diff --git a/models/spring-ai-mistral-ai/src/main/java/org/springframework/ai/mistralai/MistralAiChatClient.java b/models/spring-ai-mistral-ai/src/main/java/org/springframework/ai/mistralai/MistralAiChatClient.java
index 609c8f90f..f924b8ad9 100644
--- a/models/spring-ai-mistral-ai/src/main/java/org/springframework/ai/mistralai/MistralAiChatClient.java
+++ b/models/spring-ai-mistral-ai/src/main/java/org/springframework/ai/mistralai/MistralAiChatClient.java
@@ -16,8 +16,10 @@
 package org.springframework.ai.mistralai;
 
 import java.time.Duration;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
+import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 
 import org.slf4j.Logger;
@@ -32,18 +34,29 @@ import org.springframework.ai.chat.metadata.ChatGenerationMetadata;
 import org.springframework.ai.chat.prompt.ChatOptions;
 import org.springframework.ai.chat.prompt.Prompt;
 import org.springframework.ai.mistralai.api.MistralAiApi;
+import org.springframework.ai.mistralai.api.MistralAiApi.ChatCompletion;
+import org.springframework.ai.mistralai.api.MistralAiApi.ChatCompletionMessage;
+import org.springframework.ai.mistralai.api.MistralAiApi.ChatCompletionMessage.ToolCall;
+import org.springframework.ai.mistralai.api.MistralAiApi.ChatCompletionRequest;
 import org.springframework.ai.model.ModelOptionsUtils;
+import org.springframework.ai.model.function.AbstractFunctionCallSupport;
+import org.springframework.ai.model.function.FunctionCallbackContext;
+import org.springframework.http.ResponseEntity;
 import org.springframework.retry.RetryCallback;
 import org.springframework.retry.RetryContext;
 import org.springframework.retry.RetryListener;
 import org.springframework.retry.support.RetryTemplate;
 import org.springframework.util.Assert;
+import org.springframework.util.CollectionUtils;
 
 /**
  * @author Ricken Bazolo
+ * @author Christian Tzolov
  * @since 0.8.1
  */
-public class MistralAiChatClient implements ChatClient, StreamingChatClient {
+public class MistralAiChatClient extends
+		AbstractFunctionCallSupport<MistralAiApi.ChatCompletionMessage, MistralAiApi.ChatCompletionRequest, ResponseEntity<MistralAiApi.ChatCompletion>>
+		implements ChatClient, StreamingChatClient {
 
 	private final Logger log = LoggerFactory.getLogger(getClass());
 
@@ -69,13 +82,6 @@ public class MistralAiChatClient implements ChatClient, StreamingChatClient {
 		})
 		.build();
 
-	public MistralAiChatClient(MistralAiApi mistralAiApi, MistralAiChatOptions options) {
-		Assert.notNull(mistralAiApi, "MistralAiApi must not be null");
-		Assert.notNull(options, "Options must not be null");
-		this.mistralAiApi = mistralAiApi;
-		this.defaultOptions = options;
-	}
-
 	public MistralAiChatClient(MistralAiApi mistralAiApi) {
 		this(mistralAiApi,
 				MistralAiChatOptions.builder()
@@ -86,60 +92,41 @@ public class MistralAiChatClient implements ChatClient, StreamingChatClient {
 					.build());
 	}
 
-	/**
-	 * Accessible for testing.
-	 */
-	public MistralAiApi.ChatCompletionRequest createRequest(Prompt prompt, boolean stream) {
-		var chatCompletionMessages = prompt.getInstructions()
-			.stream()
-			.map(m -> new MistralAiApi.ChatCompletionMessage(m.getContent(),
-					MistralAiApi.ChatCompletionMessage.Role.valueOf(m.getMessageType().name())))
-			.toList();
+	public MistralAiChatClient(MistralAiApi mistralAiApi, MistralAiChatOptions options) {
+		this(mistralAiApi, options, null);
+	}
 
-		var request = new MistralAiApi.ChatCompletionRequest(chatCompletionMessages, stream);
-
-		if (this.defaultOptions != null) {
-			request = ModelOptionsUtils.merge(request, this.defaultOptions, MistralAiApi.ChatCompletionRequest.class);
-		}
-
-		if (prompt.getOptions() != null) {
-			if (prompt.getOptions() instanceof ChatOptions runtimeOptions) {
-				var updatedRuntimeOptions = ModelOptionsUtils.copyToTarget(runtimeOptions, ChatOptions.class,
-						MistralAiChatOptions.class);
-				request = ModelOptionsUtils.merge(updatedRuntimeOptions, request,
-						MistralAiApi.ChatCompletionRequest.class);
-			}
-			else {
-				throw new IllegalArgumentException("Prompt options are not of type ChatOptions: "
-						+ prompt.getOptions().getClass().getSimpleName());
-			}
-		}
-
-		return request;
+	public MistralAiChatClient(MistralAiApi mistralAiApi, MistralAiChatOptions options,
+			FunctionCallbackContext functionCallbackContext) {
+		super(functionCallbackContext);
+		Assert.notNull(mistralAiApi, "MistralAiApi must not be null");
+		Assert.notNull(options, "Options must not be null");
+		this.mistralAiApi = mistralAiApi;
+		this.defaultOptions = options;
 	}
 
 	@Override
 	public ChatResponse call(Prompt prompt) {
-		return retryTemplate.execute(ctx -> {
-			var request = createRequest(prompt, false);
+		// return retryTemplate.execute(ctx -> {
+		var request = createRequest(prompt, false);
 
-			var completionEntity = this.mistralAiApi.chatCompletionEntity(request);
+		// var completionEntity = this.mistralAiApi.chatCompletionEntity(request);
+		ResponseEntity<ChatCompletion> completionEntity = this.callWithFunctionSupport(request);
 
-			var chatCompletion = completionEntity.getBody();
-			if (chatCompletion == null) {
-				log.warn("No chat completion returned for prompt: {}", prompt);
-				return new ChatResponse(List.of());
-			}
+		var chatCompletion = completionEntity.getBody();
+		if (chatCompletion == null) {
+			log.warn("No chat completion returned for prompt: {}", prompt);
+			return new ChatResponse(List.of());
+		}
 
-			List<Generation> generations = chatCompletion.choices()
-				.stream()
-				.map(choice -> new Generation(choice.message().content(),
-						Map.of("role", choice.message().role().name()))
-					.withGenerationMetadata(ChatGenerationMetadata.from(choice.finishReason().name(), null)))
-				.toList();
+		List<Generation> generations = chatCompletion.choices()
+			.stream()
+			.map(choice -> new Generation(choice.message().content(), Map.of("role", choice.message().role().name()))
+				.withGenerationMetadata(ChatGenerationMetadata.from(choice.finishReason().name(), null)))
+			.toList();
 
-			return new ChatResponse(generations);
-		});
+		return new ChatResponse(generations);
+		// });
 	}
 
 	@Override
@@ -171,4 +158,133 @@ public class MistralAiChatClient implements ChatClient, StreamingChatClient {
 		});
 	}
 
+	/**
+	 * Accessible for testing.
+	 */
+	MistralAiApi.ChatCompletionRequest createRequest(Prompt prompt, boolean stream) {
+
+		Set<String> functionsForThisRequest = new HashSet<>();
+
+		var chatCompletionMessages = prompt.getInstructions()
+			.stream()
+			.map(m -> new MistralAiApi.ChatCompletionMessage(m.getContent(),
+					MistralAiApi.ChatCompletionMessage.Role.valueOf(m.getMessageType().name())))
+			.toList();
+
+		var request = new MistralAiApi.ChatCompletionRequest(chatCompletionMessages, stream);
+
+		if (this.defaultOptions != null) {
+			Set<String> defaultEnabledFunctions = this.handleFunctionCallbackConfigurations(this.defaultOptions,
+					!IS_RUNTIME_CALL);
+
+			functionsForThisRequest.addAll(defaultEnabledFunctions);
+
+			request = ModelOptionsUtils.merge(request, this.defaultOptions, MistralAiApi.ChatCompletionRequest.class);
+		}
+
+		if (prompt.getOptions() != null) {
+			if (prompt.getOptions() instanceof ChatOptions runtimeOptions) {
+				var updatedRuntimeOptions = ModelOptionsUtils.copyToTarget(runtimeOptions, ChatOptions.class,
+						MistralAiChatOptions.class);
+
+				Set<String> promptEnabledFunctions = this.handleFunctionCallbackConfigurations(updatedRuntimeOptions,
+						IS_RUNTIME_CALL);
+				functionsForThisRequest.addAll(promptEnabledFunctions);
+
+				request = ModelOptionsUtils.merge(updatedRuntimeOptions, request,
+						MistralAiApi.ChatCompletionRequest.class);
+			}
+			else {
+				throw new IllegalArgumentException("Prompt options are not of type ChatOptions: "
+						+ prompt.getOptions().getClass().getSimpleName());
+			}
+		}
+
+		// Add the enabled functions definitions to the request's tools parameter.
+		if (!CollectionUtils.isEmpty(functionsForThisRequest)) {
+
+			if (stream) {
+				throw new IllegalArgumentException("Currently tool functions are not supported in streaming mode");
+			}
+
+			request = ModelOptionsUtils.merge(
+					MistralAiChatOptions.builder().withTools(this.getFunctionTools(functionsForThisRequest)).build(),
+					request, ChatCompletionRequest.class);
+		}
+
+		return request;
+	}
+
+	private List<MistralAiApi.FunctionTool> getFunctionTools(Set<String> functionNames) {
+		return this.resolveFunctionCallbacks(functionNames).stream().map(functionCallback -> {
+			var function = new MistralAiApi.FunctionTool.Function(functionCallback.getDescription(),
+					functionCallback.getName(), functionCallback.getInputTypeSchema());
+			return new MistralAiApi.FunctionTool(function);
+		}).toList();
+	}
+
+	//
+	// Function Calling Support
+	//
+	@Override
+	protected ChatCompletionRequest doCreateToolResponseRequest(ChatCompletionRequest previousRequest,
+			ChatCompletionMessage responseMessage, List<ChatCompletionMessage> conversationHistory) {
+
+		// Every tool-call item requires a separate function call and a response (TOOL)
+		// message.
+		for (ToolCall toolCall : responseMessage.toolCalls()) {
+
+			var functionName = toolCall.function().name();
+			String functionArguments = toolCall.function().arguments();
+
+			if (!this.functionCallbackRegister.containsKey(functionName)) {
+				throw new IllegalStateException("No function callback found for function name: " + functionName);
+			}
+
+			String functionResponse = this.functionCallbackRegister.get(functionName).call(functionArguments);
+
+			// Add the function response to the conversation.
+			conversationHistory
+				.add(new ChatCompletionMessage(functionResponse, ChatCompletionMessage.Role.TOOL, functionName, null));
+		}
+
+		// Recursively call chatCompletionWithTools until the model doesn't call a
+		// functions anymore.
+		ChatCompletionRequest newRequest = new ChatCompletionRequest(conversationHistory, previousRequest.stream());
+		newRequest = ModelOptionsUtils.merge(newRequest, previousRequest, ChatCompletionRequest.class);
+
+		return newRequest;
+	}
+
+	@Override
+	protected List<ChatCompletionMessage> doGetUserMessages(ChatCompletionRequest request) {
+		return request.messages();
+	}
+
+	@Override
+	protected ChatCompletionMessage doGetToolResponseMessage(ResponseEntity<ChatCompletion> chatCompletion) {
+		return chatCompletion.getBody().choices().iterator().next().message();
+	}
+
+	@Override
+	protected ResponseEntity<ChatCompletion> doChatCompletion(ChatCompletionRequest request) {
+		return this.mistralAiApi.chatCompletionEntity(request);
+	}
+
+	@Override
+	protected boolean isToolFunctionCall(ResponseEntity<ChatCompletion> chatCompletion) {
+
+		var body = chatCompletion.getBody();
+		if (body == null) {
+			return false;
+		}
+
+		var choices = body.choices();
+		if (CollectionUtils.isEmpty(choices)) {
+			return false;
+		}
+
+		return !CollectionUtils.isEmpty(choices.get(0).message().toolCalls());
+	}
+
 }
diff --git a/models/spring-ai-mistral-ai/src/main/java/org/springframework/ai/mistralai/MistralAiChatOptions.java b/models/spring-ai-mistral-ai/src/main/java/org/springframework/ai/mistralai/MistralAiChatOptions.java
index ad8a08860..c47d95946 100644
--- a/models/spring-ai-mistral-ai/src/main/java/org/springframework/ai/mistralai/MistralAiChatOptions.java
+++ b/models/spring-ai-mistral-ai/src/main/java/org/springframework/ai/mistralai/MistralAiChatOptions.java
@@ -16,10 +16,22 @@
 
 package org.springframework.ai.mistralai;
 
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
 import com.fasterxml.jackson.annotation.JsonIgnore;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import org.springframework.ai.chat.prompt.ChatOptions;
+import org.springframework.ai.mistralai.api.MistralAiApi.ChatCompletionRequest.ResponseFormat;
+import org.springframework.ai.mistralai.api.MistralAiApi.ChatCompletionRequest.ToolChoice;
+import org.springframework.ai.mistralai.api.MistralAiApi.FunctionTool;
+import org.springframework.ai.model.function.FunctionCallback;
+import org.springframework.ai.model.function.FunctionCallingOptions;
+import org.springframework.boot.context.properties.NestedConfigurationProperty;
+import org.springframework.util.Assert;
 
 /**
  * @author Ricken Bazolo
@@ -27,7 +39,7 @@ import org.springframework.ai.chat.prompt.ChatOptions;
  * @since 0.8.1
  */
 @JsonInclude(JsonInclude.Include.NON_NULL)
-public class MistralAiChatOptions implements ChatOptions {
+public class MistralAiChatOptions implements FunctionCallingOptions, ChatOptions {
 
 	/**
 	 * ID of the model to use
@@ -66,6 +78,55 @@ public class MistralAiChatOptions implements ChatOptions {
 	 */
 	private @JsonProperty("random_seed") Integer randomSeed;
 
+	/**
+	 * An object specifying the format that the model must output. Setting to { "type":
+	 * "json_object" } enables JSON mode, which guarantees the message the model generates
+	 * is valid JSON.
+	 */
+	private @JsonProperty("response_format") ResponseFormat responseFormat;
+
+	/**
+	 * A list of tools the model may call. Currently, only functions are supported as a
+	 * tool. Use this to provide a list of functions the model may generate JSON inputs
+	 * for.
+	 */
+	@NestedConfigurationProperty
+	private @JsonProperty("tools") List<FunctionTool> tools;
+
+	/**
+	 * Controls which (if any) function is called by the model. none means the model will
+	 * not call a function and instead generates a message. auto means the model can pick
+	 * between generating a message or calling a function.
+	 */
+	@NestedConfigurationProperty
+	private @JsonProperty("tool_choice") ToolChoice toolChoice;
+
+	/**
+	 * MistralAI Tool Function Callbacks to register with the ChatClient. For Prompt
+	 * Options the functionCallbacks are automatically enabled for the duration of the
+	 * prompt execution. For Default Options the functionCallbacks are registered but
+	 * disabled by default. Use the enableFunctions to set the functions from the registry
+	 * to be used by the ChatClient chat completion requests.
+	 */
+	@NestedConfigurationProperty
+	@JsonIgnore
+	private List<FunctionCallback> functionCallbacks = new ArrayList<>();
+
+	/**
+	 * List of functions, identified by their names, to configure for function calling in
+	 * the chat completion requests. Functions with those names must exist in the
+	 * functionCallbacks registry. The {@link #functionCallbacks} from the PromptOptions
+	 * are automatically enabled for the duration of the prompt execution.
+	 *
+	 * Note that function enabled with the default options are enabled for all chat
+	 * completion requests. This could impact the token count and the billing. If the
+	 * functions is set in a prompt options, then the enabled functions are only active
+	 * for the duration of this prompt execution.
+	 */
+	@NestedConfigurationProperty
+	@JsonIgnore
+	private Set<String> functions = new HashSet<>();
+
 	public static Builder builder() {
 		return new Builder();
 	}
@@ -104,6 +165,38 @@ public class MistralAiChatOptions implements ChatOptions {
 			return this;
 		}
 
+		public Builder withResponseFormat(ResponseFormat responseFormat) {
+			this.options.responseFormat = responseFormat;
+			return this;
+		}
+
+		public Builder withTools(List<FunctionTool> tools) {
+			this.options.tools = tools;
+			return this;
+		}
+
+		public Builder withToolChoice(ToolChoice toolChoice) {
+			this.options.toolChoice = toolChoice;
+			return this;
+		}
+
+		public Builder withFunctionCallbacks(List<FunctionCallback> functionCallbacks) {
+			this.options.functionCallbacks = functionCallbacks;
+			return this;
+		}
+
+		public Builder withFunctions(Set<String> functionNames) {
+			Assert.notNull(functionNames, "Function names must not be null");
+			this.options.functions = functionNames;
+			return this;
+		}
+
+		public Builder withFunction(String functionName) {
+			Assert.hasText(functionName, "Function name must not be empty");
+			this.options.functions.add(functionName);
+			return this;
+		}
+
 		public MistralAiChatOptions build() {
 			return this.options;
 		}
@@ -142,6 +235,30 @@ public class MistralAiChatOptions implements ChatOptions {
 		this.randomSeed = randomSeed;
 	}
 
+	public ResponseFormat getResponseFormat() {
+		return this.responseFormat;
+	}
+
+	public void setResponseFormat(ResponseFormat responseFormat) {
+		this.responseFormat = responseFormat;
+	}
+
+	public void setTools(List<FunctionTool> tools) {
+		this.tools = tools;
+	}
+
+	public List<FunctionTool> getTools() {
+		return this.tools;
+	}
+
+	public void setToolChoice(ToolChoice toolChoice) {
+		this.toolChoice = toolChoice;
+	}
+
+	public ToolChoice getToolChoice() {
+		return this.toolChoice;
+	}
+
 	@Override
 	public Float getTemperature() {
 		return this.temperature;
@@ -174,4 +291,26 @@ public class MistralAiChatOptions implements ChatOptions {
 		throw new UnsupportedOperationException("Unsupported option: 'TopK'");
 	}
 
+	@Override
+	public List<FunctionCallback> getFunctionCallbacks() {
+		return this.functionCallbacks;
+	}
+
+	@Override
+	public void setFunctionCallbacks(List<FunctionCallback> functionCallbacks) {
+		Assert.notNull(functionCallbacks, "FunctionCallbacks must not be null");
+		this.functionCallbacks = functionCallbacks;
+	}
+
+	@Override
+	public Set<String> getFunctions() {
+		return this.functions;
+	}
+
+	@Override
+	public void setFunctions(Set<String> functions) {
+		Assert.notNull(functions, "Function must not be null");
+		this.functions = functions;
+	}
+
 }
diff --git a/models/spring-ai-mistral-ai/src/main/java/org/springframework/ai/mistralai/api/MistralAiApi.java b/models/spring-ai-mistral-ai/src/main/java/org/springframework/ai/mistralai/api/MistralAiApi.java
index 0ed9df447..bfa326cc8 100644
--- a/models/spring-ai-mistral-ai/src/main/java/org/springframework/ai/mistralai/api/MistralAiApi.java
+++ b/models/spring-ai-mistral-ai/src/main/java/org/springframework/ai/mistralai/api/MistralAiApi.java
@@ -26,17 +26,19 @@ import java.util.function.Predicate;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonInclude.Include;
 import com.fasterxml.jackson.annotation.JsonProperty;
-import com.fasterxml.jackson.core.type.TypeReference;
 import com.fasterxml.jackson.databind.DeserializationFeature;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 
+import org.springframework.ai.model.ModelOptionsUtils;
+import org.springframework.boot.context.properties.bind.ConstructorBinding;
 import org.springframework.core.ParameterizedTypeReference;
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
 import org.springframework.http.client.ClientHttpResponse;
+import org.springframework.lang.NonNull;
 import org.springframework.util.Assert;
 import org.springframework.util.CollectionUtils;
 import org.springframework.util.StreamUtils;
@@ -45,10 +47,15 @@ import org.springframework.web.client.RestClient;
 import org.springframework.web.reactive.function.client.WebClient;
 
 /**
- * Implementation of the MistralAI Embedding API:
- * <a href="https://docs.mistral.ai/api/#operation/createEmbedding">...</a> and Chat
- * Completion API:
- * <a href="https://docs.mistral.ai/api/#operation/createChatCompletion">...</a>
+ * Single-class, Java Client library for Mistral AI platform. Provides implementation for
+ * the <a href="https://docs.mistral.ai/api/#operation/createEmbedding">MistralAI
+ * Embedding API</a> and the
+ * <a href="https://docs.mistral.ai/api/#operation/createChatCompletion">Chat
+ * Completion</a> APIs.
+ * <p>
+ * Implements <b>Synchronous</b> and <b>Streaming</b> chat completion and supports latest
+ * <b>Function Calling</b> features.
+ * </p>
  *
  * @author Ricken Bazolo
  * @author Christian Tzolov
@@ -101,12 +108,12 @@ public class MistralAiApi {
 		var responseErrorHandler = new ResponseErrorHandler() {
 
 			@Override
-			public boolean hasError(ClientHttpResponse response) throws IOException {
+			public boolean hasError(@NonNull ClientHttpResponse response) throws IOException {
 				return response.getStatusCode().isError();
 			}
 
 			@Override
-			public void handleError(ClientHttpResponse response) throws IOException {
+			public void handleError(@NonNull ClientHttpResponse response) throws IOException {
 				if (response.getStatusCode().isError()) {
 					String error = StreamUtils.copyToString(response.getBody(), StandardCharsets.UTF_8);
 					String message = String.format("%s - %s", response.getStatusCode().value(), error);
@@ -151,6 +158,65 @@ public class MistralAiApi {
 
 	}
 
+	/**
+	 * Represents a tool the model may call. Currently, only functions are supported as a
+	 * tool.
+	 *
+	 * @param type The type of the tool. Currently, only 'function' is supported.
+	 * @param function The function definition.
+	 */
+	@JsonInclude(Include.NON_NULL)
+	public record FunctionTool(@JsonProperty("type") Type type, @JsonProperty("function") Function function) {
+
+		/**
+		 * Create a tool of type 'function' and the given function definition.
+		 * @param function function definition.
+		 */
+		@ConstructorBinding
+		public FunctionTool(Function function) {
+			this(Type.FUNCTION, function);
+		}
+
+		/**
+		 * Create a tool of type 'function' and the given function definition.
+		 */
+		public enum Type {
+
+			/**
+			 * Function tool type.
+			 */
+			@JsonProperty("function")
+			FUNCTION
+
+		}
+
+		/**
+		 * Function definition.
+		 *
+		 * @param description A description of what the function does, used by the model
+		 * to choose when and how to call the function.
+		 * @param name The name of the function to be called. Must be a-z, A-Z, 0-9, or
+		 * contain underscores and dashes, with a maximum length of 64.
+		 * @param parameters The parameters the functions accepts, described as a JSON
+		 * Schema object. To describe a function that accepts no parameters, provide the
+		 * value {"type": "object", "properties": {}}.
+		 */
+		public record Function(@JsonProperty("description") String description, @JsonProperty("name") String name,
+				@JsonProperty("parameters") Map<String, Object> parameters) {
+
+			/**
+			 * Create tool function definition.
+			 * @param description tool function description.
+			 * @param name tool function name.
+			 * @param jsonSchema tool function schema as json.
+			 */
+			@ConstructorBinding
+			public Function(String description, String name, String jsonSchema) {
+				this(description, name, ModelOptionsUtils.jsonToMap(jsonSchema));
+			}
+		}
+	}
+
 	/**
 	 * Usage statistics.
 	 *
@@ -163,10 +229,10 @@ public class MistralAiApi {
 	@JsonInclude(Include.NON_NULL)
 	public record Usage(
 	// @formatter:off
-		@JsonProperty("prompt_tokens") Integer promptTokens,
-		@JsonProperty("total_tokens") Integer totalTokens,
-		@JsonProperty("completion_tokens") Integer completionTokens) {
-		// @formatter:on
+		 @JsonProperty("prompt_tokens") Integer promptTokens,
+		 @JsonProperty("total_tokens") Integer totalTokens,
+		 @JsonProperty("completion_tokens") Integer completionTokens) {
+		 // @formatter:on
 	}
 
 	/**
@@ -180,10 +246,10 @@ public class MistralAiApi {
 	@JsonInclude(Include.NON_NULL)
 	public record Embedding(
 	// @formatter:off
-		@JsonProperty("index") Integer index,
-		@JsonProperty("embedding") List<Double> embedding,
-		@JsonProperty("object") String object) {
-		// @formatter:on
+		 @JsonProperty("index") Integer index,
+		 @JsonProperty("embedding") List<Double> embedding,
+		 @JsonProperty("object") String object) {
+		 // @formatter:on
 
 		/**
 		 * Create an embedding with the given index, embedding and object type set to
@@ -208,10 +274,10 @@ public class MistralAiApi {
 	@JsonInclude(Include.NON_NULL)
 	public record EmbeddingRequest<T>(
 	// @formatter:off
-		@JsonProperty("input") T input,
-		@JsonProperty("model") String model,
-		@JsonProperty("encoding_format") String encodingFormat) {
-		// @formatter:on
+		 @JsonProperty("input") T input,
+		 @JsonProperty("model") String model,
+		 @JsonProperty("encoding_format") String encodingFormat) {
+		 // @formatter:on
 
 		/**
 		 * Create an embedding request with the given input, model and encoding format set
@@ -245,11 +311,11 @@ public class MistralAiApi {
 	@JsonInclude(Include.NON_NULL)
 	public record EmbeddingList<T>(
 	// @formatter:off
-			@JsonProperty("object") String object,
-			@JsonProperty("data") List<T> data,
-			@JsonProperty("model") String model,
-			@JsonProperty("usage") Usage usage) {
-		// @formatter:on
+			 @JsonProperty("object") String object,
+			 @JsonProperty("data") List<T> data,
+			 @JsonProperty("model") String model,
+			 @JsonProperty("usage") Usage usage) {
+		 // @formatter:on
 	}
 
 	/**
@@ -298,6 +364,13 @@ public class MistralAiApi {
 	 * @param model ID of the model to use.
 	 * @param messages The prompt(s) to generate completions for, encoded as a list of
 	 * dict with role and content. The first prompt role should be user or system.
+	 * @param tools A list of tools the model may call. Currently, only functions are
+	 * supported as a tool. Use this to provide a list of functions the model may generate
+	 * JSON inputs for.
+	 * @param toolChoice Controls which (if any) function is called by the model. none
+	 * means the model will not call a function and instead generates a message. auto
+	 * means the model can pick between generating a message or calling a function. Any
+	 * means the model must call a function.
 	 * @param temperature What sampling temperature to use, between 0.0 and 1.0. Higher
 	 * values like 0.8 will make the output more random, while lower values like 0.2 will
 	 * make it more focused and deterministic. We generally recommend altering this or
@@ -317,19 +390,25 @@ public class MistralAiApi {
 	 * @param safePrompt Whether to inject a safety prompt before all conversations.
 	 * @param randomSeed The seed to use for random sampling. If set, different calls will
 	 * generate deterministic results.
+	 * @param responseFormat An object specifying the format that the model must output.
+	 * Setting to { "type": "json_object" } enables JSON mode, which guarantees the
+	 * message the model generates is valid JSON.
 	 */
 	@JsonInclude(Include.NON_NULL)
 	public record ChatCompletionRequest(
 	// @formatter:off
-			@JsonProperty("model") String model,
-			@JsonProperty("messages") List<ChatCompletionMessage> messages,
-			@JsonProperty("temperature") Float temperature,
-			@JsonProperty("top_p") Float topP,
-			@JsonProperty("max_tokens") Integer maxTokens,
-			@JsonProperty("stream") Boolean stream,
-			@JsonProperty("safe_prompt") Boolean safePrompt,
-			@JsonProperty("random_seed") Integer randomSeed) {
-		// @formatter:on
+			 @JsonProperty("model") String model,
+			 @JsonProperty("messages") List<ChatCompletionMessage> messages,
+			 @JsonProperty("tools") List<FunctionTool> tools,
+			 @JsonProperty("tool_choice") ToolChoice toolChoice,
+			 @JsonProperty("temperature") Float temperature,
+			 @JsonProperty("top_p") Float topP,
+			 @JsonProperty("max_tokens") Integer maxTokens,
+			 @JsonProperty("stream") Boolean stream,
+			 @JsonProperty("safe_prompt") Boolean safePrompt,
+			 @JsonProperty("random_seed") Integer randomSeed,
+			 @JsonProperty("response_format") ResponseFormat responseFormat) {
+		 // @formatter:on
 
 		/**
 		 * Shortcut constructor for a chat completion request with the given messages and
@@ -339,7 +418,7 @@ public class MistralAiApi {
 		 * @param model ID of the model to use.
 		 */
 		public ChatCompletionRequest(List<ChatCompletionMessage> messages, String model) {
-			this(model, messages, 0.7f, 1f, null, false, false, null);
+			this(model, messages, null, null, 0.7f, 1f, null, false, false, null, null);
 		}
 
 		/**
@@ -354,7 +433,7 @@ public class MistralAiApi {
 		 */
 		public ChatCompletionRequest(List<ChatCompletionMessage> messages, String model, Float temperature,
 				boolean stream) {
-			this(model, messages, temperature, 1f, null, stream, false, null);
+			this(model, messages, null, null, temperature, 1f, null, stream, false, null, null);
 		}
 
 		/**
@@ -367,7 +446,22 @@ public class MistralAiApi {
 		 *
 		 */
 		public ChatCompletionRequest(List<ChatCompletionMessage> messages, String model, Float temperature) {
-			this(model, messages, temperature, 1f, null, false, false, null);
+			this(model, messages, null, null, temperature, 1f, null, false, false, null, null);
+		}
+
+		/**
+		 * Shortcut constructor for a chat completion request with the given messages,
+		 * model, tools and tool choice. Streaming is set to false, temperature to 0.8 and
+		 * all other parameters are null.
+		 * @param messages A list of messages comprising the conversation so far.
+		 * @param model ID of the model to use.
+		 * @param tools A list of tools the model may call. Currently, only functions are
+		 * supported as a tool.
+		 * @param toolChoice Controls which (if any) function is called by the model.
+		 */
+		public ChatCompletionRequest(List<ChatCompletionMessage> messages, String model, List<FunctionTool> tools,
+				ToolChoice toolChoice) {
+			this(model, messages, tools, toolChoice, null, 1f, null, false, false, null, null);
 		}
 
 		/**
@@ -375,7 +469,31 @@ public class MistralAiApi {
 		 * stream.
 		 */
 		public ChatCompletionRequest(List<ChatCompletionMessage> messages, Boolean stream) {
-			this(null, messages, 0.7f, 1f, null, stream, false, null);
+			this(null, messages, null, null, 0.7f, 1f, null, stream, false, null, null);
+		}
+
+		/**
+		 * Specifies a tool the model should use. Use to force the model to call a
+		 * specific function.
+		 *
+		 */
+		public enum ToolChoice {
+
+			// @formatter:off
+			 @JsonProperty("auto") AUTO,
+			 @JsonProperty("any") ANY,
+			 @JsonProperty("none") NONE
+			 // @formatter:on
+
+		}
+
+		/**
+		 * An object specifying the format that the model must output.
+		 *
+		 * @param type Must be one of 'text' or 'json_object'.
+		 */
+		@JsonInclude(Include.NON_NULL)
+		public record ResponseFormat(@JsonProperty("type") String type) {
 		}
 	}
 
@@ -385,13 +503,27 @@ public class MistralAiApi {
 	 * @param content The contents of the message.
 	 * @param role The role of the messages author. Could be one of the {@link Role}
 	 * types.
+	 * @param toolCalls The tool calls generated by the model, such as function calls.
+	 * Applicable only for {@link Role#ASSISTANT} role and null otherwise.
 	 */
 	@JsonInclude(Include.NON_NULL)
 	public record ChatCompletionMessage(
 	// @formatter:off
-		@JsonProperty("content") String content,
-		@JsonProperty("role") Role role) {
-		// @formatter:on
+		 @JsonProperty("content") String content,
+		 @JsonProperty("role") Role role,
+		 @JsonProperty("name") String name,
+		 @JsonProperty("tool_calls") List<ToolCall> toolCalls) {
+		 // @formatter:on
+
+		/**
+		 * Create a chat completion message with the given content and role. All other
+		 * fields are null.
+		 * @param content The contents of the message.
+		 * @param role The role of the author of this message.
+		 */
+		public ChatCompletionMessage(String content, Role role) {
+			this(content, role, null, null);
+		}
 
 		/**
 		 * The role of the author of this message.
@@ -402,12 +534,39 @@ public class MistralAiApi {
 		public enum Role {
 
 			// @formatter:off
-			@JsonProperty("system") SYSTEM,
-			@JsonProperty("user") USER,
-			@JsonProperty("assistant") ASSISTANT
-			// @formatter:on
+			 @JsonProperty("system") SYSTEM,
+			 @JsonProperty("user") USER,
+			 @JsonProperty("assistant") ASSISTANT,
+			 @JsonProperty("tool") TOOL
+			 // @formatter:on
 
 		}
+
+		/**
+		 * The relevant tool call.
+		 *
+		 * @param id The ID of the tool call. This ID must be referenced when you submit
+		 * the tool outputs in using the Submit tool outputs to run endpoint.
+		 * @param type The type of tool call the output is required for. For now, this is
+		 * always function.
+		 * @param function The function definition.
+		 */
+		@JsonInclude(Include.NON_NULL)
+		public record ToolCall(@JsonProperty("id") String id, @JsonProperty("type") String type,
+				@JsonProperty("function") ChatCompletionFunction function) {
+		}
+
+		/**
+		 * The function definition.
+		 *
+		 * @param name The name of the function.
+		 * @param arguments The arguments that the model expects you to pass to the
+		 * function.
+		 */
+		@JsonInclude(Include.NON_NULL)
+		public record ChatCompletionFunction(@JsonProperty("name") String name,
+				@JsonProperty("arguments") String arguments) {
+		}
 	}
 
 	/**
@@ -416,19 +575,19 @@ public class MistralAiApi {
 	public enum ChatCompletionFinishReason {
 
 		// @formatter:off
-		/**
-		 * The model hit a natural stop point or a provided stop sequence.
-		 */
-		@JsonProperty("stop") STOP,
-		/**
-		 * The maximum number of tokens specified in the request was reached.
-		 */
-		@JsonProperty("length") LENGTH,
-		/**
-		 * The content was omitted due to a flag from our content filters.
-		 */
-		@JsonProperty("model_length") MODEL_LENGTH
-		// @formatter:on
+		 /**
+		  * The model hit a natural stop point or a provided stop sequence.
+		  */
+		 @JsonProperty("stop") STOP,
+		 /**
+		  * The maximum number of tokens specified in the request was reached.
+		  */
+		 @JsonProperty("length") LENGTH,
+		 /**
+		  * The content was omitted due to a flag from our content filters.
+		  */
+		 @JsonProperty("model_length") MODEL_LENGTH
+		 // @formatter:on
 
 	}
 
@@ -447,13 +606,13 @@ public class MistralAiApi {
 	@JsonInclude(Include.NON_NULL)
 	public record ChatCompletion(
 	// @formatter:off
-		@JsonProperty("id") String id,
-		@JsonProperty("object") String object,
-		@JsonProperty("created") Long created,
-		@JsonProperty("model") String model,
-		@JsonProperty("choices") List<Choice> choices,
-		@JsonProperty("usage") Usage usage) {
-		// @formatter:on
+		 @JsonProperty("id") String id,
+		 @JsonProperty("object") String object,
+		 @JsonProperty("created") Long created,
+		 @JsonProperty("model") String model,
+		 @JsonProperty("choices") List<Choice> choices,
+		 @JsonProperty("usage") Usage usage) {
+		 // @formatter:on
 
 		/**
 		 * Chat completion choice.
@@ -465,10 +624,10 @@ public class MistralAiApi {
 		@JsonInclude(Include.NON_NULL)
 		public record Choice(
 		// @formatter:off
-			@JsonProperty("index") Integer index,
-			@JsonProperty("message") ChatCompletionMessage message,
-			@JsonProperty("finish_reason") ChatCompletionFinishReason finishReason) {
-			// @formatter:on
+			 @JsonProperty("index") Integer index,
+			 @JsonProperty("message") ChatCompletionMessage message,
+			 @JsonProperty("finish_reason") ChatCompletionFinishReason finishReason) {
+			 // @formatter:on
 		}
 	}
 
@@ -487,12 +646,12 @@ public class MistralAiApi {
 	@JsonInclude(Include.NON_NULL)
 	public record ChatCompletionChunk(
 	// @formatter:off
-		@JsonProperty("id") String id,
-		@JsonProperty("object") String object,
-		@JsonProperty("created") Long created,
-		@JsonProperty("model") String model,
-		@JsonProperty("choices") List<ChunkChoice> choices) {
-		// @formatter:on
+		 @JsonProperty("id") String id,
+		 @JsonProperty("object") String object,
+		 @JsonProperty("created") Long created,
+		 @JsonProperty("model") String model,
+		 @JsonProperty("choices") List<ChunkChoice> choices) {
+		 // @formatter:on
 
 		/**
 		 * Chat completion choice.
@@ -504,26 +663,38 @@ public class MistralAiApi {
 		@JsonInclude(Include.NON_NULL)
 		public record ChunkChoice(
 		// @formatter:off
-			@JsonProperty("index") Integer index,
-			@JsonProperty("delta") ChatCompletionMessage delta,
-			@JsonProperty("finish_reason") ChatCompletionFinishReason finishReason) {
-			// @formatter:on
+			 @JsonProperty("index") Integer index,
+			 @JsonProperty("delta") ChatCompletionMessage delta,
+			 @JsonProperty("finish_reason") ChatCompletionFinishReason finishReason) {
+			 // @formatter:on
 		}
 	}
 
 	/**
 	 * List of well-known Mistral chat models.
 	 * https://docs.mistral.ai/platform/endpoints/#mistral-ai-generative-models
+	 *
+	 * <p>
+	 * Mistral AI provides five API endpoints featuring five leading Large Language
+	 * Models:
+	 * </p>
+	 * <ul>
+	 * <li><b>TINY</b> - open-mistral-7b (aka mistral-tiny-2312)</li>
+	 * <li><b>MIXTRAL</b> - open-mixtral-8x7b (aka mistral-small-2312)</li>
+	 * <li><b>SMALL_LATEST</b> - mistral-small-latest (aka mistral-small-2402)</li>
+	 * <li><b>MEDIUM</b> - mistral-medium-latest (aka mistral-medium-2312)</li>
+	 * <li><b>LARGE</b> - mistral-large-latest (aka mistral-large-2402)</li>
+	 * </ul>
 	 */
 	public enum ChatModel {
 
 		// @formatter:off
-		@JsonProperty("mistral-tiny") TINY("mistral-tiny"),
-		@JsonProperty("mistral-small") SMALL("mistral-small"),
-		@JsonProperty("mistral-medium") MEDIUM("mistral-medium"),
-		@JsonProperty("mistral-large") LARGE("mistral-large"),
-		@JsonProperty("mistral-xlarge") XLARGE("mistral-xlarge");
-		// @formatter:on
+		 TINY("open-mistral-7b"),
+		 MIXTRAL("open-mixtral-8x7b"),
+		 SMALL("mistral-small-latest"),
+		 MEDIUM("mistral-medium-latest"),
+		 LARGE("mistral-large-latest");
+		 // @formatter:on
 
 		private final String value;
 
@@ -544,8 +715,8 @@ public class MistralAiApi {
 	public enum EmbeddingModel {
 
 		// @formatter:off
-		@JsonProperty("mistral-embed") EMBED("mistral-embed");
-		// @formatter:on
+		 @JsonProperty("mistral-embed") EMBED("mistral-embed");
+		 // @formatter:on
 
 		private final String value;
 
@@ -595,26 +766,7 @@ public class MistralAiApi {
 			.bodyToFlux(String.class)
 			.takeUntil(SSE_DONE_PREDICATE)
 			.filter(SSE_DONE_PREDICATE.negate())
-			.map(content -> parseJson(content, ChatCompletionChunk.class));
-	}
-
-	public static Map<String, Object> parseJson(String jsonSchema) {
-		try {
-			return new ObjectMapper().readValue(jsonSchema, new TypeReference<Map<String, Object>>() {
-			});
-		}
-		catch (Exception e) {
-			throw new MistralAiApiException("Failed to parse schema: " + jsonSchema, e);
-		}
-	}
-
-	private <T> T parseJson(String json, Class<T> type) {
-		try {
-			return this.objectMapper.readValue(json, type);
-		}
-		catch (Exception e) {
-			throw new MistralAiApiException("Failed to parse schema: " + json, e);
-		}
+			.map(content -> ModelOptionsUtils.jsonToObject(content, ChatCompletionChunk.class));
 	}
 
 }
diff --git a/models/spring-ai-mistral-ai/src/test/java/org/springframework/ai/mistralai/MistralAiTestConfiguration.java b/models/spring-ai-mistral-ai/src/test/java/org/springframework/ai/mistralai/MistralAiTestConfiguration.java
index 3c774d2eb..224095f94 100644
--- a/models/spring-ai-mistral-ai/src/test/java/org/springframework/ai/mistralai/MistralAiTestConfiguration.java
+++ b/models/spring-ai-mistral-ai/src/test/java/org/springframework/ai/mistralai/MistralAiTestConfiguration.java
@@ -44,7 +44,7 @@ public class MistralAiTestConfiguration {
 	@Bean
 	public MistralAiChatClient mistralAiChatClient(MistralAiApi mistralAiApi) {
 		return new MistralAiChatClient(mistralAiApi,
-				MistralAiChatOptions.builder().withModel(MistralAiApi.ChatModel.SMALL.getValue()).build());
+				MistralAiChatOptions.builder().withModel(MistralAiApi.ChatModel.MIXTRAL.getValue()).build());
 	}
 
 }
diff --git a/models/spring-ai-mistral-ai/src/test/java/org/springframework/ai/mistralai/MistralChatCompletionRequestTest.java b/models/spring-ai-mistral-ai/src/test/java/org/springframework/ai/mistralai/MistralChatCompletionRequestTest.java
index 51c533627..df5b285d4 100644
--- a/models/spring-ai-mistral-ai/src/test/java/org/springframework/ai/mistralai/MistralChatCompletionRequestTest.java
+++ b/models/spring-ai-mistral-ai/src/test/java/org/springframework/ai/mistralai/MistralChatCompletionRequestTest.java
@@ -20,8 +20,6 @@ import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.condition.EnabledIfEnvironmentVariable;
 
 import org.springframework.ai.chat.prompt.Prompt;
-import org.springframework.ai.mistralai.MistralAiChatClient;
-import org.springframework.ai.mistralai.MistralAiChatOptions;
 import org.springframework.ai.mistralai.api.MistralAiApi;
 import org.springframework.boot.test.context.SpringBootTest;
 
diff --git a/models/spring-ai-mistral-ai/src/test/java/org/springframework/ai/mistralai/MistralEmbeddingIT.java b/models/spring-ai-mistral-ai/src/test/java/org/springframework/ai/mistralai/MistralEmbeddingIT.java
index 7a3c6f498..f456c8516 100644
--- a/models/spring-ai-mistral-ai/src/test/java/org/springframework/ai/mistralai/MistralEmbeddingIT.java
+++ b/models/spring-ai-mistral-ai/src/test/java/org/springframework/ai/mistralai/MistralEmbeddingIT.java
@@ -15,17 +15,15 @@
  */
 package org.springframework.ai.mistralai;
 
+import java.util.List;
+
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.condition.EnabledIfEnvironmentVariable;
 
 import org.springframework.ai.embedding.EmbeddingRequest;
-import org.springframework.ai.mistralai.MistralAiEmbeddingClient;
-import org.springframework.ai.mistralai.MistralAiEmbeddingOptions;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.context.SpringBootTest;
 
-import java.util.List;
-
 import static org.assertj.core.api.Assertions.assertThat;
 
 @SpringBootTest
diff --git a/models/spring-ai-mistral-ai/src/test/java/org/springframework/ai/mistralai/api/tool/MistralAiApiToolFunctionCallIT.java b/models/spring-ai-mistral-ai/src/test/java/org/springframework/ai/mistralai/api/tool/MistralAiApiToolFunctionCallIT.java
new file mode 100644
index 000000000..9539c8b7e
--- /dev/null
+++ b/models/spring-ai-mistral-ai/src/test/java/org/springframework/ai/mistralai/api/tool/MistralAiApiToolFunctionCallIT.java
@@ -0,0 +1,166 @@
+/*
+ * Copyright 2024-2024 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.ai.mistralai.api.tool;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import org.junit.jupiter.api.Disabled;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.condition.EnabledIfEnvironmentVariable;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import org.springframework.ai.mistralai.api.MistralAiApi;
+import org.springframework.ai.mistralai.api.MistralAiApi.ChatCompletion;
+import org.springframework.ai.mistralai.api.MistralAiApi.ChatCompletionMessage;
+import org.springframework.ai.mistralai.api.MistralAiApi.ChatCompletionMessage.Role;
+import org.springframework.ai.mistralai.api.MistralAiApi.ChatCompletionMessage.ToolCall;
+import org.springframework.ai.mistralai.api.MistralAiApi.ChatCompletionRequest.ToolChoice;
+import org.springframework.ai.mistralai.api.MistralAiApi.ChatCompletionRequest;
+import org.springframework.ai.mistralai.api.MistralAiApi.FunctionTool.Type;
+import org.springframework.ai.model.ModelOptionsUtils;
+import org.springframework.http.ResponseEntity;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * @author Christian Tzolov
+ */
+@EnabledIfEnvironmentVariable(named = "MISTRAL_AI_API_KEY", matches = ".+")
+@Disabled
+public class MistralAiApiToolFunctionCallIT {
+
+	private final Logger logger = LoggerFactory.getLogger(MistralAiApiToolFunctionCallIT.class);
+
+	MockWeatherService weatherService = new MockWeatherService();
+
+	static final String MISTRAL_AI_CHAT_MODEL = MistralAiApi.ChatModel.LARGE.getValue();
+
+	MistralAiApi completionApi = new MistralAiApi(System.getenv("MISTRAL_AI_API_KEY"));
+
+	@Test
+	@SuppressWarnings("null")
+	public void toolFunctionCall() throws JsonProcessingException {
+
+		// Step 1: send the conversation and available functions to the model
+		var message = new ChatCompletionMessage(
+				"What's the weather like in San Francisco, Tokyo, and Paris? Show the temperature in Celsius.",
+				Role.USER);
+
+		var functionTool = new MistralAiApi.FunctionTool(Type.FUNCTION,
+				new MistralAiApi.FunctionTool.Function(
+						"Get the weather in location. Return temperature in 30°F or 30°C format.", "getCurrentWeather",
+						ModelOptionsUtils.jsonToMap("""
+								{
+									"type": "object",
+									"properties": {
+										"location": {
+											"type": "string",
+											"description": "The city and state e.g. San Francisco, CA"
+										},
+										"unit": {
+											"type": "string",
+											"enum": ["C", "F"]
+										}
+									},
+									"required": ["location", "unit"]
+								}
+								""")));
+
+		// Or you can use the
+		// ModelOptionsUtils.getJsonSchema(FakeWeatherService.Request.class))) to
+		// auto-generate the JSON schema like:
+		// var functionTool = new MistralAiApi.FunctionTool(Type.FUNCTION, new
+		// MistralAiApi.FunctionTool.Function(
+		// "Get the weather in location. Return temperature in 30°F or 30°C format.",
+		// "getCurrentWeather",
+		// ModelOptionsUtils.getJsonSchema(MockWeatherService.Request.class)));
+
+		List<ChatCompletionMessage> messages = new ArrayList<>(List.of(message));
+
+		ChatCompletionRequest chatCompletionRequest = new ChatCompletionRequest(messages, MISTRAL_AI_CHAT_MODEL,
+				List.of(functionTool), ToolChoice.AUTO);
+
+		System.out
+			.println(new ObjectMapper().writerWithDefaultPrettyPrinter().writeValueAsString(chatCompletionRequest));
+
+		ResponseEntity<ChatCompletion> chatCompletion = completionApi.chatCompletionEntity(chatCompletionRequest);
+
+		assertThat(chatCompletion.getBody()).isNotNull();
+		assertThat(chatCompletion.getBody().choices()).isNotEmpty();
+
+		ChatCompletionMessage responseMessage = chatCompletion.getBody().choices().get(0).message();
+
+		assertThat(responseMessage.role()).isEqualTo(Role.ASSISTANT);
+		assertThat(responseMessage.toolCalls()).isNotNull();
+
+		// Check if the model wanted to call a function
+		if (responseMessage.toolCalls() != null) {
+
+			// extend conversation with assistant's reply.
+			messages.add(responseMessage);
+
+			// Send the info for each function call and function response to the model.
+			for (ToolCall toolCall : responseMessage.toolCalls()) {
+				var functionName = toolCall.function().name();
+				if ("getCurrentWeather".equals(functionName)) {
+					MockWeatherService.Request weatherRequest = fromJson(toolCall.function().arguments(),
+							MockWeatherService.Request.class);
+
+					MockWeatherService.Response weatherResponse = weatherService.apply(weatherRequest);
+
+					// extend conversation with function response.
+					messages.add(new ChatCompletionMessage("" + weatherResponse.temp() + weatherRequest.unit(),
+							Role.TOOL, functionName, null));
+				}
+			}
+
+			var functionResponseRequest = new ChatCompletionRequest(messages, MISTRAL_AI_CHAT_MODEL, 0.8f);
+
+			ResponseEntity<ChatCompletion> chatCompletion2 = completionApi
+				.chatCompletionEntity(functionResponseRequest);
+
+			logger.info("Final response: " + chatCompletion2.getBody());
+
+			assertThat(chatCompletion2.getBody().choices()).isNotEmpty();
+
+			assertThat(chatCompletion2.getBody().choices().get(0).message().role()).isEqualTo(Role.ASSISTANT);
+			assertThat(chatCompletion2.getBody().choices().get(0).message().content()).contains("San Francisco")
+				.containsAnyOf("30.0°C", "30°C");
+			assertThat(chatCompletion2.getBody().choices().get(0).message().content()).contains("Tokyo")
+				.containsAnyOf("10.0°C", "10°C");
+			;
+			assertThat(chatCompletion2.getBody().choices().get(0).message().content()).contains("Paris")
+				.containsAnyOf("15.0°C", "15°C");
+			;
+		}
+
+	}
+
+	private static <T> T fromJson(String json, Class<T> targetClass) {
+		try {
+			return new ObjectMapper().readValue(json, targetClass);
+		}
+		catch (JsonProcessingException e) {
+			throw new RuntimeException(e);
+		}
+	}
+
+}
\ No newline at end of file
diff --git a/models/spring-ai-mistral-ai/src/test/java/org/springframework/ai/mistralai/api/tool/MockWeatherService.java b/models/spring-ai-mistral-ai/src/test/java/org/springframework/ai/mistralai/api/tool/MockWeatherService.java
new file mode 100644
index 000000000..82dd94e1e
--- /dev/null
+++ b/models/spring-ai-mistral-ai/src/test/java/org/springframework/ai/mistralai/api/tool/MockWeatherService.java
@@ -0,0 +1,91 @@
+/*
+ * Copyright 2024-2024 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.ai.mistralai.api.tool;
+
+import java.util.function.Function;
+
+import com.fasterxml.jackson.annotation.JsonClassDescription;
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonInclude.Include;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonPropertyDescription;
+
+/**
+ * @author Christian Tzolov
+ */
+public class MockWeatherService implements Function<MockWeatherService.Request, MockWeatherService.Response> {
+
+	/**
+	 * Weather Function request.
+	 */
+	@JsonInclude(Include.NON_NULL)
+	@JsonClassDescription("Weather API request")
+	public record Request(@JsonProperty(required = true,
+			value = "location") @JsonPropertyDescription("The city and state e.g. San Francisco, CA") String location,
+			@JsonProperty(required = true, value = "unit") @JsonPropertyDescription("Temperature unit") Unit unit) {
+	}
+
+	/**
+	 * Temperature units.
+	 */
+	public enum Unit {
+
+		/**
+		 * Celsius.
+		 */
+		C("metric"),
+		/**
+		 * Fahrenheit.
+		 */
+		F("imperial");
+
+		/**
+		 * Human readable unit name.
+		 */
+		public final String unitName;
+
+		private Unit(String text) {
+			this.unitName = text;
+		}
+
+	}
+
+	/**
+	 * Weather Function response.
+	 */
+	public record Response(double temp, double feels_like, double temp_min, double temp_max, int pressure, int humidity,
+			Unit unit) {
+	}
+
+	@Override
+	public Response apply(Request request) {
+
+		double temperature = 0;
+		if (request.location().contains("Paris")) {
+			temperature = 15;
+		}
+		else if (request.location().contains("Tokyo")) {
+			temperature = 10;
+		}
+		else if (request.location().contains("San Francisco")) {
+			temperature = 30;
+		}
+
+		return new Response(temperature, 15, 20, 2, 53, 45, Unit.C);
+	}
+
+}
\ No newline at end of file
diff --git a/models/spring-ai-mistral-ai/src/test/java/org/springframework/ai/mistralai/api/tool/PaymentStatusFunctionCallingIT.java b/models/spring-ai-mistral-ai/src/test/java/org/springframework/ai/mistralai/api/tool/PaymentStatusFunctionCallingIT.java
new file mode 100644
index 000000000..65a60cb35
--- /dev/null
+++ b/models/spring-ai-mistral-ai/src/test/java/org/springframework/ai/mistralai/api/tool/PaymentStatusFunctionCallingIT.java
@@ -0,0 +1,176 @@
+/*
+ * Copyright 2024-2024 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.ai.mistralai.api.tool;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.function.Function;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.condition.EnabledIfEnvironmentVariable;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import org.springframework.ai.mistralai.api.MistralAiApi;
+import org.springframework.ai.mistralai.api.MistralAiApi.ChatCompletion;
+import org.springframework.ai.mistralai.api.MistralAiApi.ChatCompletionMessage;
+import org.springframework.ai.mistralai.api.MistralAiApi.ChatCompletionMessage.Role;
+import org.springframework.ai.mistralai.api.MistralAiApi.ChatCompletionMessage.ToolCall;
+import org.springframework.ai.mistralai.api.MistralAiApi.ChatCompletionRequest;
+import org.springframework.ai.mistralai.api.MistralAiApi.ChatCompletionRequest.ToolChoice;
+import org.springframework.ai.mistralai.api.MistralAiApi.FunctionTool;
+import org.springframework.ai.mistralai.api.MistralAiApi.FunctionTool.Type;
+// import org.springframework.ai.model.ModelOptionsUtils;
+import org.springframework.http.ResponseEntity;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Demonstrates how to use function calling suing Mistral AI Java API:
+ * {@link MistralAiApi}.
+ *
+ * It is based on the <a href="https://docs.mistral.ai/guides/function-calling/">Mistral
+ * AI Function Calling</a> guide.
+ *
+ * @author Christian Tzolov
+ * @since 0.8.1
+ */
+@EnabledIfEnvironmentVariable(named = "MISTRAL_AI_API_KEY", matches = ".+")
+public class PaymentStatusFunctionCallingIT {
+
+	private final Logger logger = LoggerFactory.getLogger(PaymentStatusFunctionCallingIT.class);
+
+	// Assuming we have the following data
+	public static final Map<String, StatusDate> DATA = Map.of("T1001", new StatusDate("Paid", "2021-10-05"), "T1002",
+			new StatusDate("Unpaid", "2021-10-06"), "T1003", new StatusDate("Paid", "2021-10-07"), "T1004",
+			new StatusDate("Paid", "2021-10-05"), "T1005", new StatusDate("Pending", "2021-10-08"));
+
+	record StatusDate(String status, String date) {
+	}
+
+	public record Transaction(@JsonProperty(required = true, value = "transaction_id") String transactionId) {
+	}
+
+	public record Status(@JsonProperty(required = true, value = "status") String status) {
+	}
+
+	public record Date(@JsonProperty(required = true, value = "date") String date) {
+	}
+
+	private static class RetrievePaymentStatus implements Function<Transaction, Status> {
+
+		@Override
+		public Status apply(Transaction paymentTransaction) {
+			return new Status(DATA.get(paymentTransaction.transactionId).status);
+		}
+
+	}
+
+	private static class RetrievePaymentDate implements Function<Transaction, Date> {
+
+		@Override
+		public Date apply(Transaction paymentTransaction) {
+			return new Date(DATA.get(paymentTransaction.transactionId).date);
+		}
+
+	}
+
+	static Map<String, Function<Transaction, ?>> functions = Map.of("retrieve_payment_status",
+			new RetrievePaymentStatus(), "retrieve_payment_date", new RetrievePaymentDate());
+
+	@Test
+	@SuppressWarnings("null")
+	public void toolFunctionCall() throws JsonProcessingException {
+
+		var transactionJsonSchema = """
+				{
+					"type": "object",
+					"properties": {
+						"transaction_id": {
+							"type": "string",
+							"description": "The transaction id"
+						}
+					},
+					"required": ["transaction_id"]
+				}
+				""";
+
+		// Alternatively, generate the JSON schema using the ModelOptionsUtils helper:
+		//
+		// var transactionJsonSchema = ModelOptionsUtils.getJsonSchema(Transaction.class,
+		// false);
+
+		var paymentStatusTool = new FunctionTool(Type.FUNCTION, new FunctionTool.Function(
+				"Get payment status of a transaction", "retrieve_payment_status", transactionJsonSchema));
+
+		var paymentDateTool = new FunctionTool(Type.FUNCTION, new FunctionTool.Function(
+				"Get payment date of a transaction", "retrieve_payment_date", transactionJsonSchema));
+
+		List<ChatCompletionMessage> messages = new ArrayList<>(
+				List.of(new ChatCompletionMessage("What's the status of my transaction with id T1001?", Role.USER)));
+
+		MistralAiApi mistralApi = new MistralAiApi(System.getenv("MISTRAL_AI_API_KEY"));
+
+		ResponseEntity<ChatCompletion> response = mistralApi.chatCompletionEntity(new ChatCompletionRequest(messages,
+				MistralAiApi.ChatModel.LARGE.getValue(), List.of(paymentStatusTool, paymentDateTool), ToolChoice.AUTO));
+
+		ChatCompletionMessage responseMessage = response.getBody().choices().get(0).message();
+
+		assertThat(responseMessage.role()).isEqualTo(Role.ASSISTANT);
+		assertThat(responseMessage.toolCalls()).isNotNull();
+
+		// extend conversation with assistant's reply.
+		messages.add(responseMessage);
+
+		// Send the info for each function call and function response to the model.
+		for (ToolCall toolCall : responseMessage.toolCalls()) {
+
+			var functionName = toolCall.function().name();
+			// Map the function, JSON arguments into a Transaction object.
+			Transaction transaction = jsonToObject(toolCall.function().arguments(), Transaction.class);
+			// Call the target function with the transaction object.
+			var result = functions.get(functionName).apply(transaction);
+
+			// Extend conversation with function response.
+			// The functionName is used to identify the function response!
+			messages.add(new ChatCompletionMessage(result.toString(), Role.TOOL, functionName, null));
+		}
+
+		response = mistralApi
+			.chatCompletionEntity(new ChatCompletionRequest(messages, MistralAiApi.ChatModel.LARGE.getValue()));
+
+		var responseContent = response.getBody().choices().get(0).message().content();
+		logger.info("Final response: " + responseContent);
+
+		assertThat(responseContent).containsIgnoringCase("T1001");
+		assertThat(responseContent).containsIgnoringCase("Paid");
+	}
+
+	private static <T> T jsonToObject(String json, Class<T> targetClass) {
+		try {
+			return new ObjectMapper().readValue(json, targetClass);
+		}
+		catch (JsonProcessingException e) {
+			throw new RuntimeException(e);
+		}
+	}
+
+}
diff --git a/models/spring-ai-openai/src/main/java/org/springframework/ai/openai/OpenAiChatClient.java b/models/spring-ai-openai/src/main/java/org/springframework/ai/openai/OpenAiChatClient.java
index b1fefe699..62f7bfe61 100644
--- a/models/spring-ai-openai/src/main/java/org/springframework/ai/openai/OpenAiChatClient.java
+++ b/models/spring-ai-openai/src/main/java/org/springframework/ai/openai/OpenAiChatClient.java
@@ -277,7 +277,8 @@ public class OpenAiChatClient extends
 			String functionResponse = this.functionCallbackRegister.get(functionName).call(functionArguments);
 
 			// Add the function response to the conversation.
-			conversationHistory.add(new ChatCompletionMessage(functionResponse, Role.TOOL, null, toolCall.id(), null));
+			conversationHistory
+				.add(new ChatCompletionMessage(functionResponse, Role.TOOL, functionName, toolCall.id(), null));
 		}
 
 		// Recursively call chatCompletionWithTools until the model doesn't call a
@@ -291,7 +292,6 @@ public class OpenAiChatClient extends
 	@Override
 	protected List<ChatCompletionMessage> doGetUserMessages(ChatCompletionRequest request) {
 		return request.messages();
-
 	}
 
 	@Override
@@ -316,7 +316,7 @@ public class OpenAiChatClient extends
 			return false;
 		}
 
-		return choices.get(0).message().toolCalls() != null;
+		return !CollectionUtils.isEmpty(choices.get(0).message().toolCalls());
 	}
 
 }
diff --git a/models/spring-ai-openai/src/main/java/org/springframework/ai/openai/OpenAiChatOptions.java b/models/spring-ai-openai/src/main/java/org/springframework/ai/openai/OpenAiChatOptions.java
index b1f03c3c7..3ebb1c9db 100644
--- a/models/spring-ai-openai/src/main/java/org/springframework/ai/openai/OpenAiChatOptions.java
+++ b/models/spring-ai-openai/src/main/java/org/springframework/ai/openai/OpenAiChatOptions.java
@@ -31,7 +31,6 @@ import org.springframework.ai.chat.prompt.ChatOptions;
 import org.springframework.ai.model.function.FunctionCallback;
 import org.springframework.ai.model.function.FunctionCallingOptions;
 import org.springframework.ai.openai.api.OpenAiApi.ChatCompletionRequest.ResponseFormat;
-import org.springframework.ai.openai.api.OpenAiApi.ChatCompletionRequest.ToolChoice;
 import org.springframework.ai.openai.api.OpenAiApi.FunctionTool;
 import org.springframework.boot.context.properties.NestedConfigurationProperty;
 import org.springframework.util.Assert;
@@ -52,7 +51,7 @@ public class OpenAiChatOptions implements FunctionCallingOptions, ChatOptions {
 	 * Number between -2.0 and 2.0. Positive values penalize new tokens based on their existing
 	 * frequency in the text so far, decreasing the model's likelihood to repeat the same line verbatim.
 	 */
-	private @JsonProperty("frequency_penalty") Float frequencyPenalty = 0.0f;
+	private @JsonProperty("frequency_penalty") Float frequencyPenalty;
 	/**
 	 * Modify the likelihood of specified tokens appearing in the completion. Accepts a JSON object
 	 * that maps tokens (specified by their token ID in the tokenizer) to an associated bias value from -100 to 100.
@@ -70,7 +69,7 @@ public class OpenAiChatOptions implements FunctionCallingOptions, ChatOptions {
 	 * How many chat completion choices to generate for each input message. Note that you will be charged based
 	 * on the number of generated tokens across all of the choices. Keep n as 1 to minimize costs.
 	 */
-	private @JsonProperty("n") Integer n = 1;
+	private @JsonProperty("n") Integer n;
 	/**
 	 * Number between -2.0 and 2.0. Positive values penalize new tokens based on whether they
 	 * appear in the text so far, increasing the model's likelihood to talk about new topics.
@@ -98,7 +97,7 @@ public class OpenAiChatOptions implements FunctionCallingOptions, ChatOptions {
 	 * more random, while lower values like 0.2 will make it more focused and deterministic. We generally recommend
 	 * altering this or top_p but not both.
 	 */
-	private @JsonProperty("temperature") Float temperature = 0.8f;
+	private @JsonProperty("temperature") Float temperature;
 	/**
 	 * An alternative to sampling with temperature, called nucleus sampling, where the model considers the
 	 * results of the tokens with top_p probability mass. So 0.1 means only the tokens comprising the top 10%
@@ -116,10 +115,9 @@ public class OpenAiChatOptions implements FunctionCallingOptions, ChatOptions {
 	 * function and instead generates a message. auto means the model can pick between generating a message or calling a
 	 * function. Specifying a particular function via {"type: "function", "function": {"name": "my_function"}} forces
 	 * the model to call that function. none is the default when no functions are present. auto is the default if
-	 * functions are present.
+	 * functions are present. Use the {@link ToolChoiceBuilder} to create a tool choice object.
 	 */
-	@NestedConfigurationProperty
-	private @JsonProperty("tool_choice") ToolChoice toolChoice;
+	private @JsonProperty("tool_choice") String toolChoice;
 	/**
 	 * A unique identifier representing your end-user, which can help OpenAI to monitor and detect abuse.
 	 */
@@ -225,7 +223,7 @@ public class OpenAiChatOptions implements FunctionCallingOptions, ChatOptions {
 			return this;
 		}
 
-		public Builder withToolChoice(ToolChoice toolChoice) {
+		public Builder withToolChoice(String toolChoice) {
 			this.options.toolChoice = toolChoice;
 			return this;
 		}
@@ -358,11 +356,11 @@ public class OpenAiChatOptions implements FunctionCallingOptions, ChatOptions {
 		this.tools = tools;
 	}
 
-	public ToolChoice getToolChoice() {
+	public String getToolChoice() {
 		return this.toolChoice;
 	}
 
-	public void setToolChoice(ToolChoice toolChoice) {
+	public void setToolChoice(String toolChoice) {
 		this.toolChoice = toolChoice;
 	}
 
diff --git a/models/spring-ai-openai/src/main/java/org/springframework/ai/openai/api/OpenAiApi.java b/models/spring-ai-openai/src/main/java/org/springframework/ai/openai/api/OpenAiApi.java
index 37cc23abb..1f954f158 100644
--- a/models/spring-ai-openai/src/main/java/org/springframework/ai/openai/api/OpenAiApi.java
+++ b/models/spring-ai-openai/src/main/java/org/springframework/ai/openai/api/OpenAiApi.java
@@ -17,6 +17,7 @@
 package org.springframework.ai.openai.api;
 
 import java.io.IOException;
+import java.nio.charset.StandardCharsets;
 import java.util.List;
 import java.util.Map;
 import java.util.function.Consumer;
@@ -25,20 +26,20 @@ import java.util.function.Predicate;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonInclude.Include;
 import com.fasterxml.jackson.annotation.JsonProperty;
-import com.fasterxml.jackson.core.type.TypeReference;
-import com.fasterxml.jackson.databind.DeserializationFeature;
-import com.fasterxml.jackson.databind.ObjectMapper;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 
+import org.springframework.ai.model.ModelOptionsUtils;
 import org.springframework.boot.context.properties.bind.ConstructorBinding;
 import org.springframework.core.ParameterizedTypeReference;
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
 import org.springframework.http.client.ClientHttpResponse;
+import org.springframework.lang.NonNull;
 import org.springframework.util.Assert;
 import org.springframework.util.CollectionUtils;
+import org.springframework.util.StreamUtils;
 import org.springframework.web.client.ResponseErrorHandler;
 import org.springframework.web.client.RestClient;
 import org.springframework.web.reactive.function.client.WebClient;
@@ -59,7 +60,6 @@ public class OpenAiApi {
 
 	private final RestClient restClient;
 	private final WebClient webClient;
-	private final ObjectMapper objectMapper;
 
 	/**
 	 * Create an new chat completion api with base URL set to https://api.openai.com
@@ -89,8 +89,6 @@ public class OpenAiApi {
 	 */
 	public OpenAiApi(String baseUrl, String openAiToken, RestClient.Builder restClientBuilder) {
 
-		this.objectMapper = new ObjectMapper().configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
-
 		Consumer<HttpHeaders> jsonContentHeaders = headers -> {
 			headers.setBearerAuth(openAiToken);
 			headers.setContentType(MediaType.APPLICATION_JSON);
@@ -99,19 +97,19 @@ public class OpenAiApi {
 		var responseErrorHandler = new ResponseErrorHandler() {
 
 			@Override
-			public boolean hasError(ClientHttpResponse response) throws IOException {
+			public boolean hasError(@NonNull ClientHttpResponse response) throws IOException {
 				return response.getStatusCode().isError();
 			}
 
 			@Override
-			public void handleError(ClientHttpResponse response) throws IOException {
+			public void handleError(@NonNull ClientHttpResponse response) throws IOException {
 				if (response.getStatusCode().isError()) {
+					String error = StreamUtils.copyToString(response.getBody(), StandardCharsets.UTF_8);
+					String message = String.format("%s - %s", response.getStatusCode().value(), error);
 					if (response.getStatusCode().is4xxClientError()) {
-						throw new OpenAiApiClientErrorException(String.format("%s - %s", response.getStatusCode().value(),
-							OpenAiApi.this.objectMapper.readValue(response.getBody(), ResponseError.class)));
+						throw new OpenAiApiClientErrorException(message);
 					}
-					throw new OpenAiApiException(String.format("%s - %s", response.getStatusCode().value(),
-							OpenAiApi.this.objectMapper.readValue(response.getBody(), ResponseError.class)));
+					throw new OpenAiApiException(message);
 				}
 			}
 		};
@@ -129,6 +127,9 @@ public class OpenAiApi {
 	}
 
 
+	/**
+	 * Non HTTP Error related exceptions
+	 */
 	public static class OpenAiApiException extends RuntimeException {
 
 		public OpenAiApiException(String message) {
@@ -157,29 +158,6 @@ public class OpenAiApi {
 		}
 	}
 
-	/**
-	 * API error response.
-	 * @param error Error details.
-	 */
-	@JsonInclude(Include.NON_NULL)
-	public record ResponseError(@JsonProperty("error") Error error) {
-
-		/**
-		 * Error details.
-		 * @param message Error message.
-		 * @param type Error type.
-		 * @param param Error parameter.
-		 * @param code Error code.
-		 */
-		@JsonInclude(Include.NON_NULL)
-		public record Error(
-				@JsonProperty("message") String message,
-				@JsonProperty("type") String type,
-				@JsonProperty("param") String param,
-				@JsonProperty("code") String code) {
-		}
-	}
-
 	/**
 	 * Represents a tool the model may call. Currently, only functions are supported as a tool.
 	 *
@@ -234,7 +212,7 @@ public class OpenAiApi {
 			 */
 			@ConstructorBinding
 			public Function(String description, String name, String jsonSchema) {
-				this(description, name, parseJson(jsonSchema));
+				this(description, name, ModelOptionsUtils.jsonToMap(jsonSchema));
 			}
 		}
 	}
@@ -278,7 +256,7 @@ public class OpenAiApi {
 	 * function and instead generates a message. auto means the model can pick between generating a message or calling a
 	 * function. Specifying a particular function via {"type: "function", "function": {"name": "my_function"}} forces
 	 * the model to call that function. none is the default when no functions are present. auto is the default if
-	 * functions are present.
+	 * functions are present. Use the {@link ToolChoiceBuilder} to create the tool choice value.
 	 * @param user A unique identifier representing your end-user, which can help OpenAI to monitor and detect abuse.
 	 *
 	 */
@@ -298,7 +276,7 @@ public class OpenAiApi {
 			@JsonProperty("temperature") Float temperature,
 			@JsonProperty("top_p") Float topP,
 			@JsonProperty("tools") List<FunctionTool> tools,
-			@JsonProperty("tool_choice") ToolChoice toolChoice,
+			@JsonProperty("tool_choice") String toolChoice,
 			@JsonProperty("user") String user) {
 
 		/**
@@ -309,7 +287,7 @@ public class OpenAiApi {
 		 * @param temperature What sampling temperature to use, between 0 and 1.
 		 */
 		public ChatCompletionRequest(List<ChatCompletionMessage> messages, String model, Float temperature) {
-			this(messages, model, 0.0f, null, null, 1, 0.0f,
+			this(messages, model, null, null, null, null, null,
 					null, null, null, false, temperature, null,
 					null, null, null);
 		}
@@ -324,7 +302,7 @@ public class OpenAiApi {
 		 * as they become available, with the stream terminated by a data: [DONE] message.
 		 */
 		public ChatCompletionRequest(List<ChatCompletionMessage> messages, String model, Float temperature, boolean stream) {
-			this(messages, model, 0.0f, null, null, 1, 0.0f,
+			this(messages, model, null, null, null, null, null,
 					null, null, null, stream, temperature, null,
 					null, null, null);
 		}
@@ -339,8 +317,8 @@ public class OpenAiApi {
 		 * @param toolChoice Controls which (if any) function is called by the model.
 		 */
 		public ChatCompletionRequest(List<ChatCompletionMessage> messages, String model,
-				List<FunctionTool> tools, ToolChoice toolChoice) {
-			this(messages, model, 0.0f, null, null, 1, 0.0f,
+				List<FunctionTool> tools, String toolChoice) {
+			this(messages, model, null, null, null, null, null,
 					null, null, null, false, 0.8f, null,
 					tools, toolChoice, null);
 		}
@@ -360,23 +338,23 @@ public class OpenAiApi {
 		}
 
 		/**
-		 * Specifies a tool the model should use. Use to force the model to call a specific function.
-		 *
-		 * @param type The type of the tool. Currently, only 'function' is supported.
-		 * @param function single field map for type 'name':'your function name'.
+		 * Helper factory that creates a tool_choice of type 'none', 'auto' or selected function by name.
 		 */
-		@JsonInclude(Include.NON_NULL)
-		public record ToolChoice(
-				@JsonProperty("type") String type,
-				@JsonProperty("function") Map<String, String> function) {
+		public static class ToolChoiceBuilder {
+			/**
+			 * Model can pick between generating a message or calling a function.
+			 */
+			public static final String AUTO = "none";
+			/**
+			 * Model will not call a function and instead generates a message
+			 */
+			public static final String NONE = "none";
 
 			/**
-			 * Create a tool choice of type 'function' and name 'functionName'.
-			 * @param functionName Function name of the tool.
+			 * Specifying a particular function forces the model to call that function.
 			 */
-			@ConstructorBinding
-			public ToolChoice(String functionName) {
-				this("function", Map.of("name", functionName));
+			public static String FUNCTION(String functionName) {
+				return ModelOptionsUtils.toJsonString(Map.of("type", "function", "function", Map.of("name", functionName)));
 			}
 		}
 
@@ -676,7 +654,7 @@ public class OpenAiApi {
 				.takeUntil(SSE_DONE_PREDICATE)
 				// filters out the "[DONE]" message.
 				.filter(SSE_DONE_PREDICATE.negate())
-				.map(content -> parseJson(content, ChatCompletionChunk.class));
+				.map(content -> ModelOptionsUtils.jsonToObject(content, ChatCompletionChunk.class));
 	}
 
 	/**
@@ -795,25 +773,5 @@ public class OpenAiApi {
 				.toEntity(new ParameterizedTypeReference<>() {
 				});
 	}
-
-	public static Map<String, Object> parseJson(String jsonSchema) {
-		try {
-			return new ObjectMapper().readValue(jsonSchema,
-					new TypeReference<Map<String, Object>>() {
-					});
-		}
-		catch (Exception e) {
-			throw new OpenAiApiException("Failed to parse schema: " + jsonSchema, e);
-		}
-	}
-
-	private <T> T parseJson(String json, Class<T> type) {
-		try {
-			return this.objectMapper.readValue(json, type);
-		}
-		catch (Exception e) {
-			throw new OpenAiApiException("Failed to parse schema: " + json, e);
-		}
-	}
 }
 // @formatter:on
diff --git a/models/spring-ai-openai/src/main/java/org/springframework/ai/openai/api/OpenAiImageApi.java b/models/spring-ai-openai/src/main/java/org/springframework/ai/openai/api/OpenAiImageApi.java
index 95939db71..92b3607cf 100644
--- a/models/spring-ai-openai/src/main/java/org/springframework/ai/openai/api/OpenAiImageApi.java
+++ b/models/spring-ai-openai/src/main/java/org/springframework/ai/openai/api/OpenAiImageApi.java
@@ -16,6 +16,7 @@
 package org.springframework.ai.openai.api;
 
 import java.io.IOException;
+import java.nio.charset.StandardCharsets;
 import java.util.List;
 import java.util.function.Consumer;
 
@@ -26,12 +27,12 @@ import com.fasterxml.jackson.databind.ObjectMapper;
 
 import org.springframework.ai.openai.api.OpenAiApi.OpenAiApiClientErrorException;
 import org.springframework.ai.openai.api.OpenAiApi.OpenAiApiException;
-import org.springframework.ai.openai.api.OpenAiApi.ResponseError;
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
 import org.springframework.http.client.ClientHttpResponse;
 import org.springframework.util.Assert;
+import org.springframework.util.StreamUtils;
 import org.springframework.web.client.ResponseErrorHandler;
 import org.springframework.web.client.RestClient;
 
@@ -78,13 +79,12 @@ public class OpenAiImageApi {
 			@Override
 			public void handleError(ClientHttpResponse response) throws IOException {
 				if (response.getStatusCode().isError()) {
+					String error = StreamUtils.copyToString(response.getBody(), StandardCharsets.UTF_8);
+					String message = String.format("%s - %s", response.getStatusCode().value(), error);
 					if (response.getStatusCode().is4xxClientError()) {
-						throw new OpenAiApiClientErrorException(String.format("%s - %s",
-								response.getStatusCode().value(),
-								OpenAiImageApi.this.objectMapper.readValue(response.getBody(), ResponseError.class)));
+						throw new OpenAiApiClientErrorException(message);
 					}
-					throw new OpenAiApiException(String.format("%s - %s", response.getStatusCode().value(),
-							OpenAiImageApi.this.objectMapper.readValue(response.getBody(), ResponseError.class)));
+					throw new OpenAiApiException(message);
 				}
 			}
 		};
diff --git a/models/spring-ai-openai/src/test/java/org/springframework/ai/openai/chat/api/tool/OpenAiApiToolFunctionCallIT.java b/models/spring-ai-openai/src/test/java/org/springframework/ai/openai/chat/api/tool/OpenAiApiToolFunctionCallIT.java
index 825c3f5f4..b213b35d2 100644
--- a/models/spring-ai-openai/src/test/java/org/springframework/ai/openai/chat/api/tool/OpenAiApiToolFunctionCallIT.java
+++ b/models/spring-ai-openai/src/test/java/org/springframework/ai/openai/chat/api/tool/OpenAiApiToolFunctionCallIT.java
@@ -26,6 +26,7 @@ import org.junit.jupiter.api.condition.EnabledIfEnvironmentVariable;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import org.springframework.ai.model.ModelOptionsUtils;
 import org.springframework.ai.openai.api.OpenAiApi;
 import org.springframework.ai.openai.api.OpenAiApi.ChatCompletion;
 import org.springframework.ai.openai.api.OpenAiApi.ChatCompletionMessage;
@@ -63,7 +64,7 @@ public class OpenAiApiToolFunctionCallIT {
 		var functionTool = new OpenAiApi.FunctionTool(Type.FUNCTION,
 				new OpenAiApi.FunctionTool.Function(
 						"Get the weather in location. Return temperature in 30°F or 30°C format.", "getCurrentWeather",
-						OpenAiApi.parseJson("""
+						ModelOptionsUtils.jsonToMap("""
 								{
 									"type": "object",
 									"properties": {
@@ -129,7 +130,7 @@ public class OpenAiApiToolFunctionCallIT {
 
 					// extend conversation with function response.
 					messages.add(new ChatCompletionMessage("" + weatherResponse.temp() + weatherRequest.unit(),
-							Role.TOOL, null, toolCall.id(), null));
+							Role.TOOL, functionName, toolCall.id(), null));
 				}
 			}
 
diff --git a/spring-ai-core/src/main/java/org/springframework/ai/model/ModelOptionsUtils.java b/spring-ai-core/src/main/java/org/springframework/ai/model/ModelOptionsUtils.java
index bcd1e7974..7ca8e205f 100644
--- a/spring-ai-core/src/main/java/org/springframework/ai/model/ModelOptionsUtils.java
+++ b/spring-ai-core/src/main/java/org/springframework/ai/model/ModelOptionsUtils.java
@@ -30,6 +30,7 @@ import java.util.stream.Collectors;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.core.type.TypeReference;
+import com.fasterxml.jackson.databind.DeserializationFeature;
 import com.fasterxml.jackson.databind.JsonNode;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.SerializationFeature;
@@ -59,6 +60,7 @@ import org.springframework.util.CollectionUtils;
 public final class ModelOptionsUtils {
 
 	private final static ObjectMapper OBJECT_MAPPER = new ObjectMapper()
+		.disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES)
 		.disable(SerializationFeature.FAIL_ON_EMPTY_BEANS);
 
 	private final static List<String> BEAN_MERGE_FIELD_EXCISIONS = List.of("class");
@@ -88,6 +90,22 @@ public final class ModelOptionsUtils {
 	private static TypeReference<HashMap<String, Object>> MAP_TYPE_REF = new TypeReference<HashMap<String, Object>>() {
 	};
 
+	/**
+	 * Converts the given JSON string to an Object of the given type.
+	 * @param <T> the type of the object to return.
+	 * @param json the JSON string to convert to an object.
+	 * @param type the type of the object to return.
+	 * @return Object instance of the given type.
+	 */
+	public static <T> T jsonToObject(String json, Class<T> type) {
+		try {
+			return OBJECT_MAPPER.readValue(json, type);
+		}
+		catch (Exception e) {
+			throw new RuntimeException("Failed to json: " + json, e);
+		}
+	}
+
 	/**
 	 * Converts the given object to a JSON string.
 	 * @param object the object to convert to a JSON string.
diff --git a/spring-ai-spring-boot-autoconfigure/pom.xml b/spring-ai-spring-boot-autoconfigure/pom.xml
index d2d1bfef6..19161a088 100644
--- a/spring-ai-spring-boot-autoconfigure/pom.xml
+++ b/spring-ai-spring-boot-autoconfigure/pom.xml
@@ -296,11 +296,18 @@
 		</dependency>
 
 		<dependency>
-            <groupId>org.testcontainers</groupId>
-            <artifactId>qdrant</artifactId>
-            <version>1.19.6</version>
-            <scope>test</scope>
-        </dependency>
+			<groupId>org.testcontainers</groupId>
+			<artifactId>qdrant</artifactId>
+			<version>1.19.6</version>
+			<scope>test</scope>
+		</dependency>
+
+		<dependency>
+			<groupId>org.skyscreamer</groupId>
+			<artifactId>jsonassert</artifactId>
+			<version>1.5.0</version>
+			<scope>test</scope>
+		</dependency>
 
 
 	</dependencies>
diff --git a/spring-ai-spring-boot-autoconfigure/src/main/java/org/springframework/ai/autoconfigure/mistralai/MistralAiAutoConfiguration.java b/spring-ai-spring-boot-autoconfigure/src/main/java/org/springframework/ai/autoconfigure/mistralai/MistralAiAutoConfiguration.java
index 376586eaa..cffaec366 100644
--- a/spring-ai-spring-boot-autoconfigure/src/main/java/org/springframework/ai/autoconfigure/mistralai/MistralAiAutoConfiguration.java
+++ b/spring-ai-spring-boot-autoconfigure/src/main/java/org/springframework/ai/autoconfigure/mistralai/MistralAiAutoConfiguration.java
@@ -16,18 +16,23 @@
 
 package org.springframework.ai.autoconfigure.mistralai;
 
-import org.springframework.ai.embedding.EmbeddingClient;
+import java.util.List;
+
 import org.springframework.ai.mistralai.MistralAiChatClient;
 import org.springframework.ai.mistralai.MistralAiEmbeddingClient;
 import org.springframework.ai.mistralai.api.MistralAiApi;
+import org.springframework.ai.model.function.FunctionCallback;
+import org.springframework.ai.model.function.FunctionCallbackContext;
 import org.springframework.boot.autoconfigure.AutoConfiguration;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.boot.autoconfigure.web.client.RestClientAutoConfiguration;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
+import org.springframework.context.ApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.util.Assert;
+import org.springframework.util.CollectionUtils;
 import org.springframework.util.StringUtils;
 import org.springframework.web.client.RestClient;
 
@@ -61,12 +66,17 @@ public class MistralAiAutoConfiguration {
 	@ConditionalOnProperty(prefix = MistralAiChatProperties.CONFIG_PREFIX, name = "enabled", havingValue = "true",
 			matchIfMissing = true)
 	public MistralAiChatClient mistralAiChatClient(MistralAiCommonProperties commonProperties,
-			MistralAiChatProperties chatProperties, RestClient.Builder restClientBuilder) {
+			MistralAiChatProperties chatProperties, RestClient.Builder restClientBuilder,
+			List<FunctionCallback> toolFunctionCallbacks, FunctionCallbackContext functionCallbackContext) {
 
 		var mistralAiApi = mistralAiApi(chatProperties.getApiKey(), commonProperties.getApiKey(),
 				chatProperties.getBaseUrl(), commonProperties.getBaseUrl(), restClientBuilder);
 
-		return new MistralAiChatClient(mistralAiApi, chatProperties.getOptions());
+		if (!CollectionUtils.isEmpty(toolFunctionCallbacks)) {
+			chatProperties.getOptions().getFunctionCallbacks().addAll(toolFunctionCallbacks);
+		}
+
+		return new MistralAiChatClient(mistralAiApi, chatProperties.getOptions(), functionCallbackContext);
 	}
 
 	private MistralAiApi mistralAiApi(String apiKey, String commonApiKey, String baseUrl, String commonBaseUrl,
@@ -81,4 +91,12 @@ public class MistralAiAutoConfiguration {
 		return new MistralAiApi(resoledBaseUrl, resolvedApiKey, restClientBuilder);
 	}
 
+	@Bean
+	@ConditionalOnMissingBean
+	public FunctionCallbackContext springAiFunctionManager(ApplicationContext context) {
+		FunctionCallbackContext manager = new FunctionCallbackContext();
+		manager.setApplicationContext(context);
+		return manager;
+	}
+
 }
diff --git a/spring-ai-spring-boot-autoconfigure/src/main/java/org/springframework/ai/autoconfigure/mistralai/MistralAiChatProperties.java b/spring-ai-spring-boot-autoconfigure/src/main/java/org/springframework/ai/autoconfigure/mistralai/MistralAiChatProperties.java
index 3578d7a9c..47e3dc027 100644
--- a/spring-ai-spring-boot-autoconfigure/src/main/java/org/springframework/ai/autoconfigure/mistralai/MistralAiChatProperties.java
+++ b/spring-ai-spring-boot-autoconfigure/src/main/java/org/springframework/ai/autoconfigure/mistralai/MistralAiChatProperties.java
@@ -17,6 +17,7 @@
 package org.springframework.ai.autoconfigure.mistralai;
 
 import org.springframework.ai.mistralai.MistralAiChatOptions;
+import org.springframework.ai.mistralai.api.MistralAiApi;
 import org.springframework.boot.context.properties.ConfigurationProperties;
 import org.springframework.boot.context.properties.NestedConfigurationProperty;
 
@@ -30,7 +31,7 @@ public class MistralAiChatProperties extends MistralAiParentProperties {
 
 	public static final String CONFIG_PREFIX = "spring.ai.mistral.chat";
 
-	public static final String DEFAULT_CHAT_MODEL = "mistral-tiny";
+	public static final String DEFAULT_CHAT_MODEL = MistralAiApi.ChatModel.TINY.getValue();
 
 	private static final Double DEFAULT_TEMPERATURE = 0.7;
 
diff --git a/spring-ai-spring-boot-autoconfigure/src/main/java/org/springframework/ai/autoconfigure/mistralai/MistralAiEmbeddingProperties.java b/spring-ai-spring-boot-autoconfigure/src/main/java/org/springframework/ai/autoconfigure/mistralai/MistralAiEmbeddingProperties.java
index 79ab498c5..5c46ec6f7 100644
--- a/spring-ai-spring-boot-autoconfigure/src/main/java/org/springframework/ai/autoconfigure/mistralai/MistralAiEmbeddingProperties.java
+++ b/spring-ai-spring-boot-autoconfigure/src/main/java/org/springframework/ai/autoconfigure/mistralai/MistralAiEmbeddingProperties.java
@@ -18,6 +18,7 @@ package org.springframework.ai.autoconfigure.mistralai;
 
 import org.springframework.ai.document.MetadataMode;
 import org.springframework.ai.mistralai.MistralAiEmbeddingOptions;
+import org.springframework.ai.mistralai.api.MistralAiApi;
 import org.springframework.boot.context.properties.ConfigurationProperties;
 import org.springframework.boot.context.properties.NestedConfigurationProperty;
 
@@ -30,7 +31,7 @@ public class MistralAiEmbeddingProperties extends MistralAiParentProperties {
 
 	public static final String CONFIG_PREFIX = "spring.ai.mistralai.embedding";
 
-	public static final String DEFAULT_EMBEDDING_MODEL = "mistral-embed";
+	public static final String DEFAULT_EMBEDDING_MODEL = MistralAiApi.EmbeddingModel.EMBED.getValue();
 
 	public static final String DEFAULT_ENCODING_FORMAT = "float";
 
diff --git a/spring-ai-spring-boot-autoconfigure/src/test/java/org/springframework/ai/autoconfigure/mistralai/tool/PaymentStatusBeanIT.java b/spring-ai-spring-boot-autoconfigure/src/test/java/org/springframework/ai/autoconfigure/mistralai/tool/PaymentStatusBeanIT.java
new file mode 100644
index 000000000..ffc5f4c0c
--- /dev/null
+++ b/spring-ai-spring-boot-autoconfigure/src/test/java/org/springframework/ai/autoconfigure/mistralai/tool/PaymentStatusBeanIT.java
@@ -0,0 +1,112 @@
+/*
+ * Copyright 2024-2024 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.ai.autoconfigure.mistralai.tool;
+
+import java.util.List;
+import java.util.Map;
+import java.util.function.Function;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.condition.EnabledIfEnvironmentVariable;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import org.springframework.ai.autoconfigure.mistralai.MistralAiAutoConfiguration;
+import org.springframework.ai.chat.ChatResponse;
+import org.springframework.ai.chat.messages.UserMessage;
+import org.springframework.ai.chat.prompt.Prompt;
+import org.springframework.ai.mistralai.MistralAiChatClient;
+import org.springframework.ai.mistralai.MistralAiChatOptions;
+import org.springframework.ai.mistralai.api.MistralAiApi;
+import org.springframework.boot.autoconfigure.AutoConfigurations;
+import org.springframework.boot.autoconfigure.web.client.RestClientAutoConfiguration;
+import org.springframework.boot.test.context.runner.ApplicationContextRunner;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Description;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+@EnabledIfEnvironmentVariable(named = "MISTRAL_AI_API_KEY", matches = ".*")
+class PaymentStatusBeanIT {
+
+	private final Logger logger = LoggerFactory.getLogger(PaymentStatusBeanIT.class);
+
+	private final ApplicationContextRunner contextRunner = new ApplicationContextRunner()
+		.withPropertyValues("spring.ai.mistralai.apiKey=" + System.getenv("MISTRAL_AI_API_KEY"))
+		.withConfiguration(AutoConfigurations.of(RestClientAutoConfiguration.class, MistralAiAutoConfiguration.class))
+		.withUserConfiguration(Config.class);
+
+	@Test
+	void functionCallTest() {
+
+		contextRunner
+			.withPropertyValues("spring.ai.mistral.chat.options.model=" + MistralAiApi.ChatModel.LARGE.getValue())
+			.run(context -> {
+
+				MistralAiChatClient chatClient = context.getBean(MistralAiChatClient.class);
+
+				ChatResponse response = chatClient
+					.call(new Prompt(List.of(new UserMessage("What's the status of my transaction with id T1001?")),
+							MistralAiChatOptions.builder()
+								.withFunction("retrievePaymentStatus")
+								.withFunction("retrievePaymentDate")
+								.build()));
+
+				logger.info("Response: {}", response);
+
+				assertThat(response.getResult().getOutput().getContent()).containsIgnoringCase("T1001");
+				assertThat(response.getResult().getOutput().getContent()).containsIgnoringCase("paid");
+			});
+	}
+
+	// Assuming we have the following data
+	public static final Map<String, StatusDate> DATA = Map.of("T1001", new StatusDate("Paid", "2021-10-05"), "T1002",
+			new StatusDate("Unpaid", "2021-10-06"), "T1003", new StatusDate("Paid", "2021-10-07"), "T1004",
+			new StatusDate("Paid", "2021-10-05"), "T1005", new StatusDate("Pending", "2021-10-08"));
+
+	record StatusDate(String status, String date) {
+	}
+
+	@Configuration
+	static class Config {
+
+		public record Transaction(@JsonProperty(required = true, value = "transaction_id") String transactionId) {
+		}
+
+		public record Status(@JsonProperty(required = true, value = "status") String status) {
+		}
+
+		public record Date(@JsonProperty(required = true, value = "date") String date) {
+		}
+
+		@Bean
+		@Description("Get payment status of a transaction")
+		public Function<Transaction, Status> retrievePaymentStatus() {
+			return (transaction) -> new Status(DATA.get(transaction.transactionId).status());
+		}
+
+		@Bean
+		@Description("Get payment date of a transaction")
+		public Function<Transaction, Date> retrievePaymentDate() {
+			return (transaction) -> new Date(DATA.get(transaction.transactionId).date());
+		}
+
+	}
+
+}
\ No newline at end of file
diff --git a/spring-ai-spring-boot-autoconfigure/src/test/java/org/springframework/ai/autoconfigure/mistralai/tool/PaymentStatusBeanOpenAiIT.java b/spring-ai-spring-boot-autoconfigure/src/test/java/org/springframework/ai/autoconfigure/mistralai/tool/PaymentStatusBeanOpenAiIT.java
new file mode 100644
index 000000000..98bc1283e
--- /dev/null
+++ b/spring-ai-spring-boot-autoconfigure/src/test/java/org/springframework/ai/autoconfigure/mistralai/tool/PaymentStatusBeanOpenAiIT.java
@@ -0,0 +1,119 @@
+/*
+ * Copyright 2024-2024 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.ai.autoconfigure.mistralai.tool;
+
+import java.util.List;
+import java.util.Map;
+import java.util.function.Function;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.condition.EnabledIfEnvironmentVariable;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import org.springframework.ai.autoconfigure.openai.OpenAiAutoConfiguration;
+import org.springframework.ai.chat.ChatResponse;
+import org.springframework.ai.chat.messages.UserMessage;
+import org.springframework.ai.chat.prompt.Prompt;
+import org.springframework.ai.mistralai.api.MistralAiApi;
+import org.springframework.ai.openai.OpenAiChatClient;
+import org.springframework.ai.openai.OpenAiChatOptions;
+import org.springframework.boot.autoconfigure.AutoConfigurations;
+import org.springframework.boot.autoconfigure.web.client.RestClientAutoConfiguration;
+import org.springframework.boot.test.context.runner.ApplicationContextRunner;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Description;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Same test as {@link PaymentStatusBeanIT.java} but using {@link OpenAiChatClient} for
+ * Mistral AI Function Calling implementation.
+ *
+ * @author Christian Tzolov
+ */
+@EnabledIfEnvironmentVariable(named = "MISTRAL_AI_API_KEY", matches = ".*")
+class PaymentStatusBeanOpenAiIT {
+
+	private final Logger logger = LoggerFactory.getLogger(PaymentStatusBeanIT.class);
+
+	private final ApplicationContextRunner contextRunner = new ApplicationContextRunner()
+		.withPropertyValues("spring.ai.openai.apiKey=" + System.getenv("MISTRAL_AI_API_KEY"),
+				"spring.ai.openai.chat.base-url=https://api.mistral.ai")
+		.withConfiguration(AutoConfigurations.of(RestClientAutoConfiguration.class, OpenAiAutoConfiguration.class))
+		.withUserConfiguration(Config.class);
+
+	@Test
+	void functionCallTest() {
+
+		contextRunner
+			.withPropertyValues("spring.ai.openai.chat.options.model=" + MistralAiApi.ChatModel.SMALL.getValue())
+			.run(context -> {
+
+				OpenAiChatClient chatClient = context.getBean(OpenAiChatClient.class);
+
+				ChatResponse response = chatClient
+					.call(new Prompt(List.of(new UserMessage("What's the status of my transaction with id T1001?")),
+							OpenAiChatOptions.builder()
+								.withFunction("retrievePaymentStatus")
+								.withFunction("retrievePaymentDate")
+								.build()));
+
+				logger.info("Response: {}", response);
+
+				assertThat(response.getResult().getOutput().getContent()).containsIgnoringCase("T1001");
+				assertThat(response.getResult().getOutput().getContent()).containsIgnoringCase("paid");
+			});
+	}
+
+	// Assuming we have the following data
+	public static final Map<String, StatusDate> DATA = Map.of("T1001", new StatusDate("Paid", "2021-10-05"), "T1002",
+			new StatusDate("Unpaid", "2021-10-06"), "T1003", new StatusDate("Paid", "2021-10-07"), "T1004",
+			new StatusDate("Paid", "2021-10-05"), "T1005", new StatusDate("Pending", "2021-10-08"));
+
+	record StatusDate(String status, String date) {
+	}
+
+	@Configuration
+	static class Config {
+
+		public record Transaction(@JsonProperty(required = true, value = "transaction_id") String transactionId) {
+		}
+
+		public record Status(@JsonProperty(required = true, value = "status") String status) {
+		}
+
+		public record Date(@JsonProperty(required = true, value = "date") String date) {
+		}
+
+		@Bean
+		@Description("Get payment status of a transaction")
+		public Function<Transaction, Status> retrievePaymentStatus() {
+			return (transaction) -> new Status(DATA.get(transaction.transactionId).status());
+		}
+
+		@Bean
+		@Description("Get payment date of a transaction")
+		public Function<Transaction, Date> retrievePaymentDate() {
+			return (transaction) -> new Date(DATA.get(transaction.transactionId).date());
+		}
+
+	}
+
+}
\ No newline at end of file
diff --git a/spring-ai-spring-boot-autoconfigure/src/test/java/org/springframework/ai/autoconfigure/mistralai/tool/PaymentStatusPromptIT.java b/spring-ai-spring-boot-autoconfigure/src/test/java/org/springframework/ai/autoconfigure/mistralai/tool/PaymentStatusPromptIT.java
new file mode 100644
index 000000000..77b89270e
--- /dev/null
+++ b/spring-ai-spring-boot-autoconfigure/src/test/java/org/springframework/ai/autoconfigure/mistralai/tool/PaymentStatusPromptIT.java
@@ -0,0 +1,97 @@
+/*
+ * Copyright 2024-2024 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.ai.autoconfigure.mistralai.tool;
+
+import java.util.List;
+import java.util.Map;
+import java.util.function.Function;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.condition.EnabledIfEnvironmentVariable;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import org.springframework.ai.autoconfigure.mistralai.MistralAiAutoConfiguration;
+import org.springframework.ai.chat.ChatResponse;
+import org.springframework.ai.chat.messages.UserMessage;
+import org.springframework.ai.chat.prompt.Prompt;
+import org.springframework.ai.mistralai.MistralAiChatClient;
+import org.springframework.ai.mistralai.MistralAiChatOptions;
+import org.springframework.ai.mistralai.api.MistralAiApi;
+import org.springframework.ai.model.function.FunctionCallbackWrapper;
+import org.springframework.boot.autoconfigure.AutoConfigurations;
+import org.springframework.boot.autoconfigure.web.client.RestClientAutoConfiguration;
+import org.springframework.boot.test.context.runner.ApplicationContextRunner;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+@EnabledIfEnvironmentVariable(named = "MISTRAL_AI_API_KEY", matches = ".*")
+public class PaymentStatusPromptIT {
+
+	private final Logger logger = LoggerFactory.getLogger(WeatherServicePromptIT.class);
+
+	private final ApplicationContextRunner contextRunner = new ApplicationContextRunner()
+		.withPropertyValues("spring.ai.mistralai.apiKey=" + System.getenv("MISTRAL_AI_API_KEY"))
+		.withConfiguration(AutoConfigurations.of(RestClientAutoConfiguration.class, MistralAiAutoConfiguration.class));
+
+	public record Transaction(@JsonProperty(required = true, value = "transaction_id") String id) {
+	}
+
+	public record Status(@JsonProperty(required = true, value = "status") String status) {
+	}
+
+	record StatusDate(String status, String date) {
+	}
+
+	// Assuming we have the following payment data.
+	public static final Map<Transaction, StatusDate> DATA = Map.of(new Transaction("T1001"),
+			new StatusDate("Paid", "2021-10-05"), new Transaction("T1002"), new StatusDate("Unpaid", "2021-10-06"),
+			new Transaction("T1003"), new StatusDate("Paid", "2021-10-07"), new Transaction("T1004"),
+			new StatusDate("Paid", "2021-10-05"), new Transaction("T1005"), new StatusDate("Pending", "2021-10-08"));
+
+	@Test
+	void functionCallTest() {
+		contextRunner
+			.withPropertyValues("spring.ai.mistral.chat.options.model=" + MistralAiApi.ChatModel.SMALL.getValue())
+			.run(context -> {
+
+				MistralAiChatClient chatClient = context.getBean(MistralAiChatClient.class);
+
+				UserMessage userMessage = new UserMessage("What's the status of my transaction with id T1001?");
+
+				var promptOptions = MistralAiChatOptions.builder()
+					.withFunctionCallbacks(List.of(FunctionCallbackWrapper.builder(new Function<Transaction, Status>() {
+						public Status apply(Transaction transaction) {
+							return new Status(DATA.get(transaction).status());
+						}
+					})
+						.withName("retrievePaymentStatus")
+						.withDescription("Get payment status of a transaction")
+						.build()))
+					.build();
+
+				ChatResponse response = chatClient.call(new Prompt(List.of(userMessage), promptOptions));
+
+				logger.info("Response: {}", response);
+
+				assertThat(response.getResult().getOutput().getContent()).containsIgnoringCase("T1001");
+				assertThat(response.getResult().getOutput().getContent()).containsIgnoringCase("paid");
+			});
+	}
+
+}
\ No newline at end of file
diff --git a/spring-ai-spring-boot-autoconfigure/src/test/java/org/springframework/ai/autoconfigure/mistralai/tool/WeatherServicePromptIT.java b/spring-ai-spring-boot-autoconfigure/src/test/java/org/springframework/ai/autoconfigure/mistralai/tool/WeatherServicePromptIT.java
new file mode 100644
index 000000000..cea101cf2
--- /dev/null
+++ b/spring-ai-spring-boot-autoconfigure/src/test/java/org/springframework/ai/autoconfigure/mistralai/tool/WeatherServicePromptIT.java
@@ -0,0 +1,120 @@
+/*
+ * Copyright 2024-2024 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.ai.autoconfigure.mistralai.tool;
+
+import java.util.List;
+import java.util.function.Function;
+
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonInclude.Include;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.condition.EnabledIfEnvironmentVariable;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import org.springframework.ai.autoconfigure.mistralai.MistralAiAutoConfiguration;
+import org.springframework.ai.autoconfigure.mistralai.tool.WeatherServicePromptIT.MyWeatherService.Request;
+import org.springframework.ai.autoconfigure.mistralai.tool.WeatherServicePromptIT.MyWeatherService.Response;
+import org.springframework.ai.chat.ChatResponse;
+import org.springframework.ai.chat.messages.UserMessage;
+import org.springframework.ai.chat.prompt.Prompt;
+import org.springframework.ai.mistralai.MistralAiChatClient;
+import org.springframework.ai.mistralai.MistralAiChatOptions;
+import org.springframework.ai.mistralai.api.MistralAiApi;
+import org.springframework.ai.mistralai.api.MistralAiApi.ChatCompletionRequest.ToolChoice;
+import org.springframework.ai.model.function.FunctionCallbackWrapper;
+import org.springframework.boot.autoconfigure.AutoConfigurations;
+import org.springframework.boot.autoconfigure.web.client.RestClientAutoConfiguration;
+import org.springframework.boot.test.context.runner.ApplicationContextRunner;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * @author Christian Tzolov
+ * @since 0.8.1
+ */
+@EnabledIfEnvironmentVariable(named = "MISTRAL_AI_API_KEY", matches = ".*")
+public class WeatherServicePromptIT {
+
+	private final Logger logger = LoggerFactory.getLogger(WeatherServicePromptIT.class);
+
+	private final ApplicationContextRunner contextRunner = new ApplicationContextRunner()
+		.withPropertyValues("spring.ai.mistralai.api-key=" + System.getenv("MISTRAL_AI_API_KEY"))
+		.withConfiguration(AutoConfigurations.of(RestClientAutoConfiguration.class, MistralAiAutoConfiguration.class));
+
+	@Test
+	void promptFunctionCall() {
+		contextRunner
+			.withPropertyValues("spring.ai.mistral.chat.options.model=" + MistralAiApi.ChatModel.LARGE.getValue())
+			.run(context -> {
+
+				MistralAiChatClient chatClient = context.getBean(MistralAiChatClient.class);
+
+				UserMessage userMessage = new UserMessage("What's the weather like in Paris?");
+				// UserMessage userMessage = new UserMessage("What's the weather like in
+				// San Francisco, Tokyo, and
+				// Paris?");
+
+				var promptOptions = MistralAiChatOptions.builder()
+					.withToolChoice(ToolChoice.AUTO)
+					.withFunctionCallbacks(List.of(FunctionCallbackWrapper.builder(new MyWeatherService())
+						.withName("CurrentWeatherService")
+						.withDescription("Get the current weather in requested location")
+						.build()))
+					.build();
+
+				ChatResponse response = chatClient.call(new Prompt(List.of(userMessage), promptOptions));
+
+				logger.info("Response: {}", response);
+
+				assertThat(response.getResult().getOutput().getContent()).containsAnyOf("15", "15.0");
+				// assertThat(response.getResult().getOutput().getContent()).contains("30.0",
+				// "10.0", "15.0");
+			});
+	}
+
+	public static class MyWeatherService implements Function<Request, Response> {
+
+		// @formatter:off
+		public enum Unit { C, F }
+
+		@JsonInclude(Include.NON_NULL)
+		public record Request(
+				@JsonProperty(required = true, value = "location") String location,
+				@JsonProperty(required = true, value = "unit") Unit unit) {}
+
+		public record Response(double temperature, Unit unit) {}
+		// @formatter:on
+
+		@Override
+		public Response apply(Request request) {
+			if (request.location().contains("Paris")) {
+				return new Response(15, request.unit());
+			}
+			else if (request.location().contains("Tokyo")) {
+				return new Response(10, request.unit());
+			}
+			else if (request.location().contains("San Francisco")) {
+				return new Response(30, request.unit());
+			}
+			throw new IllegalArgumentException("Invalid request: " + request);
+		}
+
+	}
+
+}
\ No newline at end of file
diff --git a/spring-ai-spring-boot-autoconfigure/src/test/java/org/springframework/ai/autoconfigure/openai/OpenAiPropertiesTests.java b/spring-ai-spring-boot-autoconfigure/src/test/java/org/springframework/ai/autoconfigure/openai/OpenAiPropertiesTests.java
index cc80bac4c..5c3237a12 100644
--- a/spring-ai-spring-boot-autoconfigure/src/test/java/org/springframework/ai/autoconfigure/openai/OpenAiPropertiesTests.java
+++ b/spring-ai-spring-boot-autoconfigure/src/test/java/org/springframework/ai/autoconfigure/openai/OpenAiPropertiesTests.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2024 the original author or authors.
+ * Copyright 2024-2024 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,15 +16,15 @@
 
 package org.springframework.ai.autoconfigure.openai;
 
-import java.util.Map;
-
 import org.junit.jupiter.api.Test;
+import org.skyscreamer.jsonassert.JSONAssert;
+import org.skyscreamer.jsonassert.JSONCompareMode;
 
 import org.springframework.ai.openai.OpenAiChatClient;
 import org.springframework.ai.openai.OpenAiEmbeddingClient;
 import org.springframework.ai.openai.OpenAiImageClient;
 import org.springframework.ai.openai.api.OpenAiApi.ChatCompletionRequest.ResponseFormat;
-import org.springframework.ai.openai.api.OpenAiApi.ChatCompletionRequest.ToolChoice;
+import org.springframework.ai.openai.api.OpenAiApi.ChatCompletionRequest.ToolChoiceBuilder;
 import org.springframework.ai.openai.api.OpenAiApi.FunctionTool.Type;
 import org.springframework.boot.autoconfigure.AutoConfigurations;
 import org.springframework.boot.autoconfigure.web.client.RestClientAutoConfiguration;
@@ -218,7 +218,8 @@ public class OpenAiPropertiesTests {
 				"spring.ai.openai.chat.options.temperature=0.55",
 				"spring.ai.openai.chat.options.topP=0.56",
 
-				"spring.ai.openai.chat.options.toolChoice.functionName=toolChoiceFunctionName",
+				// "spring.ai.openai.chat.options.toolChoice.functionName=toolChoiceFunctionName",
+				"spring.ai.openai.chat.options.toolChoice=" + ToolChoiceBuilder.FUNCTION("toolChoiceFunctionName"),
 
 				"spring.ai.openai.chat.options.tools[0].function.name=myFunction1",
 				"spring.ai.openai.chat.options.tools[0].function.description=function description",
@@ -272,8 +273,9 @@ public class OpenAiPropertiesTests {
 				assertThat(chatProperties.getOptions().getTemperature()).isEqualTo(0.55f);
 				assertThat(chatProperties.getOptions().getTopP()).isEqualTo(0.56f);
 
-				assertThat(chatProperties.getOptions().getToolChoice())
-					.isEqualTo(new ToolChoice("function", Map.of("name", "toolChoiceFunctionName")));
+				JSONAssert.assertEquals("{\"type\":\"function\",\"function\":{\"name\":\"toolChoiceFunctionName\"}}",
+						chatProperties.getOptions().getToolChoice(), JSONCompareMode.LENIENT);
+
 				assertThat(chatProperties.getOptions().getUser()).isEqualTo("userXYZ");
 
 				assertThat(chatProperties.getOptions().getTools()).hasSize(1);