Strip PHPStan agent-detector env vars when spawning PHPStan

server/src/lib/process.ts

@@ -13,6 +13,7 @@ import type { Disposable } from 'vscode';
 import type { Readable } from 'stream';
 import type { LogPrefix } from './log';
 import { log } from './log';
+import { stripPhpstanAgentDetectorEnvVars } from '../../../shared/phpstanSpawnEnv';
 
 export class Process implements AsyncDisposable {
 	private readonly _children: Set<number> = new Set();
@@ -178,6 +179,10 @@ export class Process implements AsyncDisposable {
 			'Spawning PHPStan, command: ',
 			[binStr, ...args.map((a) => `"${a}"`)].join(' ')
 		);
+		const spawnEnv = stripPhpstanAgentDetectorEnvVars({
+			...process.env,
+			...options.env,
+		});
 		const proc = await (async () => {
 			if (process.platform === 'win32') {
 				const codePage = await this._getCodePage();
@@ -194,6 +199,7 @@ export class Process implements AsyncDisposable {
 						{
 							cwd: options.cwd,
 							encoding: 'utf-8',
+							env: spawnEnv,
 						}
 					);
 				}
@@ -203,6 +209,7 @@ export class Process implements AsyncDisposable {
 			});
 			return spawn(binStr, args, {
 				...options,
+				env: spawnEnv,
 				stdio: ['pipe', 'pipe', 'overlapped'],
 			});
 		})();

server/src/start/getVersion.ts

@@ -1,3 +1,4 @@
+import { stripPhpstanAgentDetectorEnvVars } from '../../../shared/phpstanSpawnEnv';
 import { ConfigurationManager } from '../lib/checkConfigManager';
 import { SPAWN_ARGS } from '../../../shared/constants';
 import type { ClassConfig } from '../lib/types';
@@ -18,10 +19,15 @@ export async function getVersion(
 	// Test if we can get the PHPStan version
 	const cwd = await ConfigurationManager.getCwd(classConfig, true);
 	const workspaceRoot = (await classConfig.workspaceFolders.get())?.default;
+	const workspaceRootPath =
+		workspaceRoot &&
+		typeof (workspaceRoot as { fsPath?: unknown }).fsPath === 'string'
+			? (workspaceRoot as { fsPath: string }).fsPath
+			: undefined;
 	const binConfigResult = await ConfigurationManager.getBinComand(
 		classConfig,
 		cwd ?? undefined,
-		workspaceRoot?.fsPath
+		workspaceRootPath
 	);
 	if (!binConfigResult.success) {
 		return {
@@ -34,6 +40,7 @@ export async function getVersion(
 		const binArgs = binConfigResult.getBinCommand(['--version']);
 		const proc = spawn(binArgs[0], binArgs.slice(1), {
 			...SPAWN_ARGS,
+			env: stripPhpstanAgentDetectorEnvVars({ ...process.env }),
 		});
 
 		let data = '';

shared/phpstanSpawnEnv.ts

@@ -0,0 +1,28 @@
+/**
+ * Environment variable names PHPStan uses to detect AI coding agents
+ * (see PHPStan AgentDetector). When the extension runs inside an agent-capable
+ * editor, these may be set and skew analysis; they are cleared for child processes.
+ */
+export const PHPSTAN_AGENT_DETECTOR_ENV_VARS = [
+	'AI_AGENT',
+	'CURSOR_TRACE_ID',
+	'CURSOR_AGENT',
+	'GEMINI_CLI',
+	'CODEX_SANDBOX',
+	'AUGMENT_AGENT',
+	'OPENCODE_CLIENT',
+	'OPENCODE',
+	'CLAUDECODE',
+	'CLAUDE_CODE',
+	'REPL_ID',
+] as const;
+
+export function stripPhpstanAgentDetectorEnvVars<T extends NodeJS.ProcessEnv>(
+	env: T
+): T {
+	const out = { ...env };
+	for (const key of PHPSTAN_AGENT_DETECTOR_ENV_VARS) {
+		delete out[key];
+	}
+	return out;
+}