diff --git a/client/src/api/client.ts b/client/src/api/client.ts
index 4f1598b..33ce717 100644
--- a/client/src/api/client.ts
+++ b/client/src/api/client.ts
@@ -36,7 +36,14 @@ class ApiClient {
 
     if (!response.ok) {
       const error = await response.json().catch(() => ({ message: 'Request failed' }));
-      throw new ApiError(error.message || `HTTP ${response.status}`, response.status, error);
+      let message = error.message || `HTTP ${response.status}`;
+      if (error.errors && typeof error.errors === 'object') {
+        const details = Object.entries(error.errors)
+          .map(([field, msgs]) => `${field}: ${Array.isArray(msgs) ? msgs.join(', ') : msgs}`)
+          .join('; ');
+        if (details) message = details;
+      }
+      throw new ApiError(message, response.status, error);
     }
 
     return response.json();
@@ -75,7 +82,14 @@ class ApiClient {
 
     if (!response.ok) {
       const error = await response.json().catch(() => ({ message: 'Upload failed' }));
-      throw new Error(error.message || `HTTP ${response.status}`);
+      let message = error.message || `HTTP ${response.status}`;
+      if (error.errors && typeof error.errors === 'object') {
+        const details = Object.entries(error.errors)
+          .map(([field, msgs]) => `${field}: ${Array.isArray(msgs) ? msgs.join(', ') : msgs}`)
+          .join('; ');
+        if (details) message = details;
+      }
+      throw new ApiError(message, response.status, error);
     }
 
     return response.json();