feat(autoconfigure): Support both FunctionCallback and ToolCallback in ToolCallingAutoConfiguration

- Extends the ToolCallingAutoConfiguration to support both FunctionCallback and ToolCallback types.
- The toolCallbackResolver bean now handles both callback types through ObjectProvider injection.
- Added comprehensive tests to verify the resolution of multiple function and tool callbacks.
- Introduce new StaticToolCallbackProvider implementation
- Update ToolCallbackProvider to return FunctionCallback[]
- Migrate from List to ToolCallbackProvider in configurations
- Update tests to use new provider pattern
- Enhance tool callback providers to support multiple clients
  - Refactor AsyncMcpToolCallbackProvider and SyncMcpToolCallbackProvider to handle multiple MCP clients
  - Add ToolCallbackProvider support to ChatClient API
  - Deprecate direct tool callback list methods in favor of providers
  - Fix typos in Closeable class names
  - Update MCP documentation with new examples and usage patterns

Signed-off-by: Christian Tzolov <christian.tzolov@broadcom.com>

spring-ai-core/src/main/java/org/springframework/ai/chat/client/ChatClient.java

@@ -36,6 +36,7 @@ import org.springframework.ai.converter.StructuredOutputConverter;
 import org.springframework.ai.model.Media;
 import org.springframework.ai.model.function.FunctionCallback;
 import org.springframework.ai.tool.ToolCallback;
+import org.springframework.ai.tool.ToolCallbackProvider;
 import org.springframework.core.ParameterizedTypeReference;
 import org.springframework.core.io.Resource;
 import org.springframework.lang.Nullable;
@@ -223,6 +224,8 @@ public interface ChatClient {
 
 		ChatClientRequestSpec tools(Object... toolObjects);
 
+		ChatClientRequestSpec tools(ToolCallbackProvider... toolCallbackProviders);
+
 		@Deprecated
 		<I, O> ChatClientRequestSpec functions(FunctionCallback... functionCallbacks);
 
@@ -290,6 +293,8 @@ public interface ChatClient {
 
 		Builder defaultTools(Object... toolObjects);
 
+		Builder defaultTools(ToolCallbackProvider... toolCallbackProviders);
+
 		/**
 		 * @deprecated in favor of {@link #defaultTools(String...)}
 		 */

spring-ai-core/src/main/java/org/springframework/ai/chat/client/DefaultChatClient.java

@@ -35,6 +35,7 @@ import io.micrometer.observation.ObservationRegistry;
 import io.micrometer.observation.contextpropagation.ObservationThreadLocalAccessor;
 
 import org.springframework.ai.tool.ToolCallback;
+import org.springframework.ai.tool.ToolCallbackProvider;
 import org.springframework.ai.tool.ToolCallbacks;
 import reactor.core.publisher.Flux;
 import reactor.core.scheduler.Schedulers;
@@ -871,6 +872,16 @@ public class DefaultChatClient implements ChatClient {
 			return this;
 		}
 
+		@Override
+		public ChatClientRequestSpec tools(ToolCallbackProvider... toolCallbackProviders) {
+			Assert.notNull(toolCallbackProviders, "toolCallbackProviders cannot be null");
+			Assert.noNullElements(toolCallbackProviders, "toolCallbackProviders cannot contain null elements");
+			for (ToolCallbackProvider toolCallbackProvider : toolCallbackProviders) {
+				this.functionCallbacks.addAll(List.of(toolCallbackProvider.getToolCallbacks()));
+			}
+			return this;
+		}
+
 		@Deprecated // Use tools()
 		public ChatClientRequestSpec functions(String... functionBeanNames) {
 			return tools(functionBeanNames);

spring-ai-core/src/main/java/org/springframework/ai/chat/client/DefaultChatClientBuilder.java

@@ -36,6 +36,7 @@ import org.springframework.ai.chat.model.ToolContext;
 import org.springframework.ai.chat.prompt.ChatOptions;
 import org.springframework.ai.model.function.FunctionCallback;
 import org.springframework.ai.tool.ToolCallback;
+import org.springframework.ai.tool.ToolCallbackProvider;
 import org.springframework.core.io.Resource;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
@@ -173,6 +174,12 @@ public class DefaultChatClientBuilder implements Builder {
 		return this;
 	}
 
+	@Override
+	public Builder defaultTools(ToolCallbackProvider... toolCallbackProviders) {
+		this.defaultRequest.tools(toolCallbackProviders);
+		return this;
+	}
+
 	@Deprecated // Use defaultTools()
 	public <I, O> Builder defaultFunction(String name, String description, java.util.function.Function<I, O> function) {
 		this.defaultRequest

spring-ai-core/src/main/java/org/springframework/ai/tool/StaticToolCallbackProvider.java

@@ -0,0 +1,90 @@
+/*
+* Copyright 2025 - 2025 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.tool;
+
+import java.util.List;
+
+import org.springframework.ai.model.function.FunctionCallback;
+import org.springframework.util.Assert;
+
+/**
+ * A simple implementation of {@link ToolCallbackProvider} that maintains a static array
+ * of {@link FunctionCallback} objects. This provider is immutable after construction and
+ * provides a straightforward way to supply a fixed set of tool callbacks to AI models.
+ *
+ * <p>
+ * This implementation is thread-safe as it maintains an immutable array of callbacks that
+ * is set during construction and cannot be modified afterwards.
+ *
+ * <p>
+ * Example usage: <pre>{@code
+ * FunctionCallback callback1 = new MyFunctionCallback();
+ * FunctionCallback callback2 = new AnotherFunctionCallback();
+ *
+ * // Create provider with varargs constructor
+ * ToolCallbackProvider provider1 = new StaticToolCallbackProvider(callback1, callback2);
+ *
+ * // Or create provider with List constructor
+ * List<FunctionCallback> callbacks = Arrays.asList(callback1, callback2);
+ * ToolCallbackProvider provider2 = new StaticToolCallbackProvider(callbacks);
+ * }</pre>
+ *
+ * @author Christian Tzolov
+ * @since 1.0.0
+ * @see ToolCallbackProvider
+ * @see FunctionCallback
+ */
+public class StaticToolCallbackProvider implements ToolCallbackProvider {
+
+	private final FunctionCallback[] toolCallbacks;
+
+	/**
+	 * Constructs a new StaticToolCallbackProvider with the specified array of function
+	 * callbacks.
+	 * @param toolCallbacks the array of function callbacks to be provided by this
+	 * provider. Must not be null, though an empty array is permitted.
+	 * @throws IllegalArgumentException if the toolCallbacks array is null
+	 */
+	public StaticToolCallbackProvider(FunctionCallback... toolCallbacks) {
+		Assert.notNull(toolCallbacks, "ToolCallbacks must not be null");
+		this.toolCallbacks = toolCallbacks;
+	}
+
+	/**
+	 * Constructs a new StaticToolCallbackProvider with the specified list of function
+	 * callbacks. The list is converted to an array internally.
+	 * @param toolCallbacks the list of function callbacks to be provided by this
+	 * provider. Must not be null and must not contain null elements.
+	 * @throws IllegalArgumentException if the toolCallbacks list is null or contains null
+	 * elements
+	 */
+	public StaticToolCallbackProvider(List<? extends FunctionCallback> toolCallbacks) {
+		Assert.noNullElements(toolCallbacks, "toolCallbacks cannot contain null elements");
+		this.toolCallbacks = toolCallbacks.toArray(new FunctionCallback[0]);
+	}
+
+	/**
+	 * Returns the array of function callbacks held by this provider.
+	 * @return an array containing all function callbacks provided during construction.
+	 * The returned array is a direct reference to the internal array, as the callbacks
+	 * are expected to be immutable.
+	 */
+	@Override
+	public FunctionCallback[] getToolCallbacks() {
+		return this.toolCallbacks;
+	}
+
+}

spring-ai-core/src/main/java/org/springframework/ai/tool/ToolCallbackProvider.java

@@ -16,6 +16,10 @@
 
 package org.springframework.ai.tool;
 
+import java.util.List;
+
+import org.springframework.ai.model.function.FunctionCallback;
+
 /**
  * Provides {@link ToolCallback} instances for tools defined in different sources.
  *
@@ -24,6 +28,14 @@ package org.springframework.ai.tool;
  */
 public interface ToolCallbackProvider {
 
-	ToolCallback[] getToolCallbacks();
+	FunctionCallback[] getToolCallbacks();
+
+	public static ToolCallbackProvider from(List<? extends FunctionCallback> toolCallbacks) {
+		return new StaticToolCallbackProvider(toolCallbacks);
+	}
+
+	public static ToolCallbackProvider from(FunctionCallback... toolCallbacks) {
+		return new StaticToolCallbackProvider(toolCallbacks);
+	}
 
 }