diff --git a/server.js b/server.js
index 475baa7..a618e4a 100644
--- a/server.js
+++ b/server.js
@@ -49,13 +49,23 @@ app.post('/api/chat', (req, res) => {
         res.write(`data: ${JSON.stringify({ text: chunk.toString() })}\n\n`);
     });
 
+    let stderrBuf = '';
     proc.stderr.on('data', (chunk) => {
-        console.error('[claude stderr]', chunk.toString().substring(0, 300));
+        const s = chunk.toString();
+        stderrBuf += s;
+        console.error('[claude stderr]', s.substring(0, 500));
     });
 
-    proc.on('close', (code) => {
+    proc.on('error', (err) => {
+        console.error('[spawn error]', err.message);
+        res.write(`data: ${JSON.stringify({ error: `spawn: ${err.message}` })}\n\n`);
+    });
+
+    proc.on('close', (code, signal) => {
+        console.log(`[claude close] code=${code} signal=${signal} stderr=${stderrBuf.substring(0,300)}`);
         if (code !== 0) {
-            res.write(`data: ${JSON.stringify({ error: `Ошибка (code ${code}). Проверь auth: claude --version` })}\n\n`);
+            const msg = stderrBuf.trim() || `code=${code} signal=${signal}`;
+            res.write(`data: ${JSON.stringify({ error: msg.substring(0, 500) })}\n\n`);
         }
         res.write('data: [DONE]\n\n');
         res.end();