Release v0.44.0

What's Changed

• feat: defer tool loading to enable Anthropic's "Tool Search" pattern by @wolfeidau in #644
• fix: return an error if the responseWriter does not support Flush by @JoelPfaffDD in #652
• Add Icons support for MCP spec 2025-11-25 compliance by @dask-58 in #660
• fix: add ErrUnauthorized sentinel for static token 401 responses by @ezynda3 in #661
• Add lastModified field to Annotations for MCP spec 2025-11-25 by @dask-58 in #663
• Add server-side support for MCP tasks by @JAORMX in #635
• fix: drain all pending notification before writing the response to avoid missing notifications by @archit-harness in #670
• fix for nil resources slice by @furysama in #665
• Add docstrings for annotation-related functions by @ezynda3 in #673
• fix: add timeout for SSE response waiting to prevent indefinite blocking by @everfid-ever in #668
• Try OAuth Authorization Server Metadata first by @staugaard in #669
• fix(oauth): check for OAuth error responses even when status code is 200 by @sd2k in #646
• fix: Add missing session cleanup to the StreamableHTTPServer DELETE handler by @cnnrznn in #667
• Implement Elicitation URL mode for MCP spec 2025-11-25 by @dask-58 in #666
• feat: Add Host header override support for manual DNS resolution by @ComingCL in #674
• fix: low mcp version been selected by mcp server, mcp server may also raise 'unsupported protocol version 2025-11-25' error by @yuehaii in #687
• Add AdditionalProperties to ToolInputSchema by @mohit-gupta-glean in #678
• fix: fix TestSSE_SendRequest_Timeout flaky test by @everfid-ever in #683
• feat:add version 2025-11-25 & unit test for version by @CocaineCong in #684
• fix: use sync.Once for thread-safe Close in StreamableHTTP by @semihbkgr in #685
• docs: fix ListTools usage to include ListToolsRequest parameter by @everfid-ever in #681
• fix: return 404 instead of 400 for invalid session IDs by @burugo in #689
• fix: rename NewToolResultAudio second parameter from imageData to aud… by @mosesyu95 in #691
• Server handlers implementation for auto-completion by @ezraisw in #679
• Fix: the header information set by the client being lost. by @button-chen in #686
• Set test client info by @urisimchoni in #692
• refactor: fix modernize lint issues by @alexandear in #699
• refactor: simplify tests with the usetesting linter by @alexandear in #703
• typo: fix duplicate description of mcp-go in README by @milairhu in #701
• feat(server): implement task-augmented tools capability by @ezynda3 in #707
• tool "properties" and "required" fields missing if set them as null, AdditionalProperties can't be masharl by @yuehaii in #713
• Fix no way to detect connection closure in non-NO_ERROR cases by @manx98 in #709
• fix: accept HTTP 204 No Content in SendNotification by @satish-karri-glean in #717
• fix: use custom session id generator when provided by @FlameHost10 in #715
• fix: SendRequest hangs forever when server process dies by @ichoosetoaccept in #714

New Contributors

• @wolfeidau made their first contribution in #644
• @JoelPfaffDD made their first contribution in #652
• @dask-58 made their first contribution in #660
• @JAORMX made their first contribution in #635
• @archit-harness made their first contribution in #670
• @furysama made their first contribution in #665
• @everfid-ever made their first contribution in #668
• @staugaard made their first contribution in #669
• @cnnrznn made their first contribution in #667
• @ComingCL made their first contribution in #674
• @mohit-gupta-glean made their first contribution in #678
• @semihbkgr made their first contribution in #685
• @burugo made their first contribution in #689
• @mosesyu95 made their first contribution in #691
• @ezraisw made their first contribution in #679
• @urisimchoni made their first contribution in #692
• @alexandear made their first contribution in #699
• @milairhu made their first contribution in #701
• @manx98 made their first contribution in #709
• @satish-karri-glean made their first contribution in #717
• @FlameHost10 made their first contribution in #715
• @ichoosetoaccept made their first contribution in #714

Full Changelog: v0.43.2...v0.44.0

Release v0.44.0-beta.3

v0.44.0-beta.3

Release v0.44.0-beta.2

What's Changed

• Implement Elicitation URL mode for MCP spec 2025-11-25 by @dask-58 in #666
• feat: Add Host header override support for manual DNS resolution by @ComingCL in #674
• fix: low mcp version been selected by mcp server, mcp server may also raise 'unsupported protocol version 2025-11-25' error by @yuehaii in #687
• Add AdditionalProperties to ToolInputSchema by @mohit-gupta-glean in #678
• fix: fix TestSSE_SendRequest_Timeout flaky test by @everfid-ever in #683
• feat:add version 2025-11-25 & unit test for version by @CocaineCong in #684
• fix: use sync.Once for thread-safe Close in StreamableHTTP by @semihbkgr in #685
• docs: fix ListTools usage to include ListToolsRequest parameter by @everfid-ever in #681
• fix: return 404 instead of 400 for invalid session IDs by @burugo in #689
• fix: rename NewToolResultAudio second parameter from imageData to aud… by @mosesyu95 in #691
• Server handlers implementation for auto-completion by @ezraisw in #679
• Fix: the header information set by the client being lost. by @button-chen in #686

New Contributors

• @ComingCL made their first contribution in #674
• @mohit-gupta-glean made their first contribution in #678
• @semihbkgr made their first contribution in #685
• @burugo made their first contribution in #689
• @mosesyu95 made their first contribution in #691
• @ezraisw made their first contribution in #679

Full Changelog: v0.44.0-beta.1...v0.44.0-beta.2

Release v0.44.0-beta.1

What's Changed

• feat: defer tool loading to enable Anthropic's "Tool Search" pattern by @wolfeidau in #644
• fix: return an error if the responseWriter does not support Flush by @JoelPfaffDD in #652
• Add Icons support for MCP spec 2025-11-25 compliance by @dask-58 in #660
• fix: add ErrUnauthorized sentinel for static token 401 responses by @ezynda3 in #661
• Add lastModified field to Annotations for MCP spec 2025-11-25 by @dask-58 in #663
• Add server-side support for MCP tasks by @JAORMX in #635
• fix: drain all pending notification before writing the response to avoid missing notifications by @archit-harness in #670
• fix for nil resources slice by @furysama in #665
• Add docstrings for annotation-related functions by @ezynda3 in #673
• fix: add timeout for SSE response waiting to prevent indefinite blocking by @everfid-ever in #668
• Try OAuth Authorization Server Metadata first by @staugaard in #669
• fix(oauth): check for OAuth error responses even when status code is 200 by @sd2k in #646
• fix: Add missing session cleanup to the StreamableHTTPServer DELETE handler by @cnnrznn in #667

New Contributors

• @wolfeidau made their first contribution in #644
• @JoelPfaffDD made their first contribution in #652
• @dask-58 made their first contribution in #660
• @JAORMX made their first contribution in #635
• @archit-harness made their first contribution in #670
• @furysama made their first contribution in #665
• @everfid-ever made their first contribution in #668
• @staugaard made their first contribution in #669
• @cnnrznn made their first contribution in #667

Full Changelog: v0.43.2...v0.44.0-beta.1

Release v0.43.2

What's Changed

• fix: notification break the client tool call by @yuehaii in #642
• fix: handle either $defs or definitions field when unmarshaling ToolArgumentsSchema by @sd2k in #645

Full Changelog: v0.43.1...v0.43.2

Release v0.43.1

What's Changed

• fix: create StatelessGeneratingSessionIdManager to fix multi-instance deployments by @ezynda3 in #641
• fix: implement SessionWithClientInfo for streamableHttpSession by @Anko59 in #640

New Contributors

• @Anko59 made their first contribution in #640

Full Changelog: v0.43.0...v0.43.1

Release v0.43.0

What's Changed

• feat: add support for custom HTTP headers in client requests by @matthisholleville in #546
• feat: add SessionWithResourceTemplates for session-specific resource templates by @ezynda3 in #624
• feat(mcp): Add SessionIdManagerResolver interface for request-based session management by @aradyaron in #626
• feat(mcp): add HTTP and Stdio client Roots feature by @yuehaii in #620
• feat(mcp): add Title field to Implementation struct per MCP spec by @ezynda3 in #633
• fix(toocall): properly set custom header to ensure correct request handling by @cx215133873 in #632

New Contributors

• @aradyaron made their first contribution in #626
• @yuehaii made their first contribution in #620
• @cx215133873 made their first contribution in #632

Full Changelog: v0.42.0...v0.43.0

Release v0.43.0-beta.3

What's Changed

• feat(mcp): Add SessionIdManagerResolver interface for request-based session management by @aradyaron in #626
• feat(mcp): add HTTP and Stdio client Roots feature by @yuehaii in #620

New Contributors

• @aradyaron made their first contribution in #626
• @yuehaii made their first contribution in #620

Full Changelog: v0.43.0-beta.2...v0.43.0-beta.3

Release v0.43.0-beta.2

What's Changed

• feat: add SessionWithResourceTemplates for session-specific resource templates by @ezynda3 in #624

Full Changelog: v0.43.0-beta.1...v0.43.0-beta.2

Release v0.43.0-beta.1

What's Changed

• feat: add support for custom HTTP headers in client requests by @matthisholleville in #546

Full Changelog: v0.42.0...v0.43.0-beta.1