[Release] langchain-ai/langchain langchain-core==1.5.3: langchain-core==1.5.3

langchain-core version 1.5.3 has been released with a critical bug fix that enables fallback to the LANGSMITH_API_KEY environment variable for gateway authentication. This patch release addresses an issue where the gateway authentication mechanism was not properly falling back to the LANGSMITH_API_KEY when the primary authentication method was unavailable. The fix ensures more robust authentication handling for users integrating with LangSmith gateway services.

Key Points

• •langchain-core 1.5.3 is a patch release following version 1.5.2
• •Primary fix: Gateway authentication now falls back to LANGSMITH_API_KEY environment variable
• •Improves authentication robustness for LangSmith gateway integration
• •Addresses authentication failure scenarios where primary method was unavailable
• •Enables seamless credential fallback mechanism for improved user experience
• •Patch release indicates backward compatibility is maintained

Workflow Diagram

Concepts