[Release] langchain-ai/langchain langchain==1.3.12: langchain==1.3.12

LangChain v1.3.12 release includes critical bug fixes for tool retry middleware interrupt propagation, shell middleware process-group handling, and Anthropic cache marker sanitization on fallback retries. The release also improves code quality through ruff style fixes and enhanced type annotations in agent middleware tests. These changes enhance reliability and stability of LangChain's middleware and agent execution systems.

Key Points

• •Fixed interrupt propagation through ToolRetryMiddleware to ensure proper signal handling during tool retries
• •Resolved shared process-group kill issue in shell middleware to prevent unintended process termination
• •Sanitized Anthropic cache markers on fallback retries to maintain cache consistency and prevent marker corruption
• •Applied ruff preview rule fixes in langchain_v1 and standard-tests for improved code style compliance
• •Enhanced type annotations in agent middleware tests for better type safety and IDE support
• •Focus on middleware stability and reliability improvements for production agent deployments
• •Maintains backward compatibility while fixing critical execution path issues

Workflow Diagram

Concepts