This will add the ability to add an AsyncCallbackManager (handler) for
the reducer chain, which would be able to stream the tokens via the
`async def on_llm_new_token` callback method
Fixes # (issue)
[5532](https://github.com/hwchase17/langchain/issues/5532)
@hwchase17 @agola11
The following code snippet explains how this change would be used to
enable `reduce_llm` with streaming support in a `map_reduce` chain
I have tested this change and it works for the streaming use-case of
reducer responses. I am happy to share more information if this makes
solution sense.
```
AsyncHandler
..........................
class StreamingLLMCallbackHandler(AsyncCallbackHandler):
"""Callback handler for streaming LLM responses."""
def __init__(self, websocket):
self.websocket = websocket
# This callback method is to be executed in async
async def on_llm_new_token(self, token: str, **kwargs: Any) -> None:
resp = ChatResponse(sender="bot", message=token, type="stream")
await self.websocket.send_json(resp.dict())
Chain
..........
stream_handler = StreamingLLMCallbackHandler(websocket)
stream_manager = AsyncCallbackManager([stream_handler])
streaming_llm = ChatOpenAI(
streaming=True,
callback_manager=stream_manager,
verbose=False,
temperature=0,
)
main_llm = OpenAI(
temperature=0,
verbose=False,
)
doc_chain = load_qa_chain(
llm=main_llm,
reduce_llm=streaming_llm,
chain_type="map_reduce",
callback_manager=manager
)
qa_chain = ConversationalRetrievalChain(
retriever=vectorstore.as_retriever(),
combine_docs_chain=doc_chain,
question_generator=question_generator,
callback_manager=manager,
)
# Here `acall` will trigger `acombine_docs` on `map_reduce` which should then call `_aprocess_result` which in turn will call `self.combine_document_chain.arun` hence async callback will be awaited
result = await qa_chain.acall(
{"question": question, "chat_history": chat_history}
)
```
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I used the APIChain sometimes it failed during the intermediate step
when generating the api url and calling the `request` function. After
some digging, I found the url sometimes includes the space at the
beginning, like `%20https://...api.com` which causes the `
self.requests_wrapper.get` internal function to fail.
Including a little string preprocessing `.strip` to remove the space
seems to improve the robustness of the APIchain to make sure it can send
the request and retrieve the API result more reliably.
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Based on the inspiration from the SQL chain, the following three
parameters are added to Graph Cypher Chain.
- top_k: Limited the number of results from the database to be used as
context
- return_direct: Return database results without transforming them to
natural language
- return_intermediate_steps: Return intermediate steps
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`load_qa_with_sources_chain` method already support four type of chain,
including `map_rerank`. update document to prevent any misunderstandings
😀.

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Fixes # (issue)
No, just update document.
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Fixes#3983
Mimicing what we do for saving and loading VectorDBQA chain, I added the
logic for RetrievalQA chain.
Also added a unit test. I did not find how we test other chains for
their saving and loading functionality, so I just added a file with one
test case. Let me know if there are recommended ways to test it.
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---------
Co-authored-by: Harrison Chase <hw.chase.17@gmail.com>
# Allow callbacks to monitor ConversationalRetrievalChain
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I ran into an issue where load_qa_chain was not passing the callbacks
down to the child LLM chains, and so made sure that callbacks are
propagated. There are probably more improvements to do here but this
seemed like a good place to stop.
Note that I saw a lot of references to callbacks_manager, which seems to
be deprecated. I left that code alone for now.
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Adding a class attribute "return_generated_question" to class
"BaseConversationalRetrievalChain". If set to `True`, the chain's output
has a key "generated_question" with the question generated by the
sub-chain `question_generator` as the value. This way the generated
question can be logged.
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# Check if generated Cypher code is wrapped in backticks
Some LLMs like the VertexAI like to explain how they generated the
Cypher statement and wrap the actual code in three backticks:

I have observed a similar pattern with OpenAI chat models in a
conversational settings, where multiple user and assistant message are
provided to the LLM to generate Cypher statements, where then the LLM
wants to maybe apologize for previous steps or explain its thoughts.
Interestingly, both OpenAI and VertexAI wrap the code in three backticks
if they are doing any explaining or apologizing. Checking if the
generated cypher is wrapped in backticks seems like a low-hanging fruit
to expand the cypher search to other LLMs and conversational settings.
# Fixed multi input prompt for MapReduceChain
Added `kwargs` support for inner chains of `MapReduceChain` via
`from_params` method
Currently the `from_method` method of intialising `MapReduceChain` chain
doesn't work if prompt has multiple inputs. It happens because it uses
`StuffDocumentsChain` and `MapReduceDocumentsChain` underneath, both of
them require specifying `document_variable_name` if `prompt` of their
`llm_chain` has more than one `input`.
With this PR, I have added support for passing their respective `kwargs`
via the `from_params` method.
## Fixes https://github.com/hwchase17/langchain/issues/4752
## Who can review?
@dev2049 @hwchase17 @agola11
---------
Co-authored-by: imeckr <chandanroutray2012@gmail.com>
# Removed deprecated llm attribute for load_chain
Currently `load_chain` for some chain types expect `llm` attribute to be
present but `llm` is deprecated attribute for those chains and might not
be persisted during their `chain.save`.
Fixes#5224
[(issue)](https://github.com/hwchase17/langchain/issues/5224)
## Who can review?
@hwchase17
@dev2049
---------
Co-authored-by: imeckr <chandanroutray2012@gmail.com>
# Add async support for (LLM) routing chains
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Add asynchronous LLM calls support for the routing chains. More
specifically:
- Add async `aroute` function (i.e. async version of `route`) to the
`RouterChain` which calls the routing LLM asynchronously
- Implement the async `_acall` for the `LLMRouterChain`
- Implement the async `_acall` function for `MultiRouteChain` which
first calls asynchronously the routing chain with its new `aroute`
function, and then calls asynchronously the relevant destination chain.
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# Add example to LLMMath to help with power operator
Add example to LLMMath that helps the model to interpret `^` as the power operator rather than the python xor operator.
# Improve Cypher QA prompt
The current QA prompt is optimized for networkX answer generation, which
returns all the possible triples.
However, Cypher search is a bit more focused and doesn't necessary
return all the context information.
Due to that reason, the model sometimes refuses to generate an answer
even though the information is provided:

To fix this issue, I have updated the prompt. Interestingly, I tried
many variations with less instructions and they didn't work properly.
However, the current fix works nicely.

# Reuse `length_func` in `MapReduceDocumentsChain`
Pretty straightforward refactor in `MapReduceDocumentsChain`. Reusing
the local variable `length_func`, instead of the longer alternative
`self.combine_document_chain.prompt_length`.
@hwchase17
# changed ValueError to ImportError
Code cleaning.
Fixed inconsistencies in ImportError handling. Sometimes it raises
ImportError and sometime ValueError.
I've changed all cases to the `raise ImportError`
Also:
- added installation instruction in the error message, where it missed;
- fixed several installation instructions in the error message;
- fixed several error handling in regards to the ImportError
Without the addition of 'in its original language', the condensing
response, more often than not, outputs the rephrased question in
English, even when the conversation is in another language. This
question in English then transfers to the question in the retrieval
prompt and the chatbot is stuck in English.
I'm sometimes surprised that this does not happen more often, but
apparently the GPT models are smart enough to understand that when the
template contains
Question: ....
Answer:
then the answer should be in in the language of the question.
# fix: agenerate miss run_manager args in llm.py
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Fixes # (issue)
fix: agenerate miss run_manager args in llm.py
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# Removed usage of deprecated methods
Replaced `SQLDatabaseChain` deprecated direct initialisation with
`from_llm` method
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---------
Co-authored-by: imeckr <chandanroutray2012@gmail.com>
Co-authored-by: Dev 2049 <dev.dev2049@gmail.com>
# Fixed query checker for SQLDatabaseChain
When `SQLDatabaseChain`'s llm attribute was deprecated, the query
checker stopped working if `SQLDatabaseChain` is initialised via
`from_llm` method. With this fix, `SQLDatabaseChain`'s query checker
would use the same `llm` as used in the `llm_chain`
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Co-authored-by: imeckr <chandanroutray2012@gmail.com>
fixes a syntax error mentioned in
#2027 and #3305
another PR to remedy is in #3385, but I believe that is not tacking the
core problem.
Also #2027 mentions a solution that works:
add to the prompt:
'The SQL query should be outputted plainly, do not surround it in quotes
or anything else.'
To me it seems strange to first ask for:
SQLQuery: "SQL Query to run"
and then to tell the LLM not to put the quotes around it. Other
templates (than the sql one) do not use quotes in their steps.
This PR changes that to:
SQLQuery: SQL Query to run
# Provide get current date function dialect for other DBs
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Fixes # (issue)
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# Enhance the prompt to make the LLM generate right date for real today
Fixes # (issue)
Currently, if the user's question contains `today`, the clickhouse
always points to an old date. This may be related to the fact that the
GPT training data is relatively old.
# Fix minor issues in self-query retriever prompt formatting
I noticed a few minor issues with the self-query retriever's prompt
while using it, so here's PR to fix them 😇
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Any import that touches langchain.retrievers currently requires Lark.
Here's one attempt to fix. Not very pretty, very open to other ideas.
Alternatives I thought of are 1) make Lark requirement, 2) put
everything in parser.py in the try/except. Neither sounds much better
Related to #4316, #4275
Currently, MultiPromptChain instantiates a ChatOpenAI LLM instance for
the default chain to use if none of the prompts passed match. This seems
like an error as it means that you can't use your choice of LLM, or
configure how to instantiate the default LLM (e.g. passing in an API key
that isn't in the usual env variable).