[Release] langchain-ai/langchain langchain-core==1.5.4: langchain-core==1.5.4

langchain-core version 1.5.4 is a maintenance release focused on bug fixes and compatibility improvements. Key updates include Pydantic 2.14 compatibility, fixes for StructuredPrompt mutation issues, proper handling of tool arguments and schemas, and improvements to streaming and callback mechanisms. The release addresses 13 specific issues across core functionality, infrastructure, and documentation.

Key Points

• •Pydantic 2.14 compatibility fix ensures the library works with the latest Pydantic versions
• •StructuredPrompt no longer mutates caller kwargs, preventing unintended side effects
• •RootModel runnables now preserve flat tool args schema for proper serialization
• •Event loops created internally in streaming tracers are properly closed to prevent resource leaks
• •OpenAI file blocks are preserved during processing, maintaining data integrity
• •Tool argument handling improved for BaseTool subclasses with proper injection support
• •filter_args now respects include_injected=False parameter for fine-grained control
• •Streaming callback options are redacted to protect sensitive information
• •Text stream projections now have proper type annotations for better IDE support
• •Reserved argument names for tools are documented to prevent naming conflicts

Workflow Diagram

Concepts