Refactor agent path handling for Windows in Cursor Agent plugin

- Introduced a default agent path function for Windows to streamline the agent binary path configuration.
- Updated the README to clarify the default agent binary path on Windows.
- Enhanced the `AcpClient` and `CursorAgentSettingTab` to utilize the new path handling logic, ensuring compatibility with Windows shell requirements.

Author: jspada200

README.md

@@ -98,6 +98,7 @@ npx tsc -noEmit -skipLibCheck
 
 ## Troubleshooting
 
+- **Windows — default path and `agent.cmd`** — If you leave **Agent binary path** empty, the plugin uses `%LOCALAPPDATA%\cursor-agent\agent.cmd` (the usual Cursor CLI shim on Windows), not `~/.local/bin/agent`. If you set the path yourself, use the full path to `agent.cmd` (or another real executable). On recent Node.js versions, `.cmd` / `.bat` / `.ps1` shims must be launched with a shell; the plugin does that automatically for those extensions.
 - **`agent: command not found` in Terminal** — The installer often puts the binary at `~/.local/bin/agent`, which may not be on your shell `PATH`. Either add that directory to `PATH` in `~/.zshrc`, or log in with the full path:  
   `~/.local/bin/agent login`  
   In the plugin, set **Agent binary path** to that full path (the default is already `~/.local/bin/agent` expanded to an absolute path, which does **not** rely on `PATH`).

package-lock.json

@@ -1,6 +1,7 @@
 import { spawn, type ChildProcessWithoutNullStreams } from "child_process";
 import * as fs from "fs";
 import * as readline from "readline";
+import { agentPathRequiresWindowsShell } from "../agentModels";
 import { augmentPathEnv } from "../util/agentEnv";
 import type { AgentFileLogger } from "../logging/agentFileLog";
 import type { JsonRpcRequest, JsonRpcResponse, SessionPromptPart } from "./types";
@@ -106,6 +107,7 @@ export class AcpClient {
 		this.proc = spawn(opt.agentPath, args, {
 			env: mergedEnv,
 			stdio: ["pipe", "pipe", "pipe"],
+			...(agentPathRequiresWindowsShell(opt.agentPath) ? { shell: true } : {}),
 		});
 
 		this.proc.stderr?.on("data", (chunk: Buffer) => {

src/acp/client.ts

@@ -5,14 +5,35 @@ import * as path from "path";
 import type { AgentFileLogger } from "./logging/agentFileLog";
 import { augmentPathEnv } from "./util/agentEnv";
 
+/** Default install layout for the Cursor Agent CLI on Windows (see `%LOCALAPPDATA%\\cursor-agent\\`). */
+function defaultAgentPathWhenUnset(): string {
+	if (process.platform === "win32") {
+		const localAppData =
+			process.env.LOCALAPPDATA ?? path.join(os.homedir(), "AppData", "Local");
+		return path.join(localAppData, "cursor-agent", "agent.cmd");
+	}
+	return path.join(os.homedir(), ".local", "bin", "agent");
+}
+
 export function expandAgentPath(configured: string): string {
 	const p = configured.trim();
 	if (p) return p.replace(/^~(?=$|[\\/])/, os.homedir());
-	return path.join(os.homedir(), ".local", "bin", "agent");
+	return defaultAgentPathWhenUnset();
+}
+
+/**
+ * Node 22+ on Windows: `spawn` / `execFile` on `.cmd`, `.bat`, or `.ps1` without `shell: true`
+ * fails with `EINVAL` (security-related behavior). Cursor’s Windows shim is usually `agent.cmd`.
+ */
+export function agentPathRequiresWindowsShell(agentPath: string): boolean {
+	if (process.platform !== "win32") return false;
+	return /\.(cmd|bat|ps1)$/i.test(agentPath.trim());
 }
 
 export function agentBinaryExists(agentPath: string): boolean {
 	try {
+		if (!fs.existsSync(agentPath)) return false;
+		if (process.platform === "win32") return true;
 		fs.accessSync(agentPath, fs.constants.X_OK);
 		return true;
 	} catch {
@@ -76,6 +97,7 @@ export async function fetchAvailableModels(
 		timeout: 45000,
 		maxBuffer: 4 * 1024 * 1024,
 		env,
+		...(agentPathRequiresWindowsShell(agentPath) ? { shell: true as const } : {}),
 	};
 
 	const run = (args: string[]) =>

src/agentModels.ts

@@ -22,7 +22,11 @@ export class CursorAgentSettingTab extends PluginSettingTab {
 
 		new Setting(containerEl)
 			.setName("Agent binary path")
-			.setDesc("Leave empty to use ~/.local/bin/agent.")
+			.setDesc(
+				process.platform === "win32"
+					? "Leave empty to use %LOCALAPPDATA%\\cursor-agent\\agent.cmd (Cursor’s Windows shim)."
+					: "Leave empty to use ~/.local/bin/agent."
+			)
 			.addText((t) =>
 				t
 					.setPlaceholder("~/.local/bin/agent")