What's Changed

• fix: handle missing finish_reason in streaming responses for LiteLLM compatibility by @fbettag in https://github.com/brainlid/langchain/pull/367
• Add support for native tool calls to ChatVertexAI by @raulchedrese in https://github.com/brainlid/langchain/pull/359
• Adds should_continue? optional function to mode step by @CaiqueMitsuoka in https://github.com/brainlid/langchain/pull/361
• Add OpenAI Deep Research integration by @fbettag in https://github.com/brainlid/langchain/pull/336
• Add parallel_tool_calls option to ChatOpenAI model by @martosaur in https://github.com/brainlid/langchain/pull/371
• Add optional AWS session token handling in BedrockHelpers by @quangngd in https://github.com/brainlid/langchain/pull/372
• fix: handle LiteLLM responses with null b64_json in OpenAIImage by @fbettag in https://github.com/brainlid/langchain/pull/368
• Add Orq AI chat by @arjan in https://github.com/brainlid/langchain/pull/377
• Add req_config to ChatModels.ChatOpenAI by @koszta in https://github.com/brainlid/langchain/pull/376
• fix(ChatGoogleAI): Handle cumulative token usage by @mweidner037 in https://github.com/brainlid/langchain/pull/373
• fix(ChatGoogleAI): Prevent error from thinking content parts by @mweidner037 in https://github.com/brainlid/langchain/pull/374
• feat(ChatGoogleAI): Full thinking config by @mweidner037 in https://github.com/brainlid/langchain/pull/375
• Support verbosity parameter for ChatOpenAI by @rohan-b99 in https://github.com/brainlid/langchain/pull/379
• add retry_on_fallback? to chat model definition and all models by @brainlid in https://github.com/brainlid/langchain/pull/350
• Prep for v0.4.o-rc.3 by @brainlid in https://github.com/brainlid/langchain/pull/380

New Contributors

• @martosaur made their first contribution in https://github.com/brainlid/langchain/pull/371
• @quangngd made their first contribution in https://github.com/brainlid/langchain/pull/372
• @arjan made their first contribution in https://github.com/brainlid/langchain/pull/377
• @koszta made their first contribution in https://github.com/brainlid/langchain/pull/376
• @rohan-b99 made their first contribution in https://github.com/brainlid/langchain/pull/379

Full Changelog: https://github.com/brainlid/langchain/compare/v0.4.0-rc.2...v0.4.0-rc.3