modelcontextprotocol/java-sdk

View on GitHub

The official Java SDK for Model Context Protocol servers and clients. Maintained in collaboration with Spring AI

Stars: 3.7k
Forks: 1.1k
Open beginner issues: 0
Indexed issues: 113
Avg merge: 1d 15h
Merged PRs (30d): 9

Dominant language: Java
License: MIT
Last GitHub push: Sep 18, 2026
Latest indexed: Sep 20, 2026
Contributing guide: Contributing guide
Code of conduct: Code of conduct
Beginner labels: good first issue help wanted

Beginner friendly Everything

Open All

113 issues indexed so far

Add Checkstyle for Automated Code Style Enforcement Open

enhancement waiting for triage

Difficulty 3/5 1-2 days Newbie friendliness 35/100

modelcontextprotocol/java-sdk#399 · 3 comments · Opened Jul 15, 2025
Expose Nullable / Nonnull on public properties / methods Open

enhancement P3

Difficulty 4/5 3-5 days Newbie friendliness 45/100

modelcontextprotocol/java-sdk#395 · Opened Jul 14, 2025
Initialization errors in McpAsyncClient not emitted immediately Open

needs confirmation waiting for user

Difficulty 3/5 1-2 days Newbie friendliness 48/100

modelcontextprotocol/java-sdk#393 · 3 comments · 3 reactions · Opened Jul 13, 2025
StdioServerTransportProvider uses incorrect Mono.zip operator Open

bug good first issue P3 ready for work

Difficulty 2/5 1-3 hours Newbie friendliness 52/100

modelcontextprotocol/java-sdk#303 · 2 comments · Opened Jun 11, 2025
Add X-Accel-Buffering: no Header for SSE Responses Open

area/server enhancement good first issue P2

Difficulty 3/5 1-2 days Newbie friendliness 50/100

modelcontextprotocol/java-sdk#293 · 1 comment · Opened Jun 5, 2025
Would love to be able to provide a log print about the URL request Open

question

Difficulty 3/5 1-2 days Newbie friendliness 35/100

modelcontextprotocol/java-sdk#286 · 2 comments · Opened May 31, 2025
McpServerSession lifecycle doesn't support distributed services Open

area/server enhancement feature/session-storage

Difficulty 5/5 Over a week Newbie friendliness 35/100

modelcontextprotocol/java-sdk#274 · 17 comments · 12 reactions · Opened May 28, 2025
Add group to tools Open

enhancement P3

Difficulty 4/5 3-5 days Newbie friendliness 35/100

modelcontextprotocol/java-sdk#268 · 5 comments · Opened May 27, 2025
io.modelcontextprotocol.util.Utils#resolveUri incorrectly handles nested paths Open

area/client enhancement help wanted P2

Difficulty 3/5 1-2 days Newbie friendliness 48/100

modelcontextprotocol/java-sdk#257 · 3 comments · Opened May 21, 2025
Add error logging when `onErrorResume` in McpServerSession Open

area/server enhancement P3

Difficulty 2/5 1-3 hours Newbie friendliness 45/100

modelcontextprotocol/java-sdk#249 · Opened May 19, 2025
standardize tool metadata by adding annotation classes to sdk Open

enhancement

Difficulty 5/5 Over a week Newbie friendliness 38/100

modelcontextprotocol/java-sdk#224 · 9 comments · 1 reaction · Opened May 7, 2025
Optimization - avoid unnecessary payload copy when deserializing Open

enhancement P2 ready for work

Difficulty 4/5 3-5 days Newbie friendliness 20/100

modelcontextprotocol/java-sdk#156 · 12 comments · Opened Apr 14, 2025
Support cancellation Open

enhancement help wanted P1

Difficulty 4/5 3-5 days Newbie friendliness 38/100

modelcontextprotocol/java-sdk#130 · 8 comments · 3 reactions · Opened Apr 9, 2025

modelcontextprotocol/java-sdk

Get new issues in your inbox