diff --git a/fossilize.cpp b/fossilize.cpp
index d9856497..b4948bde 100644
--- a/fossilize.cpp
+++ b/fossilize.cpp
@@ -47,6 +47,7 @@
 #include "rapidjson/writer.h"
 using namespace rapidjson;
 
+using Allocator = RAPIDJSON_DEFAULT_ALLOCATOR;
 
 #ifdef PRETTY_WRITER
 using CustomWriter = PrettyWriter<StringBuffer>;
@@ -102,7 +103,6 @@ struct HashedInfo
 	T info;
 };
 
-template <typename Allocator>
 static Value uint64_string(uint64_t value, Allocator &alloc)
 {
 	char str[17]; // 16 digits + null
@@ -9494,11 +9494,10 @@ static std::string encode_base64(const void *data_, size_t size)
 	return ret;
 }
 
-template <typename T, typename Allocator>
+template <typename T>
 static bool pnext_chain_add_json_value(Value &base, const T &t, Allocator &alloc,
                                        const DynamicStateInfo *dynamic_state_info);
 
-template <typename Allocator>
 static bool json_value(const VkSamplerCreateInfo& sampler, Allocator& alloc, Value *out_value)
 {
 	Value s(kObjectType);
@@ -9526,7 +9525,6 @@ static bool json_value(const VkSamplerCreateInfo& sampler, Allocator& alloc, Val
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkPipelineLayoutCreateInfo& layout, Allocator& alloc, Value *out_value)
 {
 	Value p(kObjectType);
@@ -9551,7 +9549,6 @@ static bool json_value(const VkPipelineLayoutCreateInfo& layout, Allocator& allo
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkShaderModuleCreateInfo& module, Allocator& alloc, Value *out_value)
 {
 	Value m(kObjectType);
@@ -9563,7 +9560,6 @@ static bool json_value(const VkShaderModuleCreateInfo& module, Allocator& alloc,
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkPipelineTessellationDomainOriginStateCreateInfo &create_info, Allocator &alloc, Value *out_value)
 {
 	Value value(kObjectType);
@@ -9574,7 +9570,6 @@ static bool json_value(const VkPipelineTessellationDomainOriginStateCreateInfo &
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkPipelineVertexInputDivisorStateCreateInfoKHR &create_info, Allocator &alloc, Value *out_value)
 {
 	Value value(kObjectType);
@@ -9598,7 +9593,6 @@ static bool json_value(const VkPipelineVertexInputDivisorStateCreateInfoKHR &cre
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkPipelineRasterizationDepthClipStateCreateInfoEXT &create_info, Allocator &alloc, Value *out_value)
 {
 	Value value(kObjectType);
@@ -9610,7 +9604,6 @@ static bool json_value(const VkPipelineRasterizationDepthClipStateCreateInfoEXT
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkPipelineRasterizationStateStreamCreateInfoEXT &create_info, Allocator &alloc, Value *out_value)
 {
 	Value value(kObjectType);
@@ -9622,7 +9615,6 @@ static bool json_value(const VkPipelineRasterizationStateStreamCreateInfoEXT &cr
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkRenderPassMultiviewCreateInfo &create_info, Allocator &alloc, Value *out_value)
 {
 	Value value(kObjectType);
@@ -9656,7 +9648,6 @@ static bool json_value(const VkRenderPassMultiviewCreateInfo &create_info, Alloc
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkDescriptorSetLayoutBindingFlagsCreateInfoEXT &create_info, Allocator &alloc, Value *out_value)
 {
 	Value value(kObjectType);
@@ -9674,7 +9665,6 @@ static bool json_value(const VkDescriptorSetLayoutBindingFlagsCreateInfoEXT &cre
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkPipelineColorBlendAdvancedStateCreateInfoEXT &create_info, Allocator &alloc, Value *out_value)
 {
 	Value value(kObjectType);
@@ -9688,7 +9678,6 @@ static bool json_value(const VkPipelineColorBlendAdvancedStateCreateInfoEXT &cre
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkPipelineRasterizationConservativeStateCreateInfoEXT &create_info, Allocator &alloc, Value *out_value)
 {
 	Value value(kObjectType);
@@ -9702,7 +9691,6 @@ static bool json_value(const VkPipelineRasterizationConservativeStateCreateInfoE
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkPipelineRasterizationLineStateCreateInfoKHR &create_info, Allocator &alloc, Value *out_value)
 {
 	Value value(kObjectType);
@@ -9717,7 +9705,6 @@ static bool json_value(const VkPipelineRasterizationLineStateCreateInfoKHR &crea
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkPipelineShaderStageRequiredSubgroupSizeCreateInfoEXT &create_info, Allocator &alloc, Value *out_value)
 {
 	Value value(kObjectType);
@@ -9728,7 +9715,6 @@ static bool json_value(const VkPipelineShaderStageRequiredSubgroupSizeCreateInfo
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkMutableDescriptorTypeCreateInfoEXT &create_info, Allocator &alloc, Value *out_value)
 {
 	Value value(kObjectType);
@@ -9749,7 +9735,6 @@ static bool json_value(const VkMutableDescriptorTypeCreateInfoEXT &create_info,
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkAttachmentDescriptionStencilLayout &create_info, Allocator &alloc, Value *out_value)
 {
 	Value value(kObjectType);
@@ -9760,7 +9745,6 @@ static bool json_value(const VkAttachmentDescriptionStencilLayout &create_info,
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkAttachmentReferenceStencilLayout &create_info, Allocator &alloc, Value *out_value)
 {
 	Value value(kObjectType);
@@ -9770,7 +9754,6 @@ static bool json_value(const VkAttachmentReferenceStencilLayout &create_info, Al
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkPipelineRenderingCreateInfoKHR &create_info, Allocator &alloc, Value *out_value)
 {
 	Value value(kObjectType);
@@ -9791,7 +9774,6 @@ static bool json_value(const VkPipelineRenderingCreateInfoKHR &create_info, Allo
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkPipelineColorWriteCreateInfoEXT &create_info, Allocator &alloc, Value *out_value,
                        const DynamicStateInfo *dynamic_state_info)
 {
@@ -9814,7 +9796,6 @@ static bool json_value(const VkPipelineColorWriteCreateInfoEXT &create_info, All
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkPipelineRasterizationProvokingVertexStateCreateInfoEXT &create_info, Allocator &alloc, Value *out_value)
 {
 	Value value(kObjectType);
@@ -9825,7 +9806,6 @@ static bool json_value(const VkPipelineRasterizationProvokingVertexStateCreateIn
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkSamplerCustomBorderColorCreateInfoEXT &create_info, Allocator &alloc, Value *out_value)
 {
 	Value value(kObjectType);
@@ -9841,7 +9821,6 @@ static bool json_value(const VkSamplerCustomBorderColorCreateInfoEXT &create_inf
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkSamplerReductionModeCreateInfo &create_info, Allocator &alloc, Value *out_value)
 {
 	Value value(kObjectType);
@@ -9852,7 +9831,6 @@ static bool json_value(const VkSamplerReductionModeCreateInfo &create_info, Allo
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkRenderPassInputAttachmentAspectCreateInfo &create_info, Allocator &alloc, Value *out_value)
 {
 	Value value(kObjectType);
@@ -9873,7 +9851,6 @@ static bool json_value(const VkRenderPassInputAttachmentAspectCreateInfo &create
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkPipelineDiscardRectangleStateCreateInfoEXT &create_info, Allocator &alloc, Value *out_value,
                        const DynamicStateInfo *dynamic_state_info)
 {
@@ -9902,7 +9879,6 @@ static bool json_value(const VkPipelineDiscardRectangleStateCreateInfoEXT &creat
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkMemoryBarrier2KHR &create_info, Allocator &alloc, Value *out_value)
 {
 	Value value(kObjectType);
@@ -9916,7 +9892,6 @@ static bool json_value(const VkMemoryBarrier2KHR &create_info, Allocator &alloc,
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkGraphicsPipelineLibraryCreateInfoEXT &create_info, Allocator &alloc, Value *out_value)
 {
 	Value value(kObjectType);
@@ -9926,7 +9901,6 @@ static bool json_value(const VkGraphicsPipelineLibraryCreateInfoEXT &create_info
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkPipelineFragmentShadingRateStateCreateInfoKHR &create_info, Allocator &alloc, Value *out_value,
                        const DynamicStateInfo *dynamic_state_info)
 {
@@ -9950,7 +9924,6 @@ static bool json_value(const VkPipelineFragmentShadingRateStateCreateInfoKHR &cr
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkSamplerYcbcrConversionCreateInfo &create_info, Allocator &alloc, Value *out_value)
 {
 	Value value(kObjectType);
@@ -9974,7 +9947,6 @@ static bool json_value(const VkSamplerYcbcrConversionCreateInfo &create_info, Al
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkPipelineLibraryCreateInfoKHR &create_info, Allocator &alloc,
                        bool in_pnext_chain, Value *out_value)
 {
@@ -9998,7 +9970,6 @@ static bool json_value(const VkPipelineLibraryCreateInfoKHR &create_info, Alloca
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkPipelineViewportDepthClipControlCreateInfoEXT &create_info,
                        Allocator &alloc, Value *out_value)
 {
@@ -10009,7 +9980,6 @@ static bool json_value(const VkPipelineViewportDepthClipControlCreateInfoEXT &cr
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkRenderPassCreationControlEXT &create_info,
                        Allocator &alloc, Value *out_value)
 {
@@ -10020,7 +9990,6 @@ static bool json_value(const VkRenderPassCreationControlEXT &create_info,
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkSamplerBorderColorComponentMappingCreateInfoEXT &create_info,
                        Allocator &alloc, Value *out_value)
 {
@@ -10037,7 +10006,6 @@ static bool json_value(const VkSamplerBorderColorComponentMappingCreateInfoEXT &
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkMultisampledRenderToSingleSampledInfoEXT &create_info,
                        Allocator &alloc, Value *out_value)
 {
@@ -10049,7 +10017,6 @@ static bool json_value(const VkMultisampledRenderToSingleSampledInfoEXT &create_
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkDepthBiasRepresentationInfoEXT &create_info,
                        Allocator &alloc, Value *out_value)
 {
@@ -10061,7 +10028,6 @@ static bool json_value(const VkDepthBiasRepresentationInfoEXT &create_info,
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkRenderPassFragmentDensityMapCreateInfoEXT &create_info,
                        Allocator &alloc, Value *out_value)
 {
@@ -10075,7 +10041,6 @@ static bool json_value(const VkRenderPassFragmentDensityMapCreateInfoEXT &create
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkSampleLocationsInfoEXT &create_info,
                        Allocator &alloc, Value *out_value)
 {
@@ -10107,7 +10072,6 @@ static bool json_value(const VkSampleLocationsInfoEXT &create_info,
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkPipelineRobustnessCreateInfoEXT &create_info,
                        Allocator &alloc, Value *out_value)
 {
@@ -10121,7 +10085,6 @@ static bool json_value(const VkPipelineRobustnessCreateInfoEXT &create_info,
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkPipelineCreateFlags2CreateInfoKHR &create_info, Allocator &alloc, Value *out_value)
 {
 	Value value(kObjectType);
@@ -10131,7 +10094,6 @@ static bool json_value(const VkPipelineCreateFlags2CreateInfoKHR &create_info, A
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkPipelineViewportDepthClampControlCreateInfoEXT &create_info, Allocator &alloc, Value *out_value)
 {
 	Value value(kObjectType);
@@ -10150,7 +10112,6 @@ static bool json_value(const VkPipelineViewportDepthClampControlCreateInfoEXT &c
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkRenderingAttachmentLocationInfoKHR &create_info, Allocator &alloc, Value *out_value)
 {
 	Value value(kObjectType);
@@ -10169,7 +10130,6 @@ static bool json_value(const VkRenderingAttachmentLocationInfoKHR &create_info,
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkRenderingInputAttachmentIndexInfoKHR &create_info, Allocator &alloc, Value *out_value)
 {
 	Value value(kObjectType);
@@ -10193,7 +10153,6 @@ static bool json_value(const VkRenderingInputAttachmentIndexInfoKHR &create_info
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkPipelineFragmentDensityMapLayeredCreateInfoVALVE &create_info, Allocator &alloc, Value *out_value)
 {
 	Value value(kObjectType);
@@ -10203,7 +10162,6 @@ static bool json_value(const VkPipelineFragmentDensityMapLayeredCreateInfoVALVE
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkRayTracingPipelineClusterAccelerationStructureCreateInfoNV &create_info, Allocator &alloc, Value *out_value)
 {
 	Value value(kObjectType);
@@ -10213,7 +10171,6 @@ static bool json_value(const VkRayTracingPipelineClusterAccelerationStructureCre
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkShaderDescriptorSetAndBindingMappingInfoEXT &create_info, Allocator &alloc, Value *out_value)
 {
 	Value value(kObjectType);
@@ -10387,12 +10344,11 @@ static bool json_value(const VkShaderDescriptorSetAndBindingMappingInfoEXT &crea
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkSubpassDescriptionDepthStencilResolve &create_info, Allocator &alloc, Value *out_value);
-template <typename Allocator>
 static bool json_value(const VkFragmentShadingRateAttachmentInfoKHR &create_info, Allocator &alloc, Value *out_value);
+static bool json_value(const VkPipelineSampleLocationsStateCreateInfoEXT &create_info, Allocator &alloc, Value *out_value,
+					   const DynamicStateInfo *dynamic_state_info);
 
-template <typename Allocator>
 static bool pnext_chain_json_value(const void *pNext, Allocator &alloc, Value *out_value,
                                    const DynamicStateInfo *dynamic_state_info)
 {
@@ -10641,7 +10597,7 @@ static bool pnext_chain_json_value(const void *pNext, Allocator &alloc, Value *o
 	return true;
 }
 
-template <typename T, typename Allocator>
+template <typename T>
 static bool pnext_chain_add_json_value(Value &base, const T &t, Allocator &alloc,
                                        const DynamicStateInfo *dynamic_state_info)
 {
@@ -10655,7 +10611,6 @@ static bool pnext_chain_add_json_value(Value &base, const T &t, Allocator &alloc
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkAttachmentReference2 &att, Allocator &alloc, Value *out_value)
 {
 	Value value(kObjectType);
@@ -10669,7 +10624,6 @@ static bool json_value(const VkAttachmentReference2 &att, Allocator &alloc, Valu
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkSubpassDescriptionDepthStencilResolve &create_info, Allocator &alloc, Value *out_value)
 {
 	Value value(kObjectType);
@@ -10687,7 +10641,6 @@ static bool json_value(const VkSubpassDescriptionDepthStencilResolve &create_inf
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkFragmentShadingRateAttachmentInfoKHR &create_info, Allocator &alloc, Value *out_value)
 {
 	Value value(kObjectType);
@@ -10708,7 +10661,6 @@ static bool json_value(const VkFragmentShadingRateAttachmentInfoKHR &create_info
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkPipelineSampleLocationsStateCreateInfoEXT &create_info, Allocator &alloc, Value *out_value,
                        const DynamicStateInfo *dynamic_state_info)
 {
@@ -10753,7 +10705,6 @@ static bool json_value(const VkPipelineSampleLocationsStateCreateInfoEXT &create
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkComputePipelineCreateInfo& pipe, Allocator& alloc, Value *out_value)
 {
 	Value p(kObjectType);
@@ -10798,7 +10749,6 @@ static bool json_value(const VkComputePipelineCreateInfo& pipe, Allocator& alloc
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkDescriptorSetLayoutCreateInfo& layout, Allocator& alloc, Value *out_value)
 {
 	Value l(kObjectType);
@@ -10831,7 +10781,6 @@ static bool json_value(const VkDescriptorSetLayoutCreateInfo& layout, Allocator&
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkRenderPassCreateInfo& pass, Allocator& alloc, Value *out_value)
 {
 	Value json_object(kObjectType);
@@ -10957,7 +10906,6 @@ static bool json_value(const VkRenderPassCreateInfo& pass, Allocator& alloc, Val
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkRenderPassCreateInfo2 &pass, Allocator &alloc, Value *out_value)
 {
 	Value json_object(kObjectType);
@@ -11095,7 +11043,6 @@ static bool json_value(const VkRenderPassCreateInfo2 &pass, Allocator &alloc, Va
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkPipelineShaderStageCreateInfo *pStages, uint32_t stageCount,
                        Allocator &alloc, Value *out_value)
 {
@@ -11138,7 +11085,6 @@ static bool json_value(const VkPipelineShaderStageCreateInfo *pStages, uint32_t
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkPipelineDynamicStateCreateInfo &dynamic, Allocator &alloc, Value *out_value)
 {
 	Value dyn(kObjectType);
@@ -11152,7 +11098,6 @@ static bool json_value(const VkPipelineDynamicStateCreateInfo &dynamic, Allocato
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkRayTracingPipelineCreateInfoKHR &pipe, Allocator &alloc, Value *out_value)
 {
 	Value p(kObjectType);
@@ -11215,7 +11160,6 @@ static bool json_value(const VkRayTracingPipelineCreateInfoKHR &pipe, Allocator
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkGraphicsPipelineCreateInfo &pipe,
                        const StateRecorder::SubpassMeta &subpass_meta,
                        Allocator &alloc, Value *out_value)
@@ -11497,8 +11441,7 @@ static bool json_value(const VkGraphicsPipelineCreateInfo &pipe,
 	return true;
 }
 
-template <typename AllocType>
-static void serialize_application_info_inline(Value &value, const VkApplicationInfo &info, AllocType &alloc)
+static void serialize_application_info_inline(Value &value, const VkApplicationInfo &info, Allocator &alloc)
 {
 	if (info.pApplicationName)
 		value.AddMember("applicationName", StringRef(info.pApplicationName), alloc);
@@ -11509,7 +11452,6 @@ static void serialize_application_info_inline(Value &value, const VkApplicationI
 	value.AddMember("apiVersion", info.apiVersion, alloc);
 }
 
-template <typename Allocator>
 static bool json_value(const VkPhysicalDeviceRobustness2FeaturesEXT &create_info, Allocator &alloc, Value *out_value)
 {
 	Value value(kObjectType);
@@ -11521,7 +11463,6 @@ static bool json_value(const VkPhysicalDeviceRobustness2FeaturesEXT &create_info
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkPhysicalDeviceImageRobustnessFeaturesEXT &create_info, Allocator &alloc, Value *out_value)
 {
 	Value value(kObjectType);
@@ -11531,7 +11472,6 @@ static bool json_value(const VkPhysicalDeviceImageRobustnessFeaturesEXT &create_
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkPhysicalDeviceFragmentShadingRateEnumsFeaturesNV &create_info, Allocator &alloc, Value *out_value)
 {
 	Value value(kObjectType);
@@ -11543,7 +11483,6 @@ static bool json_value(const VkPhysicalDeviceFragmentShadingRateEnumsFeaturesNV
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkPhysicalDeviceFragmentShadingRateFeaturesKHR &create_info, Allocator &alloc, Value *out_value)
 {
 	Value value(kObjectType);
@@ -11555,7 +11494,6 @@ static bool json_value(const VkPhysicalDeviceFragmentShadingRateFeaturesKHR &cre
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkPhysicalDeviceMeshShaderFeaturesEXT &create_info, Allocator &alloc, Value *out_value)
 {
 	Value value(kObjectType);
@@ -11569,7 +11507,6 @@ static bool json_value(const VkPhysicalDeviceMeshShaderFeaturesEXT &create_info,
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkPhysicalDeviceMeshShaderFeaturesNV &create_info, Allocator &alloc, Value *out_value)
 {
 	Value value(kObjectType);
@@ -11580,7 +11517,6 @@ static bool json_value(const VkPhysicalDeviceMeshShaderFeaturesNV &create_info,
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkPhysicalDeviceDescriptorBufferFeaturesEXT &create_info, Allocator &alloc, Value *out_value)
 {
 	Value value(kObjectType);
@@ -11593,7 +11529,6 @@ static bool json_value(const VkPhysicalDeviceDescriptorBufferFeaturesEXT &create
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkPhysicalDeviceShaderObjectFeaturesEXT &create_info, Allocator &alloc, Value *out_value)
 {
 	Value value(kObjectType);
@@ -11603,7 +11538,6 @@ static bool json_value(const VkPhysicalDeviceShaderObjectFeaturesEXT &create_inf
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkPhysicalDevicePrimitivesGeneratedQueryFeaturesEXT &create_info, Allocator &alloc, Value *out_value)
 {
 	Value value(kObjectType);
@@ -11615,7 +11549,6 @@ static bool json_value(const VkPhysicalDevicePrimitivesGeneratedQueryFeaturesEXT
 	return true;
 }
 
-template <typename Allocator>
 static bool json_value(const VkPhysicalDeviceImage2DViewOf3DFeaturesEXT &create_info, Allocator &alloc, Value *out_value)
 {
 	Value value(kObjectType);
@@ -11626,7 +11559,6 @@ static bool json_value(const VkPhysicalDeviceImage2DViewOf3DFeaturesEXT &create_
 	return true;
 }
 
-template <typename Allocator>
 static bool pnext_chain_pdf2_json_value(const void *pNext, Allocator &alloc, Value *out_value)
 {
 	Value nexts(kArrayType);
@@ -11700,7 +11632,7 @@ static bool pnext_chain_pdf2_json_value(const void *pNext, Allocator &alloc, Val
 	return true;
 }
 
-template <typename T, typename Allocator>
+template <typename T>
 static bool pnext_chain_pdf2_add_json_value(Value &base, const T &t, Allocator &alloc)
 {
 	if (t.pNext)
@@ -11713,8 +11645,7 @@ static bool pnext_chain_pdf2_add_json_value(Value &base, const T &t, Allocator &
 	return true;
 }
 
-template <typename AllocType>
-static bool serialize_physical_device_features_inline(Value &value, const VkPhysicalDeviceFeatures2 &features, AllocType &alloc)
+static bool serialize_physical_device_features_inline(Value &value, const VkPhysicalDeviceFeatures2 &features, Allocator &alloc)
 {
 	value.AddMember("robustBufferAccess", features.features.robustBufferAccess, alloc);
 	if (!pnext_chain_pdf2_add_json_value(value, features, alloc))
diff --git a/fossilize_application_filter.cpp b/fossilize_application_filter.cpp
index cb7c22aa..88434112 100644
--- a/fossilize_application_filter.cpp
+++ b/fossilize_application_filter.cpp
@@ -36,6 +36,8 @@
 #include "rapidjson/writer.h"
 using namespace rapidjson;
 
+using Allocator = RAPIDJSON_DEFAULT_ALLOCATOR;
+
 namespace Fossilize
 {
 enum { FOSSILIZE_APPLICATION_INFO_FILTER_VERSION = 2 };
@@ -141,7 +143,13 @@ struct ApplicationInfoFilter::Impl
 	bool needs_buckets(const VkApplicationInfo *info);
 	Hash get_bucket_hash(const VkPhysicalDeviceProperties2 *props,
 	                     const VkApplicationInfo *info,
-	                     const void *device_pnext);
+	                     const void *device_pnext,
+	                     Value *json, Allocator *json_allocator);
+
+	std::string get_bucket_json_description(
+		const VkPhysicalDeviceProperties2 *props2,
+		const VkApplicationInfo *info,
+		const void *device_pnext);
 
 	const char *(*getenv_wrapper)(const char *, void *) = nullptr;
 	void *getenv_userdata = nullptr;
@@ -225,7 +233,8 @@ static void hash_variant(Hasher &h, VariantDependency dep,
                          const VkPhysicalDeviceProperties2 *props,
                          const VkApplicationInfo *info,
                          const void *device_pnext,
-                         bool feature_hash)
+                         bool feature_hash,
+                         Value *json, Allocator *json_allocator)
 {
 	const VkApplicationInfo default_app_info = { VK_STRUCTURE_TYPE_APPLICATION_INFO };
 	bool hash_enabled = true;
@@ -236,8 +245,13 @@ static void hash_variant(Hasher &h, VariantDependency dep,
 	switch (dep)
 	{
 	case VariantDependency::VendorID:
-		h.u32(props ? props->properties.vendorID : 0);
+	{
+		uint32_t vendorID = props ? props->properties.vendorID : 0;
+		if (json)
+			json->AddMember("VendorID", vendorID, *json_allocator);
+		h.u32(vendorID);
 		break;
+	}
 
 	case VariantDependency::MutableDescriptorType:
 	{
@@ -246,6 +260,8 @@ static void hash_variant(Hasher &h, VariantDependency dep,
 				device_pnext);
 
 		bool enabled = mut && mut->mutableDescriptorType;
+		if (json)
+			json->AddMember("MutableDescriptorType", int(enabled), *json_allocator);
 
 		if (feature_hash)
 		{
@@ -271,6 +287,9 @@ static void hash_variant(Hasher &h, VariantDependency dep,
 		bool enabled = (bda && bda->bufferDeviceAddress) ||
 		               (features12 && features12->bufferDeviceAddress);
 
+		if (json)
+			json->AddMember("BufferDeviceAddress", int(enabled), *json_allocator);
+
 		if (feature_hash)
 		{
 			hash_enabled = enabled;
@@ -292,6 +311,9 @@ static void hash_variant(Hasher &h, VariantDependency dep,
 		                       vrs->pipelineFragmentShadingRate ||
 		                       vrs->primitiveFragmentShadingRate);
 
+		if (json)
+			json->AddMember("FragmentShadingRate", int(enabled), *json_allocator);
+
 		if (feature_hash)
 		{
 			hash_enabled = enabled;
@@ -304,6 +326,21 @@ static void hash_variant(Hasher &h, VariantDependency dep,
 			h.u32(uint32_t(vrs && vrs->attachmentFragmentShadingRate));
 			h.u32(uint32_t(vrs && vrs->pipelineFragmentShadingRate));
 			h.u32(uint32_t(vrs && vrs->primitiveFragmentShadingRate));
+
+			if (json)
+			{
+				json->AddMember("attachmentFragmentShadingRate",
+				                int(vrs && vrs->attachmentFragmentShadingRate),
+				                *json_allocator);
+
+				json->AddMember("pipelineFragmentShadingRate",
+								int(vrs && vrs->pipelineFragmentShadingRate),
+								*json_allocator);
+
+				json->AddMember("primitiveFragmentShadingRate",
+								int(vrs && vrs->primitiveFragmentShadingRate),
+								*json_allocator);
+			}
 		}
 		break;
 	}
@@ -317,6 +354,9 @@ static void hash_variant(Hasher &h, VariantDependency dep,
 		bool enabled = (dynamic_rendering && dynamic_rendering->dynamicRendering) ||
 		               (features13 && features13->dynamicRendering);
 
+		if (json)
+			json->AddMember("DynamicRendering", int(enabled), *json_allocator);
+
 		if (feature_hash)
 		{
 			hash_enabled = enabled;
@@ -340,6 +380,9 @@ static void hash_variant(Hasher &h, VariantDependency dep,
 		bool enabled = (indexing && indexing->descriptorBindingUniformBufferUpdateAfterBind) ||
 		               (features12 && features12->descriptorBindingUniformBufferUpdateAfterBind);
 
+		if (json)
+			json->AddMember("BindlessUBO", int(enabled), *json_allocator);
+
 		if (feature_hash)
 		{
 			hash_enabled = enabled;
@@ -366,6 +409,9 @@ static void hash_variant(Hasher &h, VariantDependency dep,
 		bool enabled = descriptor_buffer && (descriptor_buffer->descriptorBuffer ||
 		                                     descriptor_buffer->descriptorBufferPushDescriptors);
 
+		if (json)
+			json->AddMember("DescriptorBuffer", int(enabled), *json_allocator);
+
 		if (feature_hash)
 		{
 			hash_enabled = enabled;
@@ -379,6 +425,16 @@ static void hash_variant(Hasher &h, VariantDependency dep,
 			h.u32(uint32_t(descriptor_buffer && descriptor_buffer->descriptorBufferPushDescriptors));
 			// The other feature bits are highly unlikely to ever affect
 			// pipeline construction in application in any meaningful way.
+			if (json)
+			{
+				json->AddMember("descriptorBuffer",
+				                int(descriptor_buffer && descriptor_buffer->descriptorBuffer),
+				                *json_allocator);
+
+				json->AddMember("descriptorBufferPushDescriptors",
+								int(descriptor_buffer && descriptor_buffer->descriptorBufferPushDescriptors),
+								*json_allocator);
+			}
 		}
 		break;
 	}
@@ -391,6 +447,9 @@ static void hash_variant(Hasher &h, VariantDependency dep,
 
 		bool enabled = descriptor_heap && descriptor_heap->descriptorHeap;
 
+		if (json)
+			json->AddMember("DescriptorHeap", int(enabled), *json_allocator);
+
 		if (feature_hash)
 		{
 			hash_enabled = enabled;
@@ -405,42 +464,62 @@ static void hash_variant(Hasher &h, VariantDependency dep,
 	}
 
 	case VariantDependency::ApplicationVersion:
+		if (json)
+			json->AddMember("ApplicationVersion", info->applicationVersion, *json_allocator);
 		h.u32(info->applicationVersion);
 		break;
 
 	case VariantDependency::ApplicationVersionMajor:
+		if (json)
+			json->AddMember("ApplicationVersionMajor", VK_VERSION_MAJOR(info->applicationVersion), *json_allocator);
 		h.u32(VK_VERSION_MAJOR(info->applicationVersion));
 		break;
 
 	case VariantDependency::ApplicationVersionMinor:
+		if (json)
+			json->AddMember("ApplicationVersionMinor", VK_VERSION_MINOR(info->applicationVersion), *json_allocator);
 		h.u32(VK_VERSION_MINOR(info->applicationVersion));
 		break;
 
 	case VariantDependency::ApplicationVersionPatch:
+		if (json)
+			json->AddMember("ApplicationVersionPatch", VK_VERSION_PATCH(info->applicationVersion), *json_allocator);
 		h.u32(VK_VERSION_PATCH(info->applicationVersion));
 		break;
 
 	case VariantDependency::EngineVersion:
+		if (json)
+			json->AddMember("EngineVersion", info->engineVersion, *json_allocator);
 		h.u32(info->engineVersion);
 		break;
 
 	case VariantDependency::EngineVersionMajor:
+		if (json)
+			json->AddMember("EngineVersionMajor", VK_VERSION_MAJOR(info->engineVersion), *json_allocator);
 		h.u32(VK_VERSION_MAJOR(info->engineVersion));
 		break;
 
 	case VariantDependency::EngineVersionMinor:
+		if (json)
+			json->AddMember("EngineVersionMinor", VK_VERSION_MINOR(info->engineVersion), *json_allocator);
 		h.u32(VK_VERSION_MINOR(info->engineVersion));
 		break;
 
 	case VariantDependency::EngineVersionPatch:
+		if (json)
+			json->AddMember("EngineVersionPatch", VK_VERSION_PATCH(info->engineVersion), *json_allocator);
 		h.u32(VK_VERSION_PATCH(info->engineVersion));
 		break;
 
 	case VariantDependency::ApplicationName:
+		if (json)
+			json->AddMember("ApplicationName", StringRef(info->pApplicationName ? info->pApplicationName : ""), *json_allocator);
 		h.string(info->pApplicationName ? info->pApplicationName : "");
 		break;
 
 	case VariantDependency::EngineName:
+		if (json)
+			json->AddMember("EngineName", StringRef(info->pEngineName ? info->pEngineName : ""), *json_allocator);
 		h.string(info->pEngineName ? info->pEngineName : "");
 		break;
 
@@ -449,9 +528,28 @@ static void hash_variant(Hasher &h, VariantDependency dep,
 	}
 }
 
+std::string ApplicationInfoFilter::Impl::get_bucket_json_description(
+		const VkPhysicalDeviceProperties2 *props2, const VkApplicationInfo *info,
+		const void *device_pnext)
+{
+	Document doc;
+	doc.SetObject();
+	Value bucket(kObjectType);
+	get_bucket_hash(props2, info, device_pnext, &bucket, &doc.GetAllocator());
+	doc.AddMember("bucket", bucket, doc.GetAllocator());
+
+	StringBuffer buf;
+	PrettyWriter<StringBuffer> writer(buf);
+	doc.Accept(writer);
+	std::string str;
+	str.insert(str.end(), buf.GetString(), buf.GetString() + buf.GetLength());
+	return str;
+}
+
 Hash ApplicationInfoFilter::Impl::get_bucket_hash(const VkPhysicalDeviceProperties2 *props,
                                                   const VkApplicationInfo *info,
-                                                  const void *device_pnext)
+                                                  const void *device_pnext,
+                                                  Value *json, Allocator *json_allocator)
 {
 	Hasher h;
 	bool use_default_variant = true;
@@ -464,9 +562,9 @@ Hash ApplicationInfoFilter::Impl::get_bucket_hash(const VkPhysicalDeviceProperti
 		{
 			use_default_variant = false;
 			for (auto &dep : itr->second.variant_dependencies)
-				hash_variant(h, dep, props, info, device_pnext, false);
+				hash_variant(h, dep, props, info, device_pnext, false, json, json_allocator);
 			for (auto &dep : itr->second.variant_dependencies_feature)
-				hash_variant(h, dep, props, info, device_pnext, true);
+				hash_variant(h, dep, props, info, device_pnext, true, json, json_allocator);
 		}
 	}
 
@@ -478,24 +576,47 @@ Hash ApplicationInfoFilter::Impl::get_bucket_hash(const VkPhysicalDeviceProperti
 		{
 			use_default_variant = false;
 			for (auto &dep : itr->second.variant_dependencies)
-				hash_variant(h, dep, props, info, device_pnext, false);
+				hash_variant(h, dep, props, info, device_pnext, false, json, json_allocator);
 			for (auto &dep : itr->second.variant_dependencies_feature)
-				hash_variant(h, dep, props, info, device_pnext, true);
+				hash_variant(h, dep, props, info, device_pnext, true, json, json_allocator);
+
+			Value applicationDeltas(kArrayType);
+			Value engineDeltas(kArrayType);
+
 			for (auto &dep : itr->second.application_version_deltas)
+			{
 				if (info->applicationVersion >= dep)
+				{
 					h.u32(dep ^ 0xabba);
+					if (json)
+						applicationDeltas.PushBack(dep, *json_allocator);
+				}
+			}
+
 			for (auto &dep : itr->second.engine_version_deltas)
+			{
 				if (info->engineVersion >= dep)
+				{
 					h.u32(dep ^ 0xcafe);
+					if (json)
+						engineDeltas.PushBack(dep, *json_allocator);
+				}
+			}
+
+			if (json)
+			{
+				json->AddMember("applicationVersionBucketDeltas", applicationDeltas, *json_allocator);
+				json->AddMember("engineVersionBucketDeltas", engineDeltas, *json_allocator);
+			}
 		}
 	}
 
 	if (use_default_variant)
 	{
 		for (auto &dep : default_variant_dependencies)
-			hash_variant(h, dep, props, info, device_pnext, false);
+			hash_variant(h, dep, props, info, device_pnext, false, json, json_allocator);
 		for (auto &dep : default_variant_dependencies_feature)
-			hash_variant(h, dep, props, info, device_pnext, true);
+			hash_variant(h, dep, props, info, device_pnext, true, json, json_allocator);
 	}
 
 	return h.get();
@@ -924,7 +1045,13 @@ Hash ApplicationInfoFilter::get_bucket_hash(const VkPhysicalDeviceProperties2 *p
                                             const VkApplicationInfo *info,
                                             const void *device_pnext)
 {
-	return impl->get_bucket_hash(props, info, device_pnext);
+	return impl->get_bucket_hash(props, info, device_pnext, nullptr, nullptr);
+}
+
+std::string ApplicationInfoFilter::get_bucket_json_description(
+		const VkPhysicalDeviceProperties2 *props, const VkApplicationInfo *info, const void *device_pnext)
+{
+	return impl->get_bucket_json_description(props, info, device_pnext);
 }
 
 bool ApplicationInfoFilter::should_record_immutable_samplers(const VkApplicationInfo *info)
diff --git a/fossilize_application_filter.hpp b/fossilize_application_filter.hpp
index 0e2c88eb..4b688bc1 100644
--- a/fossilize_application_filter.hpp
+++ b/fossilize_application_filter.hpp
@@ -22,6 +22,7 @@
 
 #pragma once
 #include "fossilize_types.hpp"
+#include <string>
 
 struct VkApplicationInfo;
 struct VkPhysicalDeviceFeatures2;
@@ -53,6 +54,10 @@ class ApplicationInfoFilter
 	                     const void *device_pnext);
 	bool should_record_immutable_samplers(const VkApplicationInfo *info);
 
+	std::string get_bucket_json_description(const VkPhysicalDeviceProperties2 *props,
+	                                        const VkApplicationInfo *info,
+	                                        const void *device_pnext);
+
 private:
 	ApplicationInfoFilter();
 	struct Impl;
diff --git a/fossilize_db.cpp b/fossilize_db.cpp
index edc6e464..d4996d4c 100644
--- a/fossilize_db.cpp
+++ b/fossilize_db.cpp
@@ -427,6 +427,10 @@ bool DatabaseInterface::set_bucket_path(const char *, const char *)
 	return false;
 }
 
+void DatabaseInterface::set_bucket_info(const char *)
+{
+}
+
 static size_t deduce_imported_size(const void *mapped, size_t maximum_size)
 {
 	size_t total_size = 0;
@@ -1933,6 +1937,23 @@ struct ConcurrentDatabase : DatabaseInterface
 		}
 
 		base_path += "/";
+
+		if (!bucket_info.empty())
+		{
+			auto info_path = base_path + "bucket.json";
+			FILE *file = fopen(info_path.c_str(), "w");
+			if (file)
+			{
+				fputs(bucket_info.c_str(), file);
+				fclose(file);
+			}
+			else
+			{
+				LOGE("Failed to create file \"%s\".\n", info_path.c_str());
+				return false;
+			}
+		}
+
 		if (!Path::touch(base_path + "TOUCH"))
 			LOGW("Failed to touch last access in %s.\n", base_path.c_str());
 		base_path += "/" + bucket_basename;
@@ -2378,9 +2399,15 @@ struct ConcurrentDatabase : DatabaseInterface
 		return true;
 	}
 
+	void set_bucket_info(const char *json) override
+	{
+		bucket_info = json;
+	}
+
 	std::string base_path;
 	std::string bucket_dirname;
 	std::string bucket_basename;
+	std::string bucket_info;
 	DatabaseMode mode;
 	std::unique_ptr<DatabaseInterface> readonly_interface;
 	std::unique_ptr<DatabaseInterface> writeonly_interface;
diff --git a/fossilize_db.hpp b/fossilize_db.hpp
index 1230ec96..7b39b2ed 100644
--- a/fossilize_db.hpp
+++ b/fossilize_db.hpp
@@ -197,6 +197,11 @@ class DatabaseInterface
 	// See further comments after create_concurrent_database().
 	virtual bool set_bucket_path(const char *bucket_dirname, const char *bucket_basename);
 
+	// When using buckets, it's possible to add a bucket.json to the bucket to make it easy
+	// to check which configuration the bucket belongs to.
+	// This info does not have semantic meaning for parsing of an archive and can be discarded.
+	virtual void set_bucket_info(const char *json);
+
 	// Request termination of prepare() which can take a long time for very
 	// large archives.  This is useful if running prepare() on a thread and the need
 	// arises to stop loading the database.
diff --git a/layer/bucket-reverse.py b/layer/bucket-reverse.py
new file mode 100644
index 00000000..bdb260a1
--- /dev/null
+++ b/layer/bucket-reverse.py
@@ -0,0 +1,243 @@
+#!/usr/bin/env python3
+
+import sys
+import argparse
+import json
+
+class Hasher:
+    def __init__(self):
+        self._h = 0xcbf29ce484222325
+        pass
+
+    def _iterate_value(self, value : int):
+        self._h = (self._h * 0x100000001b3) ^ value
+        self._h = self._h & 0xffffffffffffffff
+
+    def u32(self, value : int):
+        self._iterate_value(value & 0xffffffff)
+
+    def boolean(self, value : bool):
+        self._iterate_value(int(value))
+
+    def string(self, value : str):
+        self._iterate_value(0xff)
+        for c in value:
+            self._iterate_value(ord(c) & 0xff)
+
+    def get(self):
+        return self._h
+
+def version_major(version : int) -> int:
+    return (version >> 22) & 0x3ff
+def version_minor(version : int) -> int:
+    return (version >> 12) & 0x3ff
+def version_patch(version : int) -> int:
+    return (version >> 0) & 0xfff
+
+def make_version(major : int, minor : int) -> int:
+    return (major << 22) | (minor << 12)
+
+# VendorIDs we expect to see.
+VendorIDs = [
+    0x1002, # AMD
+    0x8086, # Intel
+    0x10de, # NV
+    0x5143, # QCOM
+]
+
+def dep_to_stype(dep : str) -> int:
+    match dep:
+        case 'MutableDescriptorType': return 1000351000
+        case 'BufferDeviceAddress': return 1000257000
+        case 'DynamicRendering': return 1000044003
+        case 'BindlessUBO': return 1000161001
+        case 'DescriptorHeap': return 1000135009
+        case 'DescriptorBuffer': return 1000316002
+        case _: return 0
+
+def reverse_engine_version(filter : dict, hash : int, engine_name : str, engine_version) -> Optional[dict]:
+    num_variant_deps = len(filter['bucketVariantDependencies']) if 'bucketVariantDependencies' in filter else 0
+    num_variant_feature_deps = len(filter['bucketVariantFeatureDependencies']) if 'bucketVariantFeatureDependencies' in filter else 0
+    num_bucket_deltas = len(filter['engineVersionBucketDeltas']) if 'engineVersionBucketDeltas' in filter else 0
+    num_variants = 1 << (num_variant_deps + num_variant_feature_deps + num_bucket_deltas)
+
+    if num_variant_deps != 0:
+        # VendorID consumes 2 bits instead of 1.
+        if 'VendorID' in filter['bucketVariantDependencies']:
+            num_variants <<= 1
+
+        # Implied by outer arguments.
+        if 'EngineVersionMajor' in filter['bucketVariantDependencies']:
+            num_variants >>= 1
+        if 'EngineVersionMinor' in filter['bucketVariantDependencies']:
+            num_variants >>= 1
+        if 'EngineName' in filter['bucketVariantDependencies']:
+            num_variants >>= 1
+
+    for variant in range(num_variants):
+        h = Hasher()
+
+        # Per app hashing
+        h.u32(0)
+        # Per engine hashing
+        h.u32(0)
+
+        candidate = {}
+        bit_index = 0
+
+        # Hash in the same way that fossilize application filter would do.
+        if num_variant_deps != 0:
+            for dep in filter['bucketVariantDependencies']:
+                if dep == 'EngineVersionMajor':
+                    candidate[dep] = engine_version[0]
+                    h.u32(engine_version[0])
+                elif dep == 'EngineVersionMinor':
+                    candidate[dep] = engine_version[1]
+                    h.u32(engine_version[1])
+                elif dep == 'EngineName':
+                    candidate[dep] = engine_name
+                    h.string(engine_name)
+                elif 'Engine' in dep:
+                    return None
+                elif 'Application' in dep:
+                    return None
+                elif dep == 'VendorID':
+                    vendor_id = VendorIDs[(variant >> bit_index) & 3]
+                    candidate[dep] = vendor_id
+                    h.u32(vendor_id)
+                    bit_index += 2
+                else:
+                    state_bit = (variant >> bit_index) & 1
+                    candidate[dep] = state_bit
+                    h.u32(state_bit)
+
+                    # Subfeature hashing
+                    if dep == 'FragmentShadingRate':
+                        h.u32(1) # attachmentFragmentShadingRate
+                        h.u32(1) # pipelineFragmentShadingRate
+                        h.u32(1) # primitiveFragmentShadingRate
+                    elif dep == 'DescriptorBuffer':
+                        h.u32(1) # descriptorBuffer
+                        h.u32(1 if engine_name == 'vkd3d' else 0) # descriptorBufferPushDescriptor
+
+                    bit_index += 1
+
+        if num_variant_feature_deps != 0:
+            for dep in filter['bucketVariantFeatureDependencies']:
+                state_bit = (variant >> bit_index) & 1
+                candidate[dep] = state_bit
+                if state_bit:
+                    h.u32(dep_to_stype(dep))
+                    if dep == 'BindlessUBO':
+                        h.u32(10)
+
+                    # Subfeature hashing
+                    if dep == 'FragmentShadingRate':
+                        h.u32(1) # attachmentFragmentShadingRate
+                        h.u32(1) # pipelineFragmentShadingRate
+                        h.u32(1) # primitiveFragmentShadingRate
+                    elif dep == 'DescriptorBuffer':
+                        h.u32(1) # descriptorBuffer
+                        h.u32(1 if engine_name == 'vkd3d' else 0) # descriptorBufferPushDescriptor
+                    else:
+                        h.u32(1) # generic
+
+                bit_index += 1
+
+        if num_bucket_deltas != 0:
+            deltas = []
+            for dep in filter['engineVersionBucketDeltas']:
+                if make_version(engine_version[0], engine_version[1]) >= dep:
+                    h.u32(dep ^ 0xcafe)
+                    deltas.append(dep)
+                bit_index += 1
+            candidate['engineVersionBucketDeltas'] = deltas
+
+        #print(f'Engine {engine_name}, version {engine_version[0]}.{engine_version[1]}, candidate {candidate} yields hash {hex(h.get())}')
+
+        if h.get() == hash:
+            return { 'bucket' : candidate }
+    return None
+
+def reverse_engine_version_range(filter : dict, hash : int, engine_name : str,
+                                 minimum_version, maximum_version, maximum_minor_version) -> Optional[dict]:
+    # Iterate over all possible versions of the engine in the hope we'll strike gold.
+    maximum_major_version = maximum_version[0]
+    while minimum_version[0] <= maximum_major_version:
+        while minimum_version[1] <= maximum_minor_version:
+            if minimum_version[0] == maximum_version[0] and minimum_version[1] > maximum_version[1]:
+                return None
+            res = reverse_engine_version(filter, hash, engine_name, minimum_version)
+            if res:
+                return res
+            minimum_version = (minimum_version[0], minimum_version[1] + 1)
+        minimum_version = (minimum_version[0] + 1, 0)
+
+    return None
+
+def reverse_bucket_hash_vkd3d(filter : dict, hash : int) -> Optional[dict]:
+    # The Steam filter uses these. That's what we care about.
+    if 'minimumEngineVersion' not in filter:
+        return None
+
+    minimum_version = (version_major(filter['minimumEngineVersion']), version_minor(filter['minimumEngineVersion']))
+    return reverse_engine_version_range(filter, hash, 'vkd3d', minimum_version, (3, 1), 14)
+
+def reverse_bucket_hash_dxvk(filter : dict, hash : int) -> Optional[dict]:
+    # The Steam filter uses these. That's what we care about.
+    if 'minimumEngineVersion' not in filter:
+        return None
+
+    minimum_version = (version_major(filter['minimumEngineVersion']), version_minor(filter['minimumEngineVersion']))
+    # The minor version is not relevant for DXVK, but there are bucket delta hashes.
+    return reverse_engine_version_range(filter, hash, 'DXVK', minimum_version, (3, 1), 0)
+
+# filter is a loaded dict of the fossilize_engine_filters.json.
+def reverse_bucket_hash(filter : dict, hash : int) -> Optional[dict]:
+    if 'asset' not in filter:
+        return None
+    if filter['asset'] != 'FossilizeApplicationInfoFilter':
+        return None
+    if filter['version'] != 1:
+        return None
+    if 'engineFilters' not in filter:
+        return None
+
+    engine_filters = filter['engineFilters']
+    for engine_filter in engine_filters:
+        if engine_filter == 'DXVK':
+            result = reverse_bucket_hash_dxvk(engine_filters[engine_filter], hash)
+            if result:
+                return result
+        elif engine_filter == 'vkd3d':
+            result = reverse_bucket_hash_vkd3d(engine_filters[engine_filter], hash)
+            if result:
+                return result
+        else:
+            # We only know how to reverse these two. We don't use buckets for anything else right now.
+            pass
+
+def main():
+    parser = argparse.ArgumentParser(description = 'Tool for reversing a bucket hash back to its bucket.json')
+    parser.add_argument('--filter', type = str, help = 'Path to fossilize_engine_filters.json')
+    parser.add_argument('--hash', type = str, help = 'Bucket hash')
+    args = parser.parse_args()
+
+    if not args.filter:
+        raise ArgumentError('Must define --filter')
+    if not args.hash:
+        raise ArgumentError('Must define --hash')
+
+    hash = int(args.hash, 16)
+    with open(args.filter, 'r') as f:
+        filter_dict = json.loads(f.read())
+
+    bucket = reverse_bucket_hash(filter_dict, hash)
+    if bucket:
+        print(json.dumps(bucket, indent = 4))
+    else:
+        print('Could not reverse the bucket')
+        sys.exit(1)
+
+if __name__ == '__main__':
+    main()
\ No newline at end of file
diff --git a/layer/instance.cpp b/layer/instance.cpp
index 11522329..f74d0a31 100644
--- a/layer/instance.cpp
+++ b/layer/instance.cpp
@@ -432,6 +432,8 @@ StateRecorder *Instance::getStateRecorderForDevice(const VkPhysicalDevicePropert
 		Hash bucketHash = infoFilter->get_bucket_hash(props, appInfo, device_pnext);
 		sprintf(bucketPath, "%016" PRIx64, bucketHash);
 
+		std::string bucketInfo = infoFilter->get_bucket_json_description(props, appInfo, device_pnext);
+
 		// For convenience. Makes filenames similar in top-level directory and bucket directories.
 		auto basename = Path::basename(serializationPath);
 		auto prefix = basename;
@@ -440,6 +442,8 @@ StateRecorder *Instance::getStateRecorderForDevice(const VkPhysicalDevicePropert
 		prefix += hashString;
 
 		entry.interface->set_bucket_path(bucketPath, prefix.c_str());
+		if (!bucketInfo.empty())
+			entry.interface->set_bucket_info(bucketInfo.c_str());
 
 		if (entry.last_use_interface)
 		{
diff --git a/test/application_info_filter_test.cpp b/test/application_info_filter_test.cpp
index 67313dd8..591cbb8d 100644
--- a/test/application_info_filter_test.cpp
+++ b/test/application_info_filter_test.cpp
@@ -136,7 +136,7 @@ R"delim(
 
 	std::unique_ptr<Fossilize::ApplicationInfoFilter> filter_handle;
 	filter_handle.reset(Fossilize::ApplicationInfoFilter::parse(".__test_appinfo.json",
-																getenv_wrapper, &data));
+	                                                            getenv_wrapper, &data));
 
 	if (!filter_handle)
 	{
@@ -388,12 +388,19 @@ R"delim(
 		if (hash14 != hash15)
 			return EXIT_FAILURE;
 
+		std::string json15 = filter.get_bucket_json_description(&props2, &appinfo, &features2);
+
 		// Spot check for ApplicationName.
 		appinfo.pApplicationName = "foo";
 		auto hash16 = filter.get_bucket_hash(&props2, &appinfo, &features2);
 		if (hash16 == hash15)
 			return EXIT_FAILURE;
 
+		// Check that the JSON changed too.
+		std::string json16 = filter.get_bucket_json_description(&props2, &appinfo, &features2);
+		if (json15 == json16)
+			return EXIT_FAILURE;
+
 		// Check that the default variant hash is used.
 		appinfo.pApplicationName = "blah";
 		appinfo.pEngineName = "blah2";
@@ -439,34 +446,58 @@ R"delim(
 		features2.pNext = &descriptor_buffer_features;
 		if (filter.get_bucket_hash(&props2, &appinfo, &features2) != hash1)
 			return EXIT_FAILURE;
+		std::string json1 = filter.get_bucket_json_description(&props2, &appinfo, &features2);
 
 		features2.pNext = &descriptor_heap_features;
 		if (filter.get_bucket_hash(&props2, &appinfo, &features2) != hash1)
 			return EXIT_FAILURE;
 
+		// Check for JSON invariance. Not sure if rapidjson guarantees this, but seems like it.
+		std::string json2 = filter.get_bucket_json_description(&props2, &appinfo, &features2);
+		if (json2 != json1)
+			return EXIT_FAILURE;
+
 		features2.pNext = &bda_features;
 		if (filter.get_bucket_hash(&props2, &appinfo, &features2) != hash1)
 			return EXIT_FAILURE;
+		std::string json3 = filter.get_bucket_json_description(&props2, &appinfo, &features2);
+		if (json3 != json1)
+			return EXIT_FAILURE;
 
 		features2.pNext = &vulkan12_features;
 		if (filter.get_bucket_hash(&props2, &appinfo, &features2) != hash1)
 			return EXIT_FAILURE;
+		std::string json4 = filter.get_bucket_json_description(&props2, &appinfo, &features2);
+		if (json4 != json1)
+			return EXIT_FAILURE;
 
 		features2.pNext = &vulkan13_features;
 		if (filter.get_bucket_hash(&props2, &appinfo, &features2) != hash1)
 			return EXIT_FAILURE;
+		std::string json5 = filter.get_bucket_json_description(&props2, &appinfo, &features2);
+		if (json5 != json1)
+			return EXIT_FAILURE;
 
 		features2.pNext = &indexing_features;
 		if (filter.get_bucket_hash(&props2, &appinfo, &features2) != hash1)
 			return EXIT_FAILURE;
+		std::string json6 = filter.get_bucket_json_description(&props2, &appinfo, &features2);
+		if (json6 != json1)
+			return EXIT_FAILURE;
 
 		features2.pNext = &mutable_features;
 		if (filter.get_bucket_hash(&props2, &appinfo, &features2) != hash1)
 			return EXIT_FAILURE;
+		std::string json7 = filter.get_bucket_json_description(&props2, &appinfo, &features2);
+		if (json7 != json1)
+			return EXIT_FAILURE;
 
 		features2.pNext = &vrs_features;
 		if (filter.get_bucket_hash(&props2, &appinfo, &features2) != hash1)
 			return EXIT_FAILURE;
+		std::string json8 = filter.get_bucket_json_description(&props2, &appinfo, &features2);
+		if (json8 != json1)
+			return EXIT_FAILURE;
 
 		features2.pNext = &descriptor_buffer_features;
 		descriptor_buffer_features.descriptorBuffer = VK_TRUE;