Files
langchain/libs/core
Nick Hollon 07c71ae632 docs(core): document positional-fallback fragility in bridge
When a provider emits content_blocks without an `index` field (e.g.
anthropic `_stream` with coerce_content_to_string=True for pure text),
the bridge's positional-0 fallback merges successive chunks into one
block. This works correctly today because the only coerced-string path
in the anthropic integration is mutually exclusive with any structured
(indexed) emission. Document the scenario that would surface the gap
and the two ways to close it (native _stream_chat_model_events hook or
'continue on anonymous key' bridge rule) so a future integration
doesn't discover the edge case the hard way.
2026-04-21 13:25:52 -04:00
..

🦜🍎 LangChain Core

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Looking for the JS/TS version? Check out LangChain.js.

To help you ship LangChain apps to production faster, check out LangSmith. LangSmith is a unified developer platform for building, testing, and monitoring LLM applications.

Quick Install

pip install langchain-core

🤔 What is this?

LangChain Core contains the base abstractions that power the LangChain ecosystem.

These abstractions are designed to be as modular and simple as possible.

The benefit of having these abstractions is that any provider can implement the required interface and then easily be used in the rest of the LangChain ecosystem.

⛰️ Why build on top of LangChain Core?

The LangChain ecosystem is built on top of langchain-core. Some of the benefits:

  • Modularity: We've designed Core around abstractions that are independent of each other, and not tied to any specific model provider.
  • Stability: We are committed to a stable versioning scheme, and will communicate any breaking changes with advance notice and version bumps.
  • Battle-tested: Core components have the largest install base in the LLM ecosystem, and are used in production by many companies.

📖 Documentation

For full documentation, see the API reference. For conceptual guides, tutorials, and examples on using LangChain, see the LangChain Docs. You can also chat with the docs using Chat LangChain.

📕 Releases & Versioning

See our Releases and Versioning policies.

💁 Contributing

As an open-source project in a rapidly developing field, we are extremely open to contributions, whether it be in the form of a new feature, improved infrastructure, or better documentation.

For detailed information on how to contribute, see the Contributing Guide.