diff --git a/lib/pi-provider.js b/lib/pi-provider.js
index 210291d..c4efd81 100644
--- a/lib/pi-provider.js
+++ b/lib/pi-provider.js
@@ -14,7 +14,18 @@ let operationId = 0;
 
 function resolvePiModelsConfigFile(env = process.env) {
   const configured = String(env.PI_MODELS_CONFIG || '').trim();
-  return configured ? path.resolve(configured) : path.join(os.homedir(), '.pi', 'agent', 'models.json');
+  if (configured) return path.resolve(configured);
+
+  const candidates = [];
+  if (process.getuid && process.getuid() === 0) {
+    candidates.push('/home/sts/.pi/agent/models.json');
+  }
+  candidates.push(path.join(os.homedir(), '.pi', 'agent', 'models.json'));
+  candidates.push('/root/.pi/agent/models.json');
+
+  return candidates.find((candidate) => {
+    try { return fs.existsSync(path.dirname(candidate)) || fs.existsSync(candidate); } catch (_) { return false; }
+  }) || candidates[0];
 }
 
 function normalizeBaseUrl(baseUrl) {
@@ -75,16 +86,41 @@ function readConfig(configFile) {
 
 function writeConfigAtomic(configFile, config) {
   const dir = path.dirname(configFile);
+  const owner = resolveOwnerForPath(dir);
   fs.mkdirSync(dir, { recursive: true });
+  chownIfPossible(dir, owner);
   const tempFile = path.join(dir, `.${path.basename(configFile)}.${process.pid}.${Date.now()}.tmp`);
   try {
     fs.writeFileSync(tempFile, `${JSON.stringify(config, null, 2)}\n`, { encoding: 'utf8', mode: 0o600 });
     fs.renameSync(tempFile, configFile);
+    chownIfPossible(configFile, owner);
   } finally {
     try { fs.unlinkSync(tempFile); } catch (_) {}
   }
 }
 
+function resolveOwnerForPath(targetPath) {
+  let current = targetPath;
+  while (current && current !== path.dirname(current)) {
+    try {
+      const stat = fs.statSync(current);
+      return { uid: stat.uid, gid: stat.gid };
+    } catch (_) {
+      current = path.dirname(current);
+    }
+  }
+  return null;
+}
+
+function chownIfPossible(targetPath, owner) {
+  if (!owner || !(process.getuid && process.getuid() === 0)) return;
+  try {
+    fs.chownSync(targetPath, owner.uid, owner.gid);
+  } catch (error) {
+    log.warn('pi-provider', `chown failed for ${targetPath}: ${error.message}`);
+  }
+}
+
 function sameModels(left, right) {
   const ids = (models) => (models || []).map((model) => model.id).sort();
   return JSON.stringify(ids(left)) === JSON.stringify(ids(right));