diff --git a/deps/ox/src/ox/mc/read.hpp b/deps/ox/src/ox/mc/read.hpp
index a8ff438c..2338b6f2 100644
--- a/deps/ox/src/ox/mc/read.hpp
+++ b/deps/ox/src/ox/mc/read.hpp
@@ -15,6 +15,7 @@
 #include <ox/model/types.hpp>
 #include <ox/std/buffer.hpp>
 #include <ox/std/byteswap.hpp>
+#include <ox/std/optional.hpp>
 #include <ox/std/string.hpp>
 #include <ox/std/trace.hpp>
 #include <ox/std/vector.hpp>
@@ -33,15 +34,13 @@ class MetalClawReaderTemplate: public ModelHandlerBase<MetalClawReaderTemplate<R
 		FieldBitmapReader<Reader> m_fieldPresence;
 		std::size_t m_fields = 0;
 		std::size_t m_field = 0;
-		int m_unionIdx = -1;
+		ox::Optional<int> m_unionIdx;
 		Reader &m_reader;
-		MetalClawReaderTemplate<Reader> *m_parent = nullptr;
 
 	public:
 		explicit constexpr MetalClawReaderTemplate(
 				Reader &reader,
-				int unionIdx = -1,
-				MetalClawReaderTemplate<Reader> *parent = nullptr) noexcept;
+				ox::Optional<int> const&unionIdx = {}) noexcept;
 
 		constexpr ~MetalClawReaderTemplate() noexcept;
 
@@ -108,7 +107,7 @@ class MetalClawReaderTemplate: public ModelHandlerBase<MetalClawReaderTemplate<R
 		 * Returns a MetalClawReader to parse a child object.
 		 */
 		[[nodiscard]]
-		constexpr MetalClawReaderTemplate<Reader> child(const char *name, int unionIdx = -1) noexcept;
+		constexpr MetalClawReaderTemplate<Reader> child(const char *name, ox::Optional<int> unionIdx = {}) noexcept;
 
 		/**
 		 * Indicates whether or not the next field to be read is present.
@@ -136,12 +135,10 @@ class MetalClawReaderTemplate: public ModelHandlerBase<MetalClawReaderTemplate<R
 template<Reader_c Reader>
 constexpr MetalClawReaderTemplate<Reader>::MetalClawReaderTemplate(
 		Reader &reader,
-		int unionIdx,
-		MetalClawReaderTemplate *parent) noexcept:
+		ox::Optional<int> const&unionIdx) noexcept:
 		m_fieldPresence(reader),
 		m_unionIdx(unionIdx),
-		m_reader(reader),
-		m_parent(parent) {
+		m_reader(reader) {
 }
 
 template<Reader_c Reader>
@@ -194,7 +191,7 @@ constexpr Error MetalClawReaderTemplate<Reader>::field(const char*, uint64_t *va
 
 template<Reader_c Reader>
 constexpr Error MetalClawReaderTemplate<Reader>::field(const char*, bool *val) noexcept {
-	if (m_unionIdx == -1 || static_cast<std::size_t>(m_unionIdx) == m_field) {
+	if (!m_unionIdx.has_value() || static_cast<std::size_t>(*m_unionIdx) == m_field) {
 		auto const result = m_fieldPresence.get(static_cast<std::size_t>(m_field));
 		*val = result.value;
 		oxReturnError(result);
@@ -206,7 +203,7 @@ constexpr Error MetalClawReaderTemplate<Reader>::field(const char*, bool *val) n
 // array handler
 template<Reader_c Reader>
 constexpr Error MetalClawReaderTemplate<Reader>::field(const char *name, auto *val, std::size_t valLen) noexcept {
-	if (m_unionIdx == -1 || static_cast<std::size_t>(m_unionIdx) == m_field) {
+	if (!m_unionIdx.has_value() || static_cast<std::size_t>(*m_unionIdx) == m_field) {
 		if (m_fieldPresence.get(static_cast<std::size_t>(m_field))) {
 			// read the length
 			std::size_t bytesRead = 0;
@@ -232,7 +229,7 @@ constexpr Error MetalClawReaderTemplate<Reader>::field(const char *name, auto *v
 template<Reader_c Reader>
 template<typename T>
 constexpr Error MetalClawReaderTemplate<Reader>::field(const char*, HashMap<String, T> *val) noexcept {
-	if (m_unionIdx == -1 || static_cast<std::size_t>(m_unionIdx) == m_field) {
+	if (!m_unionIdx.has_value() || static_cast<std::size_t>(*m_unionIdx) == m_field) {
 		if (m_fieldPresence.get(static_cast<std::size_t>(m_field))) {
 			// read the length
 			oxRequire(g, m_reader.tellg());
@@ -264,7 +261,7 @@ template<Reader_c Reader>
 template<typename T>
 constexpr Error MetalClawReaderTemplate<Reader>::field(const char *name, T *val) noexcept {
 	if constexpr(isVector_v<T>) {
-		if (m_unionIdx == -1 || static_cast<std::size_t>(m_unionIdx) == m_field) {
+		if (!m_unionIdx.has_value() || static_cast<std::size_t>(*m_unionIdx) == m_field) {
 			// set size of val if the field is present, don't worry about it if not
 			if (m_fieldPresence.get(static_cast<std::size_t>(m_field))) {
 				oxRequire(len, arrayLength(name, false));
@@ -276,7 +273,7 @@ constexpr Error MetalClawReaderTemplate<Reader>::field(const char *name, T *val)
 		++m_field;
 		return {};
 	} else if constexpr(isArray_v<T>) {
-		if (m_unionIdx == -1 || static_cast<std::size_t>(m_unionIdx) == m_field) {
+		if (!m_unionIdx.has_value() || static_cast<std::size_t>(*m_unionIdx) == m_field) {
 			// set size of val if the field is present, don't worry about it if not
 			if (m_fieldPresence.get(static_cast<std::size_t>(m_field))) {
 				oxRequire(len, arrayLength(name, false));
@@ -289,7 +286,7 @@ constexpr Error MetalClawReaderTemplate<Reader>::field(const char *name, T *val)
 		++m_field;
 		return {};
 	} else {
-		if ((m_unionIdx == -1 || static_cast<std::size_t>(m_unionIdx) == m_field) && val) {
+		if ((!m_unionIdx.has_value() || static_cast<std::size_t>(*m_unionIdx) == m_field) && val) {
 			if (m_fieldPresence.get(static_cast<std::size_t>(m_field))) {
 				auto reader = child("");
 				oxReturnError(model(reader.interface(), val));
@@ -303,9 +300,9 @@ constexpr Error MetalClawReaderTemplate<Reader>::field(const char *name, T *val)
 template<Reader_c Reader>
 template<typename U, bool force>
 constexpr Error MetalClawReaderTemplate<Reader>::field(const char*, UnionView<U, force> val) noexcept {
-	if ((m_unionIdx == -1 || static_cast<std::size_t>(m_unionIdx) == m_field) && val.get()) {
+	if ((!m_unionIdx.has_value() || static_cast<std::size_t>(*m_unionIdx) == m_field) && val.get()) {
 		if (m_fieldPresence.get(static_cast<std::size_t>(m_field))) {
-			auto reader = child("", val.idx());
+			auto reader = child("", ox::Optional<int>(ox::in_place_t{}, val.idx()));
 			oxReturnError(model(reader.interface(), val.get()));
 		}
 	}
@@ -316,7 +313,7 @@ constexpr Error MetalClawReaderTemplate<Reader>::field(const char*, UnionView<U,
 template<Reader_c Reader>
 template<std::size_t SmallStringSize>
 constexpr Error MetalClawReaderTemplate<Reader>::field(const char*, BasicString<SmallStringSize> *val) noexcept {
-	if (m_unionIdx == -1 || static_cast<std::size_t>(m_unionIdx) == m_field) {
+	if (!m_unionIdx.has_value() || static_cast<std::size_t>(*m_unionIdx) == m_field) {
 		if (m_fieldPresence.get(static_cast<std::size_t>(m_field))) {
 			// read the length
 			std::size_t bytesRead = 0;
@@ -382,7 +379,7 @@ constexpr Error MetalClawReaderTemplate<Reader>::fieldCString(const char*, char
 
 template<Reader_c Reader>
 constexpr Error MetalClawReaderTemplate<Reader>::fieldCString(const char*, char **val, std::size_t buffLen) noexcept {
-	if (m_unionIdx == -1 || static_cast<std::size_t>(m_unionIdx) == m_field) {
+	if (!m_unionIdx.has_value() || static_cast<std::size_t>(*m_unionIdx) == m_field) {
 		if (m_fieldPresence.get(static_cast<std::size_t>(m_field))) {
 			// read the length
 			std::size_t bytesRead = 0;
@@ -410,7 +407,7 @@ constexpr Error MetalClawReaderTemplate<Reader>::fieldCString(const char*, char
 
 template<Reader_c Reader>
 constexpr Result<ArrayLength> MetalClawReaderTemplate<Reader>::arrayLength(const char*, bool pass) noexcept {
-	if (m_unionIdx == -1 || static_cast<std::size_t>(m_unionIdx) == m_field) {
+	if (!m_unionIdx.has_value() || static_cast<std::size_t>(*m_unionIdx) == m_field) {
 		if (m_fieldPresence.get(static_cast<std::size_t>(m_field))) {
 			// read the length
 			std::size_t bytesRead = 0;
@@ -427,7 +424,7 @@ constexpr Result<ArrayLength> MetalClawReaderTemplate<Reader>::arrayLength(const
 
 template<Reader_c Reader>
 constexpr Result<StringLength> MetalClawReaderTemplate<Reader>::stringLength(const char*) noexcept {
-	if (m_unionIdx == -1 || static_cast<std::size_t>(m_unionIdx) == m_field) {
+	if (!m_unionIdx.has_value() || static_cast<std::size_t>(*m_unionIdx) == m_field) {
 		if (m_fieldPresence.get(static_cast<std::size_t>(m_field))) {
 			// read the length
 			std::size_t bytesRead = 0;
@@ -442,7 +439,7 @@ constexpr Result<StringLength> MetalClawReaderTemplate<Reader>::stringLength(con
 template<Reader_c Reader>
 template<typename I>
 constexpr Error MetalClawReaderTemplate<Reader>::readInteger(I *val) noexcept {
-	if (m_unionIdx == -1 || static_cast<std::size_t>(m_unionIdx) == m_field) {
+	if (!m_unionIdx.has_value() || static_cast<std::size_t>(*m_unionIdx) == m_field) {
 		if (m_fieldPresence.get(static_cast<std::size_t>(m_field))) {
 			std::size_t bytesRead = 0;
 			auto const result = mc::decodeInteger<I>(m_reader, &bytesRead);
@@ -459,7 +456,7 @@ constexpr Error MetalClawReaderTemplate<Reader>::readInteger(I *val) noexcept {
 template<Reader_c Reader>
 template<typename T, typename CB>
 constexpr Error MetalClawReaderTemplate<Reader>::field(const char*, CB cb) noexcept {
-	if (m_unionIdx == -1 || static_cast<std::size_t>(m_unionIdx) == m_field) {
+	if (!m_unionIdx.has_value() || static_cast<std::size_t>(*m_unionIdx) == m_field) {
 		if (m_fieldPresence.get(static_cast<std::size_t>(m_field))) {
 			// read the length
 			std::size_t bytesRead = 0;
@@ -491,8 +488,10 @@ constexpr ox::Error MetalClawReaderTemplate<Reader>::setTypeInfo(
 }
 
 template<Reader_c Reader>
-constexpr MetalClawReaderTemplate<Reader> MetalClawReaderTemplate<Reader>::child(const char*, int unionIdx) noexcept {
-	return MetalClawReaderTemplate<Reader>(m_reader, unionIdx, this);
+constexpr MetalClawReaderTemplate<Reader> MetalClawReaderTemplate<Reader>::child(
+		const char*,
+		ox::Optional<int> unionIdx) noexcept {
+	return MetalClawReaderTemplate<Reader>(m_reader, unionIdx);
 }
 
 template<Reader_c Reader>
diff --git a/deps/ox/src/ox/mc/write.hpp b/deps/ox/src/ox/mc/write.hpp
index cc905c35..9b3c1015 100644
--- a/deps/ox/src/ox/mc/write.hpp
+++ b/deps/ox/src/ox/mc/write.hpp
@@ -16,6 +16,7 @@
 #include <ox/std/buffer.hpp>
 #include <ox/std/byteswap.hpp>
 #include <ox/std/hashmap.hpp>
+#include <ox/std/optional.hpp>
 #include <ox/std/string.hpp>
 #include <ox/std/types.hpp>
 #include <ox/std/units.hpp>
@@ -34,12 +35,12 @@ class MetalClawWriter {
 		ox::Vector<uint8_t, 16> m_presenceMapBuff{};
 		FieldBitmap m_fieldPresence;
 		int m_field = 0;
-		int m_unionIdx = -1;
+		ox::Optional<int> m_unionIdx;
 		std::size_t m_writerBeginP{};
 		Writer &m_writer;
 
 	public:
-		constexpr explicit MetalClawWriter(Writer &writer, int unionIdx = -1) noexcept;
+		constexpr explicit MetalClawWriter(Writer &writer, ox::Optional<int> const&unionIdx = {}) noexcept;
 
 		constexpr ~MetalClawWriter() noexcept = default;
 
@@ -114,7 +115,7 @@ class MetalClawWriter {
 	private:
 		constexpr Error appendInteger(Integer_c auto val) noexcept {
 			bool fieldSet = false;
-			if (val && (m_unionIdx == -1 || m_unionIdx == m_field)) {
+			if (val && (!m_unionIdx.has_value() || *m_unionIdx == m_field)) {
 				auto mi = mc::encodeInteger(val);
 				oxReturnError(m_writer.write(reinterpret_cast<const char*>(mi.data), mi.length));
 				fieldSet = true;
@@ -130,7 +131,7 @@ extern template class ModelHandlerInterface<MetalClawWriter<BufferWriter>>;
 extern template class ModelHandlerInterface<MetalClawWriter<CharBuffWriter>>;
 
 template<Writer_c Writer>
-constexpr MetalClawWriter<Writer>::MetalClawWriter(Writer &writer, int unionIdx) noexcept:
+constexpr MetalClawWriter<Writer>::MetalClawWriter(Writer &writer, ox::Optional<int> const&unionIdx) noexcept:
 	m_fieldPresence(m_presenceMapBuff.data(), m_presenceMapBuff.size()),
 	m_unionIdx(unionIdx),
 	m_writerBeginP(writer.tellp()),
@@ -179,7 +180,7 @@ constexpr Error MetalClawWriter<Writer>::field(const char*, const uint64_t *val)
 
 template<Writer_c Writer>
 constexpr Error MetalClawWriter<Writer>::field(const char*, const bool *val) noexcept {
-	if (m_unionIdx == -1 || m_unionIdx == m_field) {
+	if (!m_unionIdx.has_value() || *m_unionIdx == m_field) {
 		oxReturnError(m_fieldPresence.set(static_cast<std::size_t>(m_field), *val));
 	}
 	++m_field;
@@ -190,7 +191,7 @@ template<Writer_c Writer>
 template<std::size_t SmallStringSize>
 constexpr Error MetalClawWriter<Writer>::field(const char*, const BasicString<SmallStringSize> *val) noexcept {
 	bool fieldSet = false;
-	if (val->len() && (m_unionIdx == -1 || m_unionIdx == m_field)) {
+	if (val->len() && (!m_unionIdx.has_value() || *m_unionIdx == m_field)) {
 		// write the length
 		const auto strLen = mc::encodeInteger(val->len());
 		oxReturnError(m_writer.write(reinterpret_cast<const char*>(strLen.data), strLen.length));
@@ -212,7 +213,7 @@ constexpr Error MetalClawWriter<Writer>::field(const char *name, const BString<L
 template<Writer_c Writer>
 constexpr Error MetalClawWriter<Writer>::fieldCString(const char*, const char *const*val, std::size_t) noexcept {
 	bool fieldSet = false;
-	if (m_unionIdx == -1 || m_unionIdx == m_field) {
+	if (!m_unionIdx.has_value() || *m_unionIdx == m_field) {
 		const auto strLen = *val ? ox_strlen(*val) : 0;
 		// write the length
 		const auto strLenBuff = mc::encodeInteger(strLen);
@@ -239,7 +240,7 @@ constexpr Error MetalClawWriter<Writer>::fieldCString(const char *name, const ch
 template<Writer_c Writer>
 constexpr Error MetalClawWriter<Writer>::fieldCString(const char*, const char *val, std::size_t strLen) noexcept {
 	bool fieldSet = false;
-	if (strLen && (m_unionIdx == -1 || m_unionIdx == m_field)) {
+	if (strLen && (!m_unionIdx.has_value() || *m_unionIdx == m_field)) {
 		// write the length
 		const auto strLenBuff = mc::encodeInteger(strLen);
 		oxReturnError(m_writer.write(reinterpret_cast<const char*>(strLenBuff.data), strLenBuff.length));
@@ -259,7 +260,7 @@ constexpr Error MetalClawWriter<Writer>::field(const char*, const T *val) noexce
 		return field(nullptr, val->data(), val->size());
 	} else {
 		bool fieldSet = false;
-		if (val && (m_unionIdx == -1 || m_unionIdx == m_field)) {
+		if (val && (!m_unionIdx.has_value() || *m_unionIdx == m_field)) {
 			MetalClawWriter<Writer> writer(m_writer);
 			ModelHandlerInterface<MetalClawWriter<Writer>> handler{&writer};
 			oxReturnError(model(&handler, val));
@@ -276,8 +277,8 @@ template<Writer_c Writer>
 template<typename U, bool force>
 constexpr Error MetalClawWriter<Writer>::field(const char*, UnionView<U, force> val) noexcept {
 	bool fieldSet = false;
-	if (val.get() && (m_unionIdx == -1 || m_unionIdx == m_field)) {
-		MetalClawWriter<Writer> writer(m_writer, val.idx());
+	if (val.get() && (!m_unionIdx.has_value() || *m_unionIdx == m_field)) {
+		MetalClawWriter<Writer> writer(m_writer, ox::Optional<int>(ox::in_place, val.idx()));
 		ModelHandlerInterface handler{&writer};
 		oxReturnError(model(&handler, val.get()));
 		oxReturnError(writer.finalize());
@@ -292,7 +293,7 @@ template<Writer_c Writer>
 template<typename T>
 constexpr Error MetalClawWriter<Writer>::field(const char*, const T *val, std::size_t len) noexcept {
 	bool fieldSet = false;
-	if (len && (m_unionIdx == -1 || m_unionIdx == m_field)) {
+	if (len && (!m_unionIdx.has_value() || *m_unionIdx == m_field)) {
 		// write the length
 		const auto arrLen = mc::encodeInteger(len);
 		oxReturnError(m_writer.write(reinterpret_cast<const char*>(arrLen.data), arrLen.length));
@@ -317,7 +318,7 @@ constexpr Error MetalClawWriter<Writer>::field(const char*, const HashMap<String
 	const auto &keys = val->keys();
 	const auto len = keys.size();
 	bool fieldSet = false;
-	if (len && (m_unionIdx == -1 || m_unionIdx == m_field)) {
+	if (len && (!m_unionIdx.has_value() || *m_unionIdx == m_field)) {
 		// write the length
 		const auto arrLen = mc::encodeInteger(len);
 		oxReturnError(m_writer.write(reinterpret_cast<const char*>(arrLen.data), arrLen.length));