All notable changes to the MCP Java SDK are documented in the GitHub Releases, which serve as the canonical, detailed changelog for every version. This file summarizes the release history and the currently maintained release lines.
Versioning follows Semantic Versioning; see VERSIONING.md for the breaking-change policy and SECURITY.md for the supported-versions security policy.
| Line | Latest | Spec revision | Status |
|---|---|---|---|
| 2.0.x | 2.0.1 (2026-08-19) | 2025-11-25 | Active development |
| 1.1.x | 1.1.4 (2026-08-19) | 2025-06-18 | Security patches only |
| 0.18.x | 0.18.4 (2026-08-19) | 2025-06-18 | Security patches only |
- Bound STDIO and HTTP client/server reads to a configurable maximum size
Full notes: v2.0.1 release
First major release since 1.x, tracking the 2025-11-25 MCP specification. Upgrading from 1.x? See the v2 migration guide.
- New JSON compatibility foundation for forward/backward wire compatibility, with pluggable Jackson 2 / Jackson 3 serialization modules
- Spec-accurate schema: enforced required fields, lenient wire deserialization
- End-to-end validation of tool inputs and embedded JSON Schema documents (JSON Schema 2020-12, SEP-1613)
- Richer elicitation: client-side schema defaults (SEP-1034), URL elicitation (SEP-1036), form-based elicitation schemas
- Icons and metadata support (SEP-973)
- Streamable HTTP first: SSE transports deprecated in favor of Streamable HTTP
- Module restructuring:
mcp-core,mcp-json-jackson2,mcp-json-jackson3,mcp-bom
Full notes: v2.0.0 release (preceded by milestones M1, M2, M3, RC1).