LangChain

LangChain is the most widely used LLM orchestration framework, and its value is coverage: whatever model, vector store, loader or tool you need, there is almost certainly a LangChain integration for it already. The community is large enough that most problems have a prior answer.

The recurring criticism

The abstractions can get in the way. Chains, agents and wrappers add layers between your code and the model, and when something breaks, debugging through those layers is harder than debugging a direct API call. Many teams start with LangChain for the integrations and later strip it back to the parts they actually use.

Who should use it

Teams that want maximum integration coverage and community support, and prototypes that need to touch many different services quickly. If you value a thin, transparent stack and your integration needs are modest, a lighter framework — or direct API calls — will be easier to maintain.