diff --git a/src/constants.ts b/src/constants.ts
index c01d59ac..372e70db 100644
--- a/src/constants.ts
+++ b/src/constants.ts
@@ -160,6 +160,11 @@ export const TOP_LEVEL_FIELDS: {
     type: Array,
     templatable: true,
   },
+  appLaunchURL: {
+    required: false,
+    type: 'string',
+    templatable: true,
+  },
   // Expiration Keys
   expirationDate: {
     type: 'string', // W3C date, as a string
diff --git a/src/lib/base-pass.ts b/src/lib/base-pass.ts
index 6e63c2bb..abce759d 100644
--- a/src/lib/base-pass.ts
+++ b/src/lib/base-pass.ts
@@ -191,6 +191,21 @@ export class PassBase extends PassStructure {
     else delete this.fields.associatedStoreIdentifiers;
   }
 
+  /**
+   * A URL the system passes to the associated app from
+   * associatedStoreIdentifiers during launch.
+   */
+  get appLaunchURL(): ApplePass['appLaunchURL'] {
+    return this.fields.appLaunchURL;
+  }
+  set appLaunchURL(v: ApplePass['appLaunchURL']) {
+    if (!v) {
+      delete this.fields.appLaunchURL;
+    } else {
+      this.fields.appLaunchURL = v;
+    }
+  }
+
   /**
    * Brief description of the pass, used by the iOS accessibility technologies.
    * Don’t try to include all of the data on the pass in its description,