- The McpSyncServer wraps an async server. By default, reactive
operations are scheduled on a bounded-elastic scheduler, to offload
blocking work and prevent accidental blocking of non-blocking
operations.
- With the default behavior, there will be thead ops, even in a blocking
context, which means thread-locals from the request thread will be
lost. This is inconenvient for frameworks that store state in
thread-locals.
- This commit adds the ability to avoid offloading, when the user is
sure they are executing code in a blocking environment. Work happens
in the calling thread, and thread-locals are available throughout the
execution.
- Add HttpClientStreamableHttpTransport implementing the 2025-03-26 MCP specification
- Add ResponseSubscribers utility for handling different HTTP response body types
- Refactor HttpClientSseClientTransport to use reactive streams instead of FlowSseClient
- Remove FlowSseClient in favor of reactive stream patterns
- Use Disposable-based connection management instead of CountDownLatch
- Replace message endpoint discovery with Sinks.One approach
- Improve error handling by replacing doOnError/onErrorResume with onErrorComplete
- Add test coverage for new Streamable HTTP transport
- Add resiliency tests for connection handling and session invalidation
BREAKING CHANGE: FlowSseClient has been removed in favor of reactive streams
Signed-off-by: Christian Tzolov <christian.tzolov@broadcom.com>
Co-authored-by: Dariusz Jędrzejczyk <dariusz.jedrzejczyk@broadcom.com>
- Add PaginatedRequest and ReadResourceRequest to Request sealed interface
- Add default meta() and progressToken() methods to Request interface
- Add _meta parameter support to request classes:
- ReadResourceRequest, GetPromptRequest, CallToolRequest
- CreateMessageRequest, ElicitRequest, CompleteRequest, PaginatedRequest
- Add builder methods for progress token configuration
- Add message field to ProgressNotification
- Maintain backward compatibility with existing constructors
- Add _meta field to the InitialRequest record
Signed-off-by: Christian Tzolov <christian.tzolov@broadcom.com>
- Add ping() method to McpAsyncServerExchange that sends ping requests to clients
- Add ping() method to McpSyncServerExchange as synchronous wrapper
- Add OBJECT_TYPE_REF constant for ping response type handling
- Create McpSyncServerExchangeTests.java with full test coverage
- Add ping integration tests across WebFlux, WebMVC, and HttpServlet transports
Follow up of #203
Signed-off-by: Christian Tzolov <christian.tzolov@broadcom.com>
- Wrap the list responses in immutable lists.
- Add test to verify the immutable responses.
- Better timeout handling
Signed-off-by: Christian Tzolov <christian.tzolov@broadcom.com>
- 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 <christian.tzolov@broadcom.com>
- Add ping request handler that responds with empty Map instead of null
- Ensure compliance with MCP protocol requirement for ping responses
- Add test for ping message request handling
Signed-off-by: Christian Tzolov <christian.tzolov@broadcom.com>
- Add nextCursor field to ListRootsResult for cursor-based pagination
- Implement automatic pagination in McpAsyncServerExchange.listRoots()
- Automatically fetches and combines all pages into single result
- Refactor McpAsyncServerExchange.listRoots() to return Collections.unmodifiableList
- Update tests to verify pagination functionality
- Add test suite for McpAsyncServerExchange covering:
- listRoots() pagination scenarios and edge cases
- Logging notification with level filtering
- Elicitation creation with various capabilities
- Message creation with sampling capabilities
- Error handling and validation scenarios
- Verify sendNotification calls in logging notification tests
- Verify sendRequest is never called when capabilities are missing
Signed-off-by: Christian Tzolov <christian.tzolov@broadcom.com>
* feat: Propagate Context to eager connect via McpClientSession
In order to allow the initial connection to have contextual information
in the reactive chain, the McpClientSession should be able to transform
the McpClientTransport#connect result, e.g. to attach Context items.
This change introduces a new constructor for sessions that makes it
possible.
Signed-off-by: Dariusz Jędrzejczyk <dariusz.jedrzejczyk@broadcom.com>
---------
Signed-off-by: Dariusz Jędrzejczyk <dariusz.jedrzejczyk@broadcom.com>
This enables servers to notify clients when specific resources are updated,
allowing clients to react to individual resource changes rather than just
list changes.
- Add ResourcesUpdatedNotification schema with uri field
- Add METHOD_NOTIFICATION_RESOURCES_UPDATED constant
- Implement notifyResourcesUpdated() methods in McpAsyncServer and McpSyncServer
- Add client-side support for resource update consumers and handlers
- Client automatically reads updated resource content when notification received
- Add tests for both async and sync server implementations
Signed-off-by: Christian Tzolov <christian.tzolov@broadcom.com>
This change enhances the client API by providing both paginated access for fine-grained
control and convenience methods for retrieving complete result sets automatically.
- Implement "list all" methods that automatically handle pagination using expand/reduce operations
- Replace null parameters with McpSchema.FIRST_PAGE constant for better readability
- Add tests for both paginated and "list all" functionality
- Update method javadocs to clarify pagination behavior
- Maintain backward compatibility
Signed-off-by: Christian Tzolov <christian.tzolov@broadcom.com>
The size field helps hosts display file sizes and estimate context window usage.
- Add size parameter to Resource record for tracking raw content size in bytes
- Implement Builder pattern for Resource construction with validation
- Add deprecated constructor for backwards compatibility
- Add tests for builder pattern and field validation
Resolves#330
Signed-off-by: Christian Tzolov <christian.tzolov@broadcom.com>
Updates all Content types to represent annotations as nested objects
instead of directly on the content itself.
- Refactor TextContent, ImageContent, and EmbeddedResource to use Annotations object instead of separate audience/priority fields
- Add backward-compatible deprecated methods for audience() and priority() accessors
- Add parameterized tests for message annotations across different message types (success, error, debug)
- Test both text and image content annotations with proper priority and audience validation
This brings the implementation in line with the content types as modeled by the specification:
c87a0da6d8/schema/2025-03-26/schema.json (L1970-L1973)
- Add explicit Void type parameter to Mono.defer() call
- Chain .then() to Mono.delay() to ensure consistent Mono<Void> return type
Signed-off-by: Christian Tzolov <christian.tzolov@broadcom.com>
- Add testSampling() methods to AbstractMcpAsyncClientTests and AbstractMcpSyncClientTests
Signed-off-by: Christian Tzolov <christian.tzolov@broadcom.com>
Co-authored-by: Christian Tzolov <christian.tzolov@broadcom.com>
- Add AudioContent record class implementing Annotated and Content interfaces
- Update Content sealed interface to permit AudioContent
- Add audio type handling in Content.type() method
- Include AudioContent in JsonSubTypes annotation for polymorphic deserialization
- Add comprehensive tests for AudioContent serialization and deserialization
- Update error message test to include audio in known type ids
c87a0da6d8/schema/2025-03-26/schema.ts (L987-L1009)
- Replace single documentation link with organized list of sections
- Add direct links to Features, Architecture, Dependencies, Client, and Server docs
- Improve navigation and discoverability of specific documentation topics
Signed-off-by: Christian Tzolov <christian.tzolov@broadcom.com>
An implementation of Streamable HTTP Client with WebFlux WebClient.
Aside from implementing the specification, several improvements have been incorporated throughout the client-side of the architecture.
The changes cover:
- resilience tests using toxiproxy in testcontainers
- integration tests using updated everything-server with streamableHttp support
- improved logging
- session invalidation handling (both transport session and JSON-RPC concept of session)
- implicit initialization and burst protection (in case of concurrent `Mcp(Sync|Async)Client` use
- more logging, e.g. stdio process lifecycle logs
Related #72, #273, #253, #107, #105
Signed-off-by: Dariusz Jędrzejczyk <dariusz.jedrzejczyk@broadcom.com>
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
Before this fix the execution of the maven surefire
plugin with Java 21 logged warnings that mockito should be added as
a java agent, because the self-attaching won't be supported in future
java releases.
In Java 24 the test just broke.
This problem is solved by modifying the pom.xml of the parent and doing
this changes:
* Adding mockito as a java agent.
* Removing the surefireArgLine from the properties. This can be
added back when it's needed (for example when JaCoCo will be used).
Furthermore, the pom.xml in the mcp-spring-* modules now have
the byte-buddy dependency included, as the test would otherwise break
when trying to mock McpSchema#CreateMessageRequest.
Fixes#187
Co-authored-by: Dariusz Jędrzejczyk <dariusz.jedrzejczyk@broadcom.com>
Implement URI template functionality for MCP resources, allowing dynamic
resource URIs with variables in the format {variableName}.
- Enable resource URIs with variable placeholders (e.g., "/api/users/{userId}")
- Automatic extraction of variable values from request URIs
- Validation of template arguments in completions
- Matching of request URIs against templates
- Add new URI template management interfaces and implementations
- Enhanced resource template listing to include templated resources
- Updated resource request handling to support template matching
- Test coverage for URI template functionality
- Adding a configurable uriTemplateManagerFactory field to both AsyncSpecification and SyncSpecification classes
- Adding builder methods to allow setting a custom URI template manager factory
- Modifying constructors to pass the URI template manager factory to the server implementation
- Updating the server implementation to use the provided factory
- Add bulk registration methods for async completions
Signed-off-by: Christian Tzolov <christian.tzolov@broadcom.com>
Added support for $defs and definitions properties in JsonSchema record to handle JSON Schema references properly. Added tests to verify both formats work correctly.
The JsonSchema test approach uses serialization/deserialization round-trip validation instead of property-by-property assertions. This makes tests more maintainable and less likely to break when new properties are added.
🤖 Generated with [Claude Code](https://claude.ai/code)
---------
Co-authored-by: Claude <noreply@anthropic.com>
/**
* The server's response to a completion/complete request
*/
export
interface CompleteResult extends Result {
completion: {
/**
*
An array of completion values. Must not exceed 100 items.
*/
values: string[];
/**
* The total number of completion options
available. This can exceed the number of values actually sent in the
response.
*/
total?: number;
/**
* Indicates whether
there are additional completion options beyond those provided in the
current response, even if the exact total is unknown.
*/
hasMore?: boolean;
};
}
Improve endpoint URI handling by supporting both relative paths
and properly validated absolute URIs.
- Implement URI resolution in HttpClientSseClientTransport:
- Change baseUri field from String to URI type
- Add Utils.resolveUri method to handle both absolute and relative URIs
- Resolve relative URIs against the base URI
- Validate absolute URIs to ensure they match base URI's scheme, authority, and path
- Add parameterized tests for various URI resolution scenarios
- Add ByteBuddy dependency for HttpClient mocking and update Mockito
Signed-off-by: Christian Tzolov <christian.tzolov@broadcom.com>
Add completion API support to the MCP protocol implementation:
- Add CompleteRequest and CompleteResult schema classes
- Implement completion capabilities in ServerCapabilities
- Add completion handlers in McpAsyncServer and McpServer
- Add completion client methods in McpAsyncClient and McpSyncClient
- Add CompletionRefKey and completion specifications in McpServerFeatures
- Add integration test for completion functionality
- Fix isPresent() check to use isEmpty() in WebMvcSseServerTransportProvider
- Replace McpServerFeatures.CompletionRefKey by McpSchemaCompleteReference
Co-authored-by: Christian Tzolov <christian.tzolov@broadcom.com>
Signed-off-by: jitokim <pigberger70@gmail.com>
