Implement client-side sampling features in the Model Context Protocol (MCP) server:
- Add createMessage method to McpAsyncServer and McpSyncServer for LLM sampling
- Move MockMcpTransport to separate file for reusability
- Add integration tests for sampling functionality
- Test error handling for uninitialized clients and missing capabilities
The sampling implementation allows servers to request LLM completions from
clients while maintaining client-side control over model access and permissions.
Resolves#42
- Implement roots change notification handler in McpAsyncServer
- Add rootsChangeConsumer builder methods to support single and multiple consumers
- Rename info() builder method to serverInfo() for clarity
- Add comprehensive tests for roots change notification functionality
- Add default server info implementation in Builder
Resolves#39
Add getter methods to expose server and client capabilities and implementation
info in McpAsyncClient and McpSyncClient. Store server metadata received during
initialization for later access.
Add getter methods to expose server and client capabilities and implementation
information in both McpAsyncServer and McpSyncServer classes. Store client
metadata received during initialization for later retrieval.
- Add client and server-side logging capabilities with configurable severity levels
- Implement logging message notifications with DEBUG to EMERGENCY levels
- Add logging consumers for client-side log handling
- Update documentation with logging examples and configuration
- Add comprehensive tests for logging functionality
- Fix typo in README.md (notificaiotn -> notification)
- Centralize MCP method names as constants
- Move all JSON-RPC method names to McpSchema class as static constants
- Replace hardcoded method strings with constant references in McpAsyncClient
and McpAsyncServer
- Update test cases to use new method name constants
Resolves#35
- Reorganize McpAsyncServer code into logical sections (Lifecycle, Tool, Resource, Prompt Management)
- (bug) Fix resource registration to use URI instead of name as map key
- Improve error logging in StdioServerTransport with helper methods
- Clean up documentation and add transport mode descriptions
- Update sample server configuration with clearer method names and organization
- Replace bounded elastic schedulers with single thread executors
- Add timeouts to MCP server tests
- Enhance error handling in StdioServerTransport
- Comment out unused PaginatedRequest unmarshalling
- Simplify shutdown logic in StdioServerTransport
Removes custom stream injection capability from StdioServerTransport and
simplifies it to only use System.in/out.
Updates related tests to use System streams instead of piped streams.
- Add isClosing flag to coordinate graceful shutdown
- Synchronize output stream writes to prevent race conditions
- Enhance error handling in stream processing
- Add delay for pending message processing during shutdown
- Improve connection state tracking in tests
- Implement MCP server with async/sync support and builder pattern configuration
- Add Server stdio/SSE transport layers with robust error handling
- Convert McpClient and McpServer to interfaces for better extensibility
- Add sampling capabilities for LLM interactions (text/image)
- Implement dynamic root management and runtime tool management
- Add comprehensive prompt and resource capabilities
- Add support for dynamic root management (add/remove roots at runtime)
Architecture Changes
- Introduce registration records for tools, resources, and prompts
- Improve thread safety with concurrent collections
- Enhance resource template handling
- Implement builder patterns for Server/Client capabilities
- Add support for server capabilities and implementation info
Transport Layer:
- Implement SseServerTransport with SSE endpoints
- Add StdioServerTransport for process-based communication
- Reorganize transport packages for better organization
- Improve transport error handling and shutdown processes
Documentation:
- Add detailed MCP reference documentation
- Include architecture diagrams and API documentation
- Add comprehensive test coverage for all components
- Include sample projects demonstrating stdio/SSE transports
BREAKING CHANGES:
Transport Package Reorganization
- Move StdioClientTransport to o.s.ai.mcp.client.transport
- Move SseClientTransport to o.s.ai.mcp.client.transport
- Move ServerParameters to o.s.ai.mcp.client.transport
- StdioClientTransport.errorHandler changed to private with
setter method Migration: Use setErrorHandler() method
instead of direct field access
API Changes
- Replace static factory methods with builder pattern
- Update ServerCapabilities to use builder pattern
- Make StdioClientTransport.errorHandler private with setter
- Replace rootsListProvider with direct root management
- Remove deprecated static factory methods
Resolves #27,#25,#24,#11
Related to #12
- Adds default logging for tools, resources and prompts change notifications.
- Introduces Utils class with collection and string helper methods.
- Ensures notification handlers are always registered with at least a default logging consumer.
- Add resourcesChangeNotificationHandler and promptsChangeNotificationHandler with non-blocking execution
- Add builder methods for resources and prompts change consumers
- Add test coverage for all notification handlers
- Update documentation to cover all three notification types (tools, resources, prompts)
- Consolidate notification documentation under unified Change Notifications section
- Ensure consistent non-blocking behavior using boundedElastic scheduler
All notification handlers follow the same pattern of non-blocking execution and error handling,
providing a consistent approach to change notifications across the system.
Resolves#20
- Add toolsChangeNotificationHandler with non-blocking consumer execution using boundedElastic scheduler
- Add toolsChangeConsumer builder method to McpClient for easy configuration
- Add comprehensive test coverage for tools change notifications
- Update documentation with tools change notification features and examples
The implementation ensures consumers are executed non-blockingly on the boundedElastic scheduler,
preventing performance impact from blocking implementations while maintaining proper error handling and logging.
Part of #20
- Add roots list capability to allow servers to understand filesystem boundaries
- Move architecture diagram and add detailed documentation for transports and sessions
- Enhance client capabilities with roots and sampling features
- Rename withRequestTimeout to requestTimeout for better API consistency
- Add tests for roots list functionality
Resolves#8
- The core module has been refactored to remove unnecessary abstraction
between the SSE transport and the STDIO transport.
- Tests have been improved and no longer complain about multiple
subscriptions to single-subscriber Sink.
- SSE transport layer is now assuming non-blocking execution and no longer
makes thread hops when not needed.
- Decouple ObjectMapper and error handling from AbstractMcpTransport
and remove later.
Additional improvements:
- Rename transport classes to better reflect client-side role (*ServerTransport -> *ClientTransport)
- Introduce fluent builder pattern for client configuration
- Simplify DefaultMcpSession by removing ObjectMapper dependency
- Move unmarshal responsibility to transport layer
- Update documentation and diagrams to reflect new architecture
- Clean up test implementations
- Add comprehensive documentation for MCP session components in MCP-SESSION.md
- Add logging and error handling in McpAsyncClient
- Update test configurations and dependencies
- Add reactor-netty-http and spring-context test dependencies
Resolves#6
- Add Server-Sent Events (SSE) transport implementation with test coverage
- Add detailed documentation for both SSE and STDIO transports
- Extract common test logic into abstract base classes
- Add testcontainers support for SSE integration tests
- Replace System.out with SLF4J logging
- Externalize dependency versions to properties
- Implement endpoint event handling per MCP spec
- Add message endpoint sink for reliable message routing
- Improve error handling and graceful shutdown
- Update core module README with expanded features and examples
- Add dependency version properties and logging configuration
- Update architecture and class diagrams
Resolves#4
Add overloaded methods for list operations (tools, resources, templates, prompts)
that don't require a cursor parameter, simplifying the API for basic use cases
where pagination is not needed.
- Doubles the default timeout from 10s to 20s in McpAsyncClient
- Updates corresponding timeout values in test classes
- Enables previously disabled async client tests
