- Add WebMvcStatelessServerTransport for mcp-spring-webmvc module
- Add HttpServletStatelessServerTransport for mcp module
- Implement builder patterns for AsyncToolSpecification and SyncToolSpecification
- Create AbstractStatelessIntegrationTests base class for shared test functionality
- Add integration tests for both transport implementations
Signed-off-by: Christian Tzolov <christian.tzolov@broadcom.com>
- Add protocolVersion() method to transport and transport provider interfaces and implementations
- Replace hardcoded HTTP header strings with HttpHeaders constants
- Update protocol versions to be transport-specific rather than global
- Deprecate McpSchema.LATEST_PROTOCOL_VERSION in favor of transport-specific versions
- Standardize header names: MCP-Protocol-Version, mcp-session-id, last-event-id
- Update clients and servers to use transport.protocolVersion() for initialization
- Refactor tests to use transport-specific protocol versions
- Include MCP-Protocol-Version header in all GET/POST/DELETE requests
- Update WebClientStreamableHttpTransport, WebFluxSseClientTransport,
HttpClientSseClientTransport, and HttpClientStreamableHttpTransport
Related to #398 , #363 , #250
Signed-off-by: Christian Tzolov <christian.tzolov@broadcom.com>
- Add KeepAliveScheduler utility class for configurable periodic session pings
- Integrate keep-alive support in WebFlux, WebMVC, and HttpServlet SSE transport providers
- Add keepAliveInterval configuration option to all transport provider builders
- Deprecate existing constructors in favor of builder pattern with enhanced configuration
- Update graceful shutdown to properly clean up keep-alive schedulers
- Add unit tests for KeepAliveScheduler functionality
Implements MCP specification recommendations for connection health detection:
- Configurable ping frequency to suit different network environments
- Optional keep-alive (disabled by default) to avoid excessive network overhead
- Proper resource cleanup to prevent connection leaks
https://modelcontextprotocol.io/specification/2025-06-18/basic/utilities/ping#implementation-considerationsResolves: #414, #158
Replaces #353
Signed-off-by: Christian Tzolov <christian.tzolov@broadcom.com>
Implementation of the Streamable HTTP transport provider for the Servlet API.
---
Signed-off-by: Christian Tzolov <christian.tzolov@broadcom.com>
Co-authored-by: Christian Tzolov <christian.tzolov@broadcom.com>
Co-authored-by: Zachary German <zdgerman@amazon.com>
- Add WebMvcStreamableServerTransportProvider with SSE support for streamable sessions
- Support GET, POST, DELETE endpoints for MCP protocol operations
- Implement thread-safe SSE operations using ReentrantLock in WebMvcSseServerTransportProvider
- Add test infrastructure with AbstractMcpClientServerIntegrationTests
- Refactor WebMvcStreamableIntegrationTests to use parameterized tests
- Support testing with both HttpClient and WebFlux transports
- Add streamable transport tests for both async and sync server modes
- Refactor existing WebMVC SSE integration tests to use shared test base
- Add error handling improvements in McpStreamableServerSession
- Update dependencies: add json-unit-assertj for enhanced JSON testing
- Reorganize POM dependencies and add mcp-spring-webflux test dependency
- Wrap handler invocations with Mono.defer for lazy evaluation
- Wrap consumer, tool, resource, prompt, and completion handler calls with Mono.defer()
- Ensures proper lazy evaluation and error handling in reactive streams
Related to #72
Signed-off-by: Christian Tzolov <christian.tzolov@broadcom.com>
Signed-off-by: Dariusz Jędrzejczyk <dariusz.jedrzejczyk@broadcom.com>
Co-authored-by: Dariusz Jędrzejczyk <dariusz.jedrzejczyk@broadcom.com>
- Add WebFluxStreamableServerTransportProvider for streamable HTTP sessions
- Add WebFluxStatelessServerTransport for stateless HTTP MCP servers
- Add McpStatelessServerFeatures, McpStatelessServerHandler, McpStatelessRequestHandler, McpStatelessNotificationHandler
- Refactor server architecture to support multiple transport categories:
streamable, single-session, stateless
- Introduce McpTransportContext for transport-level metadata extraction
- Add session management capabilities for streamable HTTP connections
- Update MCP protocol version to 2025-03-26
- Add test coverage for new transport implementations
- Implement integration tests for both stateless and streamable transports
Signed-off-by: Dariusz Jędrzejczyk <dariusz.jedrzejczyk@broadcom.com>
Signed-off-by: Christian Tzolov <christian.tzolov@broadcom.com>
Co-authored-by: Christian Tzolov <christian.tzolov@broadcom.com>
Addresses issues with servers like Shopify that violate MCP/HTTP specs:
- Prioritize application/json in Accept headers to fix content-type issues
- Handle non-compliant notification non-empty responses
- Add status code validation and null safety improvements
Resolves#406
Signed-off-by: Christian Tzolov <christian.tzolov@broadcom.com>
- Add JsonSchemaValidator interface and DefaultJsonSchemaValidator implementation
- put the JsonSchemaValidator classes into a dedicated spec package
- add schema caching to DefaultJsonSchemaValidator for better performance
- Extend Tool schema to support outputSchema field for defining expected output structure
- Add structuredContent field to CallToolResult for validated structured responses
- Implement automatic validation of tool outputs against their defined schemas
- Add comprehensive test coverage for structured output validation scenarios
- Add json-schema-validator and json-unit-assertj dependencies for validation and testing
- Update McpServer builders to accept custom JsonSchemaValidator instances
- Ensure backward compatibility with existing tools without output schemas
This implements the MCP specification requirement that tools with output schemas
must provide structured results conforming to those schemas, with automatic
validation and error handling for non-conforming outputs.
https://modelcontextprotocol.io/specification/2025-06-18/server/tools#structured-content
Signed-off-by: Christian Tzolov <christian.tzolov@broadcom.com>
Tool handlers now receive CallToolRequest instead of raw arguments to
enable access to additional metadata parameters like progressToken
- Deprecate handlers that take only Map<String, Object> arguments
- Introduce new handlers that receive the full CallToolRequest object
- Maintain backward compatibility with deprecated call handlers
- Enhance API to provide access to complete tool request context beyond just arguments
- Add builder pattern for AsyncToolSpecification and SyncToolSpecification
- Add duplicate tool name validation during server building and runtime registration
- Update all test files to use new callTool handlers and builder pattern
- Add test coverage for new builder functionality and CallToolRequest handling
Signed-off-by: Christian Tzolov <christian.tzolov@broadcom.com>
Currently, JDK HttpClient SSE implementation incorrectly handles a
non-2xx HTTP response code for POST. Instead of immediately failing the
caller, it ignores the issue and the user awaits until the timeout kicks
in.
Set HttpClient to use HTTP/1.1 version explicitly for tests
A related problem happened with the WebClient Streamable HTTP
implementation, where the error was swallowed for non-400 responses.
Signed-off-by: Dariusz Jędrzejczyk <dariusz.jedrzejczyk@broadcom.com>
- Add BaseMetadata interface with name() and title() methods for consistent metadata handling
- The Prompt, PromptArgument, Resource, ResourceTemplate, ResuorceLink, PromptReference, Tool,
and Implementation classes implement the BaseMetadata interface, adding a new, optional title field
- Update constructors to support backward compatibility while allowing title specification
- Modify ResourceContent interface to extend BaseMetadata
- Update all test cases to accommodate new title parameter
The title field provides human-readable display names optimized for UI contexts,
while name remains for programmatic/logical use. This change maintains backward compatibility.
Signed-off-by: Christian Tzolov <christian.tzolov@broadcom.com>
Co-authored-by: Christian Tzolov <christian.tzolov@broadcom.com>
- 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 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>
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>
- 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>
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>
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>
- Replace StepVerifier with assertWith for cleaner test assertions
- Add try-with-resources blocks for proper client resource management
- Use closeGracefully().block() for proper server shutdown
Signed-off-by: Dariusz Jędrzejczyk <dariusz.jedrzejczyk@broadcom.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.
- Add TestUtil class with findAvailablePort() method to the mcp-test module
- Add findAvailablePort() method to TomcatTestUtil classes
- Replace hardcoded port numbers with dynamic port allocation
Signed-off-by: Christian Tzolov <christian.tzolov@broadcom.com>
Replace index-based assertions with content-based lookups using a notification map.
This change makes the tests more resilient by removing the dependency on
notification order, which is important for asynchronous messaging tests.
Signed-off-by: Christian Tzolov <christian.tzolov@broadcom.com>
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>
Add error handling to return a 404 NOT_FOUND response when a request
is made with a non-existent session ID. This prevents potential
NullPointerExceptions when processing requests with invalid session IDs.
Signed-off-by: Christian Tzolov <christian.tzolov@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>
