- 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 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)
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
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>
Adds the ability to configure request timeouts for MCP server operations. This enhancement
allows setting a custom duration to wait for server responses before timing out requests,
which applies to all requests made through the client including tool calls, resource access,
and prompt operations.
- Add requestTimeout parameter to McpServerSession constructor
- Add requestTimeout field and builder method to server classes
- Pass timeout configuration through to session creation
- Add tests for both success and failure scenarios across different transport implementations
- Default timeout is set to 10 seconds if not explicitly configured.
Refactors the MCP logging system to use the exchange mechanism for sending
logging notifications only to specific client sessions rather than broadcasting to all clients.
- Move logging notification delivery from server-wide broadcast to per-session exchange
- Implement per-session minimum logging level tracking and filtering
- Add proper logging level filtering at the exchange level
- Change setLoggingLevel from notification to request/response pattern (breaking change)
- Deprecate global server.loggingNotification in favor of exchange.loggingNotification
- Add SetLevelRequest record to McpSchema
- Add integration test demonstrating filtered logging notifications
Resolves#131
Signed-off-by: Christian Tzolov <christian.tzolov@broadcom.com>
Co-authored-by: Dariusz Jędrzejczyk <dariusz.jedrzejczyk@broadcom.com>
* refactor: change notification params type from Map<String,Object> to Object
This change generalizes the parameter type for notification methods across the MCP framework,
allowing for more flexible parameter passing. Instead of requiring parameters to be structured
as a Map<String,Object>, the API now accepts any Object as parameters.
The primary motivation is to simplify client usage by allowing direct passing of strongly-typed
objects without requiring conversion to a Map first, as demonstrated in the McpAsyncServer
logging notification implementation.
Affected components:
- McpSession interface and implementations
- McpServerTransportProvider interface and implementations
- McpSchema JSONRPCNotification record
---------
Signed-off-by: Christian Tzolov <christian.tzolov@broadcom.com>
- Add builder customizeClient() and customizeRequest() methods
- Enable HTTP client and request configuration through consumer-based customization
- Deprecate direct constructors in favor of the more flexible builder approach
- Add test coverage for customization capabilities
Co-authored-by: Christian Tzolov <christian.tzolov@broadcom.com>
Signed-off-by: Christian Tzolov <christian.tzolov@broadcom.com>
Enhance HttpServletSseServerTransportProvider to support deployment under non-root context paths by:
- Adding baseUrl field and DEFAULT_BASE_URL constant
- Creating new constructor that accepts a baseUrl parameter
- Extending Builder with baseUrl configuration method
- Prepending baseUrl to message endpoint in SSE events
- Add HttpServletSseServerCustomContextPathTests to verify custom context path functionality
- Extract common Tomcat server setup code to TomcatTestUtil for test reuse
Related to #79
Signed-off-by: Christian Tzolov <christian.tzolov@broadcom.com>
Enhances FlowSseClient and HttpClientSseClientTransport to accept a custom HttpRequest.Builder,
allowing for greater flexibility when configuring HTTP requests.
This enables clients to customize headers, timeouts, and other request properties across
all SSE connections and message sending operations.
Signed-off-by: Christian Tzolov <christian.tzolov@broadcom.com>
- Add constructor to CallToolResult with one String entry
- Add a new constructor to CallToolRequest that accepts JSON string arguments
- Implement a builder pattern for CallToolResult with methods for adding content items
- Add test coverage for new functionality
Signed-off-by: Christian Tzolov <christian.tzolov@broadcom.com>
Co-authored-by: Christian Tzolov <christian.tzolov@broadcom.com>
- Add support for customizable SSE endpoints in HttpClientSseClientTransport
- Replace pathInfo with requestURI in HttpServletSseServerTransportProvider for more reliable endpoint matching
- Implement builder pattern to support the customization options
Related to #40
Signed-off-by: Christian Tzolov <christian.tzolov@broadcom.com>
Co-authored-by: Christian Tzolov <christian.tzolov@broadcom.com>
