Improved the OpenAI provider (#548)

app/MindWork AI Studio/Provider/OpenAI/ProviderOpenAI.cs

@@ -30,16 +30,20 @@ public sealed class ProviderOpenAI(ILogger logger) : BaseProvider("https://api.o
             yield break;
         
         // Unfortunately, OpenAI changed the name of the system prompt based on the model.
-        // All models that start with "o" (the omni aka reasoning models) and all GPT4o models
-        // have the system prompt named "developer". All other models have the system prompt
-        // named "system". We need to check this to get the correct system prompt.
+        // All models that start with "o" (the omni aka reasoning models), all GPT4o models,
+        // and all newer models have the system prompt named "developer". All other models
+        // have the system prompt named "system". We need to check this to get the correct
+        // system prompt.
         //
         // To complicate it even more: The early versions of reasoning models, which are released
         // before the 17th of December 2024, have no system prompt at all. We need to check this
         // as well.
         
         // Apply the basic rule first:
-        var systemPromptRole = chatModel.Id.StartsWith('o') || chatModel.Id.Contains("4o") ? "developer" : "system";
+        var systemPromptRole =
+            chatModel.Id.StartsWith('o') ||
+            chatModel.Id.StartsWith("gpt-5", StringComparison.Ordinal) ||
+            chatModel.Id.Contains("4o") ? "developer" : "system";
         
         // Check if the model is an early version of the reasoning models:
         systemPromptRole = chatModel.Id switch
@@ -51,53 +55,113 @@ public sealed class ProviderOpenAI(ILogger logger) : BaseProvider("https://api.o
             
             _ => systemPromptRole,
         };
-        
-        this.logger.LogInformation($"Using the system prompt role '{systemPromptRole}' for model '{chatModel.Id}'.");
 
+        // Read the model capabilities:
+        var modelCapabilities = this.GetModelCapabilities(chatModel);
+        
+        // Check if we are using the Responses API or the Chat Completion API:
+        var usingResponsesAPI = modelCapabilities.Contains(Capability.RESPONSES_API);
+        
+        // Prepare the request path based on the API we are using:
+        var requestPath = usingResponsesAPI ? "responses" : "chat/completions";
+        
+        this.logger.LogInformation("Using the system prompt role '{SystemPromptRole}' and the '{RequestPath}' API for model '{ChatModelId}'.", systemPromptRole, requestPath, chatModel.Id);
+        
         // Prepare the system prompt:
         var systemPrompt = new Message
         {
             Role = systemPromptRole,
             Content = chatThread.PrepareSystemPrompt(settingsManager, chatThread, this.logger),
         };
-        
-        // Prepare the OpenAI HTTP chat request:
-        var openAIChatRequest = JsonSerializer.Serialize(new ChatRequest
+
+        //
+        // Prepare the tools we want to use:
+        //
+        IList<Tool> tools = modelCapabilities.Contains(Capability.WEB_SEARCH) switch
         {
-            Model = chatModel.Id,
-            
-            // Build the messages:
-            // - First of all the system prompt
-            // - Then none-empty user and AI messages
-            Messages = [systemPrompt, ..chatThread.Blocks.Where(n => n.ContentType is ContentType.TEXT && !string.IsNullOrWhiteSpace((n.Content as ContentText)?.Text)).Select(n => new Message
+            true => [ Tools.WEB_SEARCH ],
+            _ => []
+        };
+        
+        //
+        // Create the request: either for the Responses API or the Chat Completion API
+        //
+        var openAIChatRequest = usingResponsesAPI switch
+        {
+            // Chat Completion API request:
+            false => JsonSerializer.Serialize(new ChatCompletionAPIRequest
             {
-                Role = n.Role switch
-                {
-                    ChatRole.USER => "user",
-                    ChatRole.AI => "assistant",
-                    ChatRole.AGENT => "assistant",
-                    ChatRole.SYSTEM => systemPromptRole,
-
-                    _ => "user",
-                },
-
-                Content = n.Content switch
-                {
-                    ContentText text => text.Text,
-                    _ => string.Empty,
-                }
-            }).ToList()],
-
-            Seed = chatThread.Seed,
+                Model = chatModel.Id,
             
-            // Right now, we only support streaming completions:
-            Stream = true,
-        }, JSON_SERIALIZER_OPTIONS);
+                // Build the messages:
+                // - First of all the system prompt
+                // - Then none-empty user and AI messages
+                Messages = [systemPrompt, ..chatThread.Blocks.Where(n => n.ContentType is ContentType.TEXT && !string.IsNullOrWhiteSpace((n.Content as ContentText)?.Text)).Select(n => new Message
+                {
+                    Role = n.Role switch
+                    {
+                        ChatRole.USER => "user",
+                        ChatRole.AI => "assistant",
+                        ChatRole.AGENT => "assistant",
+                        ChatRole.SYSTEM => systemPromptRole,
+
+                        _ => "user",
+                    },
+
+                    Content = n.Content switch
+                    {
+                        ContentText text => text.Text,
+                        _ => string.Empty,
+                    }
+                }).ToList()],
+            
+                // Right now, we only support streaming completions:
+                Stream = true,
+            }, JSON_SERIALIZER_OPTIONS),
+            
+            // Responses API request:
+            true => JsonSerializer.Serialize(new ResponsesAPIRequest
+            {
+                Model = chatModel.Id,
+            
+                // Build the messages:
+                // - First of all the system prompt
+                // - Then none-empty user and AI messages
+                Input = [systemPrompt, ..chatThread.Blocks.Where(n => n.ContentType is ContentType.TEXT && !string.IsNullOrWhiteSpace((n.Content as ContentText)?.Text)).Select(n => new Message
+                {
+                    Role = n.Role switch
+                    {
+                        ChatRole.USER => "user",
+                        ChatRole.AI => "assistant",
+                        ChatRole.AGENT => "assistant",
+                        ChatRole.SYSTEM => systemPromptRole,
+
+                        _ => "user",
+                    },
+
+                    Content = n.Content switch
+                    {
+                        ContentText text => text.Text,
+                        _ => string.Empty,
+                    }
+                }).ToList()],
+            
+                // Right now, we only support streaming completions:
+                Stream = true,
+                
+                // We do not want to store any data on OpenAI's servers:
+                Store = false,
+                
+                // Tools we want to use:
+                Tools = tools,
+                
+            }, JSON_SERIALIZER_OPTIONS),
+        };
 
         async Task<HttpRequestMessage> RequestBuilder()
         {
             // Build the HTTP post request:
-            var request = new HttpRequestMessage(HttpMethod.Post, "chat/completions");
+            var request = new HttpRequestMessage(HttpMethod.Post, requestPath);
 
             // Set the authorization header:
             request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", await requestedSecret.Secret.Decrypt(ENCRYPTION));
@@ -106,29 +170,35 @@ public sealed class ProviderOpenAI(ILogger logger) : BaseProvider("https://api.o
             request.Content = new StringContent(openAIChatRequest, Encoding.UTF8, "application/json");
             return request;
         }
+
+        if (usingResponsesAPI)
+            await foreach (var content in this.StreamResponsesInternal<ResponsesDeltaStreamLine, ResponsesAnnotationStreamLine>("OpenAI", RequestBuilder, token))
+                yield return content;
         
-        await foreach (var content in this.StreamChatCompletionInternal<ResponseStreamLine>("OpenAI", RequestBuilder, token))
-            yield return content;
+        else
+            await foreach (var content in this.StreamChatCompletionInternal<ChatCompletionDeltaStreamLine, ChatCompletionAnnotationStreamLine>("OpenAI", RequestBuilder, token))
+                yield return content;
     }
 
     #pragma warning disable CS1998 // Async method lacks 'await' operators and will run synchronously
+    
     /// <inheritdoc />
     public override async IAsyncEnumerable<ImageURL> StreamImageCompletion(Model imageModel, string promptPositive, string promptNegative = FilterOperator.String.Empty, ImageURL referenceImageURL = default, [EnumeratorCancellation] CancellationToken token = default)
     {
         yield break;
     }
+    
     #pragma warning restore CS1998 // Async method lacks 'await' operators and will run synchronously
 
     /// <inheritdoc />
     public override async Task<IEnumerable<Model>> GetTextModels(string? apiKeyProvisional = null, CancellationToken token = default)
     {
-        var models = await this.LoadModels(["gpt-", "o1-", "o3-", "o4-"], token, apiKeyProvisional);
+        var models = await this.LoadModels(["chatgpt-", "gpt-", "o1-", "o3-", "o4-"], token, apiKeyProvisional);
         return models.Where(model => !model.Id.Contains("image", StringComparison.OrdinalIgnoreCase) &&
                                      !model.Id.Contains("realtime", StringComparison.OrdinalIgnoreCase) &&
                                      !model.Id.Contains("audio", StringComparison.OrdinalIgnoreCase) &&
                                      !model.Id.Contains("tts", StringComparison.OrdinalIgnoreCase) &&
-                                     !model.Id.Contains("transcribe", StringComparison.OrdinalIgnoreCase) &&
-                                     !model.Id.Contains("o1-pro", StringComparison.OrdinalIgnoreCase));
+                                     !model.Id.Contains("transcribe", StringComparison.OrdinalIgnoreCase));
     }
 
     /// <inheritdoc />
@@ -147,6 +217,26 @@ public sealed class ProviderOpenAI(ILogger logger) : BaseProvider("https://api.o
     {
         var modelName = model.Id.ToLowerInvariant().AsSpan();
         
+        if (modelName is "gpt-4o-search-preview")
+            return
+                [
+                    Capability.TEXT_INPUT,
+                    Capability.TEXT_OUTPUT,
+                    
+                    Capability.WEB_SEARCH,
+                    Capability.CHAT_COMPLETION_API,
+                ];
+        
+        if (modelName is "gpt-4o-mini-search-preview")
+            return
+                [
+                    Capability.TEXT_INPUT,
+                    Capability.TEXT_OUTPUT,
+                    
+                    Capability.WEB_SEARCH,
+                    Capability.CHAT_COMPLETION_API,
+                ];
+        
         if (modelName.StartsWith("o1-mini"))
             return
                 [
@@ -154,32 +244,63 @@ public sealed class ProviderOpenAI(ILogger logger) : BaseProvider("https://api.o
                     Capability.TEXT_OUTPUT,
                     
                     Capability.ALWAYS_REASONING,
+                    Capability.CHAT_COMPLETION_API,
                 ];
         
+        if(modelName is "gpt-3.5-turbo")
+            return
+            [
+                Capability.TEXT_INPUT,
+                Capability.TEXT_OUTPUT,
+                Capability.RESPONSES_API,
+            ];
+        
+        if(modelName.StartsWith("gpt-3.5"))
+            return
+            [
+                Capability.TEXT_INPUT,
+                Capability.TEXT_OUTPUT,
+                Capability.CHAT_COMPLETION_API,
+            ];
+
+        if (modelName.StartsWith("chatgpt-4o-"))
+            return
+            [
+                Capability.TEXT_INPUT, Capability.MULTIPLE_IMAGE_INPUT,
+                Capability.TEXT_OUTPUT,
+                Capability.RESPONSES_API,
+            ];
+        
         if (modelName.StartsWith("o3-mini"))
             return
                 [
                     Capability.TEXT_INPUT,
                     Capability.TEXT_OUTPUT,
                     
-                    Capability.ALWAYS_REASONING, Capability.FUNCTION_CALLING
+                    Capability.ALWAYS_REASONING, Capability.FUNCTION_CALLING,
+                    Capability.RESPONSES_API,
                 ];
         
-        if (modelName.StartsWith("o4-mini") || modelName.StartsWith("o1") || modelName.StartsWith("o3"))
+        if (modelName.StartsWith("o4-mini") || modelName.StartsWith("o3"))
             return
                 [
                     Capability.TEXT_INPUT, Capability.MULTIPLE_IMAGE_INPUT,
                     Capability.TEXT_OUTPUT,
                     
-                    Capability.ALWAYS_REASONING, Capability.FUNCTION_CALLING
+                    Capability.ALWAYS_REASONING, Capability.FUNCTION_CALLING,
+                    Capability.WEB_SEARCH,
+                    Capability.RESPONSES_API,
                 ];
         
-        if(modelName.StartsWith("gpt-3.5"))
+        if (modelName.StartsWith("o1"))
             return
-                [
-                    Capability.TEXT_INPUT,
-                    Capability.TEXT_OUTPUT,
-                ];
+            [
+                Capability.TEXT_INPUT, Capability.MULTIPLE_IMAGE_INPUT,
+                Capability.TEXT_OUTPUT,
+                    
+                Capability.ALWAYS_REASONING, Capability.FUNCTION_CALLING,
+                Capability.RESPONSES_API,
+            ];
         
         if(modelName.StartsWith("gpt-4-turbo"))
             return
@@ -187,7 +308,8 @@ public sealed class ProviderOpenAI(ILogger logger) : BaseProvider("https://api.o
                     Capability.TEXT_INPUT, Capability.MULTIPLE_IMAGE_INPUT,
                     Capability.TEXT_OUTPUT,
                     
-                    Capability.FUNCTION_CALLING
+                    Capability.FUNCTION_CALLING,
+                    Capability.RESPONSES_API,
                 ];
         
         if(modelName is "gpt-4" || modelName.StartsWith("gpt-4-"))
@@ -195,14 +317,37 @@ public sealed class ProviderOpenAI(ILogger logger) : BaseProvider("https://api.o
                 [
                     Capability.TEXT_INPUT,
                     Capability.TEXT_OUTPUT,
+                    Capability.RESPONSES_API,
                 ];
         
+        if(modelName.StartsWith("gpt-5-nano"))
+            return
+            [
+                Capability.TEXT_INPUT, Capability.MULTIPLE_IMAGE_INPUT,
+                Capability.TEXT_OUTPUT,
+                
+                Capability.FUNCTION_CALLING, Capability.ALWAYS_REASONING,
+                Capability.RESPONSES_API,
+            ];
+        
+        if(modelName is "gpt-5" || modelName.StartsWith("gpt-5-"))
+            return
+            [
+                Capability.TEXT_INPUT, Capability.MULTIPLE_IMAGE_INPUT,
+                Capability.TEXT_OUTPUT,
+                
+                Capability.FUNCTION_CALLING, Capability.ALWAYS_REASONING,
+                Capability.WEB_SEARCH,
+                Capability.RESPONSES_API,
+            ];
+        
         return
             [
                 Capability.TEXT_INPUT, Capability.MULTIPLE_IMAGE_INPUT,
                 Capability.TEXT_OUTPUT,
                 
                 Capability.FUNCTION_CALLING,
+                Capability.RESPONSES_API,
             ];
     }