diff --git a/haystack_experimental/util/openapi.py b/haystack_experimental/util/openapi.py
index fef95de7..94b7614b 100644
--- a/haystack_experimental/util/openapi.py
+++ b/haystack_experimental/util/openapi.py
@@ -18,9 +18,7 @@
 from haystack_experimental.util.schema_conversion import anthropic_converter, cohere_converter, openai_converter
 
 VALID_HTTP_METHODS = ["get", "put", "post", "delete", "options", "head", "patch", "trace"]
-
 MIN_REQUIRED_OPENAPI_SPEC_VERSION = 3
-
 logger = logging.getLogger(__name__)
 
 
@@ -28,7 +26,6 @@ class AuthenticationStrategy:
     """
     Represents an authentication strategy that can be applied to an HTTP request.
     """
-
     def apply_auth(self, security_scheme: Dict[str, Any], request: Dict[str, Any]):
         """
         Apply the authentication strategy to the given request.
@@ -41,7 +38,6 @@ def apply_auth(self, security_scheme: Dict[str, Any], request: Dict[str, Any]):
 @dataclass
 class ApiKeyAuthentication(AuthenticationStrategy):
     """API key authentication strategy."""
-
     api_key: Optional[str] = None
 
     def apply_auth(self, security_scheme: Dict[str, Any], request: Dict[str, Any]):
@@ -67,7 +63,6 @@ def apply_auth(self, security_scheme: Dict[str, Any], request: Dict[str, Any]):
 @dataclass
 class HTTPAuthentication(AuthenticationStrategy):
     """HTTP authentication strategy."""
-
     username: Optional[str] = None
     password: Optional[str] = None
     token: Optional[str] = None
@@ -235,8 +230,7 @@ def get_security_schemes(self) -> Dict[str, Dict[str, Any]]:
         """
         Get the security schemes from the OpenAPI specification.
         """
-        components = self.spec_dict.get("components", {})
-        return components.get("securitySchemes", {})
+        return self.spec_dict.get("components", {}).get("securitySchemes", {})
 
 
 class ClientConfiguration:
@@ -391,27 +385,7 @@ def send_request(request: Dict[str, Any]) -> Dict[str, Any]:
         return send_request
 
     def _build_request(self, operation: Operation, **kwargs) -> Any:
-        request = {
-            "url": self._build_url(operation, **kwargs),
-            "method": operation.method.lower(),
-            "headers": self._build_headers(operation, **kwargs),
-            "params": self._build_query_params(operation, **kwargs),
-            "json": self._build_request_body(operation, **kwargs),
-        }
-        return request
-
-    def _build_headers(self, operation: Operation, **kwargs) -> Dict[str, str]:
-        headers = {}
-        for parameter in operation.get_parameters("header"):
-            param_value = kwargs.get(parameter["name"], None)
-            if param_value:
-                headers[parameter["name"]] = str(param_value)
-            elif parameter.get("required", False):
-                raise ValueError(f"Missing required header parameter: {parameter['name']}")
-        return headers
-
-    def _build_url(self, operation: Operation, **kwargs) -> str:
-        server_url = operation.get_server()
+        # url
         path = operation.path
         for parameter in operation.get_parameters("path"):
             param_value = kwargs.get(parameter["name"], None)
@@ -419,9 +393,18 @@ def _build_url(self, operation: Operation, **kwargs) -> str:
                 path = path.replace(f"{{{parameter['name']}}}", str(param_value))
             elif parameter.get("required", False):
                 raise ValueError(f"Missing required path parameter: {parameter['name']}")
-        return server_url + path
-
-    def _build_query_params(self, operation: Operation, **kwargs) -> Dict[str, Any]:
+        url = operation.get_server() + path
+        # method
+        method = operation.method.lower()
+        # headers
+        headers = {}
+        for parameter in operation.get_parameters("header"):
+            param_value = kwargs.get(parameter["name"], None)
+            if param_value:
+                headers[parameter["name"]] = str(param_value)
+            elif parameter.get("required", False):
+                raise ValueError(f"Missing required header parameter: {parameter['name']}")
+        # query params
         query_params = {}
         for parameter in operation.get_parameters("query"):
             param_value = kwargs.get(parameter["name"], None)
@@ -429,16 +412,16 @@ def _build_query_params(self, operation: Operation, **kwargs) -> Dict[str, Any]:
                 query_params[parameter["name"]] = param_value
             elif parameter.get("required", False):
                 raise ValueError(f"Missing required query parameter: {parameter['name']}")
-        return query_params
 
-    def _build_request_body(self, operation: Operation, **kwargs) -> Any:
+        json_payload = None
         request_body = operation.request_body
         if request_body:
             content = request_body.get("content", {})
             if "application/json" in content:
-                return {**kwargs}
-            raise NotImplementedError("Request body content type not supported")
-        return None
+                json_payload = {**kwargs}
+            else:
+                raise NotImplementedError("Request body content type not supported")
+        return {"url": url, "method": method, "headers": headers, "params": query_params, "json": json_payload}
 
     def _apply_authentication(self, auth: AuthenticationStrategy, operation: Operation, request: Dict[str, Any]):
         auth_config = auth or AuthenticationStrategy()