diff --git a/addons/addon-kitty-graphics/src/KittyGraphicsAddon.test.ts b/addons/addon-kitty-graphics/src/KittyGraphicsAddon.test.ts
index 9378e954..4066a45f 100644
--- a/addons/addon-kitty-graphics/src/KittyGraphicsAddon.test.ts
+++ b/addons/addon-kitty-graphics/src/KittyGraphicsAddon.test.ts
@@ -69,6 +69,19 @@ describe('KittyGraphicsAddon', () => {
       assert.equal(cmd.action, 'd');
       assert.equal(cmd.id, 5);
     });
+
+    it('should parse empty action as empty string', () => {
+      const cmd = parseKittyCommand('a=,f=100');
+      assert.equal(cmd.action, '');
+      assert.equal(cmd.format, 100);
+    });
+
+    it('should leave action undefined when key is not present (parser only)', () => {
+      const cmd = parseKittyCommand('f=100,i=5');
+      assert.equal(cmd.action, undefined);
+      assert.equal(cmd.format, 100);
+      assert.equal(cmd.id, 5);
+    });
   });
 
   describe('APC handler', () => {
@@ -112,6 +125,24 @@ describe('KittyGraphicsAddon', () => {
       assert.equal(addon.images.size, 1);
     });
 
+    it('should default to transmit action when action is omitted', async () => {
+      // No a= key - should default to 't' (transmit)
+      const sequence = `\x1b_Gf=100;${BLACK_1X1_BASE64}\x1b\\`;
+      await writeP(terminal, sequence);
+
+      // Image should be stored (transmit action)
+      assert.equal(addon.images.size, 1);
+    });
+
+    it('should ignore command when action is empty string', async () => {
+      // a= with no value is invalid - should be ignored
+      const sequence = `\x1b_Ga=,f=100;${BLACK_1X1_BASE64}\x1b\\`;
+      await writeP(terminal, sequence);
+
+      // Empty action is invalid, command should be ignored
+      assert.equal(addon.images.size, 0);
+    });
+
     it('should delete image by id', async () => {
       // First store an image with id=5
       await writeP(terminal, `\x1b_Ga=T,f=100,i=5;${BLACK_1X1_BASE64}\x1b\\`);
diff --git a/addons/addon-kitty-graphics/src/KittyGraphicsAddon.ts b/addons/addon-kitty-graphics/src/KittyGraphicsAddon.ts
index 10be97b7..4ce0aa8a 100644
--- a/addons/addon-kitty-graphics/src/KittyGraphicsAddon.ts
+++ b/addons/addon-kitty-graphics/src/KittyGraphicsAddon.ts
@@ -171,7 +171,7 @@ export class KittyGraphicsAddon implements ITerminalAddon, IKittyGraphicsApi {
       console.log('[KittyGraphicsAddon] Received command:', cmd);
     }
 
-    const action = cmd.action || 't';
+    const action = cmd.action ?? 't';
 
     // Actions from: https://sw.kovidgoyal.net/kitty/graphics-protocol/#control-data-reference
     switch (action) {
@@ -535,8 +535,8 @@ export class KittyGraphicsAddon implements ITerminalAddon, IKittyGraphicsApi {
    * @param cmd - The parsed Kitty command
    */
   private _handleQuery(cmd: IKittyCommand): boolean {
-    const id = cmd.id || 0;
-    const quiet = cmd.quiet || 0;
+    const id = cmd.id ?? 0;
+    const quiet = cmd.quiet ?? 0;
 
     if (this._debug) {
       console.log(`[KittyGraphicsAddon] Query received, id=${id}, quiet=${quiet}`);
diff --git a/addons/addon-kitty-graphics/src/KittyImageRenderer.ts b/addons/addon-kitty-graphics/src/KittyImageRenderer.ts
index e6a85ccf..4d950105 100644
--- a/addons/addon-kitty-graphics/src/KittyImageRenderer.ts
+++ b/addons/addon-kitty-graphics/src/KittyImageRenderer.ts
@@ -41,6 +41,23 @@ export class KittyImageRenderer implements IDisposable {
     this._terminal = terminal;
   }
 
+  public dispose(): void {
+    this._renderDisposable?.dispose();
+    this._resizeDisposable?.dispose();
+
+    // Close all bitmaps
+    for (const placement of this._placements.values()) {
+      placement.bitmap.close();
+    }
+    this._placements.clear();
+
+    if (this._canvas) {
+      this._canvas.remove();
+      this._canvas = undefined;
+      this._ctx = undefined;
+    }
+  }
+
   /**
    * Initialize the canvas layer. Called when first image is placed.
    */
@@ -217,21 +234,4 @@ export class KittyImageRenderer implements IDisposable {
       this._draw();
     }
   }
-
-  public dispose(): void {
-    this._renderDisposable?.dispose();
-    this._resizeDisposable?.dispose();
-
-    // Close all bitmaps
-    for (const placement of this._placements.values()) {
-      placement.bitmap.close();
-    }
-    this._placements.clear();
-
-    if (this._canvas) {
-      this._canvas.remove();
-      this._canvas = undefined;
-      this._ctx = undefined;
-    }
-  }
 }