Mirror of https://github.com/modelcontextprotocol/java-sdk — The official Java SDK for Model Context Protocol servers and clients. Maintained in collaboration with Spring AI
Find a file
Repository files (latest commit first)
Filename Latest commit message Latest commit date
Christian Tzolov c7736b6ec6 fix: Skip structured output validation for error tool results
This ensures that when a tool handler returns an error result, the structured
output schema validation is skipped, preventing validation failures on error
responses that don't conform to the expected output schema.

- Add validation bypass when CallToolResult.isError() is true in async/stateless servers
- Fix async tool handler chaining to properly use then() instead of block()
- Add comprehensive tests for structured output with in-handler errors
- Improve error handling to use proper JSON-RPC error codes for unknown tools
- Add findRootCause utility method for better error diagnostics
- Increase test timeouts for stability in StdioMcp client tests. These tests use npx
  to download and run the MCP "everything" server locally. The first
  test execution will download the everything server scripts and cache them locally,
  which can take more than 15 seconds. Subsequent test runs will use the cached version
  and execute faster.

Resolves #538
Related to #422

Signed-off-by: Christian Tzolov <christian.tzolov@broadcom.com>
2025-09-08 13:48:53 +02:00
.github Add CI GitHub Action and rename snapshot publish workflow 2025-03-18 13:37:49 +01:00
.mvn/wrapper initial 2024-12-06 16:41:17 +01:00
mcp fix: Skip structured output validation for error tool results 2025-09-08 13:48:53 +02:00
mcp-bom Next development version 2025-09-04 22:33:14 +02:00
mcp-spring Next development version 2025-09-04 22:33:14 +02:00
mcp-test fix: Skip structured output validation for error tool results 2025-09-08 13:48:53 +02:00
.gitattributes initial 2024-12-06 16:41:17 +01:00
.gitignore Rename modules, update .gitignore 2024-12-10 18:46:49 -05:00
CODE_OF_CONDUCT.md Add Contributing Guidelines and Code of Conduct 2025-05-16 11:47:39 +02:00
CONTRIBUTING.md Add note about force pushes 2025-05-16 11:47:39 +02:00
LICENSE Update license text and GH actions 2025-01-28 14:36:31 +01:00
migration-0.8.0.md refactor: introduce session-based architecture for MCP server (#31) 2025-03-20 21:49:51 +01:00
mvnw initial 2024-12-06 16:41:17 +01:00
mvnw.cmd initial 2024-12-06 16:41:17 +01:00
pom.xml Next development version 2025-09-04 22:33:14 +02:00
README.md typo fix 2025-06-26 13:45:52 +02:00
SECURITY.md Add Contributing Guidelines and Code of Conduct 2025-05-16 11:47:39 +02:00

MCP Java SDK

Build Status

A set of projects that provide Java SDK integration for the Model Context Protocol. This SDK enables Java applications to interact with AI models and tools through a standardized interface, supporting both synchronous and asynchronous communication patterns.

📚 Reference Documentation

MCP Java SDK documentation

For comprehensive guides and SDK API documentation

Spring AI MCP documentation

Spring AI MCP extends the MCP Java SDK with Spring Boot integration, providing both client and server starters. Bootstrap your AI applications with MCP support using Spring Initializer.

Development

Building from Source

./mvnw clean install -DskipTests

Running Tests

To run the tests you have to pre-install Docker and npx.

./mvnw test

Contributing

Contributions are welcome! Please follow the Contributing Guidelines.

Team

  • Christian Tzolov
  • Dariusz Jędrzejczyk

License

This project is licensed under the MIT License.