--- a/src/HTTPHandler.h	Tue Mar 22 01:19:21 2022 +0100
+++ b/src/HTTPHandler.h	Tue Mar 22 22:00:59 2022 +0100
@@ -21,6 +21,7 @@
 #include <vector>
 #include <codecvt>
 #include <regex>
+#include <locale>
 #include <stdexcept>
 
 #include <curl/curl.h>
@@ -47,9 +48,13 @@
 
 	class HeaderDefinition {
 	public:
-		// TODO: filters/patterns/condition
+		std::wregex url = std::wregex(L".*");
 		relpipe::common::type::StringX name;
 		relpipe::common::type::StringX value;
+
+		bool matches(const relpipe::common::type::StringX& url) const {
+			return std::regex_match(url, this->url);
+		}
 	};
 
 	std::wstring_convert<codecvt_utf8<wchar_t>> convertor; // TODO: support also other encodings.
@@ -150,6 +155,7 @@
 
 		if (attributeName == L"name") requestHeader.name = value;
 		else if (attributeName == L"value") requestHeader.value = value;
+		else if (attributeName == L"url") requestHeader.url = std::wregex(value.size() ? value : L".*"); // TODO: null instead of empty value (when supported)
 		else throw std::invalid_argument("Unsupported attribute in the header relation: " + convertor.to_bytes(attributeName + L" = " + value));
 
 		currentAttributeIndex++;
@@ -176,7 +182,7 @@
 			currentAttributeIndex = 0;
 			std::shared_ptr<HTTPClient> http(HTTPClient::open());
 
-			for (const HeaderDefinition& h : requestHeaders) appendRequestHeader(h.name, h.value);
+			for (const HeaderDefinition& h : requestHeaders) if (h.matches(convertor.from_bytes(request.url))) appendRequestHeader(h.name, h.value);
 
 			std::string body;
 			relpipe::common::type::Integer responseCode = -1;