b0e4ef3158
This PR adds a regression test covering the JSON Schema `$ref` pattern found in MCP-style schemas, where a `$ref` points into a list-based structure such as: #/properties/body/anyOf/1/properties/Message/properties/bccRecipients/items This pattern historically failed due to incorrect handling of numeric list components in `_retrieve_ref`. The underlying bug has since been fixed, and this test ensures coverage so we don't regress on list-index `$ref` resolution. The new test (`test_dereference_refs_list_index_items_ref_mcp_like`) verifies: - correct traversal into `anyOf[1]` - proper dereferencing of `items.$ref` - no errors thrown - `ccRecipients.items` is identical to the resolved schema of `bccRecipients.items` No code changes are included, just the one test — this PR adds coverage to preserve the expected behavior and documents support for this real-world MCP schema pattern. Related to #32012. --------- Co-authored-by: Mason Daugherty <mason@langchain.dev>
🦜🍎️ LangChain Core
Looking for the JS/TS version? Check out LangChain.js.
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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.
📕 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.