Extending LangChain.js

Extending LangChain's base abstractions, whether you're planning to contribute back to the open-source repo or build a bespoke internal integration, is encouraged.

Check out these guides for building your own custom classes for the following modules:

• Chat models for interfacing with chat-tuned language models.
• LLMs for interfacing with text language models.
• Output parsers for handling language model outputs.
• Retrievers for fetching context from external data sources.
• Vectorstores for interacting with vector databases.
• Agents that allow the language model to make decisions autonomously.
• Chat histories which enable memory in the form of persistent storage of chat messages and sessions.