Add _meta to ResourceLink

Author: pantanurag555

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

@@ -1841,6 +1841,8 @@ public record CompleteCompletion(
 			@JsonSubTypes.Type(value = ResourceLink.class, name = "resource_link") })
 	public sealed interface Content permits TextContent, ImageContent, AudioContent, EmbeddedResource, ResourceLink {
 
+		Map<String, Object> meta();
+
 		default String type() {
 			if (this instanceof TextContent) {
 				return "text";
@@ -2014,7 +2016,13 @@ public record ResourceLink( // @formatter:off
                 @JsonProperty("description") String description,
                 @JsonProperty("mimeType") String mimeType,
                 @JsonProperty("size") Long size,
-                @JsonProperty("annotations") Annotations annotations) implements Annotated, Content, ResourceContent { // @formatter:on
+                @JsonProperty("annotations") Annotations annotations,
+				@JsonProperty("_meta") Map<String, Object> meta) implements Annotated, Content, ResourceContent { // @formatter:on
+
+		public ResourceLink(String name, String uri, String description, String mimeType, Long size,
+				Annotations annotations) {
+			this(name, uri, description, mimeType, size, annotations, null);
+		}
 
 		public static Builder builder() {
 			return new Builder();
@@ -2034,6 +2042,8 @@ public static class Builder {
 
 			private Long size;
 
+			private Map<String, Object> meta;
+
 			public Builder name(String name) {
 				this.name = name;
 				return this;
@@ -2064,11 +2074,16 @@ public Builder size(Long size) {
 				return this;
 			}
 
+			public Builder meta(Map<String, Object> meta) {
+				this.meta = meta;
+				return this;
+			}
+
 			public ResourceLink build() {
 				Assert.hasText(uri, "uri must not be empty");
 				Assert.hasText(name, "name must not be empty");
 
-				return new ResourceLink(name, uri, description, mimeType, size, annotations);
+				return new ResourceLink(name, uri, description, mimeType, size, annotations, meta);
 			}
 
 		}

mcp/src/test/java/io/modelcontextprotocol/spec/McpSchemaTests.java

@@ -215,29 +215,30 @@ void testEmbeddedResourceWithBlobContentsDeserialization() throws Exception {
 	@Test
 	void testResourceLink() throws Exception {
 		McpSchema.ResourceLink resourceLink = new McpSchema.ResourceLink("main.rs", "file:///project/src/main.rs",
-				"Primary application entry point", "text/x-rust", null, null);
+				"Primary application entry point", "text/x-rust", null, null, Map.of("metaKey", "metaValue"));
 		String value = mapper.writeValueAsString(resourceLink);
 
 		assertThatJson(value).when(Option.IGNORING_ARRAY_ORDER)
 			.when(Option.IGNORING_EXTRA_ARRAY_ITEMS)
 			.isObject()
 			.isEqualTo(
 					json("""
-							{"type":"resource_link","name":"main.rs","uri":"file:///project/src/main.rs","description":"Primary application entry point","mimeType":"text/x-rust"}"""));
+							{"type":"resource_link","name":"main.rs","uri":"file:///project/src/main.rs","description":"Primary application entry point","mimeType":"text/x-rust","_meta":{"metaKey":"metaValue"}}"""));
 	}
 
 	@Test
 	void testResourceLinkDeserialization() throws Exception {
 		McpSchema.ResourceLink resourceLink = mapper.readValue(
 				"""
-						{"type":"resource_link","name":"main.rs","uri":"file:///project/src/main.rs","description":"Primary application entry point","mimeType":"text/x-rust"}""",
+						{"type":"resource_link","name":"main.rs","uri":"file:///project/src/main.rs","description":"Primary application entry point","mimeType":"text/x-rust","_meta":{"metaKey":"metaValue"}}""",
 				McpSchema.ResourceLink.class);
 		assertThat(resourceLink).isNotNull();
 		assertThat(resourceLink.type()).isEqualTo("resource_link");
 		assertThat(resourceLink.name()).isEqualTo("main.rs");
 		assertThat(resourceLink.uri()).isEqualTo("file:///project/src/main.rs");
 		assertThat(resourceLink.description()).isEqualTo("Primary application entry point");
 		assertThat(resourceLink.mimeType()).isEqualTo("text/x-rust");
+		assertThat(resourceLink.meta()).containsEntry("metaKey", "metaValue");
 	}
 
 	// JSON-RPC Message Types Tests
@@ -1366,7 +1367,7 @@ void testProgressNotificationWithMessage() throws Exception {
 			.isObject()
 			.isEqualTo(
 					json("""
-							{"progressToken":"progress-token-123","progress":0.5,"total":1.0,"message":"Processing file 1 of 2"},"_meta":{"key":"value"}"""));
+							{"progressToken":"progress-token-123","progress":0.5,"total":1.0,"message":"Processing file 1 of 2","_meta":{"key":"value"}}"""));
 	}
 
 	@Test