fix(cli): give the Windows service a hidden console

packages/cli/package.json

@@ -16,6 +16,13 @@
     "./run": "./src/run/index.ts",
     "./server-process": "./src/server-process.ts"
   },
+  "imports": {
+    "#hidden-console": {
+      "bun": "./src/services/hidden-console.bun.ts",
+      "node": "./src/services/hidden-console.node.ts",
+      "default": "./src/services/hidden-console.bun.ts"
+    }
+  },
   "scripts": {
     "build": "bun run script/build.ts",
     "build:node": "bun run script/build-node.ts",

packages/cli/src/server-process.ts

@@ -12,6 +12,7 @@ import { PersistentPty } from "@opencode/schema/persistent-pty"
 import { HttpServer } from "effect/unstable/http"
 import { Env } from "./env"
 import { ServiceConfig } from "./services/service-config"
+import { HiddenConsole } from "./services/hidden-console"
 import { RetainedImage } from "./services/retained-image"
 import { ServiceRegistration } from "./services/service-registration"
 import { WebUi } from "./services/web-ui"
@@ -52,7 +53,11 @@ const processEffect = Effect.fnUntraced(function* (options: Options) {
           Effect.mapError(() => new Error("Invalid PTY restart handoff")),
         )
   const global = yield* Global.Service
-  if (options.mode === "service") yield* Effect.sync(() => process.chdir(global.home))
+  if (options.mode === "service") {
+    yield* Effect.sync(() => process.chdir(global.home))
+    const status = yield* Effect.sync(() => HiddenConsole.attach())
+    if (status !== undefined) yield* Effect.logWarning("could not attach a hidden console", { status })
+  }
   return yield* Effect.scoped(
     Effect.gen(function* () {
       const foreground = options.mode === "default"

packages/cli/src/services/hidden-console.bun.ts

@@ -0,0 +1,30 @@
+import { dlopen, ptr } from "bun:ffi"
+import os from "node:os"
+
+// STD_INPUT_HANDLE, STD_OUTPUT_HANDLE, STD_ERROR_HANDLE
+const standardHandles = [-10, -11, -12]
+
+/**
+ * A detached service starts without a console, so Windows opens a visible window for every
+ * console child spawned without CREATE_NO_WINDOW (plugin code, hooks, npm's git). Allocating a
+ * windowless console gives those children one to inherit instead.
+ *
+ * Returns the failing HRESULT, or undefined when the console was attached or is unsupported.
+ */
+export function attach() {
+  if (process.platform !== "win32") return
+  // AllocConsoleWithOptions requires Windows 11 24H2 / Server 2025 (build 26100).
+  if (Number(os.release().split(".")[2]) < 26100) return
+  const kernel32 = dlopen("kernel32.dll", {
+    AllocConsoleWithOptions: { args: ["ptr", "ptr"], returns: "i32" },
+    GetStdHandle: { args: ["i32"], returns: "i64" },
+    SetStdHandle: { args: ["i32", "i64"], returns: "i32" },
+  })
+  // Allocation may point the standard handles at the new console; keep the pipes the spawner reads.
+  const handles = standardHandles.map((id) => [id, kernel32.symbols.GetStdHandle(id)] as const)
+  // ALLOC_CONSOLE_OPTIONS { mode: ALLOC_CONSOLE_MODE_NO_WINDOW, useShowWindow: FALSE, showWindow: 0 }
+  const status = kernel32.symbols.AllocConsoleWithOptions(ptr(new Int32Array([2, 0, 0])), null)
+  handles.forEach(([id, handle]) => kernel32.symbols.SetStdHandle(id, handle))
+  kernel32.close()
+  return status === 0 ? undefined : status
+}

packages/cli/src/services/hidden-console.node.ts

@@ -0,0 +1,4 @@
+// The Node build has no console binding yet, so its service keeps the console-less behavior.
+export function attach(): number | undefined {
+  return undefined
+}

packages/cli/src/services/hidden-console.ts

@@ -0,0 +1 @@
+export * as HiddenConsole from "#hidden-console"