[Release] langchain-ai/langchain langchain-core==1.2.21: langchain-core==1.2.21

langchain-core version 1.2.21 is released with bug fixes and maintenance updates. Key changes include adding missing ModelProfile fields with schema drift warnings, removing obsolete blockbuster allowlist references, and CI improvements for pytest output suppression. This patch release addresses core functionality gaps and improves development workflow stability.

Key Points

• •Added missing ModelProfile fields to prevent incomplete model configurations
• •Implemented schema drift warnings to alert developers of configuration mismatches
• •Removed stale blockbuster allowlist for deleted context module to clean up deprecated code references
• •Suppressed pytest streaming output in CI pipelines for cleaner build logs
• •Patch release (1.2.20 → 1.2.21) indicates bug fixes and minor improvements without breaking changes
• •Focus on data model integrity and developer experience improvements
• •CI/CD pipeline optimization for better visibility and maintainability

Workflow Diagram

Concepts