[Release] langchain-ai/langchain langchain-core==1.2.15: langchain-core==1.2.15

langchain-core version 1.2.15 was released with improvements to error messaging for non-JSON-serializable tool schemas, enhanced typing/documentation for chat model callbacks, and performance optimizations through deferred langsmith imports. The release also includes a new ChatAnthropicBedrock wrapper for Anthropic integration and updates to deprecated model IDs in tests.

Key Points

• •Improved error messaging for non-JSON-serializable tool schemas to provide clearer debugging information
• •Enhanced typing and documentation for on_chat_model_start callback to clarify required positional arguments
• •Optimized import performance by deferring langsmith imports to reduce initial load time
• •Reverted ChatAnthropicBedrockWrapper addition due to compatibility or design concerns
• •Added ChatAnthropicBedrock wrapper to support Anthropic models via AWS Bedrock integration
• •Updated Anthropic test suites and docstrings to replace retired model IDs with current versions
• •Code quality improvements including ruff linting fixes for better maintainability

Concepts