Add missing tool_call_id field for responses

Implements xai-org/xai-proto#15 while our fix at xai-org/xai-proto#19 isn't merged.

Author: kzu

src/GrokClient/chat.proto

@@ -486,6 +486,9 @@ message Message {
 
   // The encrypted content.
   string encrypted_content = 6;
+
+  // The ID associating this tool response with a prior invocation (for role = ROLE_TOOL).
+  string tool_call_id = 7;
 }
 
 enum MessageRole {

src/Tests/ModelsTests.cs

@@ -0,0 +1,167 @@
+using Grpc.Net.ClientFactory;
+using Microsoft.Extensions.DependencyInjection;
+using Xunit.Abstractions;
+using System.Text.Json;
+
+namespace Devlooped.Grok;
+
+public class SanityChecks(ITestOutputHelper output)
+{
+    [SecretsFact("XAI_API_KEY")]
+    public async Task ListModelsAsync()
+    {
+        var services = new ServiceCollection()
+            .AddGrokClient(Environment.GetEnvironmentVariable("XAI_API_KEY")!)
+            .BuildServiceProvider();
+
+        var client = services.GetRequiredService<Models.ModelsClient>();
+
+        var models = await client.ListLanguageModelsAsync();
+
+        Assert.NotNull(models);
+
+        foreach (var model in models)
+            output.WriteLine(model.Name);
+    }
+
+    [SecretsFact("XAI_API_KEY")]
+    public async Task ExecuteLocalFunctionWithWebSearch()
+    {
+        var services = new ServiceCollection()
+            .AddGrokClient(Environment.GetEnvironmentVariable("XAI_API_KEY")!)
+            .BuildServiceProvider();
+
+        var client = services.GetRequiredService<Chat.ChatClient>();
+
+        // Define a local function to get the current date
+        var getDateFunction = new Function
+        {
+            Name = "get_date",
+            Description = "Get the current date in YYYY-MM-DD format",
+            Parameters = JsonSerializer.Serialize(new
+            {
+                type = "object",
+                properties = new { },
+                required = Array.Empty<string>()
+            })
+        };
+
+        // Create the request with both a local function and web_search tool
+        var request = new GetCompletionsRequest
+        {
+            Model = "grok-4-1-fast",
+            Messages =
+            {
+                new Message
+                {
+                    Role = MessageRole.RoleSystem,
+                    Content = { new Content { Text = "You use the get_date function to get the current date, and Nasdaq and Yahoo finance for stocks news." } }
+                },
+                new Message
+                {
+                    Role = MessageRole.RoleUser,
+                    Content = { new Content { Text = "What's Tesla stock price today?" } }
+                }
+            },
+            Tools =
+            {
+                new Tool { Function = getDateFunction },
+                new Tool { WebSearch = new WebSearch() }
+            }
+        };
+
+        var response = await client.GetCompletionAsync(request);
+
+        Assert.NotNull(response);
+        output.WriteLine($"Response ID: {response.Id}");
+        output.WriteLine($"Model: {response.Model}");
+
+        // Check if we have outputs
+        Assert.NotEmpty(response.Outputs);
+        var firstOutput = response.Outputs[0];
+        var invokedGetDate = false;
+
+        output.WriteLine($"Finish Reason: {firstOutput.FinishReason}");
+
+        // The model should call tools
+        if (firstOutput.Message.ToolCalls.Count > 0)
+        {
+            output.WriteLine($"\nTool Calls ({firstOutput.Message.ToolCalls.Count}):");
+            
+            foreach (var toolCall in firstOutput.Message.ToolCalls)
+            {
+                output.WriteLine($"  - ID: {toolCall.Id}");
+                output.WriteLine($"    Type: {toolCall.Type}");
+                output.WriteLine($"    Status: {toolCall.Status}");
+
+                if (toolCall.Function != null)
+                {
+                    output.WriteLine($"    Function: {toolCall.Function.Name}");
+                    output.WriteLine($"    Arguments: {toolCall.Function.Arguments}");
+
+                    // If it's our local get_date function, we need to execute it
+                    if (toolCall.Function.Name == "get_date" && toolCall.Type == ToolCallType.ClientSideTool)
+                    {
+                        output.WriteLine($"    -> Local function call detected, would execute on client side");
+
+                        // Execute the function
+                        var currentDate = DateTime.Now.ToString("yyyy-MM-dd");
+                        output.WriteLine($"    -> Result: {currentDate}");
+
+                        var call = new Message
+                        {
+                            Role = MessageRole.RoleAssistant,
+                        };
+                        call.ToolCalls.AddRange(firstOutput.Message.ToolCalls);
+
+                        // Continue the conversation with the function result
+                        var followUpRequest = new GetCompletionsRequest
+                        {
+                            Model = request.Model,
+                            Messages =
+                            {
+                                request.Messages[0], // Original user message
+                                call,
+                                //new Message
+                                //{
+                                //    Role = MessageRole.RoleAssistant,
+                                //    ToolCalls = { toolCall }
+                                //},
+                                new Message
+                                {
+                                    Role = MessageRole.RoleTool,
+                                    ToolCallId = toolCall.Id,
+                                    Content = { new Content { Text = currentDate } }
+                                }
+                            },
+                            Tools = { request.Tools[0], request.Tools[1] }
+                        };
+
+                        var followUpResponse = await client.GetCompletionAsync(followUpRequest);
+                        invokedGetDate = true;
+
+                        // There should be no more tool calls after we return the client-side one.
+                        Assert.Empty(followUpResponse.Outputs.SelectMany(x => x.Message.ToolCalls));
+                    }
+                }
+            }
+        }
+
+        if (!string.IsNullOrEmpty(firstOutput.Message.Content))
+        {
+            output.WriteLine($"\nContent: {firstOutput.Message.Content}");
+        }
+
+        // Check for citations
+        if (response.Citations.Count > 0)
+        {
+            output.WriteLine($"\nCitations ({response.Citations.Count}):");
+            foreach (var citation in response.Citations)
+            {
+                output.WriteLine($"  - {citation}");
+            }
+        }
+
+        Assert.True(invokedGetDate);
+    }
+}