diff --git a/docs/user/netservices/HttpRequest.dox b/docs/user/netservices/HttpRequest.dox
index d8d32d7808..575ba74b7d 100644
--- a/docs/user/netservices/HttpRequest.dox
+++ b/docs/user/netservices/HttpRequest.dox
@@ -329,6 +329,12 @@ namespace Network {
 			<td> The URL. This must start with http or https. </td>
 			<td> Defaults to an empty \ref BUrl </td>
 		</tr>
+		<tr>
+			<td> \ref Fields() </td>
+			<td> \ref SetFields() </td>
+			<td> Additional fields set in the request header. </td>
+			<td> Defaults with no additional fields </td>
+		</tr>
 		<tr>
 			<td> \ref Method() </td>
 			<td> \ref SetMethod() </td>
@@ -472,6 +478,16 @@ namespace Network {
 //! @{
 
 
+/*!
+	\fn const BHttpFields& BHttpRequest::Fields() const noexcept
+	\brief Get the additional header fields set for the request.
+
+	The returned header fields may be empty if no additional header fields were set.
+
+	\since Haiku R1
+*/
+
+
 /*!
 	\fn const BHttpMethod& BHttpRequest::Method() const noexcept
 	\brief Get the current method for the request.
@@ -515,6 +531,26 @@ namespace Network {
 //! @{
 
 
+/*!
+	\fn void BHttpRequest::SetFields(const BHttpFields &fields)
+	\brief Set additional header \a fields for this request.
+
+	There are a few reserved fields, which cannot be set as optional fields. These currently are:
+	* \c Host
+	* \c Accept
+	* \c Accept-Encoding
+	* \c Connection
+
+	\param fields Additional fields for the header of the request.
+
+	\exception std::bad_alloc This exception may be raised if it is impossible to allocate memory.
+	\exception BHttpFields::InvalidData This exception is raised when the \a fields contain
+		reserved fields.
+
+	\since Haiku R1
+*/
+
+
 /*!
 	\fn void BHttpRequest::SetMethod(const BHttpMethod &method)
 	\brief Set the \a method for this request.
diff --git a/headers/private/netservices2/HttpRequest.h b/headers/private/netservices2/HttpRequest.h
index b9dcac4fe2..fe1c905f00 100644
--- a/headers/private/netservices2/HttpRequest.h
+++ b/headers/private/netservices2/HttpRequest.h
@@ -23,6 +23,9 @@ namespace BPrivate {
 namespace Network {
 
 
+class BHttpFields;
+
+
 class BHttpMethod {
 public:
 	// Constants for default methods in RFC 7230 section 4.2
@@ -92,11 +95,13 @@ public:
 
 	// Access
 			bool					IsEmpty() const noexcept;
+	const	BHttpFields&			Fields() const noexcept;
 	const	BHttpMethod&			Method() const noexcept;
 	const	BHttpRedirectOptions&	Redirect() const noexcept;
 	const	BUrl&					Url() const noexcept;
 
 	// Named Setters
+			void					SetFields(const BHttpFields& fields);
 			void					SetMethod(const BHttpMethod& method);
 			void					SetRedirect(const BHttpRedirectOptions& redirectOptions);
 			void					SetUrl(const BUrl& url);
diff --git a/src/kits/network/libnetservices2/HttpRequest.cpp b/src/kits/network/libnetservices2/HttpRequest.cpp
index 4b11831b09..07e8fb6e9b 100644
--- a/src/kits/network/libnetservices2/HttpRequest.cpp
+++ b/src/kits/network/libnetservices2/HttpRequest.cpp
@@ -157,12 +157,13 @@ BHttpMethod::Method() const noexcept
 static const BUrl kDefaultUrl = BUrl();
 static const BHttpMethod kDefaultMethod = BHttpMethod::Get;
 static const BHttpRedirectOptions kDefaultRedirectOptions = BHttpRedirectOptions();
-
+static const BHttpFields kDefaultOptionalFields = BHttpFields();
 
 struct BHttpRequest::Data {
 	BUrl					url = kDefaultUrl;
 	BHttpMethod				method	= kDefaultMethod;
 	BHttpRedirectOptions	redirectOptions;
+	BHttpFields				optionalFields;
 };
 
 
@@ -200,6 +201,15 @@ BHttpRequest::IsEmpty() const noexcept
 }
 
 
+const BHttpFields&
+BHttpRequest::Fields() const noexcept
+{
+	if (!fData)
+		return kDefaultOptionalFields;
+	return fData->optionalFields;
+}
+
+
 const BHttpMethod&
 BHttpRequest::Method() const noexcept
 {
@@ -227,6 +237,32 @@ BHttpRequest::Url() const noexcept
 }
 
 
+static constexpr std::array<std::string_view, 4> fReservedOptionalFieldNames = {
+	"Host"sv,
+	"Accept"sv,
+	"Accept-Encoding"sv,
+	"Connection"sv
+};
+
+
+void
+BHttpRequest::SetFields(const BHttpFields& fields)
+{
+	if (!fData)
+		fData = std::make_unique<Data>();
+
+	for (auto& field: fields) {
+		if (std::find(fReservedOptionalFieldNames.begin(), fReservedOptionalFieldNames.end(),
+			field.Name()) != fReservedOptionalFieldNames.end())
+		{
+			std::string_view fieldName = field.Name();
+			throw BHttpFields::InvalidInput(__PRETTY_FUNCTION__, BString(fieldName.data(), fieldName.size()));
+		}
+	}
+	fData->optionalFields = fields;
+}
+
+
 void
 BHttpRequest::SetMethod(const BHttpMethod& method)
 {
@@ -326,6 +362,11 @@ BHttpRequest::SerializeHeaderTo(BDataIO* target) const
 		bytesWritten += _write_to_dataio(target, "\r\n"sv);
 	}
 
+	for (const auto& field: fData->optionalFields) {
+		bytesWritten += _write_to_dataio(target, field.RawField());
+		bytesWritten += _write_to_dataio(target, "\r\n"sv);
+	}
+
 	bytesWritten += _write_to_dataio(target, "\r\n"sv);
 	return bytesWritten;
 }
diff --git a/src/tests/kits/net/netservices2/HttpProtocolTest.cpp b/src/tests/kits/net/netservices2/HttpProtocolTest.cpp
index 24412b7845..533c190b56 100644
--- a/src/tests/kits/net/netservices2/HttpProtocolTest.cpp
+++ b/src/tests/kits/net/netservices2/HttpProtocolTest.cpp
@@ -276,12 +276,13 @@ HttpProtocolTest::HttpMethodTest()
 }
 
 
-constexpr std::string_view kHaikuGetRequestText =
+constexpr std::string_view kExpectedRequestText =
 	"GET / HTTP/1.1\r\n"
 	"Host: www.haiku-os.org\r\n"
 	"Accept: *\r\n"
 	"Accept-Encoding: gzip\r\n"
-	"Connection: close\r\n\r\n";
+	"Connection: close\r\n"
+	"Api-Key: 01234567890abcdef\r\n\r\n";
 
 
 void
@@ -294,9 +295,22 @@ HttpProtocolTest::HttpRequestTest()
 	request.SetUrl(url);
 	CPPUNIT_ASSERT(request.Url() == url);
 
+	// Add Invalid HTTP fields (should throw)
+	try {
+		BHttpFields invalidField = {{"Host"sv, "haiku-os.org"sv}};
+		request.SetFields(invalidField);
+		CPPUNIT_FAIL("Should not be able to add the invalid \"Host\" field to a request");
+	} catch (BHttpFields::InvalidInput& e) {
+		// Correct; do nothing
+	}
+
+	// Add valid HTTP field
+	BHttpFields validField = {{"Api-Key"sv, "01234567890abcdef"}};
+	request.SetFields(validField);
+
 	// Validate header serialization
 	BString header = request.HeaderToString();
-	CPPUNIT_ASSERT(header.Compare(kHaikuGetRequestText.data(), kHaikuGetRequestText.size()) == 0);
+	CPPUNIT_ASSERT(header.Compare(kExpectedRequestText.data(), kExpectedRequestText.size()) == 0);
 }
 
 
@@ -326,6 +340,14 @@ private:
 };
 
 
+constexpr std::string_view kExpectedStreamText =
+	"GET / HTTP/1.1\r\n"
+	"Host: www.haiku-os.org\r\n"
+	"Accept: *\r\n"
+	"Accept-Encoding: gzip\r\n"
+	"Connection: close\r\n\r\n";
+
+
 void
 HttpProtocolTest::HttpRequestStreamTest()
 {
@@ -336,11 +358,11 @@ HttpProtocolTest::HttpRequestStreamTest()
 
 	// Test streaming the request
 	BHttpRequestStream requestStream(request);
-	RequestStreamTestIO testIO(kHaikuGetRequestText.data());
+	RequestStreamTestIO testIO(kExpectedStreamText.data());
 	bool finished = false;
 	ssize_t expectedBytesWritten = 8;
 	ssize_t expectedTotalBytesWritten = 8;
-	const ssize_t expectedTotalSize = kHaikuGetRequestText.size();
+	const ssize_t expectedTotalSize = kExpectedStreamText.size();
 	if (expectedTotalSize < 8) {
 		expectedBytesWritten = expectedTotalSize;
 		expectedTotalBytesWritten = expectedTotalSize;