diff --git a/cli/src/agents/base.ts b/cli/src/agents/base.ts
index d6411d4..f672580 100644
--- a/cli/src/agents/base.ts
+++ b/cli/src/agents/base.ts
@@ -293,6 +293,9 @@ export class ACP {
 				env: { ...process.env, ...(config.env ?? {}) },
 				stdio: ["pipe", "pipe", "pipe"],
 				shell: useShell,
+				// A shell-backed spawn allocates its own console window on Windows,
+				// which flashes on screen and can steal focus. No-op elsewhere.
+				windowsHide: true,
 			},
 		);
 
diff --git a/cli/src/agents/codex-readonly.ts b/cli/src/agents/codex-readonly.ts
index 150b6b5..dd7fa37 100644
--- a/cli/src/agents/codex-readonly.ts
+++ b/cli/src/agents/codex-readonly.ts
@@ -64,6 +64,7 @@ export async function readCodexThread(
 	const child = spawn(command, ["app-server", "--stdio"], {
 		cwd,
 		stdio: ["pipe", "pipe", "pipe"],
+		windowsHide: true,
 	});
 
 	let stderr = "";
diff --git a/cli/src/filesystem/index.ts b/cli/src/filesystem/index.ts
index 5b5f8df..ccf7327 100644
--- a/cli/src/filesystem/index.ts
+++ b/cli/src/filesystem/index.ts
@@ -711,6 +711,7 @@ export function initFilesystemHandler(conn: Connection, rootDir: string) {
 					cwd: gitRoot,
 					encoding: "utf-8",
 					stdio: ["pipe", "pipe", "pipe"], // silence stderr
+					windowsHide: true,
 				});
 			} catch {
 				// File might not exist in HEAD (new file), return empty
diff --git a/cli/src/notify.ts b/cli/src/notify.ts
index f31b820..b6903a7 100644
--- a/cli/src/notify.ts
+++ b/cli/src/notify.ts
@@ -17,16 +17,21 @@ function escapePowerShell(s: string) {
 }
 
 function run(cmd: string, args: string[]) {
-	execFile(cmd, args, { timeout: 5000 }, (error, _stdout, stderr) => {
-		if (error) {
-			logger.debug(`${cmd} failed`, error);
-			return;
-		}
+	execFile(
+		cmd,
+		args,
+		{ timeout: 5000, windowsHide: true },
+		(error, _stdout, stderr) => {
+			if (error) {
+				logger.debug(`${cmd} failed`, error);
+				return;
+			}
 
-		if (stderr?.trim()) {
-			logger.debug(`${cmd} stderr: ${stderr.trim()}`);
-		}
-	});
+			if (stderr?.trim()) {
+				logger.debug(`${cmd} stderr: ${stderr.trim()}`);
+			}
+		},
+	);
 }
 
 export function notify({ title, body }: NotifyArgs): boolean {
diff --git a/cli/src/ports.ts b/cli/src/ports.ts
index fccb8c5..a61d87d 100644
--- a/cli/src/ports.ts
+++ b/cli/src/ports.ts
@@ -111,6 +111,7 @@ export function initPortsHandler(conn: Connection) {
 				output = execSync("netstat -ano | findstr LISTENING", {
 					encoding: "utf-8",
 					timeout: 5000,
+					windowsHide: true,
 				});
 
 				const lines = output.trim().split("\n");
@@ -211,7 +212,10 @@ export function initPortsHandler(conn: Connection) {
 					}
 				}
 			} else if (platform === "win32") {
-				const result = spawnSync("netstat", ["-ano"], { encoding: "utf-8" });
+				const result = spawnSync("netstat", ["-ano"], {
+					encoding: "utf-8",
+					windowsHide: true,
+				});
 				const lines = (result.stdout || "").trim().split("\n");
 				for (const line of lines) {
 					if (!line.includes("LISTENING")) continue;
@@ -221,7 +225,9 @@ export function initPortsHandler(conn: Connection) {
 						const p = parseInt(parts[4], 10);
 						if (localAddr.endsWith(`:${portNum}`)) {
 							if (pid === null) pid = p;
-							spawnSync("taskkill", ["/F", "/PID", String(p)]);
+							spawnSync("taskkill", ["/F", "/PID", String(p)], {
+								windowsHide: true,
+							});
 						}
 					}
 				}
diff --git a/cli/src/update-and-start.ts b/cli/src/update-and-start.ts
index 8ce2898..e93dc14 100644
--- a/cli/src/update-and-start.ts
+++ b/cli/src/update-and-start.ts
@@ -34,6 +34,7 @@ export function isShellularInstalledGlobally(): Promise<boolean> {
 		const child = spawn("npm", ["list", "-g", "shellular", "--depth=0"], {
 			stdio: "ignore",
 			shell: process.platform === "win32",
+			windowsHide: true,
 		});
 
 		child.on("close", (code) => {
diff --git a/cli/src/update-runner.ts b/cli/src/update-runner.ts
index 71d711a..0bd0801 100644
--- a/cli/src/update-runner.ts
+++ b/cli/src/update-runner.ts
@@ -54,6 +54,7 @@ export async function runSelfUpdate(): Promise<void> {
 			stdio: ["ignore", logFd, logFd],
 			cwd: config.SHELLULAR_DIR,
 			env: process.env,
+			windowsHide: true,
 		});
 		child.unref();
 	} else {
diff --git a/cli/src/utils.ts b/cli/src/utils.ts
index 0225d57..0c93fae 100644
--- a/cli/src/utils.ts
+++ b/cli/src/utils.ts
@@ -91,6 +91,7 @@ export function commandExists(command: string): boolean {
 			const result = spawnSync("where", [command], {
 				stdio: "ignore",
 				shell: false,
+				windowsHide: true,
 			});
 			return result.status === 0;
 		}