Notable Changes

• Agentic: Introduce a generic agentic planner and reimplement all agentic patterns through it by @mariofusco in https://github.com/langchain4j/langchain4j/pull/3929
• MCP: WebSocket transport support by @jmartisk in https://github.com/langchain4j/langchain4j/pull/4032
• Gemini: Batch API by @Bram-- in https://github.com/langchain4j/langchain4j/pull/3942
• Anthropic: support through Vertex AI #3193 by @pbykovcoginiti in https://github.com/langchain4j/langchain4j/pull/3362

Other Changes

• docu: update versions to 1.8.0 and 1.8.0-beta15 by @dliubarskyi in https://github.com/langchain4j/langchain4j/pull/3950
• Update versions to 1.9.0-SNAPSHOT and 1.9.0-beta16-SNAPSHOT by @dliubarskyi in https://github.com/langchain4j/langchain4j/pull/3951
• Fix a typo in the OutputGuardrails annotation by @edeandrea in https://github.com/langchain4j/langchain4j/pull/3948
• Remove unnecessary MCP registry client creation during test by @jmartisk in https://github.com/langchain4j/langchain4j/pull/3963
• docs: add Agentic AI to intro by @vesense in https://github.com/langchain4j/langchain4j/pull/3966
• Fix typos in annotation and documentation by @justinchoi929 in https://github.com/langchain4j/langchain4j/pull/3997
• Generate consistent and reproducible unique names for agents by @mariofusco in https://github.com/langchain4j/langchain4j/pull/3965
• Reflect recent MCP registry updates by @jmartisk in https://github.com/langchain4j/langchain4j/pull/4016
• vertex-ai-gemini: Expose vertex apiEndpoint in builder by @eiselems in https://github.com/langchain4j/langchain4j/pull/4021
• Fix wrong method name in AgentBuilder by @mariofusco in https://github.com/langchain4j/langchain4j/pull/4033
• Update Quarkus documentation link for Easy RAG by @wadajo in https://github.com/langchain4j/langchain4j/pull/4034
• Update playwright version to 1.56.0 by @vesense in https://github.com/langchain4j/langchain4j/pull/4025
• Doc: Added SQLServer 2025 embedding store integration by @odelpozo-denodo in https://github.com/langchain4j/langchain4j/pull/3992
• Add WatsonxModerationModel and refactor LangChain4j integration by @andreadimaio in https://github.com/langchain4j/langchain4j/pull/3982
• MCP: Supply custom headers via a supplier method by @maff in https://github.com/langchain4j/langchain4j/pull/4036
• Flatten request response objects by @Bram-- in https://github.com/langchain4j/langchain4j/pull/3955
• Initializing the guardrails module by @agoncal in https://github.com/langchain4j/langchain4j/pull/3928
• Fix OpenAi token usage class cast exception by @linnaung in https://github.com/langchain4j/langchain4j/pull/3912
• Refactor ToolExecutionResult to support lazy evaluation of result tex… by @hemanthsavasere in https://github.com/langchain4j/langchain4j/pull/3960
• Fixes https://github.com/langchain4j/langchain4j/issues/3968 by @dliubarskyi in https://github.com/langchain4j/langchain4j/pull/4026
• test: add edge case and error handling tests for ParsingUtil by @alxkm in https://github.com/langchain4j/langchain4j/pull/3959
• chore(deps): update dependency org.codehaus.mojo:flatten-maven-plugin to v1.7.2 by @renovate[bot] in https://github.com/langchain4j/langchain4j/pull/3433
• CompressingQueryTransformer NullPointException by @zxyyang in https://github.com/langchain4j/langchain4j/pull/1120
• Ignoring Claude Code CLI markdown file CLAUDE.md by @agoncal in https://github.com/langchain4j/langchain4j/pull/4041
• Updates to Latest Infinispan and Jackson Versions by @karesti in https://github.com/langchain4j/langchain4j/pull/4038
• Enable case-insensitive enum deserialization in structured output parsing by @mariofusco in https://github.com/langchain4j/langchain4j/pull/4049
• Propagate root exception when json parsing fails by @mariofusco in https://github.com/langchain4j/langchain4j/pull/4046
• feat: Enable reasoning effort control for GPT-5 (o1 series) by @caio-carne1ro in https://github.com/langchain4j/langchain4j/pull/4052
• Add GPT_5_1 to open ai enum. by @Bram-- in https://github.com/langchain4j/langchain4j/pull/4054
• GitHub Models: support structured output by @hrhrng in https://github.com/langchain4j/langchain4j/pull/1917
• Allow different types of object in the argument of the agent invocation generated by the supervisor by @mariofusco in https://github.com/langchain4j/langchain4j/pull/4053
• Update qdrant client by @boris-petrov in https://github.com/langchain4j/langchain4j/pull/4077
• Refactor value classes to (nested) records in google-ai-gemini by @Bram-- in https://github.com/langchain4j/langchain4j/pull/4070
• programmatic tools return behavior by @Yoann-philippe in https://github.com/langchain4j/langchain4j/pull/4064
• feat(memory): implement dynamic window sizing for chat memory by @PaperFly-web in https://github.com/langchain4j/langchain4j/pull/4058
• Make the supervisor aware of the argument types of its subagents by @mariofusco in https://github.com/langchain4j/langchain4j/pull/4079
• feat: add video content type support to OpenAI integration by @ldaugusto in https://github.com/langchain4j/langchain4j/pull/4078
• Get rid of @Subagent annotation in declarative agentic API by @mariofusco in https://github.com/langchain4j/langchain4j/pull/4081
• #4067 Add BedrockTokenUsage with cache token usage by @blaZ3 in https://github.com/langchain4j/langchain4j/pull/4080
• Implement tool hallucination handling for streaming by @vesense in https://github.com/langchain4j/langchain4j/pull/3773
• Gemini batch chat model delete and cancel by @Bram-- in https://github.com/langchain4j/langchain4j/pull/3945
• Bump A2A SDK to version 0.3.2.Final by @mariofusco in https://github.com/langchain4j/langchain4j/pull/4090
• Add Gemini among possible model providers in agentic tests by @mariofusco in https://github.com/langchain4j/langchain4j/pull/4091
• add: implementation of removeAll(Filter) for WeaviateEmbeddingStore by @AminAK11 in https://github.com/langchain4j/langchain4j/pull/3555
• fix badge style by @vesense in https://github.com/langchain4j/langchain4j/pull/4094
• Receive and expose MCP tool metadata by @jmartisk in https://github.com/langchain4j/langchain4j/pull/4089
• Update gemini docs by @Bram-- in https://github.com/langchain4j/langchain4j/pull/4082
• Expose agentic system as tree and check key types consistency by @mariofusco in https://github.com/langchain4j/langchain4j/pull/4100
• Fix test for GOAP planner by @mariofusco in https://github.com/langchain4j/langchain4j/pull/4103
• Improve class description of ChatMessageType by @lihuagang03 in https://github.com/langchain4j/langchain4j/pull/4112
• Collect guardrail validation duration and attach it to the guardrail events by @cescoffier in https://github.com/langchain4j/langchain4j/pull/4119
• Update watsonx-ai dependency to 0.14.0 and add new parameters by @andreadimaio in https://github.com/langchain4j/langchain4j/pull/4114
• docs: Add back YugabyteDB examples to documentation by @krishna-yb in https://github.com/langchain4j/langchain4j/pull/4120
• Apply the ChatRequest transformation to all LLM calls in the same tools invocation loop by @mariofusco in https://github.com/langchain4j/langchain4j/pull/4104
• MongoDB: Update to the latest version and append framework name to MongoDB metadata by @strogiyotec in https://github.com/langchain4j/langchain4j/pull/4106
• Update the OpenAI Java SDK to 4.8.0 and fix the Azure authentication code by @jdubois in https://github.com/langchain4j/langchain4j/pull/4092
• Implement all of the Gemini Files APIs by @Bram-- in https://github.com/langchain4j/langchain4j/pull/4068
• Issue 4116 fix npe gemini base64 images by @idoberko2 in https://github.com/langchain4j/langchain4j/pull/4129
• feat: add default modelName() to EmbeddingModel and implement overrides by @raphidlee in https://github.com/langchain4j/langchain4j/pull/4133
• Parse structured results in A2A client by @mariofusco in https://github.com/langchain4j/langchain4j/pull/4127
• Gemini (async) batch embed api by @Bram-- in https://github.com/langchain4j/langchain4j/pull/4086
• feat: support Gemini 3 Pro thinking level configuration by @glaforge in https://github.com/langchain4j/langchain4j/pull/4137
• Fixes issue from #3664 and adds handling of content filtered responses by @jonathannaguin in https://github.com/langchain4j/langchain4j/pull/3978
• Add create batch from [Gemini]File methods for GoogleAiGeminiBatch{Chat,Embed}Model by @Bram-- in https://github.com/langchain4j/langchain4j/pull/4128

New Contributors

• @justinchoi929 made their first contribution in https://github.com/langchain4j/langchain4j/pull/3997
• @eiselems made their first contribution in https://github.com/langchain4j/langchain4j/pull/4021
• @wadajo made their first contribution in https://github.com/langchain4j/langchain4j/pull/4034
• @odelpozo-denodo made their first contribution in https://github.com/langchain4j/langchain4j/pull/3992
• @hemanthsavasere made their first contribution in https://github.com/langchain4j/langchain4j/pull/3960
• @zxyyang made their first contribution in https://github.com/langchain4j/langchain4j/pull/1120
• @caio-carne1ro made their first contribution in https://github.com/langchain4j/langchain4j/pull/4052
• @Yoann-philippe made their first contribution in https://github.com/langchain4j/langchain4j/pull/4064
• @PaperFly-web made their first contribution in https://github.com/langchain4j/langchain4j/pull/4058
• @ldaugusto made their first contribution in https://github.com/langchain4j/langchain4j/pull/4078
• @blaZ3 made their first contribution in https://github.com/langchain4j/langchain4j/pull/4080
• @AminAK11 made their first contribution in https://github.com/langchain4j/langchain4j/pull/3555
• @lihuagang03 made their first contribution in https://github.com/langchain4j/langchain4j/pull/4112
• @cescoffier made their first contribution in https://github.com/langchain4j/langchain4j/pull/4119
• @strogiyotec made their first contribution in https://github.com/langchain4j/langchain4j/pull/4106
• @pbykovcoginiti made their first contribution in https://github.com/langchain4j/langchain4j/pull/3362
• @idoberko2 made their first contribution in https://github.com/langchain4j/langchain4j/pull/4129
• @raphidlee made their first contribution in https://github.com/langchain4j/langchain4j/pull/4133
• @jonathannaguin made their first contribution in https://github.com/langchain4j/langchain4j/pull/3978

Full Changelog: https://github.com/langchain4j/langchain4j/compare/1.8.0...1.9.0