feat: Add elicitation support to MCP protocol

Implement elicitation capabilities allowing servers to request additional information
from users through clients during interactions. This feature provides a standardized
way for servers to gather necessary information dynamically while clients maintain
control over user interactions and data sharing.

- Add ElicitRequest and ElicitResult classes to McpSchema
- Implement elicitation handlers in client classes
- Add elicitation capabilities to server exchange classes
- Add tests for elicitation functionality with various scenarios

mcp/src/main/java/io/modelcontextprotocol/client/McpAsyncClient.java

@@ -23,6 +23,8 @@ import io.modelcontextprotocol.spec.McpSchema;
 import io.modelcontextprotocol.spec.McpSchema.ClientCapabilities;
 import io.modelcontextprotocol.spec.McpSchema.CreateMessageRequest;
 import io.modelcontextprotocol.spec.McpSchema.CreateMessageResult;
+import io.modelcontextprotocol.spec.McpSchema.ElicitRequest;
+import io.modelcontextprotocol.spec.McpSchema.ElicitResult;
 import io.modelcontextprotocol.spec.McpSchema.GetPromptRequest;
 import io.modelcontextprotocol.spec.McpSchema.GetPromptResult;
 import io.modelcontextprotocol.spec.McpSchema.ListPromptsResult;
@@ -141,6 +143,15 @@ public class McpAsyncClient {
 	 */
 	private Function<CreateMessageRequest, Mono<CreateMessageResult>> samplingHandler;
 
+	/**
+	 * MCP provides a standardized way for servers to request additional information from
+	 * users through the client during interactions. This flow allows clients to maintain
+	 * control over user interactions and data sharing while enabling servers to gather
+	 * necessary information dynamically. Servers can request structured data from users
+	 * with optional JSON schemas to validate responses.
+	 */
+	private Function<ElicitRequest, Mono<ElicitResult>> elicitationHandler;
+
 	/**
 	 * Client transport implementation.
 	 */
@@ -189,6 +200,15 @@ public class McpAsyncClient {
 			requestHandlers.put(McpSchema.METHOD_SAMPLING_CREATE_MESSAGE, samplingCreateMessageHandler());
 		}
 
+		// Elicitation Handler
+		if (this.clientCapabilities.elicitation() != null) {
+			if (features.elicitationHandler() == null) {
+				throw new McpError("Elicitation handler must not be null when client capabilities include elicitation");
+			}
+			this.elicitationHandler = features.elicitationHandler();
+			requestHandlers.put(McpSchema.METHOD_ELICITATION_CREATE, elicitationCreateHandler());
+		}
+
 		// Notification Handlers
 		Map<String, NotificationHandler> notificationHandlers = new HashMap<>();
 
@@ -500,6 +520,18 @@ public class McpAsyncClient {
 		};
 	}
 
+	// --------------------------
+	// Elicitation
+	// --------------------------
+	private RequestHandler<ElicitResult> elicitationCreateHandler() {
+		return params -> {
+			ElicitRequest request = transport.unmarshalFrom(params, new TypeReference<>() {
+			});
+
+			return this.elicitationHandler.apply(request);
+		};
+	}
+
 	// --------------------------
 	// Tools
 	// --------------------------

mcp/src/main/java/io/modelcontextprotocol/client/McpClient.java

@@ -18,6 +18,8 @@ import io.modelcontextprotocol.spec.McpTransport;
 import io.modelcontextprotocol.spec.McpSchema.ClientCapabilities;
 import io.modelcontextprotocol.spec.McpSchema.CreateMessageRequest;
 import io.modelcontextprotocol.spec.McpSchema.CreateMessageResult;
+import io.modelcontextprotocol.spec.McpSchema.ElicitRequest;
+import io.modelcontextprotocol.spec.McpSchema.ElicitResult;
 import io.modelcontextprotocol.spec.McpSchema.Implementation;
 import io.modelcontextprotocol.spec.McpSchema.Root;
 import io.modelcontextprotocol.util.Assert;
@@ -175,6 +177,8 @@ public interface McpClient {
 
 		private Function<CreateMessageRequest, CreateMessageResult> samplingHandler;
 
+		private Function<ElicitRequest, ElicitResult> elicitationHandler;
+
 		private SyncSpec(McpClientTransport transport) {
 			Assert.notNull(transport, "Transport must not be null");
 			this.transport = transport;
@@ -283,6 +287,21 @@ public interface McpClient {
 			return this;
 		}
 
+		/**
+		 * Sets a custom elicitation handler for processing elicitation message requests.
+		 * The elicitation handler can modify or validate messages before they are sent to
+		 * the server, enabling custom processing logic.
+		 * @param elicitationHandler A function that processes elicitation requests and
+		 * returns results. Must not be null.
+		 * @return This builder instance for method chaining
+		 * @throws IllegalArgumentException if elicitationHandler is null
+		 */
+		public SyncSpec elicitation(Function<ElicitRequest, ElicitResult> elicitationHandler) {
+			Assert.notNull(elicitationHandler, "Elicitation handler must not be null");
+			this.elicitationHandler = elicitationHandler;
+			return this;
+		}
+
 		/**
 		 * Adds a consumer to be notified when the available tools change. This allows the
 		 * client to react to changes in the server's tool capabilities, such as tools
@@ -364,7 +383,7 @@ public interface McpClient {
 		public McpSyncClient build() {
 			McpClientFeatures.Sync syncFeatures = new McpClientFeatures.Sync(this.clientInfo, this.capabilities,
 					this.roots, this.toolsChangeConsumers, this.resourcesChangeConsumers, this.promptsChangeConsumers,
-					this.loggingConsumers, this.samplingHandler);
+					this.loggingConsumers, this.samplingHandler, this.elicitationHandler);
 
 			McpClientFeatures.Async asyncFeatures = McpClientFeatures.Async.fromSync(syncFeatures);
 
@@ -414,6 +433,8 @@ public interface McpClient {
 
 		private Function<CreateMessageRequest, Mono<CreateMessageResult>> samplingHandler;
 
+		private Function<ElicitRequest, Mono<ElicitResult>> elicitationHandler;
+
 		private AsyncSpec(McpClientTransport transport) {
 			Assert.notNull(transport, "Transport must not be null");
 			this.transport = transport;
@@ -522,6 +543,21 @@ public interface McpClient {
 			return this;
 		}
 
+		/**
+		 * Sets a custom elicitation handler for processing elicitation message requests.
+		 * The elicitation handler can modify or validate messages before they are sent to
+		 * the server, enabling custom processing logic.
+		 * @param elicitationHandler A function that processes elicitation requests and
+		 * returns results. Must not be null.
+		 * @return This builder instance for method chaining
+		 * @throws IllegalArgumentException if elicitationHandler is null
+		 */
+		public AsyncSpec elicitation(Function<ElicitRequest, Mono<ElicitResult>> elicitationHandler) {
+			Assert.notNull(elicitationHandler, "Elicitation handler must not be null");
+			this.elicitationHandler = elicitationHandler;
+			return this;
+		}
+
 		/**
 		 * Adds a consumer to be notified when the available tools change. This allows the
 		 * client to react to changes in the server's tool capabilities, such as tools
@@ -606,7 +642,7 @@ public interface McpClient {
 			return new McpAsyncClient(this.transport, this.requestTimeout, this.initializationTimeout,
 					new McpClientFeatures.Async(this.clientInfo, this.capabilities, this.roots,
 							this.toolsChangeConsumers, this.resourcesChangeConsumers, this.promptsChangeConsumers,
-							this.loggingConsumers, this.samplingHandler));
+							this.loggingConsumers, this.samplingHandler, this.elicitationHandler));
 		}
 
 	}

mcp/src/main/java/io/modelcontextprotocol/client/McpClientFeatures.java

@@ -60,13 +60,15 @@ class McpClientFeatures {
 	 * @param promptsChangeConsumers the prompts change consumers.
 	 * @param loggingConsumers the logging consumers.
 	 * @param samplingHandler the sampling handler.
+	 * @param elicitationHandler the elicitation handler.
 	 */
 	record Async(McpSchema.Implementation clientInfo, McpSchema.ClientCapabilities clientCapabilities,
 			Map<String, McpSchema.Root> roots, List<Function<List<McpSchema.Tool>, Mono<Void>>> toolsChangeConsumers,
 			List<Function<List<McpSchema.Resource>, Mono<Void>>> resourcesChangeConsumers,
 			List<Function<List<McpSchema.Prompt>, Mono<Void>>> promptsChangeConsumers,
 			List<Function<McpSchema.LoggingMessageNotification, Mono<Void>>> loggingConsumers,
-			Function<McpSchema.CreateMessageRequest, Mono<McpSchema.CreateMessageResult>> samplingHandler) {
+			Function<McpSchema.CreateMessageRequest, Mono<McpSchema.CreateMessageResult>> samplingHandler,
+			Function<McpSchema.ElicitRequest, Mono<McpSchema.ElicitResult>> elicitationHandler) {
 
 		/**
 		 * Create an instance and validate the arguments.
@@ -77,6 +79,7 @@ class McpClientFeatures {
 		 * @param promptsChangeConsumers the prompts change consumers.
 		 * @param loggingConsumers the logging consumers.
 		 * @param samplingHandler the sampling handler.
+		 * @param elicitationHandler the elicitation handler.
 		 */
 		public Async(McpSchema.Implementation clientInfo, McpSchema.ClientCapabilities clientCapabilities,
 				Map<String, McpSchema.Root> roots,
@@ -84,14 +87,16 @@ class McpClientFeatures {
 				List<Function<List<McpSchema.Resource>, Mono<Void>>> resourcesChangeConsumers,
 				List<Function<List<McpSchema.Prompt>, Mono<Void>>> promptsChangeConsumers,
 				List<Function<McpSchema.LoggingMessageNotification, Mono<Void>>> loggingConsumers,
-				Function<McpSchema.CreateMessageRequest, Mono<McpSchema.CreateMessageResult>> samplingHandler) {
+				Function<McpSchema.CreateMessageRequest, Mono<McpSchema.CreateMessageResult>> samplingHandler,
+				Function<McpSchema.ElicitRequest, Mono<McpSchema.ElicitResult>> elicitationHandler) {
 
 			Assert.notNull(clientInfo, "Client info must not be null");
 			this.clientInfo = clientInfo;
 			this.clientCapabilities = (clientCapabilities != null) ? clientCapabilities
 					: new McpSchema.ClientCapabilities(null,
 							!Utils.isEmpty(roots) ? new McpSchema.ClientCapabilities.RootCapabilities(false) : null,
-							samplingHandler != null ? new McpSchema.ClientCapabilities.Sampling() : null);
+							samplingHandler != null ? new McpSchema.ClientCapabilities.Sampling() : null,
+							elicitationHandler != null ? new McpSchema.ClientCapabilities.Elicitation() : null);
 			this.roots = roots != null ? new ConcurrentHashMap<>(roots) : new ConcurrentHashMap<>();
 
 			this.toolsChangeConsumers = toolsChangeConsumers != null ? toolsChangeConsumers : List.of();
@@ -99,6 +104,7 @@ class McpClientFeatures {
 			this.promptsChangeConsumers = promptsChangeConsumers != null ? promptsChangeConsumers : List.of();
 			this.loggingConsumers = loggingConsumers != null ? loggingConsumers : List.of();
 			this.samplingHandler = samplingHandler;
+			this.elicitationHandler = elicitationHandler;
 		}
 
 		/**
@@ -138,9 +144,14 @@ class McpClientFeatures {
 			Function<McpSchema.CreateMessageRequest, Mono<McpSchema.CreateMessageResult>> samplingHandler = r -> Mono
 				.fromCallable(() -> syncSpec.samplingHandler().apply(r))
 				.subscribeOn(Schedulers.boundedElastic());
+
+			Function<McpSchema.ElicitRequest, Mono<McpSchema.ElicitResult>> elicitationHandler = r -> Mono
+				.fromCallable(() -> syncSpec.elicitationHandler().apply(r))
+				.subscribeOn(Schedulers.boundedElastic());
+
 			return new Async(syncSpec.clientInfo(), syncSpec.clientCapabilities(), syncSpec.roots(),
 					toolsChangeConsumers, resourcesChangeConsumers, promptsChangeConsumers, loggingConsumers,
-					samplingHandler);
+					samplingHandler, elicitationHandler);
 		}
 	}
 
@@ -156,13 +167,15 @@ class McpClientFeatures {
 	 * @param promptsChangeConsumers the prompts change consumers.
 	 * @param loggingConsumers the logging consumers.
 	 * @param samplingHandler the sampling handler.
+	 * @param elicitationHandler the elicitation handler.
 	 */
 	public record Sync(McpSchema.Implementation clientInfo, McpSchema.ClientCapabilities clientCapabilities,
 			Map<String, McpSchema.Root> roots, List<Consumer<List<McpSchema.Tool>>> toolsChangeConsumers,
 			List<Consumer<List<McpSchema.Resource>>> resourcesChangeConsumers,
 			List<Consumer<List<McpSchema.Prompt>>> promptsChangeConsumers,
 			List<Consumer<McpSchema.LoggingMessageNotification>> loggingConsumers,
-			Function<McpSchema.CreateMessageRequest, McpSchema.CreateMessageResult> samplingHandler) {
+			Function<McpSchema.CreateMessageRequest, McpSchema.CreateMessageResult> samplingHandler,
+			Function<McpSchema.ElicitRequest, McpSchema.ElicitResult> elicitationHandler) {
 
 		/**
 		 * Create an instance and validate the arguments.
@@ -174,20 +187,23 @@ class McpClientFeatures {
 		 * @param promptsChangeConsumers the prompts change consumers.
 		 * @param loggingConsumers the logging consumers.
 		 * @param samplingHandler the sampling handler.
+		 * @param elicitationHandler the elicitation handler.
 		 */
 		public Sync(McpSchema.Implementation clientInfo, McpSchema.ClientCapabilities clientCapabilities,
 				Map<String, McpSchema.Root> roots, List<Consumer<List<McpSchema.Tool>>> toolsChangeConsumers,
 				List<Consumer<List<McpSchema.Resource>>> resourcesChangeConsumers,
 				List<Consumer<List<McpSchema.Prompt>>> promptsChangeConsumers,
 				List<Consumer<McpSchema.LoggingMessageNotification>> loggingConsumers,
-				Function<McpSchema.CreateMessageRequest, McpSchema.CreateMessageResult> samplingHandler) {
+				Function<McpSchema.CreateMessageRequest, McpSchema.CreateMessageResult> samplingHandler,
+				Function<McpSchema.ElicitRequest, McpSchema.ElicitResult> elicitationHandler) {
 
 			Assert.notNull(clientInfo, "Client info must not be null");
 			this.clientInfo = clientInfo;
 			this.clientCapabilities = (clientCapabilities != null) ? clientCapabilities
 					: new McpSchema.ClientCapabilities(null,
 							!Utils.isEmpty(roots) ? new McpSchema.ClientCapabilities.RootCapabilities(false) : null,
-							samplingHandler != null ? new McpSchema.ClientCapabilities.Sampling() : null);
+							samplingHandler != null ? new McpSchema.ClientCapabilities.Sampling() : null,
+							elicitationHandler != null ? new McpSchema.ClientCapabilities.Elicitation() : null);
 			this.roots = roots != null ? new HashMap<>(roots) : new HashMap<>();
 
 			this.toolsChangeConsumers = toolsChangeConsumers != null ? toolsChangeConsumers : List.of();
@@ -195,6 +211,7 @@ class McpClientFeatures {
 			this.promptsChangeConsumers = promptsChangeConsumers != null ? promptsChangeConsumers : List.of();
 			this.loggingConsumers = loggingConsumers != null ? loggingConsumers : List.of();
 			this.samplingHandler = samplingHandler;
+			this.elicitationHandler = elicitationHandler;
 		}
 	}
 

mcp/src/main/java/io/modelcontextprotocol/server/McpAsyncServerExchange.java

@@ -36,6 +36,9 @@ public class McpAsyncServerExchange {
 	private static final TypeReference<McpSchema.ListRootsResult> LIST_ROOTS_RESULT_TYPE_REF = new TypeReference<>() {
 	};
 
+	private static final TypeReference<McpSchema.ElicitResult> ELICITATION_RESULT_TYPE_REF = new TypeReference<>() {
+	};
+
 	/**
 	 * Create a new asynchronous exchange with the client.
 	 * @param session The server session representing a 1-1 interaction.
@@ -93,6 +96,31 @@ public class McpAsyncServerExchange {
 				CREATE_MESSAGE_RESULT_TYPE_REF);
 	}
 
+	/**
+	 * Creates a new elicitation. MCP provides a standardized way for servers to request
+	 * additional information from users through the client during interactions. This flow
+	 * allows clients to maintain control over user interactions and data sharing while
+	 * enabling servers to gather necessary information dynamically. Servers can request
+	 * structured data from users with optional JSON schemas to validate responses.
+	 * @param elicitRequest The request to create a new elicitation
+	 * @return A Mono that completes when the elicitation has been resolved.
+	 * @see McpSchema.ElicitRequest
+	 * @see McpSchema.ElicitResult
+	 * @see <a href=
+	 * "https://spec.modelcontextprotocol.io/specification/client/elicitation/">Elicitation
+	 * Specification</a>
+	 */
+	public Mono<McpSchema.ElicitResult> createElicitation(McpSchema.ElicitRequest elicitRequest) {
+		if (this.clientCapabilities == null) {
+			return Mono.error(new McpError("Client must be initialized. Call the initialize method first!"));
+		}
+		if (this.clientCapabilities.elicitation() == null) {
+			return Mono.error(new McpError("Client must be configured with elicitation capabilities"));
+		}
+		return this.session.sendRequest(McpSchema.METHOD_ELICITATION_CREATE, elicitRequest,
+				ELICITATION_RESULT_TYPE_REF);
+	}
+
 	/**
 	 * Retrieves the list of all roots provided by the client.
 	 * @return A Mono that emits the list of roots result.

mcp/src/main/java/io/modelcontextprotocol/server/McpSyncServerExchange.java

@@ -64,6 +64,24 @@ public class McpSyncServerExchange {
 		return this.exchange.createMessage(createMessageRequest).block();
 	}
 
+	/**
+	 * Creates a new elicitation. MCP provides a standardized way for servers to request
+	 * additional information from users through the client during interactions. This flow
+	 * allows clients to maintain control over user interactions and data sharing while
+	 * enabling servers to gather necessary information dynamically. Servers can request
+	 * structured data from users with optional JSON schemas to validate responses.
+	 * @param elicitRequest The request to create a new elicitation
+	 * @return A result containing the elicitation response.
+	 * @see McpSchema.ElicitRequest
+	 * @see McpSchema.ElicitResult
+	 * @see <a href=
+	 * "https://spec.modelcontextprotocol.io/specification/client/elicitation/">Elicitation
+	 * Specification</a>
+	 */
+	public McpSchema.ElicitResult createElicitation(McpSchema.ElicitRequest elicitRequest) {
+		return this.exchange.createElicitation(elicitRequest).block();
+	}
+
 	/**
 	 * Retrieves the list of all roots provided by the client.
 	 * @return The list of roots result.

mcp/src/main/java/io/modelcontextprotocol/spec/McpSchema.java

@@ -94,6 +94,9 @@ public final class McpSchema {
 	// Sampling Methods
 	public static final String METHOD_SAMPLING_CREATE_MESSAGE = "sampling/createMessage";
 
+	// Elicitation Methods
+	public static final String METHOD_ELICITATION_CREATE = "elicitation/create";
+
 	private static final ObjectMapper OBJECT_MAPPER = new ObjectMapper();
 
 	// ---------------------------
@@ -131,8 +134,8 @@ public final class McpSchema {
 
 	}
 
-	public sealed interface Request
-			permits InitializeRequest, CallToolRequest, CreateMessageRequest, CompleteRequest, GetPromptRequest {
+	public sealed interface Request permits InitializeRequest, CallToolRequest, CreateMessageRequest, ElicitRequest,
+			CompleteRequest, GetPromptRequest {
 
 	}
 
@@ -221,7 +224,7 @@ public final class McpSchema {
 	public record InitializeRequest( // @formatter:off
 		@JsonProperty("protocolVersion") String protocolVersion,
 		@JsonProperty("capabilities") ClientCapabilities capabilities,
-		@JsonProperty("clientInfo") Implementation clientInfo) implements Request {		
+		@JsonProperty("clientInfo") Implementation clientInfo) implements Request {
 	} // @formatter:on
 
 	@JsonInclude(JsonInclude.Include.NON_ABSENT)
@@ -245,6 +248,8 @@ public final class McpSchema {
 	 * access to.
 	 * @param sampling Provides a standardized way for servers to request LLM sampling
 	 * (“completions” or “generations”) from language models via clients.
+	 * @param elicitation Provides a standardized way for servers to request additional
+	 * information from users through the client during interactions.
 	 *
 	 */
 	@JsonInclude(JsonInclude.Include.NON_ABSENT)
@@ -252,7 +257,8 @@ public final class McpSchema {
 	public record ClientCapabilities( // @formatter:off
 		@JsonProperty("experimental") Map<String, Object> experimental,
 		@JsonProperty("roots") RootCapabilities roots,
-		@JsonProperty("sampling") Sampling sampling) {
+		@JsonProperty("sampling") Sampling sampling,
+		@JsonProperty("elicitation") Elicitation elicitation) {
 
 		/**
 		 * Roots define the boundaries of where servers can operate within the filesystem,
@@ -264,7 +270,7 @@ public final class McpSchema {
 		 * 		  has changed since the last time the server checked.
 		 */
 		@JsonInclude(JsonInclude.Include.NON_ABSENT)
-		@JsonIgnoreProperties(ignoreUnknown = true)	
+		@JsonIgnoreProperties(ignoreUnknown = true)
 		public record RootCapabilities(
 			@JsonProperty("listChanged") Boolean listChanged) {
 		}
@@ -279,10 +285,22 @@ public final class McpSchema {
 		 * image-based interactions and optionally include context
 		 * from MCP servers in their prompts.
 		 */
-		@JsonInclude(JsonInclude.Include.NON_ABSENT)			
+		@JsonInclude(JsonInclude.Include.NON_ABSENT)
 		public record Sampling() {
 		}
 
+		/**
+		 * Provides a standardized way for servers to request additional
+		 * information from users through the client during interactions.
+		 * This flow allows clients to maintain control over user
+		 * interactions and data sharing while enabling servers to gather
+		 * necessary information dynamically. Servers can request structured
+		 * data from users with optional JSON schemas to validate responses.
+		 */
+		@JsonInclude(JsonInclude.Include.NON_ABSENT)
+		public record Elicitation() {
+		}
+
 		public static Builder builder() {
 			return new Builder();
 		}
@@ -291,6 +309,7 @@ public final class McpSchema {
 			private Map<String, Object> experimental;
 			private RootCapabilities roots;
 			private Sampling sampling;
+			private Elicitation elicitation;
 
 			public Builder experimental(Map<String, Object> experimental) {
 				this.experimental = experimental;
@@ -307,8 +326,13 @@ public final class McpSchema {
 				return this;
 			}
 
+			public Builder elicitation() {
+				this.elicitation = new Elicitation();
+				return this;
+			}
+
 			public ClientCapabilities build() {
-				return new ClientCapabilities(experimental, roots, sampling);
+				return new ClientCapabilities(experimental, roots, sampling, elicitation);
 			}
 		}
 	}// @formatter:on
@@ -326,11 +350,11 @@ public final class McpSchema {
 		@JsonInclude(JsonInclude.Include.NON_ABSENT)
 		public record CompletionCapabilities() {
 		}
-			
+
 		@JsonInclude(JsonInclude.Include.NON_ABSENT)
 		public record LoggingCapabilities() {
 		}
-	
+
 		@JsonInclude(JsonInclude.Include.NON_ABSENT)
 		public record PromptCapabilities(
 			@JsonProperty("listChanged") Boolean listChanged) {
@@ -727,11 +751,11 @@ public final class McpSchema {
 		@JsonProperty("name") String name,
 		@JsonProperty("description") String description,
 		@JsonProperty("inputSchema") JsonSchema inputSchema) {
-	
+
 		public Tool(String name, String description, String schema) {
 			this(name, description, parseSchema(schema));
 		}
-			
+
 	} // @formatter:on
 
 	private static JsonSchema parseSchema(String schema) {
@@ -758,7 +782,7 @@ public final class McpSchema {
 		@JsonProperty("arguments") Map<String, Object> arguments) implements Request {
 
 		public CallToolRequest(String name, String jsonArguments) {
-			this(name, parseJsonArguments(jsonArguments));			
+			this(name, parseJsonArguments(jsonArguments));
 		}
 
 		private static Map<String, Object> parseJsonArguments(String jsonArguments) {
@@ -893,7 +917,7 @@ public final class McpSchema {
 	@JsonProperty("costPriority") Double costPriority,
 	@JsonProperty("speedPriority") Double speedPriority,
 	@JsonProperty("intelligencePriority") Double intelligencePriority) {
-	
+
 	public static Builder builder() {
 		return new Builder();
 	}
@@ -963,7 +987,7 @@ public final class McpSchema {
 		@JsonProperty("includeContext") ContextInclusionStrategy includeContext,
 		@JsonProperty("temperature") Double temperature,
 		@JsonProperty("maxTokens") int maxTokens,
-		@JsonProperty("stopSequences") List<String> stopSequences, 			
+		@JsonProperty("stopSequences") List<String> stopSequences,
 		@JsonProperty("metadata") Map<String, Object> metadata) implements Request {
 
 		public enum ContextInclusionStrategy {
@@ -971,7 +995,7 @@ public final class McpSchema {
 			@JsonProperty("thisServer") THIS_SERVER,
 			@JsonProperty("allServers") ALL_SERVERS
 		}
-		
+
 		public static Builder builder() {
 			return new Builder();
 		}
@@ -1040,7 +1064,7 @@ public final class McpSchema {
 		@JsonProperty("content") Content content,
 		@JsonProperty("model") String model,
 		@JsonProperty("stopReason") StopReason stopReason) {
-		
+
 		public enum StopReason {
 			@JsonProperty("endTurn") END_TURN,
 			@JsonProperty("stopSequence") STOP_SEQUENCE,
@@ -1088,6 +1112,79 @@ public final class McpSchema {
 		}
 	}// @formatter:on
 
+	// Elicitation
+	/**
+	 * Used by the server to send an elicitation to the client.
+	 *
+	 * @param message The body of the elicitation message.
+	 * @param requestedSchema The elicitation response schema that must be satisfied.
+	 */
+	@JsonInclude(JsonInclude.Include.NON_ABSENT)
+	@JsonIgnoreProperties(ignoreUnknown = true)
+	public record ElicitRequest(// @formatter:off
+		@JsonProperty("message") String message,
+		@JsonProperty("requestedSchema") Map<String, Object> requestedSchema) implements Request {
+
+		public static Builder builder() {
+			return new Builder();
+		}
+
+		public static class Builder {
+			private String message;
+			private Map<String, Object> requestedSchema;
+
+			public Builder message(String message) {
+				this.message = message;
+				return this;
+			}
+
+			public Builder requestedSchema(Map<String, Object> requestedSchema) {
+				this.requestedSchema = requestedSchema;
+				return this;
+			}
+
+			public ElicitRequest build() {
+				return new ElicitRequest(message, requestedSchema);
+			}
+		}
+	}// @formatter:on
+
+	@JsonInclude(JsonInclude.Include.NON_ABSENT)
+	@JsonIgnoreProperties(ignoreUnknown = true)
+	public record ElicitResult(// @formatter:off
+		@JsonProperty("action") Action action,
+		@JsonProperty("content") Map<String, Object> content) {
+
+		public enum Action {
+			@JsonProperty("accept") ACCEPT,
+			@JsonProperty("decline") DECLINE,
+			@JsonProperty("cancel") CANCEL
+		}
+
+		public static Builder builder() {
+			return new Builder();
+		}
+
+		public static class Builder {
+			private Action action;
+			private Map<String, Object> content;
+
+			public Builder message(Action action) {
+				this.action = action;
+				return this;
+			}
+
+			public Builder content(Map<String, Object> content) {
+				this.content = content;
+				return this;
+			}
+
+			public ElicitResult build() {
+				return new ElicitResult(action, content);
+			}
+		}
+	}// @formatter:on
+
 	// ---------------------------
 	// Pagination Interfaces
 	// ---------------------------