Explicitly set auth header

Sources/MailjetKit.swift

@@ -36,14 +36,16 @@ public class MailjetKit {
     }
 
     public func send(request: MailjetKitRequest) async -> Result<[ResponseMessage], MailjetKitError> {
+        let headers: HTTPHeaders = [.authorization(username: apiKey, password: apiSecret)]
+
         let response = await session
             .request(
                 Self.requestURL,
                 method: .post,
                 parameters: request,
-                encoder: JSONParameterEncoder.default
+                encoder: JSONParameterEncoder.default,
+                headers: headers
             )
-            .authenticate(username: apiKey, password: apiSecret)
             .serializingMailjetMessages()
             .response
 

Sources/send/Request/Message/DeliveryOptions.swift

@@ -17,23 +17,23 @@ public struct DeliveryOptions: Sendable, Equatable, Codable {
 
 extension Message {
     public func addHeader(_ name: String, _ value: String) -> Self {
-        var merged = delivery.headers ?? [:]
+        var merged = delivery?.headers ?? [:]
         merged[name] = value
 
         let updatedDelivery = DeliveryOptions(
-            priority: delivery.priority,
+            priority: delivery?.priority,
             headers: merged
         )
 
         return withUpdatedDelivery(updatedDelivery)
     }
 
     public func addHeaders(_ newHeaders: [String: String]) -> Self {
-        var merged = delivery.headers ?? [:]
+        var merged = delivery?.headers ?? [:]
         for (k, v) in newHeaders { merged[k] = v }
 
         let updatedDelivery = DeliveryOptions(
-            priority: delivery.priority,
+            priority: delivery?.priority,
             headers: merged
         )
 
@@ -43,7 +43,7 @@ extension Message {
     public func withPriority(_ priority: Int?) -> Self {
         let updatedDelivery = DeliveryOptions(
             priority: priority,
-            headers: delivery.headers
+            headers: delivery?.headers
         )
 
         return withUpdatedDelivery(updatedDelivery)

Sources/send/Request/Message/Message.swift

@@ -3,16 +3,16 @@ import Foundation
 public struct Message: Sendable, Equatable, Codable {
     public let envelope: Envelope
     public let content: Content
-    public let template: TemplateOptions
-    public let tracking: Tracking
-    public let delivery: DeliveryOptions
+    public let template: TemplateOptions?
+    public let tracking: Tracking?
+    public let delivery: DeliveryOptions?
 
     public init(
         envelope: Envelope,
         content: Content,
-        template: TemplateOptions = TemplateOptions(),
-        tracking: Tracking = Tracking(),
-        delivery: DeliveryOptions = DeliveryOptions()
+        template: TemplateOptions? = nil,
+        tracking: Tracking? = nil,
+        delivery: DeliveryOptions? = nil
     ) {
         self.envelope = envelope
         self.content = content
@@ -24,9 +24,9 @@ public struct Message: Sendable, Equatable, Codable {
     public func encode(to encoder: Encoder) throws {
         try envelope.encode(to: encoder)
         try content.encode(to: encoder)
-        try template.encode(to: encoder)
-        try tracking.encode(to: encoder)
-        try delivery.encode(to: encoder)
+        if let template { try template.encode(to: encoder) }
+        if let tracking { try tracking.encode(to: encoder) }
+        if let delivery { try delivery.encode(to: encoder) }
     }
 
     public init(from decoder: Decoder) throws {
@@ -41,20 +41,14 @@ public struct Message: Sendable, Equatable, Codable {
     public init(from: Recipient, to: Recipient, subject: String, textPart: String) {
         self.init(
             envelope: Envelope(from: from, to: [to]),
-            content: Content(subject: subject, textPart: textPart),
-            template: TemplateOptions(),
-            tracking: Tracking(),
-            delivery: DeliveryOptions()
+            content: Content(subject: subject, textPart: textPart)
         )
     }
 
     public init(from: Recipient, to: Recipient, subject: String, htmlPart: String) {
         self.init(
             envelope: Envelope(from: from, to: [to]),
-            content: Content(subject: subject, htmlPart: htmlPart),
-            template: TemplateOptions(),
-            tracking: Tracking(),
-            delivery: DeliveryOptions()
+            content: Content(subject: subject, htmlPart: htmlPart)
         )
     }
 }

Sources/send/Request/Message/TemplateOptions.swift

@@ -1,7 +1,7 @@
 import Foundation
 
 public struct TemplateOptions: Sendable, Equatable, Codable {
-    public let templateID: UInt64?
+    public let templateID: UInt64
     public let templateLanguage: Bool?
     public let templateErrorReporting: Recipient?
     public let templateErrorDeliver: Bool?
@@ -16,7 +16,7 @@ public struct TemplateOptions: Sendable, Equatable, Codable {
     }
 
     public init(
-        templateID: UInt64? = nil,
+        templateID: UInt64,
         templateLanguage: Bool? = nil,
         templateErrorReporting: Recipient? = nil,
         templateErrorDeliver: Bool? = nil,