
+      return;
+    }
+    if (!bytes.length) {
+      return;
+    }
+
+    const dataPtr = this._wasm.ghostty_wasm_alloc_u8_array(bytes.length);
+    if (!dataPtr) {
+      return;
+    }
+
+    const mem = new Uint8Array(this._wasm.memory.buffer, dataPtr, bytes.length);
+    mem.set(bytes);
+    this._wasm.ghostty_raw_parser_write(this._parserHandle, dataPtr, bytes.length);
+    this._wasm.ghostty_wasm_free_u8_array(dataPtr, bytes.length);
+  }
+
+  private _drainEvents(): void | Promise<boolean> {
+    if (!this._wasm || !this._parserHandle) {
+      return;
+    }
+
+    const eventsPtr = this._wasm.ghostty_raw_parser_events_ptr(this._parserHandle);
+    const eventsLen = this._wasm.ghostty_raw_parser_events_len(this._parserHandle);
+    if (!eventsPtr || !eventsLen) {
+      this._wasm.ghostty_raw_parser_events_clear(this._parserHandle);
+      return;
+    }
+
+    this._pendingEvents = { ptr: eventsPtr, len: eventsLen };
+    this._eventIndex = 0;
+
+    const result = this._processEvents();
+    if (result) {
+      return result;
+    }
+
+    this._wasm.ghostty_raw_parser_events_clear(this._parserHandle);
+    this._pendingEvents = undefined;
+  }
+
+  private _continueAfterAsync(): void | Promise<boolean> {
+    if (!this._wasm || !this._parserHandle || !this._pendingEvents) {
+      return;
+    }
+
+    this._eventIndex++;
+    const result = this._processEvents();
+    if (result) {
+      return result;
+    }
+
+    this._wasm.ghostty_raw_parser_events_clear(this._parserHandle);
+    this._pendingEvents = undefined;
+  }
+
+  private _processEvents(): void | Promise<boolean> {
+    if (!this._pendingEvents || !this._wasm) {
+      return;
+    }
+
+    const { ptr, len } = this._pendingEvents;
+    const mem = this._wasm.memory.buffer;
+    const view = new DataView(mem);
+
+    let textStart = 0;
+    let textLen = 0;
+
+    for (; this._eventIndex < len; this._eventIndex++) {
+      const base = ptr + this._eventIndex * this._eventSize;
+      const tag = view.getInt32(base, true);
+
+      if (tag !== RawEventTag.PRINT && textLen > 0) {
+        this._flushText(view, ptr, textStart, textLen);
+        textLen = 0;
+      }
+
+      switch (tag) {
+        case RawEventTag.PRINT: {
+          if (textLen === 0) {
+            textStart = this._eventIndex;
+          }
+          textLen++;
+          break;
+        }
+        case RawEventTag.EXECUTE: {
+          const code = view.getUint32(base + 4, true);
+          this._handleExecute(code);
+          break;
+        }
+        case RawEventTag.ESC: {
+          const event = this._readEvent(view, base);
+          const ident = this._buildIdent(event.intermediates, event.final, false, [0x30, 0x7e]);
+          const handlers = this._escHandlers[ident];
+          const handlerResult = this._callEscHandlers(handlers, ident);
+          if (handlerResult) {
+            return handlerResult;
+          }
+          break;
+        }
+        case RawEventTag.CSI: {
+          const event = this._readEvent(view, base);
+          const params = this._buildParams(event.params, event.paramsLen, event.paramsSep);
+          const ident = this._buildIdent(event.intermediates, event.final, true);
+          const handlers = this._csiHandlers[ident];
+          const handlerResult = this._callCsiHandlers(handlers, ident, params);
+          if (handlerResult) {
+            return handlerResult;
+          }
+          break;
+        }
+        case RawEventTag.OSC: {
+          const event = this._readEvent(view, base);
+          const oscResult = this._handleOsc(event.code, event.dataPtr, event.dataLen);
+          if (oscResult) {
+            return oscResult;
+          }
+          break;
+        }
+        case RawEventTag.DCS_HOOK: {
+          const event = this._readEvent(view, base);
+          const params = this._buildParams(event.params, event.paramsLen, event.paramsSep);
+          const ident = this._buildIdent(event.intermediates, event.final, true);
+          this._dcsParser.hook(ident, params);
+          this.precedingJoinState = 0;
+          break;
+        }
+        case RawEventTag.DCS_PUT: {
+          const code = view.getUint32(base + 4, true);
+          this._dcsPutBuffer[0] = code;
+          this._dcsParser.put(this._dcsPutBuffer, 0, 1);
+          break;
+        }
+        case RawEventTag.DCS_UNHOOK: {
+          const dcsResult = this._dcsParser.unhook(true);
+          if (dcsResult) {
+            this._parseStack.state = ParserStackType.DCS;
+            this.precedingJoinState = 0;
+            return dcsResult as Promise<boolean>;
+          }
+          this.precedingJoinState = 0;
+          break;
+        }
+        case RawEventTag.APC_START: {
+          this._apcParser.start();
+          this.precedingJoinState = 0;
+          break;
+        }
+        case RawEventTag.APC_PUT: {
+          const code = view.getUint32(base + 4, true);
+          this._apcPutBuffer[0] = code;
+          this._apcParser.put(this._apcPutBuffer, 0, 1);
+          break;
+        }
+        case RawEventTag.APC_END: {
+          const apcResult = this._apcParser.end(true);
+          if (apcResult) {
+            this._parseStack.state = ParserStackType.APC;
+            this.precedingJoinState = 0;
+            return apcResult as Promise<boolean>;
+          }
+          this.precedingJoinState = 0;
+          break;
+        }
+      }
+    }
+
+    if (textLen > 0) {
+      this._flushText(view, ptr, textStart, textLen);
+    }
+
+    return;
+  }
+
+  private _flushText(view: DataView, ptr: number, start: number, count: number): void {
+    let remaining = count;
+    let offset = 0;
+    while (remaining > 0) {
+      const chunk = Math.min(remaining, this._utf32Scratch.length);
+      for (let i = 0; i < chunk; i++) {
+        const base = ptr + (start + offset + i) * this._eventSize;
+        const code = view.getUint32(base + 4, true);
+        this._utf32Scratch[i] = code;
+      }
+      this._printHandler(this._utf32Scratch, 0, chunk);
+      remaining -= chunk;
+      offset += chunk;
+    }
+  }
+
+  private _handleExecute(code: number): void {
+    if (this._executeHandlers[code]) {
+      this._executeHandlers[code]();
+    } else {
+      this._executeHandlerFb(code);
+    }
+    this.precedingJoinState = 0;
+  }
+
+  private _callEscHandlers(handlers: EscHandlerType[] | undefined, ident: number): void | Promise<boolean> {
+    if (!handlers) {
+      this._escHandlerFb(ident);
+      this.precedingJoinState = 0;
+      return;
+    }
+    let j = handlers.length - 1;
+    for (; j >= 0; j--) {
+      const handlerResult = handlers[j]();
+      if (handlerResult === true) {
+        break;
+      } else if (handlerResult instanceof Promise) {
+        this._parseStack.state = ParserStackType.ESC;
+        this._parseStack.handlers = handlers;
+        this._parseStack.handlerPos = j;
+        this.precedingJoinState = 0;
+        return handlerResult;
+      }
+    }
+    if (j < 0) {
+      this._escHandlerFb(ident);
+    }
+    this.precedingJoinState = 0;
+  }
+
+  private _callCsiHandlers(handlers: CsiHandlerType[] | undefined, ident: number, params: IParams): void | Promise<boolean> {
+    if (!handlers) {
+      this._csiHandlerFb(ident, params);
+      this.precedingJoinState = 0;
+      return;
+    }
+    let j = handlers.length - 1;
+    for (; j >= 0; j--) {
+      const handlerResult = handlers[j](params);
+      if (handlerResult === true) {
+        break;
+      } else if (handlerResult instanceof Promise) {
+        this._parseStack.state = ParserStackType.CSI;
+        this._resumeParams = params;
+        this._parseStack.handlers = handlers;
+        this._parseStack.handlerPos = j;
+        this.precedingJoinState = 0;
+        return handlerResult;
+      }
+    }
+    if (j < 0) {
+      this._csiHandlerFb(ident, params);
+    }
+    this.precedingJoinState = 0;
+  }
+
+  private _handleOsc(oscId: number, dataPtr: number, dataLen: number): void | Promise<boolean> {
+    console.log('handle osc');
+    if (!this._wasm) {
+      return;
+    }
+
+    let payload = '';
+    if (dataLen > 0) {
+      if (!dataPtr || dataPtr + dataLen > this._wasm.memory.buffer.byteLength) {
+        return;
+      }
+      const bytes = new Uint8Array(this._wasm.memory.buffer, dataPtr, dataLen);
+      payload = this._textDecoder.decode(bytes);
+    }
+    if (payload.indexOf('\u0000') !== -1) {
+      if (oscId === 8) {
+        const parts = payload.split('\u0000').filter((part, index, all) => {
+          if (part.length > 0) {
+            return true;
+          }
+          return index < all.length - 1;
+        });
+        if (parts.length > 0) {
+          const uri = parts[parts.length - 1] ?? '';
+          const params = parts.slice(0, -1).join(':');
+          payload = `${params};${uri}`;
+        } else {
+          payload = '';
+        }
+      } else {
+        payload = payload.replace(/\u0000+/g, '');
+      }
+    }
+    const oscPrefix = `${oscId};`;
+    const rawPayload = payload.startsWith(oscPrefix)
+      ? payload.slice(oscPrefix.length)
+      : payload;
+    let oscPayload = rawPayload;
+    if (oscId === 8 && oscPayload && !oscPayload.startsWith(';')) {
+      const sepIndex = oscPayload.indexOf(';');
+      const paramsPart = sepIndex === -1 ? oscPayload : oscPayload.slice(0, sepIndex);
+      if (!paramsPart.includes('=')) {
+        oscPayload = `;${oscPayload}`;
+      }
+    }
+    const oscString = `${oscPrefix}${oscPayload}`;
+
+    this._oscParser.start();
+    const length = this._decodeToScratch(oscString);
+    this._oscParser.put(this._utf32Scratch, 0, length);
+    const handlerResult = this._oscParser.end(true);
+    if (handlerResult) {
+      this._parseStack.state = ParserStackType.OSC;
+      this.precedingJoinState = 0;
+      return handlerResult as Promise<boolean>;
+    }
+    this.precedingJoinState = 0;
+  }
+
+  private _buildParams(params: Uint16Array, length: number, sepBits: number): Params {
+    const result = new Params(this._eventMaxParams, 256);
+    if (length === 0) {
+      result.addParam(0);
+      return result;
+    }
+
+    let i = 0;
+    while (i < length) {
+      result.addParam(params[i]);
+      if (sepBits & (1 << i)) {
+        i++;
+        while (i < length) {
+          result.addSubParam(params[i]);
+          if ((sepBits & (1 << i)) === 0) {
+            break;
+          }
+          i++;
+        }
+      }
+      i++;
+    }
+
+    return result;
+  }
+
+  private _buildIdent(intermediates: string, final: string, allowPrefix: boolean, finalRange: number[] = [0x40, 0x7e]): number {
+    let prefix: string | undefined;
+    let inters = intermediates;
+    if (allowPrefix && intermediates.length) {
+      const first = intermediates.charCodeAt(0);
+      if (first >= 0x3c && first <= 0x3f) {
+        prefix = intermediates.charAt(0);
+        inters = intermediates.substring(1);
+      }
+    }
+    return this._identifier({ prefix, intermediates: inters || undefined, final }, finalRange);
+  }
+
+  private _readEvent(view: DataView, base: number): {
+    final: string;
+    intermediates: string;
+    params: Uint16Array;
+    paramsLen: number;
+    paramsSep: number;
+    code: number;
+    dataPtr: number;
+    dataLen: number;
+  } {
+    const code = view.getUint32(base + 4, true);
+    const final = String.fromCharCode(view.getUint8(base + 8));
+    const intermediatesLen = Math.min(view.getUint8(base + 9), this._eventMaxIntermediates);
+    const paramsLen = Math.min(view.getUint8(base + 10), this._eventMaxParams);
+    const paramsSep = view.getUint32(base + 12, true);
+
+    let intermediates = '';
+    const interOffset = base + 16;
+    for (let i = 0; i < intermediatesLen; i++) {
+      intermediates += String.fromCharCode(view.getUint8(interOffset + i));
+    }
+
+    const paramsOffset = base + 16 + this._eventMaxIntermediates;
+    const params = new Uint16Array(paramsLen);
+    for (let i = 0; i < paramsLen; i++) {
+      params[i] = view.getUint16(paramsOffset + i * 2, true);
+    }
+
+    const rawDataPtrOffset = paramsOffset + this._eventMaxParams * 2;
+    const dataPtrOffset = (rawDataPtrOffset + (this._ptrSize - 1)) & ~(this._ptrSize - 1);
+    const dataPtr = view.getUint32(dataPtrOffset, true);
+    const dataLen = view.getUint32(dataPtrOffset + this._ptrSize, true);
+
+    return {
+      final,
+      intermediates,
+      params,
+      paramsLen,
+      paramsSep,
+      code,
+      dataPtr,
+      dataLen
+    };
+  }
+
+  private _decodeToScratch(text: string): number {
+    if (this._utf32Scratch.length < text.length * 2) {
+      this._utf32Scratch = new Uint32Array(text.length * 2);
+    }
+    return this._oscBuffer.decode(text, this._utf32Scratch);
+  }
+}

src/common/parser/GhosttyWasmRuntime.ts

@@ -0,0 +1,133 @@
+/**
+ * Copyright (c) 2026 The xterm.js authors. All rights reserved.
+ * @license MIT
+ */
+
+/* eslint-disable @typescript-eslint/naming-convention */
+export interface IGhosttyWasmExports {
+  memory: WebAssembly.Memory;
+  ghostty_raw_parser_new(allocPtr: number): number;
+  ghostty_raw_parser_free(parser: number): void;
+  ghostty_raw_parser_reset(parser: number): void;
+  ghostty_raw_parser_write(parser: number, dataPtr: number, len: number): void;
+  ghostty_raw_parser_events_ptr(parser: number): number;
+  ghostty_raw_parser_events_len(parser: number): number;
+  ghostty_raw_parser_events_clear(parser: number): void;
+  ghostty_raw_parser_event_size(): number;
+  ghostty_raw_parser_max_params(): number;
+  ghostty_raw_parser_max_intermediates(): number;
+  ghostty_wasm_alloc_u8_array(len: number): number;
+  ghostty_wasm_free_u8_array(ptr: number, len: number): void;
+  ghostty_xterm_buffer_new(cols: number, rows: number, maxRows: number): number;
+  ghostty_xterm_buffer_free(buffer: number): void;
+  ghostty_xterm_buffer_resize(buffer: number, cols: number, rows: number, maxRows: number): number;
+  ghostty_xterm_buffer_clear(buffer: number): void;
+  ghostty_xterm_buffer_get_cols(buffer: number): number;
+  ghostty_xterm_buffer_get_rows(buffer: number): number;
+  ghostty_xterm_buffer_get_max_rows(buffer: number): number;
+  ghostty_xterm_buffer_get_cell(buffer: number, row: number, col: number, outPtr: number): void;
+  ghostty_xterm_buffer_set_cell(buffer: number, row: number, col: number, content: number, fg: number, bg: number): void;
+  ghostty_xterm_buffer_clear_row(buffer: number, row: number, content: number, fg: number, bg: number): void;
+  ghostty_xterm_buffer_copy_row(buffer: number, srcRow: number, dstRow: number): void;
+  ghostty_xterm_buffer_get_row_wrap(buffer: number, row: number): number;
+  ghostty_xterm_buffer_set_row_wrap(buffer: number, row: number, wrap: number): void;
+}
+/* eslint-enable @typescript-eslint/naming-convention */
+
+export class GhosttyWasmRuntime {
+  private static _instancePromise: Promise<IGhosttyWasmExports> | undefined;
+  private static _instanceSync: IGhosttyWasmExports | undefined;
+
+  public static getInstance(): Promise<IGhosttyWasmExports> {
+    this._instancePromise ??= this._loadAsync();
+    return this._instancePromise;
+  }
+
+  public static getInstanceSync(): IGhosttyWasmExports {
+    this._instanceSync ??= this._loadSync();
+    return this._instanceSync;
+  }
+
+  private static async _loadAsync(): Promise<IGhosttyWasmExports> {
+    const wasmUrl = GhosttyWasmRuntime._getWasmUrl();
+    const isNode = typeof globalThis !== 'undefined' && !!(globalThis as any).process?.versions?.node;
+    if (isNode) {
+      const requireFn = (globalThis as any).require
+        ?? (globalThis as any).process?.mainModule?.require
+        ?? (globalThis as any).__xtermRequire;
+      const fs = requireFn?.('fs') as { readFile(path: string, cb: (err: Error | null, data?: Uint8Array) => void): void } | undefined;
+      if (!fs) {
+        throw new Error('Node.js async WASM loading requires require("fs")');
+      }
+      const wasmBytes = await new Promise<Uint8Array>((resolve, reject) => {
+        fs.readFile(wasmUrl, (err, data) => {
+          if (err || !data) {
+            reject(err ?? new Error(`Failed to load Ghostty WASM from ${wasmUrl}`));
+            return;
+          }
+          resolve(data);
+        });
+      });
+      const env = { log: () => {} };
+      const { instance } = await WebAssembly.instantiate(wasmBytes, { env });
+      return instance.exports as unknown as IGhosttyWasmExports;
+    }
+
+    const response = await fetch(wasmUrl);
+    if (!response.ok) {
+      throw new Error(`Failed to load Ghostty WASM from ${wasmUrl}`);
+    }
+    const wasmBytes = await response.arrayBuffer();
+    const env = { log: () => {} };
+    const { instance } = await WebAssembly.instantiate(wasmBytes, { env });
+    return instance.exports as unknown as IGhosttyWasmExports;
+  }
+
+  private static _loadSync(): IGhosttyWasmExports {
+    const wasmUrl = GhosttyWasmRuntime._getWasmUrl();
+    const isNode = typeof globalThis !== 'undefined' && !!(globalThis as any).process?.versions?.node;
+    if (!isNode && typeof document !== 'undefined') {
+      const request = new XMLHttpRequest();
+      request.open('GET', wasmUrl, false);
+      request.overrideMimeType('text/plain; charset=x-user-defined');
+      request.send(null);
+      if (request.status !== 200 || !request.responseText) {
+        throw new Error(`Failed to load Ghostty WASM from ${wasmUrl}`);
+      }
+      const binary = request.responseText;
+      const wasmBytes = new Uint8Array(binary.length);
+      for (let i = 0; i < binary.length; i++) {
+        wasmBytes[i] = binary.charCodeAt(i) & 0xFF;
+      }
+      const module = new WebAssembly.Module(wasmBytes);
+      const env = { log: () => {} };
+      const instance = new WebAssembly.Instance(module, { env });
+      return instance.exports as unknown as IGhosttyWasmExports;
+    }
+
+    // Node.js sync load for tests and headless usage.
+    const requireFn = (globalThis as any).require
+      ?? (globalThis as any).process?.mainModule?.require
+      ?? (globalThis as any).__xtermRequire;
+    const fs = requireFn?.('fs') as { readFileSync(path: string): Uint8Array } | undefined;
+    if (!fs) {
+      throw new Error('Node.js sync WASM loading requires require("fs")');
+    }
+    const wasmBytes = fs.readFileSync(wasmUrl);
+    const module = new WebAssembly.Module(wasmBytes);
+    const env = { log: () => {} };
+    const instance = new WebAssembly.Instance(module, { env });
+    return instance.exports as unknown as IGhosttyWasmExports;
+  }
+
+  private static _getWasmUrl(): string {
+    const override = (globalThis as any).XTERM_GHOSTTY_WASM_URL as string | undefined;
+    if (override) {
+      return override;
+    }
+    if (typeof document !== 'undefined') {
+      return 'vendor/ghostty-wasm/ghostty-vt.wasm';
+    }
+    return 'vendor/ghostty-wasm/ghostty-vt.wasm';
+  }
+}

src/common/services/Services.ts

@@ -3,7 +3,7 @@
  * @license MIT
  */
 
-import type { IDecoration, IDecorationOptions, ILinkHandler, ILogger, IWindowsPty, IOverviewRulerOptions } from '@xterm/xterm';
+import { IDecoration, IDecorationOptions, ILinkHandler, ILogger, IWindowsPty, type IOverviewRulerOptions } from '@xterm/xterm';
 import { CoreMouseEncoding, CoreMouseEventType, CursorInactiveStyle, CursorStyle, IAttributeData, ICharset, IColor, ICoreMouseEvent, ICoreMouseProtocol, IDecPrivateModes, IDisposable, IKittyKeyboardState, IModes, IOscLinkData, IWindowOptions } from 'common/Types';
 import { IBuffer, IBufferSet } from 'common/buffer/Types';
 import { createDecorator } from 'common/services/ServiceRegistry';

src/common/tsconfig.json

@@ -9,9 +9,9 @@
     "types": [
       "../../node_modules/@types/mocha"
     ],
+    "baseUrl": "..",
     "paths": {
-      "common/*": [ "./../common/*" ],
-      "*": [ "./../*" ]
+      "common/*": [ "./common/*" ]
     }
   },
   "include": [

src/headless/tsconfig.json

@@ -10,9 +10,9 @@
       "../../node_modules/@types/mocha",
       "../../node_modules/@types/node"
     ],
+    "baseUrl": "../",
     "paths": {
-      "common/*": [ "./../common/*" ],
-      "*": [ "./../*" ]
+      "common/*": [ "./common/*" ]
     }
   },
   "include": [

test/benchmark/tsconfig.json

@@ -12,6 +12,7 @@
     "strict": false,
     "target": "es2021",
     "module": "commonjs",
+    "baseUrl": ".",
     "paths": {
       "common/*": [ "../../src/common/*" ],
       "browser/*": [ "../../src/browser/*" ],

test/playwright/TestUtils.ts

@@ -9,10 +9,9 @@ import type { IRenderDimensions as IRenderDimensionsInternal } from 'browser/ren
 import type { IRenderService } from 'browser/services/Services';
 import type { ICoreTerminal, IDisposable, IMarker } from 'common/Types';
 import * as playwright from '@playwright/test';
+import { PageFunction } from 'playwright-core/types/structs';
 import { IBuffer, IBufferCell, IBufferLine, IBufferNamespace, IBufferRange, IDecoration, IDecorationOptions, IModes, IRenderDimensions, ITerminalInitOnlyOptions, ITerminalOptions, Terminal } from '@xterm/xterm';
 
-type PageFunction<Arg, R> = (arg: Arg) => R | Promise<R>;
-
 export interface ITestContext {
   browser: Browser;
   page: Page;
@@ -107,7 +106,7 @@ type PlaywrightApiProxy<TBaseInterface, TAsyncPropOverrides extends keyof TBaseI
 );
 
 interface ITerminalProxyCustomMethods {
-  evaluate<T>(pageFunction: PageFunction<Terminal[], T>): Promise<T>;
+  evaluate<T>(pageFunction: PageFunction<JSHandle<Terminal>[], T>): Promise<T>;
   write(data: string | Uint8Array): Promise<void>;
 }
 
@@ -289,11 +288,11 @@ export class TerminalProxy implements ITerminalProxyCustomMethods, PlaywrightApi
   public async clearTextureAtlas(): Promise<void> { return this.evaluate(([term]) => term.clearTextureAtlas()); }
   // #endregion
 
-  public async evaluate<T>(pageFunction: PageFunction<Terminal[], T>): Promise<T> {
+  public async evaluate<T>(pageFunction: PageFunction<JSHandle<Terminal>[], T>): Promise<T> {
     return this._page.evaluate(pageFunction, [await this.getHandle()]);
   }
 
-  public async evaluateHandle<T>(pageFunction: PageFunction<Terminal[], T>): Promise<JSHandle<T>> {
+  public async evaluateHandle<T>(pageFunction: PageFunction<JSHandle<Terminal>[], T>): Promise<JSHandle<T>> {
     return this._page.evaluateHandle(pageFunction, [await this.getHandle()]);
   }
 
@@ -343,7 +342,7 @@ class TerminalBufferProxy /* implements EnsureAsyncProperties<IBuffer>*/ {
     return undefined;
   }
 
-  public async evaluate<T>(pageFunction: PageFunction<IBuffer[], T>): Promise<T> {
+  public async evaluate<T>(pageFunction: PageFunction<JSHandle<IBuffer>[], T>): Promise<T> {
     return this._page.evaluate(pageFunction, [await this._handle]);
   }
 }
@@ -374,7 +373,7 @@ class TerminalBufferLine {
     return undefined;
   }
 
-  public async evaluate<T>(pageFunction: PageFunction<IBufferLine[], T>): Promise<T> {
+  public async evaluate<T>(pageFunction: PageFunction<JSHandle<IBufferLine>[], T>): Promise<T> {
     return this._page.evaluate(pageFunction, [this._handle]);
   }
 }
@@ -415,7 +414,7 @@ class TerminalBufferCell {
 
   public isAttributeDefault(): Promise<boolean> { return this.evaluate(([cell]) => cell.isAttributeDefault()); }
 
-  public async evaluate<T>(pageFunction: PageFunction<IBufferCell[], T>): Promise<T> {
+  public async evaluate<T>(pageFunction: PageFunction<JSHandle<IBufferCell>[], T>): Promise<T> {
     return this._page.evaluate(pageFunction, [this._handle]);
   }
 }
@@ -439,7 +438,7 @@ class TerminalCoreProxy {
     return this._proxy.evaluateHandle(([term]) => (term as any)._core as ICoreTerminal);
   }
 
-  public async evaluate<T>(pageFunction: PageFunction<ICoreTerminal[], T>): Promise<T> {
+  public async evaluate<T>(pageFunction: PageFunction<JSHandle<ICoreTerminal>[], T>): Promise<T> {
     return this._page.evaluate(pageFunction, [await this._getCoreHandle()]);
   }
 }

test/playwright/tsconfig.json

@@ -14,9 +14,8 @@
     "removeComments": true,
     "pretty": true,
     "strict": true,
-    "noImplicitAny": false,
     "declaration": true,
-    "moduleResolution": "node",
+    "baseUrl": ".",
     "paths": {
       "browser/*": [
         "../../src/browser/*"