langchain

Core abstractions, interfaces, and base classes for LangChain including callbacks, documents, indexing, messages, language models, and caching

Active agent factory system with middleware components for LangGraph integration, including context editing, shell execution, PII redaction, summarization, and structured output

Third-party partner integrations for LLM providers (Anthropic, OpenAI, Deepseek), embeddings (HuggingFace, Nomic), and vector stores (Chroma), plus legacy langchain_classic adapters

Document chunking and text splitting utilities supporting multiple strategies (character, HTML, Markdown, JSON, NLTK, spaCy, sentence transformers)

Standardized test suite for LangChain integrations covering chat models, embeddings, vector stores, caching, and tool testing