@@ -14,15 +14,13 @@ import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
 import { readSeen } from "./appHistory.js";
 import {
   AGENT_HANDOFF_FILE,
-  HANDOFF_READY,
   agentSession,
   desktopHint,
   desktopInstalled,
   openCommandFor,
   openInDesktop,
 } from "./desktopApp.js";
 
-// The live path (ready) is what ships once the app takes handed-over folders; CI exercises it here.
 const LIVE = { ready: true, platform: "darwin" as const, env: {}, installed: () => true };
 const MAC_DOWNLOAD = "https://hyperframes.dev/studio/download?src=cli";
 const MAC_HINT = `Keep editing by chatting with Framey in the HyperFrames desktop app → ${MAC_DOWNLOAD}`;
@@ -33,15 +31,41 @@ const never = () => {
 
 describe("openInDesktop", () => {
   it("opens and writes nothing while the app cannot take a project", () => {
-    // Only the Mac app reads a handed-over folder in a released build so far.
-    expect(HANDOFF_READY).toBe(process.platform === "darwin");
     expect(openInDesktop(FILM, { ready: false, platform: "darwin", open: never })).toEqual({
       opened: false,
       reason: "handoff-unavailable",
       downloadUrl: MAC_DOWNLOAD,
     });
   });
 
+  it("hands the folder to the Windows app on its command line, with no override", () => {
+    const launched: string[] = [];
+    const result = openInDesktop(FILM, {
+      platform: "win32",
+      env: { LOCALAPPDATA: "C:\\Users\\a\\AppData\\Local" },
+      exists: () => true,
+      launch: (executable, dir) => (launched.push(`${executable} ${dir}`), true),
+    });
+    expect(result).toMatchObject({ opened: true, app: "the HyperFrames desktop app" });
+    expect(launched).toEqual([
+      `C:\\Users\\a\\AppData\\Local\\Programs\\HyperFrames\\HyperFrames.exe ${FILM}`,
+    ]);
+  });
+
+  it("hands the folder to the Linux AppImage on its command line, with no override", () => {
+    const launched: string[] = [];
+    const result = openInDesktop(FILM, {
+      platform: "linux",
+      env: {},
+      home: "/home/a",
+      exists: () => true,
+      read: () => JSON.stringify({ appImage: "/opt/HyperFrames.AppImage" }),
+      launch: (executable, dir) => (launched.push(`${executable} ${dir}`), true),
+    });
+    expect(result).toMatchObject({ opened: true, app: "the HyperFrames desktop app" });
+    expect(launched).toEqual([`/opt/HyperFrames.AppImage ${FILM}`]);
+  });
+
   it("hands the folder to the released app when it is installed", () => {
     const asked: string[] = [];
     const result = openInDesktop(FILM, {
 
@@ -35,9 +35,8 @@ export const desktopDownloadUrl = (
 export const downloadHint = (url: string): string =>
   `Keep editing by chatting with Framey in the HyperFrames desktop app → ${url}`;
 
-// ponytail: the Mac app takes a handed-over folder since b254 (hyperframes-internal#2601); Windows and Linux join
-// once its folder-argv change ships. Until then every surface offers the download and writes no hand-off.
-export const HANDOFF_READY = process.platform === "darwin";
+// Every build of the app takes a handed-over folder: macOS as open-file, Windows and Linux on their command line.
+export const HANDOFF_READY = true;
 
 export interface AgentSession {
   engine: "claude" | "codex" | "grok";