From 2f55dd00158a85ba9a23122bb7d298a56691871f Mon Sep 17 00:00:00 2001 From: bzsurbhi Date: Wed, 25 Jun 2025 13:21:41 -0700 Subject: [PATCH] feat: add ResourceLink content type and ResourceContent interface (#341) - Add ResourceContent interface with common resource metadata methods - Implement ResourceContent in existing Resource class - Add new ResourceLink record class implementing Content and ResourceContent - Update Content interface to support ResourceLink with "resource_link" type (breaking!) - Add tests for ResourceLink serialization/deserialization - Update test expectations to include new resource_link type Signed-off-by: Christian Tzolov --- .../modelcontextprotocol/spec/McpSchema.java | 116 +++++++++++++++++- .../spec/McpSchemaTests.java | 39 +++++- 2 files changed, 146 insertions(+), 9 deletions(-) diff --git a/mcp/src/main/java/io/modelcontextprotocol/spec/McpSchema.java b/mcp/src/main/java/io/modelcontextprotocol/spec/McpSchema.java index f8eb99e..cd73c0f 100644 --- a/mcp/src/main/java/io/modelcontextprotocol/spec/McpSchema.java +++ b/mcp/src/main/java/io/modelcontextprotocol/spec/McpSchema.java @@ -479,6 +479,28 @@ public final class McpSchema { @JsonProperty("priority") Double priority) { } // @formatter:on + /** + * A common interface for resource content, which includes metadata about the resource + * such as its URI, name, description, MIME type, size, and annotations. This + * interface is implemented by both {@link Resource} and {@link ResourceLink} to + * provide a consistent way to access resource metadata. + */ + public interface ResourceContent { + + String uri(); + + String name(); + + String description(); + + String mimeType(); + + Long size(); + + Annotations annotations(); + + } + /** * A known resource that the server is capable of reading. * @@ -503,7 +525,7 @@ public final class McpSchema { @JsonProperty("description") String description, @JsonProperty("mimeType") String mimeType, @JsonProperty("size") Long size, - @JsonProperty("annotations") Annotations annotations) implements Annotated { + @JsonProperty("annotations") Annotations annotations) implements Annotated, ResourceContent { /** * @deprecated Only exists for backwards-compatibility purposes. Use @@ -1473,8 +1495,9 @@ public final class McpSchema { @JsonSubTypes({ @JsonSubTypes.Type(value = TextContent.class, name = "text"), @JsonSubTypes.Type(value = ImageContent.class, name = "image"), @JsonSubTypes.Type(value = AudioContent.class, name = "audio"), - @JsonSubTypes.Type(value = EmbeddedResource.class, name = "resource") }) - public sealed interface Content permits TextContent, ImageContent, AudioContent, EmbeddedResource { + @JsonSubTypes.Type(value = EmbeddedResource.class, name = "resource"), + @JsonSubTypes.Type(value = ResourceLink.class, name = "resource_link") }) + public sealed interface Content permits TextContent, ImageContent, AudioContent, EmbeddedResource, ResourceLink { default String type() { if (this instanceof TextContent) { @@ -1489,6 +1512,9 @@ public final class McpSchema { else if (this instanceof EmbeddedResource) { return "resource"; } + else if (this instanceof ResourceLink) { + return "resource_link"; + } throw new IllegalArgumentException("Unknown content type: " + this); } @@ -1601,6 +1627,90 @@ public final class McpSchema { } } + /** + * A known resource that the server is capable of reading. + * + * @param uri the URI of the resource. + * @param name A human-readable name for this resource. This can be used by clients to + * populate UI elements. + * @param description A description of what this resource represents. This can be used + * by clients to improve the LLM's understanding of available resources. It can be + * thought of like a "hint" to the model. + * @param mimeType The MIME type of this resource, if known. + * @param size The size of the raw resource content, in bytes (i.e., before base64 + * encoding or any tokenization), if known. This can be used by Hosts to display file + * sizes and estimate context window usage. + * @param annotations Optional annotations for the client. The client can use + * annotations to inform how objects are used or displayed. + */ + @JsonInclude(JsonInclude.Include.NON_ABSENT) + @JsonIgnoreProperties(ignoreUnknown = true) + public record ResourceLink( // @formatter:off + @JsonProperty("name") String name, + @JsonProperty("uri") String uri, + @JsonProperty("description") String description, + @JsonProperty("mimeType") String mimeType, + @JsonProperty("size") Long size, + @JsonProperty("annotations") Annotations annotations) implements Annotated, Content, ResourceContent { // @formatter:on + + public static Builder builder() { + return new Builder(); + } + + public static class Builder { + + private String name; + + private String uri; + + private String description; + + private String mimeType; + + private Annotations annotations; + + private Long size; + + public Builder name(String name) { + this.name = name; + return this; + } + + public Builder uri(String uri) { + this.uri = uri; + return this; + } + + public Builder description(String description) { + this.description = description; + return this; + } + + public Builder mimeType(String mimeType) { + this.mimeType = mimeType; + return this; + } + + public Builder annotations(Annotations annotations) { + this.annotations = annotations; + return this; + } + + public Builder size(Long size) { + this.size = size; + 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); + } + + } + } + // --------------------------- // Roots // --------------------------- diff --git a/mcp/src/test/java/io/modelcontextprotocol/spec/McpSchemaTests.java b/mcp/src/test/java/io/modelcontextprotocol/spec/McpSchemaTests.java index 3968e76..5b76ff0 100644 --- a/mcp/src/test/java/io/modelcontextprotocol/spec/McpSchemaTests.java +++ b/mcp/src/test/java/io/modelcontextprotocol/spec/McpSchemaTests.java @@ -3,23 +3,22 @@ */ package io.modelcontextprotocol.spec; -import static net.javacrumbs.jsonunit.assertj.JsonAssertions.assertThatJson; -import static net.javacrumbs.jsonunit.assertj.JsonAssertions.json; -import static org.assertj.core.api.Assertions.assertThat; -import static org.assertj.core.api.Assertions.assertThatThrownBy; - import java.util.Arrays; import java.util.Collections; import java.util.HashMap; import java.util.List; import java.util.Map; +import static org.assertj.core.api.Assertions.assertThat; +import static org.assertj.core.api.Assertions.assertThatThrownBy; import org.junit.jupiter.api.Test; import com.fasterxml.jackson.databind.ObjectMapper; import com.fasterxml.jackson.databind.exc.InvalidTypeIdException; import io.modelcontextprotocol.spec.McpSchema.TextResourceContents; +import static net.javacrumbs.jsonunit.assertj.JsonAssertions.assertThatJson; +import static net.javacrumbs.jsonunit.assertj.JsonAssertions.json; import net.javacrumbs.jsonunit.core.Option; /** @@ -60,7 +59,7 @@ public class McpSchemaTests { {"type":"WRONG","text":"XXX"}""", McpSchema.TextContent.class)) .isInstanceOf(InvalidTypeIdException.class) .hasMessageContaining( - "Could not resolve type id 'WRONG' as a subtype of `io.modelcontextprotocol.spec.McpSchema$TextContent`: known type ids = [audio, image, resource, text]"); + "Could not resolve type id 'WRONG' as a subtype of `io.modelcontextprotocol.spec.McpSchema$TextContent`: known type ids = [audio, image, resource, resource_link, text]"); } @Test @@ -168,6 +167,34 @@ public class McpSchemaTests { .isEqualTo("base64encodedblob"); } + @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); + 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"}""")); + } + + @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"}""", + 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"); + } + // JSON-RPC Message Types Tests @Test