new langchain oss release!

LangChain OSS (@LangChain_OSS)
What's new in LangChain? 🚀

🔌 Support for OpenAI's 3.0 SDK (using httpx2)
✨ Support for gemini-3.7-flash

Plus a wave of core reliability fixes from external contributors:

🛠️ Tool calling & structured output: clearer errors, respect for pydantic aliases when validating tool inputs (github.com/RinZ27, github.com/kinch-tech, github.com/charan16)

📊 Usage metadata fixes: token usage callback bugs, and cost metadata when streaming OpenRouter (github.com/Solaris-star, github.com/iroiro147)

🧱 Content & prompt hardening: guard malformed Anthropic content blocks, and preserve non-str/non-dict items in prompt templates for content blocks (github.com/Oxygen56, github.com/zerafachris)

Huge thanks to everyone who contributed! 🙏