fix(launch): passed Windows PTY arguments directly

Added a direct-argv PTY entry point and used it for Windows launch sessions so portable-pty no longer re-quotes cmd.exe command text.

Rejected direct .bat and .cmd applications with guidance to use cmd.exe /c.

Fixes #5416

crates/pi-natives/src/pty.rs

@@ -44,6 +44,27 @@ pub struct PtyStartOptions<'env> {
 	pub shell:      Option<String>,
 }
 
+/// Options for running an executable and argument vector in a PTY session.
+#[napi(object)]
+pub struct PtyArgvStartOptions<'env> {
+	/// Executable name or path.
+	pub application: String,
+	/// Arguments passed directly to the executable.
+	pub args:        Vec<String>,
+	/// Working directory for command execution.
+	pub cwd:         Option<String>,
+	/// Environment variables for this command.
+	pub env:         Option<HashMap<String, String>>,
+	/// Timeout in milliseconds before cancelling.
+	pub timeout_ms:  Option<u32>,
+	/// Abort signal for cancelling the operation.
+	pub signal:      Option<Unknown<'env>>,
+	/// PTY column count.
+	pub cols:        Option<u16>,
+	/// PTY row count.
+	pub rows:        Option<u16>,
+}
+
 /// Result of a PTY command run.
 #[napi(object)]
 pub struct PtyRunResult {
@@ -55,14 +76,19 @@ pub struct PtyRunResult {
 	pub timed_out: bool,
 }
 
+#[derive(Clone)]
+enum PtyCommand {
+	Shell { command: String, shell: Option<String> },
+	Argv { application: String, args: Vec<String> },
+}
+
 #[derive(Clone)]
 struct PtyRunConfig {
-	command: String,
+	command: PtyCommand,
 	cwd:     Option<String>,
 	env:     Option<HashMap<String, String>>,
 	cols:    u16,
 	rows:    u16,
-	shell:   Option<String>,
 }
 
 enum ReaderEvent {
@@ -106,7 +132,7 @@ impl PtySession {
 		Self { core: Arc::new(Mutex::new(None)) }
 	}
 
-	/// Start a PTY command and stream output chunks via callback.
+	/// Start a shell command and stream output chunks via callback.
 	#[napi]
 	pub fn start<'env>(
 		&self,
@@ -116,40 +142,33 @@ impl PtySession {
 		on_chunk: Option<ThreadsafeFunction<String>>,
 	) -> Result<PromiseRaw<'env, PtyRunResult>> {
 		let run_config = PtyRunConfig {
-			command: options.command,
+			command: PtyCommand::Shell { command: options.command, shell: options.shell },
 			cwd:     options.cwd,
 			env:     options.env,
 			cols:    options.cols.unwrap_or(120).clamp(20, 400),
 			rows:    options.rows.unwrap_or(40).clamp(5, 200),
-			shell:   options.shell,
 		};
-		let ct = task::CancelToken::new(options.timeout_ms, options.signal);
-		let core = Arc::clone(&self.core);
+		self.start_config(env, run_config, options.timeout_ms, options.signal, on_chunk)
+	}
 
-		// Register control channel synchronously so write()/kill() work immediately.
-		let (control_tx, control_rx) = flume::unbounded::<ControlMessage>();
-		{
-			let mut guard = core.lock();
-			if guard.is_some() {
-				return Err(Error::from_reason("PTY session already running"));
-			}
-			*guard = Some(PtySessionCore { control_tx });
-		}
-		task::future(env, "pty.start", async move {
-			let run_result =
-				tokio::task::spawn_blocking(move || run_pty_sync(run_config, on_chunk, control_rx, ct))
-					.await;
-
-			// Always clear core regardless of result
-			let mut guard = core.lock();
-			*guard = None;
-			drop(guard);
-
-			match run_result {
-				Ok(inner) => inner,
-				Err(err) => Err(Error::from_reason(format!("PTY execution task failed: {err}"))),
-			}
-		})
+	/// Start an executable with separate arguments and stream output chunks via
+	/// callback.
+	#[napi]
+	pub fn start_argv<'env>(
+		&self,
+		env: &'env Env,
+		options: PtyArgvStartOptions<'env>,
+		#[napi(ts_arg_type = "((error: Error | null, chunk: string) => void) | undefined | null")]
+		on_chunk: Option<ThreadsafeFunction<String>>,
+	) -> Result<PromiseRaw<'env, PtyRunResult>> {
+		let run_config = PtyRunConfig {
+			command: PtyCommand::Argv { application: options.application, args: options.args },
+			cwd:     options.cwd,
+			env:     options.env,
+			cols:    options.cols.unwrap_or(120).clamp(20, 400),
+			rows:    options.rows.unwrap_or(40).clamp(5, 200),
+		};
+		self.start_config(env, run_config, options.timeout_ms, options.signal, on_chunk)
 	}
 
 	/// Write raw input bytes to PTY stdin.
@@ -175,6 +194,42 @@ impl PtySession {
 }
 
 impl PtySession {
+	fn start_config<'env>(
+		&self,
+		env: &'env Env,
+		run_config: PtyRunConfig,
+		timeout_ms: Option<u32>,
+		signal: Option<Unknown<'env>>,
+		on_chunk: Option<ThreadsafeFunction<String>>,
+	) -> Result<PromiseRaw<'env, PtyRunResult>> {
+		let ct = task::CancelToken::new(timeout_ms, signal);
+		let core = Arc::clone(&self.core);
+
+		// Register control channel synchronously so write()/kill() work immediately.
+		let (control_tx, control_rx) = flume::unbounded::<ControlMessage>();
+		{
+			let mut guard = core.lock();
+			if guard.is_some() {
+				return Err(Error::from_reason("PTY session already running"));
+			}
+			*guard = Some(PtySessionCore { control_tx });
+		}
+		task::future(env, "pty.start", async move {
+			let run_result =
+				tokio::task::spawn_blocking(move || run_pty_sync(run_config, on_chunk, control_rx, ct))
+					.await;
+
+			let mut guard = core.lock();
+			*guard = None;
+			drop(guard);
+
+			match run_result {
+				Ok(inner) => inner,
+				Err(err) => Err(Error::from_reason(format!("PTY execution task failed: {err}"))),
+			}
+		})
+	}
+
 	fn send_control(&self, message: ControlMessage) -> Result<()> {
 		let guard = self.core.lock();
 		let core = guard
@@ -249,19 +304,29 @@ fn run_pty_sync(
 			.map_err(|err| Error::from_reason(format!("Failed to open PTY: {err}")))?
 	};
 
-	let shell = config.shell.as_deref().unwrap_or("sh");
-	let mut cmd = CommandBuilder::new(shell);
-	// Use shell-appropriate command execution flags
-	let lower = shell.to_lowercase();
-	if lower.ends_with("cmd.exe") || lower.ends_with("cmd") {
-		cmd.arg("/c");
-	} else if lower.contains("powershell") || lower.contains("pwsh") {
-		cmd.arg("-Command");
-	} else {
-		// sh/bash/zsh/fish etc.
-		cmd.arg("-lc");
-	}
-	cmd.arg(&config.command);
+	let mut cmd = match config.command {
+		PtyCommand::Shell { command, shell } => {
+			let shell = shell.as_deref().unwrap_or("sh");
+			let mut cmd = CommandBuilder::new(shell);
+			let lower = shell.to_lowercase();
+			if lower.ends_with("cmd.exe") || lower.ends_with("cmd") {
+				cmd.arg("/c");
+			} else if lower.contains("powershell") || lower.contains("pwsh") {
+				cmd.arg("-Command");
+			} else {
+				cmd.arg("-lc");
+			}
+			cmd.arg(command);
+			cmd
+		},
+		PtyCommand::Argv { application, args } => {
+			let mut cmd = CommandBuilder::new(application);
+			for arg in args {
+				cmd.arg(arg);
+			}
+			cmd
+		},
+	};
 	if let Some(cwd) = config.cwd.as_ref() {
 		cmd.cwd(cwd);
 	}

packages/coding-agent/CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## [Unreleased]
 
+### Fixed
+
+- Fixed the `launch` tool failing to start Windows executables because PTY commands double-escaped the application and arguments ([#5416](https://github.com/can1357/oh-my-pi/issues/5416)).
+
 ## [16.5.1] - 2026-07-14
 
 ### Changed

packages/coding-agent/src/launch/broker.ts

@@ -84,9 +84,6 @@ interface DaemonLogRead {
 function quoteShellArg(value: string): string {
 	return `'${value.replaceAll("'", `'\\''`)}'`;
 }
-function quoteCmdArg(value: string): string {
-	return `"${value.replaceAll('"', '""')}"`;
-}
 
 function terminalState(state: DaemonSnapshot["state"]): boolean {
 	return state === "exited" || state === "failed";
@@ -434,6 +431,9 @@ class DaemonBroker {
 		if (spec.detached && spec.pty) {
 			throw new Error("A detached daemon cannot allocate a PTY");
 		}
+		if (process.platform === "win32" && [".bat", ".cmd"].includes(path.extname(spec.application).toLowerCase())) {
+			throw new Error('Windows batch files require application "cmd.exe" with the batch path after "/c"');
+		}
 		const existing = this.#records.get(spec.name);
 		if (existing) await this.#refreshDetached(existing);
 		if (existing && !terminalState(existing.snapshot.state)) {
@@ -520,38 +520,47 @@ class DaemonBroker {
 	}
 
 	async #launchPty(record: ManagedDaemon, generation: number): Promise<void> {
-		const pidPath = path.join(record.dir, "process.pid");
-		await fs.rm(pidPath, { force: true });
-		const argv = [record.spec.application, ...record.spec.args];
-		const command =
-			process.platform === "win32"
-				? argv.map(quoteCmdArg).join(" ")
-				: [`printf '%s' "$$" > ${quoteShellArg(pidPath)}`, `exec ${argv.map(quoteShellArg).join(" ")}`].join("; ");
 		const session = new PtySession();
 		record.pty = session;
-		const shell = process.platform === "win32" ? process.env.COMSPEC : process.env.SHELL;
-		void session
-			.start(
+		const options = {
+			cwd: record.spec.cwd,
+			env: workerEnvFromParent({ TERM: "xterm-256color", ...record.spec.env }),
+			cols: DAEMON_PTY_COLUMNS,
+			rows: DAEMON_PTY_ROWS,
+		};
+		const onChunk = (error: Error | null, chunk: string): void => {
+			if (generation !== record.generation) return;
+			if (error) record.log?.append(`PTY output error: ${error.message}\n`);
+			if (chunk) this.#onOutput(record, generation, chunk);
+		};
+		let run: Promise<PtyRunResult>;
+		if (process.platform === "win32") {
+			run = session.startArgv(
 				{
-					command,
-					cwd: record.spec.cwd,
-					env: workerEnvFromParent({ TERM: "xterm-256color", ...record.spec.env }),
-					cols: DAEMON_PTY_COLUMNS,
-					rows: DAEMON_PTY_ROWS,
-					shell,
+					application: record.spec.application,
+					args: record.spec.args,
+					...options,
 				},
-				(error, chunk) => {
-					if (generation !== record.generation) return;
-					if (error) record.log?.append(`PTY output error: ${error.message}\n`);
-					if (chunk) this.#onOutput(record, generation, chunk);
-				},
-			)
+				onChunk,
+			);
+		} else {
+			const pidPath = path.join(record.dir, "process.pid");
+			await fs.rm(pidPath, { force: true });
+			const argv = [record.spec.application, ...record.spec.args];
+			const command = [
+				`printf '%s' "$$" > ${quoteShellArg(pidPath)}`,
+				`exec ${argv.map(quoteShellArg).join(" ")}`,
+			].join("; ");
+			run = session.start({ command, shell: process.env.SHELL, ...options }, onChunk);
+		}
+		void run
 			.then(result => this.#onPtyExit(record, generation, result))
 			.catch(error =>
 				this.#settle(record, generation, undefined, error instanceof Error ? error.message : String(error)),
 			);
 
 		if (process.platform === "win32") return;
+		const pidPath = path.join(record.dir, "process.pid");
 		const deadline = Date.now() + 5_000;
 		const pidFile = Bun.file(pidPath);
 		while (Date.now() < deadline && generation === record.generation) {

packages/natives/CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## [Unreleased]
 
+### Fixed
+
+- Fixed Windows PTY callers being forced through shell command re-quoting by adding direct executable-and-argument launching ([#5416](https://github.com/can1357/oh-my-pi/issues/5416)).
+
 ## [16.4.6] - 2026-07-12
 
 ### Added

packages/natives/native/index.d.ts

@@ -84,8 +84,10 @@ export declare class Process {
 /** Stateful PTY session for interactive stdin/stdout passthrough. */
 export declare class PtySession {
   constructor()
-  /** Start a PTY command and stream output chunks via callback. */
+  /** Start a shell command and stream output chunks via callback. */
   start(options: PtyStartOptions, onChunk?: ((error: Error | null, chunk: string) => void) | undefined | null): Promise<PtyRunResult>
+  /** Start an executable with separate arguments and stream output chunks via callback. */
+  startArgv(options: PtyArgvStartOptions, onChunk?: ((error: Error | null, chunk: string) => void) | undefined | null): Promise<PtyRunResult>
   /** Write raw input bytes to PTY stdin. */
   write(data: string): void
   /** Resize the active PTY. */
@@ -1250,6 +1252,26 @@ export interface ProcessWaitOptions {
   signal?: unknown
 }
 
+/** Options for running an executable and argument vector in a PTY session. */
+export interface PtyArgvStartOptions {
+  /** Executable name or path. */
+  application: string
+  /** Arguments passed directly to the executable. */
+  args: Array<string>
+  /** Working directory for command execution. */
+  cwd?: string
+  /** Environment variables for this command. */
+  env?: Record<string, string>
+  /** Timeout in milliseconds before cancelling. */
+  timeoutMs?: number
+  /** Abort signal for cancelling the operation. */
+  signal?: unknown
+  /** PTY column count. */
+  cols?: number
+  /** PTY row count. */
+  rows?: number
+}
+
 /** Result of a PTY command run. */
 export interface PtyRunResult {
   /** Exit code when the command completes. */

packages/natives/test/native.test.ts

@@ -613,6 +613,34 @@ describe("pi-natives", () => {
 	});
 
 	describe("pty", () => {
+		it("passes executable arguments without shell quoting", async () => {
+			const scriptPath = path.join(testDir, "pty-argv.ts");
+			const expected = ["argument with spaces", 'quote"inside', "backslash\\end"];
+			await Bun.write(scriptPath, 'process.stdout.write(JSON.stringify(process.argv.slice(2)) + "\\n");\n');
+			const session = new PtySession();
+			let output = "";
+			let callbackError: Error | null = null;
+			const result = await session.startArgv(
+				{
+					application: process.execPath,
+					args: [scriptPath, ...expected],
+					cwd: testDir,
+					timeoutMs: 5_000,
+					cols: 80,
+					rows: 24,
+				},
+				(error, chunk) => {
+					callbackError = error;
+					output += chunk;
+				},
+			);
+
+			expect(callbackError).toBeNull();
+			expect(result.exitCode).toBe(0);
+			expect(result.timedOut).toBeFalse();
+			expect(JSON.parse(output.trim())).toEqual(expected);
+		});
+
 		it("should time out detached background workloads without hanging", async () => {
 			if (process.platform === "win32" || !Bun.which("bash")) {
 				return;