Support Progress Flow for McpServer

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

@@ -177,6 +177,20 @@ public Mono<Void> loggingNotification(LoggingMessageNotification loggingMessageN
 		});
 	}
 
+	/**
+	 * Sends a notification to the client that the current progress status has changed for
+	 * long-running operations.
+	 * @param progressNotification The progress notification to send
+	 * @return A Mono that completes when the notification has been sent
+	 */
+	public Mono<Void> progressNotification(McpSchema.ProgressNotification progressNotification) {
+		if (progressNotification == null) {
+			return Mono.error(new McpError("Progress notification must not be null"));
+		}
+
+		return this.session.sendNotification(McpSchema.METHOD_NOTIFICATION_PROGRESS, progressNotification);
+	}
+
 	/**
 	 * Sends a ping request to the client.
 	 * @return A Mono that completes with clients's ping response

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

@@ -23,6 +23,7 @@
 import io.modelcontextprotocol.util.Assert;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import reactor.util.annotation.Nullable;
 
 /**
  * Based on the <a href="http://www.jsonrpc.org/specification">JSON-RPC 2.0
@@ -58,6 +59,8 @@ private McpSchema() {
 
 	public static final String METHOD_PING = "ping";
 
+	public static final String METHOD_NOTIFICATION_PROGRESS = "notifications/progress";
+
 	// Tool Methods
 	public static final String METHOD_TOOLS_LIST = "tools/list";
 
@@ -249,7 +252,7 @@ public record InitializeRequest( // @formatter:off
 				@JsonProperty("capabilities") ClientCapabilities capabilities,
 				@JsonProperty("clientInfo") Implementation clientInfo,
 				@JsonProperty("_meta") Map<String, Object> meta) implements Request {
-			
+
 			public InitializeRequest(String protocolVersion, ClientCapabilities capabilities, Implementation clientInfo) {
 				this(protocolVersion, capabilities, clientInfo, null);
 			}
@@ -462,7 +465,7 @@ public ServerCapabilities build() {
 	public record Implementation(// @formatter:off
 				@JsonProperty("name") String name,
 				@JsonProperty("title") String title,
-				@JsonProperty("version") String version) implements BaseMetadata {// @formatter:on			
+				@JsonProperty("version") String version) implements BaseMetadata {// @formatter:on
 
 		public Implementation(String name, String version) {
 			this(name, null, version);
@@ -1053,6 +1056,8 @@ private static JsonSchema parseSchema(String schema) {
 	 * tools/list.
 	 * @param arguments Arguments to pass to the tool. These must conform to the tool's
 	 * input schema.
+	 * @param meta Optional metadata about the request. This can include additional
+	 * information like `progressToken`
 	 */
 	@JsonInclude(JsonInclude.Include.NON_ABSENT)
 	@JsonIgnoreProperties(ignoreUnknown = true)
@@ -1063,9 +1068,10 @@ public record CallToolRequest(// @formatter:off
 
 				public CallToolRequest(String name, String jsonArguments) {
 						this(name, parseJsonArguments(jsonArguments), null);
-				}
-				public CallToolRequest(String name, Map<String, Object> arguments) {
-						this(name, arguments, null);
+		}
+
+		public CallToolRequest(String name, Map<String, Object> arguments) {
+			this(name, arguments, null);
 				}
 
 				private static Map<String, Object> parseJsonArguments(String jsonArguments) {
@@ -1317,7 +1323,7 @@ public record CreateMessageRequest(// @formatter:off
 				@JsonProperty("metadata") Map<String, Object> metadata,
 				@JsonProperty("_meta") Map<String, Object> meta) implements Request {
 
-				
+
 				// backwards compatibility constructor
 				public CreateMessageRequest(List<SamplingMessage> messages, ModelPreferences modelPreferences,
 											String systemPrompt, ContextInclusionStrategy includeContext,
@@ -1771,7 +1777,7 @@ public CompleteRequest(McpSchema.CompleteReference ref, CompleteArgument argumen
 		public CompleteRequest(McpSchema.CompleteReference ref, CompleteArgument argument) {
 			this(ref, argument, null, null);
 		}
-		
+
 		public record CompleteArgument(
 			@JsonProperty("name") String name,
 			@JsonProperty("value") String value) {