diff --git a/controllers/RESTController.py b/controllers/RESTController.py
index 39ff5ef..7461304 100644
--- a/controllers/RESTController.py
+++ b/controllers/RESTController.py
@@ -464,25 +464,26 @@ class APIController:
         """
         return await self._make_request_async('PUT', f'customs/edocuments/{edocument_id}/', data=data)
 
-    async def get_cer(self, id: str) -> bytes:
-        """
-        Método para obtener un certificado específico desde la API (como binario).
-        Args:
-            id: UUID del certificado a consultar
-        Returns:
-            bytes: Contenido binario del certificado
-        """
-        return await self._make_request_async('GET', f'vucem/vucem/{id}/download_cer/', return_bytes=True)
-
     async def get_key(self, id: str) -> bytes:
-        """
-        Método para obtener una llave específica desde la API (como binario).
-        Args:
-            id: UUID de la llave a consultar
-        Returns:
-            bytes: Contenido binario de la llave
-        """
-        return await self._make_request_async('GET', f'vucem/vucem/{id}/download_key/', return_bytes=True)
+        result = await self._make_request_async('GET', f'vucem/vucem/{id}/download_key/', return_bytes=True)
+        
+        if result is None:
+            logger.info(f"get_key retornó None")
+        else:
+            logger.info(f"get_key retornó {len(result)} bytes")
+        
+        return result
+
+
+    async def get_cer(self, id: str) -> bytes:
+        result = await self._make_request_async('GET', f'vucem/vucem/{id}/download_cer/', return_bytes=True)
+        
+        if result is None:
+            logger.info(f"get_cer retornó None")
+        else:
+            logger.info(f"get_cer retornó {len(result)} bytes")
+        
+        return result
 
     async def _make_request_async(self, method: str, endpoint: str, data=None, return_bytes: bool = False):
         """
diff --git a/utils/minio_client.py b/utils/minio_client.py
new file mode 100644
index 0000000..1c47db4
--- /dev/null
+++ b/utils/minio_client.py
@@ -0,0 +1,85 @@
+# microservice/utils/minio_client.py
+import os
+from minio import Minio
+from minio.error import S3Error
+from datetime import timedelta
+from typing import Optional, BinaryIO
+import logging
+
+logger = logging.getLogger(__name__)
+
+
+class MinIOClient:
+    """Cliente MinIO para FastAPI"""
+    
+    def __init__(self):
+        self.client = None
+        self.bucket_name = None
+        self._initialize()
+    
+    def _initialize(self):
+        """Inicializa el cliente MinIO"""
+        endpoint = os.environ.get('MINIO_ENDPOINT', 'minio:9000')
+        access_key = os.environ.get('MINIO_ACCESS_KEY')
+        secret_key = os.environ.get('MINIO_SECRET_KEY')
+        secure = os.environ.get('MINIO_SECURE', 'false').lower() == 'true'
+        self.bucket_name = os.environ.get('MINIO_BUCKET_NAME', 'efc-microservice-dev')
+        
+        self.client = Minio(
+            endpoint=endpoint,
+            access_key=access_key,
+            secret_key=secret_key,
+            secure=secure
+        )
+        
+        # Asegurar bucket
+        if not self.client.bucket_exists(self.bucket_name):
+            self.client.make_bucket(self.bucket_name)
+            logger.info(f"Bucket '{self.bucket_name}' creado")
+    
+    def upload_file(
+        self,
+        object_name: str,
+        file_path: str = None,
+        file_data: bytes = None,
+        content_type: str = None
+    ) -> bool:
+        """Sube archivo a MinIO (síncrono para Celery)"""
+        try:
+            if file_path:
+                self.client.fput_object(
+                    self.bucket_name,
+                    object_name,
+                    file_path,
+                    content_type=content_type
+                )
+            elif file_data:
+                import io
+                data_stream = io.BytesIO(file_data)
+                self.client.put_object(
+                    self.bucket_name,
+                    object_name,
+                    data_stream,
+                    len(file_data),
+                    content_type=content_type
+                )
+            return True
+        except Exception as e:
+            logger.error(f"Error subiendo archivo: {e}")
+            return False
+    
+    def get_presigned_url(self, object_name: str, expires: int = 3600) -> Optional[str]:
+        """Genera URL firmada"""
+        try:
+            return self.client.presigned_get_object(
+                self.bucket_name,
+                object_name,
+                expires=timedelta(seconds=expires)
+            )
+        except Exception as e:
+            logger.error(f"Error generando URL: {e}")
+            return None
+
+
+# Singleton
+minio_client = MinIOClient()
\ No newline at end of file