Thank you for contributing to LangChain!

- [ ] **PR title**: "community: deprecate vectorstores.MatchingEngine"


- [ ] **PR message**: 
- **Description:** announced a deprecation since this integration has
been moved to langchain_google_vertexai

…on (#18581)

input parameters take precedence over env variables

# Description

- **Description:** Adding MongoDB LLM Caching Layer abstraction
- **Issue:** N/A
- **Dependencies:** None
- **Twitter handle:** @mongodb

Checklist:

- [x] PR title: Please title your PR "package: description", where
"package" is whichever of langchain, community, core, experimental, etc.
is being modified. Use "docs: ..." for purely docs changes, "templates:
..." for template changes, "infra: ..." for CI changes.
  - Example: "community: add foobar LLM"
- [x] PR Message (above)
- [x] Pass lint and test: Run `make format`, `make lint` and `make test`
from the root of the package(s) you've modified to check that you're
passing lint and testing. See contribution guidelines for more
information on how to write/run tests, lint, etc:
https://python.langchain.com/docs/contributing/
- [ ] Add tests and docs: If you're adding a new integration, please
include
1. a test for the integration, preferably unit tests that do not rely on
network access,
2. an example notebook showing its use. It lives in
`docs/docs/integrations` directory.

Additional guidelines:
- Make sure optional dependencies are imported within a function.
- Please do not add dependencies to pyproject.toml files (even optional
ones) unless they are required for unit tests.
- Most PRs should not touch more than one package.
- Changes should be backwards compatible.
- If you are adding something to community, do not re-import it in
langchain.

If no one reviews your PR within a few days, please @-mention one of
@baskaryan, @efriis, @eyurtsev, @hwchase17.

---------

Co-authored-by: Jib <jib@byblack.us>

## **Description** 
Migrate the `MongoDBChatMessageHistory` to the managed
`langchain-mongodb` partner-package
## **Dependencies**
None
## **Twitter handle**
@mongodb

## **tests and docs**
- [x] Migrate existing integration test
- [x ]~ Convert existing integration test to a unit test~ Creation is
out of scope for this ticket
- [x ] ~Considering delaying work until #17470 merges to leverage the
`MockCollection` object. ~
- [x] **Lint and test**: Run `make format`, `make lint` and `make test`
from the root of the package(s) you've modified. See contribution
guidelines for more: https://python.langchain.com/docs/contributing/

---------

Co-authored-by: Erick Friis <erick@langchain.dev>

## Description
Adding in Unit Test variation for `MongoDBChatMessageHistory` package
Follow-up to #18590 

- [x] **Add tests and docs**: Unit test is what's being added
  

- [x] **Lint and test**: Run `make format`, `make lint` and `make test`
from the root of the package(s) you've modified. See contribution
guidelines for more: https://python.langchain.com/docs/contributing/

**Description:** 
modified the user_name to username to conform with the expected inputs
to TelegramChatApiLoader

**Issue:**
Current code fails in langchain-community 0.0.24 
<loader = TelegramChatApiLoader(
    chat_entity="<CHAT_URL>",  # recommended to use Entity here
    api_hash="<API HASH >",
    api_id="<API_ID>",
    user_name="",  # needed only for caching the session.
)>

#18600)

Deprecates the old langchain-hub repository. Does *not* deprecate the
new https://smith.langchain.com/hub

@PinkDraconian has correctly raised that in the event someone is loading
unsanitized user input into the `try_load_from_hub` function, they have
the ability to load files from other locations in github than the
hwchase17/langchain-hub repository.

This PR adds some more path checking to that function and deprecates the
functionality in favor of the hub built into LangSmith.

This patch updates function "run" to "invoke" in smart_llm.ipynb.
Without this patch, you see following warning.

LangChainDeprecationWarning: The function `run` was deprecated in
LangChain 0.1.0 and will be removed in 0.2.0. Use invoke instead.

    Signed-off-by: Masanari Iida <standby24x7@gmail.com>

Signed-off-by: Masanari Iida <standby24x7@gmail.com>

Neo4j tools use particular node labels and relationship types to store
metadata, but are irrelevant for text2cypher or graph generation, so we
want to ignore them in the schema representation.

…off) (#18560)

## PR title
community[patch]: Invoke callback prior to yielding token

## PR message
- Description: Invoke callback prior to yielding token in _stream_
method in llms/titan_takeoff.
- Issue: #16913 
- Dependencies: None

Added missed sections. Added descriptions.

Description: Added support for AI21 Labs model - Contextual Answers
Dependencies: ai21, ai21-tokenizer
Twitter handle: https://github.com/AI21Labs

---------

Co-authored-by: Asaf Gardin <asafg@ai21.com>
Co-authored-by: Erick Friis <erick@langchain.dev>

- **Description:** adding verbose flag to TritonTensorRTLLM, 
  - **Issue:** nope,
  - **Dependencies:** not any,
  - **Twitter handle:**

…e_threshold in DingoDB (#18106)

Update Elasticsearch README with information on how to start a
deployment.

Also make some cosmetic changes to the [Elasticsearch
docs](https://python.langchain.com/docs/integrations/vectorstores/elasticsearch).

Follow up on #17467

**Issue:** fix broken links and missing package on colab example

### Description
Changed the value specified for `content_key` in JSONLoader from a
single key to a value based on jq schema.
I created [similar
PR](#11255) before, but it
has several conflicts because of the architectural change associated
stable version release, so I re-create this PR to fit new architecture.

### Why
For json data like the following, specify `.data[].attributes.message`
for page_content and `.data[].attributes.id` or
`.data[].attributes.attributes. tags`, etc., the `content_key` must also
parse the json structure.

<details>
<summary>sample json data</summary>

```json
{
  "data": [
    {
      "attributes": {
        "message": "message1",
        "tags": [
          "tag1"
        ]
      },
      "id": "1"
    },
    {
      "attributes": {
        "message": "message2",
        "tags": [
          "tag2"
        ]
      },
      "id": "2"
    }
  ]
}
```

</details>

<details>
<summary>sample code</summary>

```python
def metadata_func(record: dict, metadata: dict) -> dict:

    metadata["source"] = None
    metadata["id"] = record.get("id")
    metadata["tags"] = record["attributes"].get("tags")

    return metadata

sample_file = "sample1.json"
loader = JSONLoader(
    file_path=sample_file,
    jq_schema=".data[]",
    content_key=".attributes.message", ## content_key is parsable into jq schema
    is_content_key_jq_parsable=True, ## this is added parameter
    metadata_func=metadata_func
)

data = loader.load()
data
```

</details>

### Dependencies
none

### Twitter handle
[kzk_maeda](https://twitter.com/kzk_maeda)

This pull request support loading documents from Yuque with Langchain.

Yuque is a professional cloud-based knowledge base for team
collaboration in documentation.

Website: https://www.yuque.com
OpenAPI: https://www.yuque.com/yuque/developer/openapi

Description: Noticed spelling errors. 'Colab' mispelt as 'Collab'.
https://python.langchain.com/docs/use_cases
Dependencies: n/a

Fix #18460

Description:

This pull request addresses two key improvements to the langchain
repository:

**Fix for Crash in Flight Search Interface**:

Previously, the code would crash when encountering a failure scenario in
the flight ticket search interface. This PR resolves this issue by
implementing a fix to handle such scenarios gracefully. Now, the code
handles failures in the flight search interface without crashing,
ensuring smoother operation.

**Documentation Update for Amadeus Toolkit**:

Prior to this update, examples provided in the documentation for the
Amadeus Toolkit were unable to run correctly due to outdated
information. This PR includes an update to the documentation, ensuring
that all examples can now be executed successfully. With this update,
users can effectively utilize the Amadeus Toolkit with accurate and
functioning examples.
These changes aim to enhance the reliability and usability of the
langchain repository by addressing issues related to error handling and
ensuring that documentation remains up-to-date and actionable.

Issue: #17375

Twitter Handle: SingletonYxx

Implement
[Retriever](https://python.langchain.com/docs/modules/data_connection/retrievers/)
interface for Elasticsearch.

I opted to only expose the `body`, which gives you full flexibility, and
none the other 68 arguments of the [search
method](https://elasticsearch-py.readthedocs.io/en/v8.12.1/api/elasticsearch.html#elasticsearch.Elasticsearch.search).

Added a user agent header for usage tracking in Elastic Cloud.

---------

Co-authored-by: Erick Friis <erick@langchain.dev>

- **Description:** Fixed some typos and copy errors in the Beta
Structured Output docs
    - **Issue:** N/A
    - **Dependencies:** Docs only
    - **Twitter handle:** @psvann

Co-authored-by: P.S. Vann <psvann@yahoo.com>

Covered by `test_evernote_loader.py`

Covered by `test_cube_semantic.py`

Added missed pages. Added links and descriptions. Foratted to the
consistent form.

…#18607)

- **Description:** Databricks SerDe uses cloudpickle instead of pickle
when serializing a user-defined function transform_input_fn since pickle
does not support functions defined in `__main__`, and cloudpickle
supports this.
- **Dependencies:** cloudpickle>=2.0.0

Added a unit test.

Integration test:
`tests/integration_tests/document_loaders/test_gitbook.py`

Integration test:
`tests/integration_tests/document_loaders/test_facebook_chat.py`

Integration tests: `test_sitemap.py` and `test_docusaurus.py`

)

Integration test:
`tests/integration_tests/document_loaders/test_email.py`

Integration tests: `tests/integration_tests/utilities/test_arxiv.py` and
`tests/integration_tests/document_loaders/test_arxiv.py`

Revamp the extraction use case documentation

---------

Co-authored-by: Harrison Chase <hw.chase.17@gmail.com>

Minor changes:
1) Set temperature to 0 (important)
2) Better qualify one of the statements with confidence

Integration test:
`tests/integration_tests/document_loaders/test_wikipedia.py`

Integration test:
`tests/integration_tests/document_loaders/test_whatsapp_chat.py`

Integration tests:
`tests/integration_tests/document_loaders/test_slack.py`