diff --git a/README.md b/README.md
index bc13e48..c2833b6 100644
--- a/README.md
+++ b/README.md
@@ -176,7 +176,7 @@ All or a subset of the rows from a partition can be retrieved using a query-
 enum TestPolymorphicOperationReturnType: PolymorphicOperationReturnType {
     typealias AttributesType = StandardPrimaryKeyAttributes
     
-    static var types: [(Codable.Type, PolymorphicOperationReturnOption<StandardPrimaryKeyAttributes, Self>)] = [
+    static let types: [(Codable.Type, PolymorphicOperationReturnOption<StandardPrimaryKeyAttributes, Self>)] = [
         (TypeA.self, .init( {.typeA($0)} )),
         (TypeB.self, .init( {.typeB($0)} )),
         ]
@@ -728,8 +728,8 @@ public struct MyTimeToLiveAttributes: TimeToLiveAttributes {
 If the `Codable` type is used for a row type also conforms to the `CustomRowTypeIdentifier`, the *rowTypeIdentifier* property of this type will be used as the RowType recorded in the database row.
 
 ```swift
-struct TypeB: Codable, CustomRowTypeIdentifier {
-    static var rowTypeIdentifier: String? = "TypeBCustom"
+struct TypeB: SCodable, CustomRowTypeIdentifier {
+    static let rowTypeIdentifier: String? = "TypeBCustom"
     
     let thirdly: String
     let fourthly: String
diff --git a/Sources/DynamoDBTables/AWSDynamoDBCompositePrimaryKeyTable+monomorphicGetItems.swift b/Sources/DynamoDBTables/AWSDynamoDBCompositePrimaryKeyTable+monomorphicGetItems.swift
index 57603d5..51f8d9a 100644
--- a/Sources/DynamoDBTables/AWSDynamoDBCompositePrimaryKeyTable+monomorphicGetItems.swift
+++ b/Sources/DynamoDBTables/AWSDynamoDBCompositePrimaryKeyTable+monomorphicGetItems.swift
@@ -42,7 +42,7 @@ public extension AWSDynamoDBCompositePrimaryKeyTable {
      monitors the unprocessed items returned in the response from DynamoDB and uses an exponential backoff algorithm to retry those items using
      the same retry configuration as the underlying DynamoDB client.
      */
-    private class MonomorphicGetItemsRetriable<AttributesType: PrimaryKeyAttributes, ItemType: Codable> {
+    private class MonomorphicGetItemsRetriable<AttributesType: PrimaryKeyAttributes, ItemType: Sendable & Codable> {
         typealias OutputType = [CompositePrimaryKey<AttributesType>: TypedDatabaseItem<AttributesType, ItemType>]
 
         let dynamodb: AWSDynamoDB.DynamoDBClient
diff --git a/Sources/DynamoDBTables/CompositePrimaryKey.swift b/Sources/DynamoDBTables/CompositePrimaryKey.swift
index 89a4d3a..34966c7 100644
--- a/Sources/DynamoDBTables/CompositePrimaryKey.swift
+++ b/Sources/DynamoDBTables/CompositePrimaryKey.swift
@@ -26,7 +26,7 @@
 
 import Foundation
 
-public protocol PrimaryKeyAttributes {
+public protocol PrimaryKeyAttributes: Sendable {
     static var partitionKeyAttributeName: String { get }
     static var sortKeyAttributeName: String { get }
     static var indexName: String? { get }
@@ -66,7 +66,7 @@ struct DynamoDBAttributesTypeCodingKey: CodingKey {
     }
 }
 
-public struct CompositePrimaryKey<AttributesType: PrimaryKeyAttributes>: Codable, CustomStringConvertible, Hashable {
+public struct CompositePrimaryKey<AttributesType: PrimaryKeyAttributes>: Sendable, Codable, CustomStringConvertible, Hashable {
     public var description: String {
         "CompositePrimaryKey(partitionKey: \(self.partitionKey), sortKey: \(self.sortKey))"
     }
diff --git a/Sources/DynamoDBTables/DynamoDBCompositePrimaryKeyTable+clobberVersionedItemWithHistoricalRow.swift b/Sources/DynamoDBTables/DynamoDBCompositePrimaryKeyTable+clobberVersionedItemWithHistoricalRow.swift
index 7d5f080..f5f621e 100644
--- a/Sources/DynamoDBTables/DynamoDBCompositePrimaryKeyTable+clobberVersionedItemWithHistoricalRow.swift
+++ b/Sources/DynamoDBTables/DynamoDBCompositePrimaryKeyTable+clobberVersionedItemWithHistoricalRow.swift
@@ -44,7 +44,7 @@ public extension DynamoDBCompositePrimaryKeyTable {
                            version number.
      - completion: completion handler providing an error that was thrown or nil
      */
-    func clobberVersionedItemWithHistoricalRow<AttributesType: PrimaryKeyAttributes, ItemType: Codable>(
+    func clobberVersionedItemWithHistoricalRow<AttributesType: PrimaryKeyAttributes, ItemType: Sendable & Codable>(
         forPrimaryKey partitionKey: String,
         andHistoricalKey historicalKey: String,
         item: ItemType,
diff --git a/Sources/DynamoDBTables/DynamoDBCompositePrimaryKeyTable+conditionallyUpdateItem.swift b/Sources/DynamoDBTables/DynamoDBCompositePrimaryKeyTable+conditionallyUpdateItem.swift
index f704ad5..1a56243 100644
--- a/Sources/DynamoDBTables/DynamoDBCompositePrimaryKeyTable+conditionallyUpdateItem.swift
+++ b/Sources/DynamoDBTables/DynamoDBCompositePrimaryKeyTable+conditionallyUpdateItem.swift
@@ -43,7 +43,7 @@ public extension DynamoDBCompositePrimaryKeyTable {
          withRetries: the number of times to attempt to retry the update before failing.
          updatedPayloadProvider: the provider that will return updated payloads.
      */
-    func conditionallyUpdateItem<AttributesType, ItemType: Codable>(
+    func conditionallyUpdateItem<AttributesType, ItemType: Sendable & Codable>(
         forKey key: CompositePrimaryKey<AttributesType>,
         withRetries retries: Int = 10,
         updatedPayloadProvider: @escaping (ItemType) async throws -> ItemType) async throws
@@ -60,7 +60,7 @@ public extension DynamoDBCompositePrimaryKeyTable {
 
     // Explicitly specify an overload with sync updatedPayloadProvider
     // to avoid the compiler matching a call site with such a provider with the EventLoopFuture-returning overload.
-    func conditionallyUpdateItem<AttributesType, ItemType: Codable>(
+    func conditionallyUpdateItem<AttributesType, ItemType: Sendable & Codable>(
         forKey key: CompositePrimaryKey<AttributesType>,
         withRetries retries: Int = 10,
         updatedPayloadProvider: @escaping (ItemType) throws -> ItemType) async throws
diff --git a/Sources/DynamoDBTables/DynamoDBCompositePrimaryKeyTable.swift b/Sources/DynamoDBTables/DynamoDBCompositePrimaryKeyTable.swift
index 8df75ad..d8ffc8d 100644
--- a/Sources/DynamoDBTables/DynamoDBCompositePrimaryKeyTable.swift
+++ b/Sources/DynamoDBTables/DynamoDBCompositePrimaryKeyTable.swift
@@ -70,7 +70,7 @@ public extension Swift.Error {
 /**
  Enumeration of the types of conditions that can be specified for an attribute.
  */
-public enum AttributeCondition {
+public enum AttributeCondition: Sendable {
     case equals(String)
     case lessThan(String)
     case lessThanOrEqual(String)
@@ -80,7 +80,7 @@ public enum AttributeCondition {
     case beginsWith(String)
 }
 
-public enum WriteEntry<AttributesType: PrimaryKeyAttributes, ItemType: Codable> {
+public enum WriteEntry<AttributesType: PrimaryKeyAttributes, ItemType: Sendable & Codable>: Sendable {
     case update(new: TypedDatabaseItem<AttributesType, ItemType>, existing: TypedDatabaseItem<AttributesType, ItemType>)
     case insert(new: TypedDatabaseItem<AttributesType, ItemType>)
     case deleteAtKey(key: CompositePrimaryKey<AttributesType>)
diff --git a/Sources/DynamoDBTables/InMemoryDynamoDBCompositePrimaryKeyTable.swift b/Sources/DynamoDBTables/InMemoryDynamoDBCompositePrimaryKeyTable.swift
index e092e2c..0a59c14 100644
--- a/Sources/DynamoDBTables/InMemoryDynamoDBCompositePrimaryKeyTable.swift
+++ b/Sources/DynamoDBTables/InMemoryDynamoDBCompositePrimaryKeyTable.swift
@@ -25,10 +25,10 @@
 //  DynamoDBTables
 //
 
-import AWSDynamoDB
+@preconcurrency import AWSDynamoDB
 import Foundation
 
-public protocol PolymorphicOperationReturnTypeConvertable {
+public protocol PolymorphicOperationReturnTypeConvertable: Sendable {
     var createDate: Foundation.Date { get }
     var rowStatus: RowStatus { get }
 
@@ -41,7 +41,7 @@ extension TypedDatabaseItem: PolymorphicOperationReturnTypeConvertable {
     }
 }
 
-public typealias ExecuteItemFilterType = (String, String, String, PolymorphicOperationReturnTypeConvertable)
+public typealias ExecuteItemFilterType = @Sendable (String, String, String, PolymorphicOperationReturnTypeConvertable)
     -> Bool
 
 public protocol InMemoryTransactionDelegate {
diff --git a/Sources/DynamoDBTables/InMemoryDynamoDBCompositePrimaryKeysProjection.swift b/Sources/DynamoDBTables/InMemoryDynamoDBCompositePrimaryKeysProjection.swift
index 39ab088..e064c1e 100644
--- a/Sources/DynamoDBTables/InMemoryDynamoDBCompositePrimaryKeysProjection.swift
+++ b/Sources/DynamoDBTables/InMemoryDynamoDBCompositePrimaryKeysProjection.swift
@@ -31,7 +31,7 @@ import Foundation
 public struct InMemoryDynamoDBCompositePrimaryKeysProjection: DynamoDBCompositePrimaryKeysProjection {
     let keysWrapper: InMemoryDynamoDBCompositePrimaryKeysProjectionStore
 
-    public init(keys: [Any] = []) {
+    public init(keys: [Sendable] = []) {
         self.keysWrapper = InMemoryDynamoDBCompositePrimaryKeysProjectionStore(keys: keys)
     }
 
@@ -39,7 +39,7 @@ public struct InMemoryDynamoDBCompositePrimaryKeysProjection: DynamoDBCompositeP
         self.keysWrapper = keysWrapper
     }
 
-    public var keys: [Any] {
+    public var keys: [Sendable] {
         get async {
             await self.keysWrapper.keys
         }
diff --git a/Sources/DynamoDBTables/InMemoryDynamoDBCompositePrimaryKeysProjectionStore.swift b/Sources/DynamoDBTables/InMemoryDynamoDBCompositePrimaryKeysProjectionStore.swift
index cce6b34..d8a2569 100644
--- a/Sources/DynamoDBTables/InMemoryDynamoDBCompositePrimaryKeysProjectionStore.swift
+++ b/Sources/DynamoDBTables/InMemoryDynamoDBCompositePrimaryKeysProjectionStore.swift
@@ -31,9 +31,9 @@ import Foundation
 // MARK: - Store implementation
 
 actor InMemoryDynamoDBCompositePrimaryKeysProjectionStore {
-    public var keys: [Any] = []
+    public var keys: [Sendable] = []
 
-    public init(keys: [Any] = []) {
+    public init(keys: [Sendable] = []) {
         self.keys = keys
     }
 
diff --git a/Sources/DynamoDBTables/PolymorphicOperationReturnType.swift b/Sources/DynamoDBTables/PolymorphicOperationReturnType.swift
index bef4b2f..cebe3a6 100644
--- a/Sources/DynamoDBTables/PolymorphicOperationReturnType.swift
+++ b/Sources/DynamoDBTables/PolymorphicOperationReturnType.swift
@@ -33,25 +33,27 @@ public protocol BatchCapableReturnType {
     func getItemKey() -> CompositePrimaryKey<AttributesType>
 }
 
-public protocol PolymorphicOperationReturnType {
+public protocol PolymorphicOperationReturnType: Sendable {
     associatedtype AttributesType: PrimaryKeyAttributes
 
     static var types: [(Codable.Type, PolymorphicOperationReturnOption<AttributesType, Self>)] { get }
 }
 
-public struct PolymorphicOperationReturnOption<AttributesType: PrimaryKeyAttributes, ReturnType> {
-    private let decodingPayloadHandler: (Decoder) throws -> ReturnType
-    private let typeConvertingPayloadHander: (Any) throws -> ReturnType
+public struct PolymorphicOperationReturnOption<AttributesType: PrimaryKeyAttributes, ReturnType>: Sendable {
+    private let decodingPayloadHandler: @Sendable (Decoder) throws -> ReturnType
+    private let typeConvertingPayloadHander: @Sendable (Any) throws -> ReturnType
 
     public init<RowType: Codable>(
-        _ payloadHandler: @escaping (TypedDatabaseItem<AttributesType, RowType>) -> ReturnType)
+        _ payloadHandler: @escaping @Sendable (TypedDatabaseItem<AttributesType, RowType>) -> ReturnType)
     {
+        @Sendable
         func newDecodingPayloadHandler(decoder: Decoder) throws -> ReturnType {
             let typedDatabaseItem: TypedDatabaseItem<AttributesType, RowType> = try TypedDatabaseItem(from: decoder)
 
             return payloadHandler(typedDatabaseItem)
         }
 
+        @Sendable
         func newTypeConvertingPayloadHandler(input: Any) throws -> ReturnType {
             guard let typedDatabaseItem = input as? TypedDatabaseItem<AttributesType, RowType> else {
                 let description = "Expected to use item type \(TypedDatabaseItem<AttributesType, RowType>.self)."
diff --git a/Sources/DynamoDBTables/PolymorphicWriteEntry.swift b/Sources/DynamoDBTables/PolymorphicWriteEntry.swift
index 6146978..c3c58f5 100644
--- a/Sources/DynamoDBTables/PolymorphicWriteEntry.swift
+++ b/Sources/DynamoDBTables/PolymorphicWriteEntry.swift
@@ -44,7 +44,7 @@ public protocol PolymorphicTransactionConstraintTransform {
 
 // Conforming types are provided by the application to express the different possible write entries
 // and how they can be converted to the table-provided transform type.
-public protocol PolymorphicWriteEntry {
+public protocol PolymorphicWriteEntry: Sendable {
     func handle<Context: PolymorphicWriteEntryContext>(context: Context) throws -> Context.WriteEntryTransformType
 
     var compositePrimaryKey: StandardCompositePrimaryKey? { get }
@@ -58,13 +58,13 @@ public extension PolymorphicWriteEntry {
 
 public typealias StandardTransactionConstraintEntry<ItemType: Codable> = TransactionConstraintEntry<StandardPrimaryKeyAttributes, ItemType>
 
-public enum TransactionConstraintEntry<AttributesType: PrimaryKeyAttributes, ItemType: Codable> {
+public enum TransactionConstraintEntry<AttributesType: PrimaryKeyAttributes, ItemType: Sendable & Codable>: Sendable {
     case required(existing: TypedDatabaseItem<AttributesType, ItemType>)
 }
 
 // Conforming types are provided by the application to express the different possible constraint entries
 // and how they can be converted to the table-provided transform type.
-public protocol PolymorphicTransactionConstraintEntry {
+public protocol PolymorphicTransactionConstraintEntry: Sendable {
     func handle<Context: PolymorphicWriteEntryContext>(context: Context) throws -> Context.WriteTransactionConstraintType
 
     var compositePrimaryKey: StandardCompositePrimaryKey? { get }
diff --git a/Sources/DynamoDBTables/RetryConfiguration.swift b/Sources/DynamoDBTables/RetryConfiguration.swift
index 02a6e75..11dc5a8 100644
--- a/Sources/DynamoDBTables/RetryConfiguration.swift
+++ b/Sources/DynamoDBTables/RetryConfiguration.swift
@@ -32,7 +32,7 @@ public typealias RetryInterval = UInt32
 /**
  Retry configuration for the requests made by a table..
  */
-public struct RetryConfiguration {
+public struct RetryConfiguration: Sendable {
     // Number of retries to be attempted
     public let numRetries: Int
     // First interval of retry in millis
@@ -80,10 +80,10 @@ public struct RetryConfiguration {
     }
 
     /// Default try configuration with 5 retries starting at 500 ms interval.
-    public static var `default` = RetryConfiguration(numRetries: 5, baseRetryInterval: 500,
+    public static let `default` = RetryConfiguration(numRetries: 5, baseRetryInterval: 500,
                                                      maxRetryInterval: 10000, exponentialBackoff: 2)
 
     /// Retry Configuration with no retries.
-    public static var noRetries = RetryConfiguration(numRetries: 0, baseRetryInterval: 0,
+    public static let noRetries = RetryConfiguration(numRetries: 0, baseRetryInterval: 0,
                                                      maxRetryInterval: 0, exponentialBackoff: 0)
 }
diff --git a/Sources/DynamoDBTables/RowWithIndex.swift b/Sources/DynamoDBTables/RowWithIndex.swift
index ee14ca6..e1942fe 100644
--- a/Sources/DynamoDBTables/RowWithIndex.swift
+++ b/Sources/DynamoDBTables/RowWithIndex.swift
@@ -51,7 +51,7 @@ public func createRowWithIndexCodingKey(stringValue: String) -> RowWithIndexCodi
     RowWithIndexCodingKey(stringValue: stringValue)!
 }
 
-public struct RowWithIndex<RowType: Codable, Identity: IndexIdentity>: Codable, CustomRowTypeIdentifier {
+public struct RowWithIndex<RowType: Sendable & Codable, Identity: IndexIdentity>: Sendable, Codable, CustomRowTypeIdentifier {
     public static var rowTypeIdentifier: String? {
         let rowTypeIdentity = getTypeRowIdentifier(type: RowType.self)
         let indexIdentity = Identity.identity
diff --git a/Sources/DynamoDBTables/RowWithItemVersion.swift b/Sources/DynamoDBTables/RowWithItemVersion.swift
index ada5eec..faca87b 100644
--- a/Sources/DynamoDBTables/RowWithItemVersion.swift
+++ b/Sources/DynamoDBTables/RowWithItemVersion.swift
@@ -26,7 +26,7 @@
 
 import Foundation
 
-public struct RowWithItemVersion<RowType: Codable>: Codable, CustomRowTypeIdentifier {
+public struct RowWithItemVersion<RowType: Sendable & Codable>: Sendable, Codable, CustomRowTypeIdentifier {
     public static var rowTypeIdentifier: String? {
         let rowTypeIdentity = getTypeRowIdentifier(type: RowType.self)
 
diff --git a/Sources/DynamoDBTables/TimeToLive.swift b/Sources/DynamoDBTables/TimeToLive.swift
index 67834bf..9b50600 100644
--- a/Sources/DynamoDBTables/TimeToLive.swift
+++ b/Sources/DynamoDBTables/TimeToLive.swift
@@ -38,7 +38,7 @@ public struct StandardTimeToLiveAttributes: TimeToLiveAttributes {
 
 public typealias StandardTimeToLive = TimeToLive<StandardTimeToLiveAttributes>
 
-public struct TimeToLive<AttributesType: TimeToLiveAttributes>: Codable, CustomStringConvertible, Hashable {
+public struct TimeToLive<AttributesType: TimeToLiveAttributes>: Sendable, Codable, CustomStringConvertible, Hashable {
     public var description: String {
         "TimeToLive(timeToLiveTimestamp: \(self.timeToLiveTimestamp)"
     }
diff --git a/Sources/DynamoDBTables/TypedDatabaseItemWithTimeToLive.swift b/Sources/DynamoDBTables/TypedDatabaseItemWithTimeToLive.swift
index f5819cc..1177c99 100644
--- a/Sources/DynamoDBTables/TypedDatabaseItemWithTimeToLive.swift
+++ b/Sources/DynamoDBTables/TypedDatabaseItemWithTimeToLive.swift
@@ -26,7 +26,7 @@
 
 import Foundation
 
-public struct RowStatus: Codable {
+public struct RowStatus: Sendable, Codable {
     public let rowVersion: Int
     public let lastUpdatedDate: Date
 
@@ -41,7 +41,7 @@ public struct RowStatus: Codable {
     }
 }
 
-public protocol DatabaseItem {
+public protocol DatabaseItem: Sendable {
     associatedtype AttributesType: PrimaryKeyAttributes
     // Default to StandardTimeToLiveAttributes for backwards compatibility
     associatedtype TimeToLiveAttributesType: TimeToLiveAttributes = StandardTimeToLiveAttributes
@@ -61,11 +61,11 @@ public extension DatabaseItem {
 public protocol StandardDatabaseItem: DatabaseItem where AttributesType == StandardPrimaryKeyAttributes {}
 
 // Default to StandardTimeToLiveAttributes for backwards compatibility
-public typealias TypedDatabaseItem<AttributesType: PrimaryKeyAttributes, RowType: Codable> = TypedDatabaseItemWithTimeToLive<AttributesType, RowType, StandardTimeToLiveAttributes>
+public typealias TypedDatabaseItem<AttributesType: PrimaryKeyAttributes, RowType: Sendable & Codable> = TypedDatabaseItemWithTimeToLive<AttributesType, RowType, StandardTimeToLiveAttributes>
 
 public struct TypedDatabaseItemWithTimeToLive<AttributesType: PrimaryKeyAttributes,
-    RowType: Codable,
-    TimeToLiveAttributesType: TimeToLiveAttributes>: DatabaseItem, Codable
+    RowType: Sendable & Codable,
+    TimeToLiveAttributesType: TimeToLiveAttributes>: DatabaseItem, Sendable, Codable
 {
     public let compositePrimaryKey: CompositePrimaryKey<AttributesType>
     public let createDate: Date
diff --git a/Tests/DynamoDBTablesTests/DynamoDBCompositePrimaryKeyTableHistoricalItemExtensionsTests.swift b/Tests/DynamoDBTablesTests/DynamoDBCompositePrimaryKeyTableHistoricalItemExtensionsTests.swift
index 3488c84..e134544 100644
--- a/Tests/DynamoDBTablesTests/DynamoDBCompositePrimaryKeyTableHistoricalItemExtensionsTests.swift
+++ b/Tests/DynamoDBTablesTests/DynamoDBCompositePrimaryKeyTableHistoricalItemExtensionsTests.swift
@@ -36,8 +36,9 @@ private typealias DatabaseRowType =
  * For these tests, a primary item Provider should always return a default value for nil arguments. The Provider Provider requires a non-nil default in order to initialize a Provider.
  */
 private func primaryItemProviderProvider(_ defaultItem: DatabaseRowType) ->
-    (DatabaseRowType?) -> DatabaseRowType
+    @Sendable (DatabaseRowType?) -> DatabaseRowType
 {
+    @Sendable
     func primaryItemProvider(_ item: DatabaseRowType?) ->
         DatabaseRowType
     {
diff --git a/Tests/DynamoDBTablesTests/DynamoDBEncoderDecoderTests.swift b/Tests/DynamoDBTablesTests/DynamoDBEncoderDecoderTests.swift
index 6cc1903..872a876 100644
--- a/Tests/DynamoDBTablesTests/DynamoDBEncoderDecoderTests.swift
+++ b/Tests/DynamoDBTablesTests/DynamoDBEncoderDecoderTests.swift
@@ -27,9 +27,6 @@
 @testable import DynamoDBTables
 import XCTest
 
-private let dynamodbEncoder = DynamoDBEncoder()
-private let dynamodbDecoder = DynamoDBDecoder()
-
 struct CoreAccountAttributes: Codable {
     var description: String
     var mappedValues: [String: String]
@@ -64,14 +61,14 @@ class DynamoDBEncoderDecoderTests: XCTestCase {
         mappedValues: ["A": "one", "B": "two"],
         notificationTargets: NotificationTargets(currentIDs: [], maximum: 20))
 
-    func testEncoderDecoder() {
+    func testEncoderDecoder() throws {
         // create key and database item to create
         let key = StandardCompositePrimaryKey(partitionKey: partitionKey, sortKey: sortKey)
         let newDatabaseItem: DatabaseItemType = StandardTypedDatabaseItem.newItem(withKey: key, andValue: self.attributes)
 
-        let encodedAttributeValue = try! dynamodbEncoder.encode(newDatabaseItem)
+        let encodedAttributeValue = try DynamoDBEncoder().encode(newDatabaseItem)
 
-        let output: DatabaseItemType = try! dynamodbDecoder.decode(encodedAttributeValue)
+        let output: DatabaseItemType = try DynamoDBDecoder().decode(encodedAttributeValue)
 
         XCTAssertEqual(newDatabaseItem.rowValue, output.rowValue)
         XCTAssertEqual(self.partitionKey, output.compositePrimaryKey.partitionKey)
@@ -80,7 +77,7 @@ class DynamoDBEncoderDecoderTests: XCTestCase {
         XCTAssertNil(output.timeToLive)
     }
 
-    func testEncoderDecoderWithTimeToLive() {
+    func testEncoderDecoderWithTimeToLive() throws {
         let timeToLiveTimestamp: Int64 = 123_456_789
         let timeToLive = StandardTimeToLive(timeToLiveTimestamp: timeToLiveTimestamp)
 
@@ -91,9 +88,9 @@ class DynamoDBEncoderDecoderTests: XCTestCase {
             andValue: self.attributes,
             andTimeToLive: timeToLive)
 
-        let encodedAttributeValue = try! dynamodbEncoder.encode(newDatabaseItem)
+        let encodedAttributeValue = try DynamoDBEncoder().encode(newDatabaseItem)
 
-        let output: DatabaseItemType = try! dynamodbDecoder.decode(encodedAttributeValue)
+        let output: DatabaseItemType = try DynamoDBDecoder().decode(encodedAttributeValue)
 
         XCTAssertEqual(newDatabaseItem.rowValue, output.rowValue)
         XCTAssertEqual(self.partitionKey, output.compositePrimaryKey.partitionKey)
diff --git a/Tests/DynamoDBTablesTests/InMemoryDynamoDBCompositePrimaryKeyTableTests.swift b/Tests/DynamoDBTablesTests/InMemoryDynamoDBCompositePrimaryKeyTableTests.swift
index 8c3a402..20ddf26 100644
--- a/Tests/DynamoDBTablesTests/InMemoryDynamoDBCompositePrimaryKeyTableTests.swift
+++ b/Tests/DynamoDBTablesTests/InMemoryDynamoDBCompositePrimaryKeyTableTests.swift
@@ -31,7 +31,7 @@ import XCTest
 enum TestPolymorphicOperationReturnType: PolymorphicOperationReturnType {
     typealias AttributesType = StandardPrimaryKeyAttributes
 
-    static var types: [(Codable.Type, PolymorphicOperationReturnOption<StandardPrimaryKeyAttributes, Self>)] = [
+    static let types: [(Codable.Type, PolymorphicOperationReturnOption<StandardPrimaryKeyAttributes, Self>)] = [
         (TestTypeA.self, .init { .testTypeA($0) }),
     ]
 
diff --git a/Tests/DynamoDBTablesTests/SimulateConcurrencyDynamoDBCompositePrimaryKeyTableTests.swift b/Tests/DynamoDBTablesTests/SimulateConcurrencyDynamoDBCompositePrimaryKeyTableTests.swift
index e1803f8..695b87f 100644
--- a/Tests/DynamoDBTablesTests/SimulateConcurrencyDynamoDBCompositePrimaryKeyTableTests.swift
+++ b/Tests/DynamoDBTablesTests/SimulateConcurrencyDynamoDBCompositePrimaryKeyTableTests.swift
@@ -33,7 +33,7 @@ private typealias DatabaseRowType = StandardTypedDatabaseItem<TestTypeA>
 enum ExpectedQueryableTypes: PolymorphicOperationReturnType {
     typealias AttributesType = StandardPrimaryKeyAttributes
 
-    static var types: [(Codable.Type, PolymorphicOperationReturnOption<StandardPrimaryKeyAttributes, Self>)] = [
+    static let types: [(Codable.Type, PolymorphicOperationReturnOption<StandardPrimaryKeyAttributes, Self>)] = [
         (TestTypeA.self, .init { .testTypeA($0) }),
     ]
 
@@ -67,7 +67,7 @@ class SimulateConcurrencyDynamoDBCompositePrimaryKeyTableTests: XCTestCase {
         var errorCount = 0
 
         for _ in 0 ..< 10 {
-            guard let item: DatabaseRowType = try! await table.getItem(forKey: key) else {
+            guard let item: DatabaseRowType = try await table.getItem(forKey: key) else {
                 return XCTFail("Expected to retrieve item and there was none")
             }
 
@@ -83,7 +83,7 @@ class SimulateConcurrencyDynamoDBCompositePrimaryKeyTableTests: XCTestCase {
 
         try await table.deleteItem(forKey: key)
 
-        let nowDeletedItem: DatabaseRowType? = try! await table.getItem(forKey: key)
+        let nowDeletedItem: DatabaseRowType? = try await table.getItem(forKey: key)
         XCTAssertNil(nowDeletedItem)
     }
 
@@ -128,7 +128,7 @@ class SimulateConcurrencyDynamoDBCompositePrimaryKeyTableTests: XCTestCase {
         var errorCount = 0
 
         for _ in 0 ..< 10 {
-            let query: [ExpectedQueryableTypes] = try! await table.query(forPartitionKey: "partitionId",
+            let query: [ExpectedQueryableTypes] = try await table.query(forPartitionKey: "partitionId",
                                                                          sortKeyCondition: .equals("sortId"))
 
             guard query.count == 1, case let .testTypeA(firstDatabaseItem) = query[0] else {
@@ -155,7 +155,7 @@ class SimulateConcurrencyDynamoDBCompositePrimaryKeyTableTests: XCTestCase {
 
         try await table.deleteItem(forKey: key)
 
-        let nowDeletedItem: DatabaseRowType? = try! await table.getItem(forKey: key)
+        let nowDeletedItem: DatabaseRowType? = try await table.getItem(forKey: key)
         XCTAssertNil(nowDeletedItem)
     }
 
@@ -173,7 +173,7 @@ class SimulateConcurrencyDynamoDBCompositePrimaryKeyTableTests: XCTestCase {
         var errorCount = 0
 
         for _ in 0 ..< 10 {
-            let query: [DatabaseRowType] = try! await table.monomorphicQuery(forPartitionKey: "partitionId",
+            let query: [DatabaseRowType] = try await table.monomorphicQuery(forPartitionKey: "partitionId",
                                                                              sortKeyCondition: .equals("sortId"))
 
             guard query.count == 1, let firstQuery = query.first else {
@@ -198,7 +198,7 @@ class SimulateConcurrencyDynamoDBCompositePrimaryKeyTableTests: XCTestCase {
 
         try await table.deleteItem(forKey: key)
 
-        let nowDeletedItem: DatabaseRowType? = try! await table.getItem(forKey: key)
+        let nowDeletedItem: DatabaseRowType? = try await table.getItem(forKey: key)
         XCTAssertNil(nowDeletedItem)
     }
 
@@ -227,7 +227,7 @@ class SimulateConcurrencyDynamoDBCompositePrimaryKeyTableTests: XCTestCase {
 
         try await table.deleteItem(forKey: key)
 
-        let nowDeletedItem: DatabaseRowType? = try! await table.getItem(forKey: key)
+        let nowDeletedItem: DatabaseRowType? = try await table.getItem(forKey: key)
         XCTAssertNil(nowDeletedItem)
     }
 }
diff --git a/Tests/DynamoDBTablesTests/SmokeDynamoDBTestInput.swift b/Tests/DynamoDBTablesTests/SmokeDynamoDBTestInput.swift
index 930b089..101e448 100644
--- a/Tests/DynamoDBTablesTests/SmokeDynamoDBTestInput.swift
+++ b/Tests/DynamoDBTablesTests/SmokeDynamoDBTestInput.swift
@@ -29,7 +29,7 @@ import Foundation
 enum AllQueryableTypes: PolymorphicOperationReturnType {
     typealias AttributesType = StandardPrimaryKeyAttributes
 
-    static var types: [(Codable.Type, PolymorphicOperationReturnOption<StandardPrimaryKeyAttributes, Self>)] = [
+    static let types: [(Codable.Type, PolymorphicOperationReturnOption<StandardPrimaryKeyAttributes, Self>)] = [
         (TypeA.self, .init { .typeA($0) }),
         (TypeB.self, .init { .typeB($0) }),
     ]
@@ -41,22 +41,22 @@ enum AllQueryableTypes: PolymorphicOperationReturnType {
 enum SomeQueryableTypes: PolymorphicOperationReturnType {
     typealias AttributesType = StandardPrimaryKeyAttributes
 
-    static var types: [(Codable.Type, PolymorphicOperationReturnOption<StandardPrimaryKeyAttributes, Self>)] = [
+    static let types: [(Codable.Type, PolymorphicOperationReturnOption<StandardPrimaryKeyAttributes, Self>)] = [
         (TypeA.self, .init { .typeA($0) }),
     ]
 
     case typeA(StandardTypedDatabaseItem<TypeA>)
 }
 
-struct GSI1PKIndexIdentity: IndexIdentity {
-    static var codingKey = createRowWithIndexCodingKey(stringValue: "GSI-1-PK")
-    static var identity = "GSI1PK"
+struct GSI1PKIndexIdentity: IndexIdentity, Sendable {
+    static let codingKey = createRowWithIndexCodingKey(stringValue: "GSI-1-PK")
+    static let identity = "GSI1PK"
 }
 
 enum AllQueryableTypesWithIndex: PolymorphicOperationReturnType {
     typealias AttributesType = StandardPrimaryKeyAttributes
 
-    static var types: [(Codable.Type, PolymorphicOperationReturnOption<StandardPrimaryKeyAttributes, Self>)] = [
+    static let types: [(Codable.Type, PolymorphicOperationReturnOption<StandardPrimaryKeyAttributes, Self>)] = [
         (RowWithIndex<TypeA, GSI1PKIndexIdentity>.self, .init { .typeAWithIndex($0) }),
         (TypeB.self, .init { .typeB($0) }),
     ]
@@ -65,7 +65,7 @@ enum AllQueryableTypesWithIndex: PolymorphicOperationReturnType {
     case typeB(StandardTypedDatabaseItem<TestTypeB>)
 }
 
-struct TypeA: Codable {
+struct TypeA: Codable, Sendable {
     let firstly: String
     let secondly: String
 
@@ -76,7 +76,7 @@ struct TypeA: Codable {
 }
 
 struct TypeB: Codable, CustomRowTypeIdentifier {
-    static var rowTypeIdentifier: String? = "TypeBCustom"
+    static let rowTypeIdentifier: String? = "TypeBCustom"
 
     let thirdly: String
     let fourthly: String
diff --git a/Tests/DynamoDBTablesTests/SmokeDynamoDBTests.swift b/Tests/DynamoDBTablesTests/SmokeDynamoDBTests.swift
index e8eb403..12288a1 100644
--- a/Tests/DynamoDBTablesTests/SmokeDynamoDBTests.swift
+++ b/Tests/DynamoDBTablesTests/SmokeDynamoDBTests.swift
@@ -28,9 +28,6 @@ import AWSDynamoDB
 @testable import DynamoDBTables
 import XCTest
 
-private let dynamodbEncoder = DynamoDBEncoder()
-private let dynamodbDecoder = DynamoDBDecoder()
-
 private func createDecoder() -> JSONDecoder {
     let jsonDecoder = JSONDecoder()
     #if os(Linux)
@@ -67,13 +64,13 @@ class DynamoDBTablesTests: XCTestCase {
         }
 
         guard let databaseItem: StandardTypedDatabaseItem<TypeA> = try assertNoThrow(
-            dynamodbDecoder.decode(jsonAttributeValue))
+            DynamoDBDecoder().decode(jsonAttributeValue))
         else {
             return
         }
 
         guard let decodeAttributeValue = try assertNoThrow(
-            dynamodbEncoder.encode(databaseItem))
+            DynamoDBEncoder().encode(databaseItem))
         else {
             return
         }
@@ -96,13 +93,13 @@ class DynamoDBTablesTests: XCTestCase {
         }
 
         guard let databaseItem: StandardTypedDatabaseItem<TypeA> = try assertNoThrow(
-            dynamodbDecoder.decode(jsonAttributeValue))
+            DynamoDBDecoder().decode(jsonAttributeValue))
         else {
             return
         }
 
         guard let decodeAttributeValue = try assertNoThrow(
-            dynamodbEncoder.encode(databaseItem))
+            DynamoDBEncoder().encode(databaseItem))
         else {
             return
         }
@@ -125,7 +122,7 @@ class DynamoDBTablesTests: XCTestCase {
         }
 
         guard let databaseItem: StandardTypedDatabaseItem<TypeA> = try assertNoThrow(
-            dynamodbDecoder.decode(attributeValue))
+            DynamoDBDecoder().decode(attributeValue))
         else {
             return
         }
@@ -151,7 +148,7 @@ class DynamoDBTablesTests: XCTestCase {
         }
 
         guard let databaseItem: StandardTypedDatabaseItem<TypeA> = try assertNoThrow(
-            dynamodbDecoder.decode(attributeValue))
+            DynamoDBDecoder().decode(attributeValue))
         else {
             return
         }
@@ -182,7 +179,7 @@ class DynamoDBTablesTests: XCTestCase {
 
         let itemsOptional: [ReturnTypeDecodable<AllQueryableTypes>]? = try assertNoThrow(
             attributeValues.map { value in
-                try dynamodbDecoder.decode(value)
+                try DynamoDBDecoder().decode(value)
             })
 
         guard let items = itemsOptional else {
@@ -233,7 +230,7 @@ class DynamoDBTablesTests: XCTestCase {
 
         do {
             let _: [ReturnTypeDecodable<SomeQueryableTypes>] = try attributeValues.map { value in
-                try dynamodbDecoder.decode(value)
+                try DynamoDBDecoder().decode(value)
             }
         } catch let DynamoDBTableError.unexpectedType(provided: provided) {
             XCTAssertEqual(provided, "TypeBCustom")
@@ -257,7 +254,7 @@ class DynamoDBTablesTests: XCTestCase {
 
         let itemsOptional: [ReturnTypeDecodable<AllQueryableTypesWithIndex>]? = try assertNoThrow(
             attributeValues.map { value in
-                try dynamodbDecoder.decode(value)
+                try DynamoDBDecoder().decode(value)
             })
 
         guard let items = itemsOptional else {
diff --git a/Tests/DynamoDBTablesTests/TestConfiguration.swift b/Tests/DynamoDBTablesTests/TestConfiguration.swift
index 1bfe83c..9ff59e8 100644
--- a/Tests/DynamoDBTablesTests/TestConfiguration.swift
+++ b/Tests/DynamoDBTablesTests/TestConfiguration.swift
@@ -33,7 +33,7 @@ struct TestTypeA: Codable, Equatable {
 }
 
 struct TestTypeB: Codable, Equatable, CustomRowTypeIdentifier {
-    static var rowTypeIdentifier: String? = "TypeBCustom"
+    static let rowTypeIdentifier: String? = "TypeBCustom"
 
     let thirdly: String
     let fourthly: String
@@ -56,7 +56,7 @@ struct TestTypeC: Codable {
 enum TestQueryableTypes: PolymorphicOperationReturnType {
     typealias AttributesType = StandardPrimaryKeyAttributes
 
-    static var types: [(Codable.Type, PolymorphicOperationReturnOption<StandardPrimaryKeyAttributes, Self>)] = [
+    static let types: [(Codable.Type, PolymorphicOperationReturnOption<StandardPrimaryKeyAttributes, Self>)] = [
         (TestTypeA.self, .init { .testTypeA($0) }),
         (TestTypeB.self, .init { .testTypeB($0) }),
     ]