This example assumes using Google.Gemini; is in scope and apiKey contains your Google.Gemini API key.
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60 | using var client = new GeminiClient(apiKey);
var modelId = GetGenerateContentModelId();
try
{
var getWeatherTool = AIFunctionFactory.Create(
(string location) => $"The weather in {location} is 72°F and sunny.",
name: "get_weather",
description: "Gets the current weather for a given location.");
IChatClient chatClient = client;
var messages = new List<ChatMessage>
{
new(ChatRole.User, "What is the weather in Paris?"),
};
// First turn: model requests tool call
var response = await chatClient.GetResponseAsync(
messages,
new ChatOptions
{
ModelId = modelId,
Tools = [getWeatherTool],
});
var functionCall = response.Messages
.SelectMany(m => m.Contents)
.OfType<FunctionCallContent>()
.FirstOrDefault();
// Verify thought signature is preserved on function call content
// (Gemini API requires it to be echoed back in subsequent turns)
if (functionCall!.AdditionalProperties?.TryGetValue("gemini.thoughtSignature", out var sig) == true)
{
}
// Add assistant message with function call and tool result
messages.AddRange(response.Messages);
var toolResult = await getWeatherTool.InvokeAsync(
functionCall.Arguments is { } args ? new AIFunctionArguments(args) : null);
messages.Add(new ChatMessage(ChatRole.Tool,
[
new FunctionResultContent(functionCall.CallId, toolResult),
]));
// Second turn: model should produce a final text response
// (this verifies the thought signature round-trip works — the API
// rejects requests with missing thought signatures)
var finalResponse = await chatClient.GetResponseAsync(
messages,
new ChatOptions
{
ModelId = modelId,
Tools = [getWeatherTool],
});
}
catch (ApiException ex) when (ex.StatusCode is System.Net.HttpStatusCode.TooManyRequests)
{
}
|