diff --git a/Demo/DemoChat/Sources/UI/DetailView.swift b/Demo/DemoChat/Sources/UI/DetailView.swift
index 05b8a4f6..61556aae 100644
--- a/Demo/DemoChat/Sources/UI/DetailView.swift
+++ b/Demo/DemoChat/Sources/UI/DetailView.swift
@@ -290,6 +290,8 @@ struct ChatBubble: View {
               Spacer(minLength: 24)
             case .system:
                 EmptyView()
+            case .developer:
+                EmptyView()
             }
         }
     }
diff --git a/Sources/OpenAI/Public/Models/ChatQuery.swift b/Sources/OpenAI/Public/Models/ChatQuery.swift
index c635ad3c..f8ebd140 100644
--- a/Sources/OpenAI/Public/Models/ChatQuery.swift
+++ b/Sources/OpenAI/Public/Models/ChatQuery.swift
@@ -111,6 +111,7 @@ public struct ChatQuery: Equatable, Codable, Streamable {
     public enum ChatCompletionMessageParam: Codable, Equatable {
 
         case system(Self.SystemMessageParam)
+        case developer(Self.DeveloperMessageParam)
         case user(Self.UserMessageParam)
         case assistant(Self.AssistantMessageParam)
         case tool(Self.ToolMessageParam)
@@ -119,6 +120,8 @@ public struct ChatQuery: Equatable, Codable, Streamable {
             switch self {
             case .system(let systemMessage):
                 return Self.UserMessageParam.Content.string(systemMessage.content)
+            case .developer(let developerMessage):
+                return Self.UserMessageParam.Content.string(developerMessage.content)
             case .user(let userMessage):
                 return userMessage.content
             case .assistant(let assistantMessage):
@@ -135,6 +138,8 @@ public struct ChatQuery: Equatable, Codable, Streamable {
             switch self {
             case .system(let systemMessage):
                 return systemMessage.role
+            case .developer(let developerMessage):
+                return developerMessage.role
             case .user(let userMessage):
                 return userMessage.role
             case .assistant(let assistantMessage):
@@ -148,6 +153,8 @@ public struct ChatQuery: Equatable, Codable, Streamable {
             switch self {
             case .system(let systemMessage):
                 return systemMessage.name
+            case .developer(let developerMessage):
+                return developerMessage.name
             case .user(let userMessage):
                 return userMessage.name
             case .assistant(let assistantMessage):
@@ -189,6 +196,12 @@ public struct ChatQuery: Equatable, Codable, Streamable {
                 } else {
                     return nil
                 }
+            case .developer:
+                if let content {
+                    self = .developer(.init(content: content, name: name))
+                } else {
+                    return nil
+                }
             case .user:
                 if let content {
                     self = .user(.init(content: .init(string: content), name: name))
@@ -227,6 +240,8 @@ public struct ChatQuery: Equatable, Codable, Streamable {
         ) {
             if role == .system {
                 self = .system(.init(content: content, name: name))
+            } else if role == .developer {
+                self = .developer(.init(content: content, name: name))
             } else {
                 return nil
             }
@@ -274,6 +289,8 @@ public struct ChatQuery: Equatable, Codable, Streamable {
             switch self {
             case .system(let a0):
                 try container.encode(a0)
+            case .developer(let a0):
+                try container.encode(a0)
             case .user(let a0):
                 try container.encode(a0)
             case .assistant(let a0):
@@ -285,6 +302,7 @@ public struct ChatQuery: Equatable, Codable, Streamable {
 
         enum CodingKeys: CodingKey {
             case system
+            case developer
             case user
             case assistant
             case tool
@@ -314,6 +332,31 @@ public struct ChatQuery: Equatable, Codable, Streamable {
                 case name
             }
         }
+        
+        public struct DeveloperMessageParam: Codable, Equatable {
+            public typealias Role = ChatQuery.ChatCompletionMessageParam.Role
+
+            /// The contents of the developer message.
+            public let content: String
+            /// The role of the messages author, in this case developer.
+            public let role: Self.Role = .developer
+            /// An optional name for the participant. Provides the model information to differentiate between participants of the same role.
+            public let name: String?
+
+            public init(
+                content: String,
+                name: String? = nil
+            ) {
+                self.content = content
+                self.name = name
+            }
+
+            enum CodingKeys: CodingKey {
+                case content
+                case role
+                case name
+            }
+        }
 
         public struct UserMessageParam: Codable, Equatable {
             public typealias Role = ChatQuery.ChatCompletionMessageParam.Role
@@ -570,6 +613,7 @@ public struct ChatQuery: Equatable, Codable, Streamable {
 
         public enum Role: String, Codable, Equatable, CaseIterable {
             case system
+            case developer
             case user
             case assistant
             case tool
diff --git a/Sources/OpenAI/Public/Models/ChatResult.swift b/Sources/OpenAI/Public/Models/ChatResult.swift
index 5f718282..0bd43056 100644
--- a/Sources/OpenAI/Public/Models/ChatResult.swift
+++ b/Sources/OpenAI/Public/Models/ChatResult.swift
@@ -126,6 +126,8 @@ extension ChatQuery.ChatCompletionMessageParam {
         switch try messageContainer.decode(Role.self, forKey: .role) {
         case .system:
             self = try .system(.init(from: decoder))
+        case .developer:
+            self = try .developer(.init(from: decoder))
         case .user:
             self = try .user(.init(from: decoder))
         case .assistant: