Add req_config to ChatOpenAIResponses by @xxdavid in https://github.com/brainlid/langchain/pull/415
Add thinking config to vertex ai by @mattmatters in https://github.com/brainlid/langchain/pull/423
Add support for OpenAI Response API Stateful context by @cjimison in https://github.com/brainlid/langchain/pull/425
Fixes image file_id content type for ChatOpenAIResponses by @sezaru in https://github.com/brainlid/langchain/pull/438
fix(ChatMistralAI): missing error handling and fallback mechanism on server outages (#434) by @xu-chris in https://github.com/brainlid/langchain/pull/435
feat(ChatMistralAI): add support for parallel tool calls by @xu-chris in https://github.com/brainlid/langchain/pull/433
use elixir 1.17 by @nbw in https://github.com/brainlid/langchain/pull/427
feat(GoogleChatAI): add thought_signature support for Gemini 3 function calls by @abh1shek-sh in https://github.com/brainlid/langchain/pull/431
Don't include top_p for gpt-5.2+ in ChatOpenAIResponses by @montebrown in https://github.com/brainlid/langchain/pull/428
Fix Mistral 'thinking' content parts by @arjan in https://github.com/brainlid/langchain/pull/418
Add verbose_api field to ChatPerplexity and ChatMistralAI by @arjan in https://github.com/brainlid/langchain/pull/416
Add support for OpenAI reasoning/thinking events in ChatOpenAIResponses by @arjan in https://github.com/brainlid/langchain/pull/421
Add new reasoning effort values to ChatOpenAIResponses by @xxdavid in https://github.com/brainlid/langchain/pull/419
fix "Support reasoning_content of deepseek model" introducing UI bug … by @kayuapi in https://github.com/brainlid/langchain/pull/429
Support json schema in vertex ai by @mattmatters in https://github.com/brainlid/langchain/pull/424
Base work for new agent library by @brainlid in https://github.com/brainlid/langchain/pull/442
fix ChatGrok tool call arguments and message flattening by @KristerV in https://github.com/brainlid/langchain/pull/420
Revert "fix ChatGrok tool call arguments and message flattening" by @brainlid in https://github.com/brainlid/langchain/pull/445
prep for v0.5.0 release by @brainlid in https://github.com/brainlid/langchain/pull/451
New Contributors
@cjimison made their first contribution in https://github.com/brainlid/langchain/pull/425
@sezaru made their first contribution in https://github.com/brainlid/langchain/pull/438
@xu-chris made their first contribution in https://github.com/brainlid/langchain/pull/435
@nbw made their first contribution in https://github.com/brainlid/langchain/pull/427
@abh1shek-sh made their first contribution in https://github.com/brainlid/langchain/pull/431
@kayuapi made their first contribution in https://github.com/brainlid/langchain/pull/429
@KristerV made their first contribution in https://github.com/brainlid/langchain/pull/420
Full Changelog: https://github.com/brainlid/langchain/compare/v0.4.1...v0.5.0