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Conversational Feedback #12590

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21 changes: 21 additions & 0 deletions templates/conversational-feedback/LICENSE
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MIT License

Copyright (c) 2023 LangChain, Inc.

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
86 changes: 86 additions & 0 deletions templates/conversational-feedback/README.md
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# Chat Feedback Template

This template captures implicit feedback from human behavior in a simple chat bot. It instructs an LLM to reference a user's responses within a conversation to evaluate the chat bot's previous replies.
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Nice.

1/ IIUC, this is performing chat evaluations w/o explicit user-feedback, which is very useful. We might create a top-level shortened summary that just states this clearly. It's the first eval template, so very cool to have.

2/ We might explicitly mention that your chat app should be implemented (or called) in chain.py and call out specifically where as a placeholder. AFAICT, any chat runnable can simply append:

    .with_config(
        run_name="ChatBot",
        callbacks=[
            EvaluatorCallbackHandler(
                evaluators=[
                    ResponseEffectivenessEvaluator(evaluate_response_effectiveness)
                ]
            )
        ],

3/ Where to go fetch the evals in LangSmith? May be nice to show screenshot.

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Cool cool. For (1), are you saying on top of the README that's here? (is it too roundabout)?

For (2) - yes albeit it needs a 'last_run_id' to be passed around so that the feedback can be assigned to the previous response trace. If we didn't care about the exact credit assignment, or if we had a better way of tracking conversations, this would be easier/better

For (3) def. I'll do that.


[Chat bots](https://python.langchain.com/docs/use_cases/chatbots) serve as one of the most common interfaces for deploying LLMs. The quality of chat bots varies, making continuous development important. But users are wont to leave explicit feedback through mechanisms like thumbs-up or thumbs-down buttons. Furthermore, traditional analytics such as "session length" or "conversation length" often lack clarity. However, multi-turn conversations with a chat bot can provide a wealth of information, which we can transform into metrics for fine-tuning, evaluation, and product analytics.

Taking [Chat Langchain](https://chat.langchain.com/) as a case study, only about 0.04% of all queries receive explicit feedback. Yet, approximately 70% of the queries are follow-ups to previous questions. A significant portion of these follow-up queries continue useful information we can use to infer the quality of the previous AI response.

## LangSmith Feedback

[LangSmith](https://smith.langchain.com/) is a platform for building production-grade LLM applications. Beyond its debugging and offline evaluation features, LangSmith helps you capture both user and model-assisted feedback to refine your LLM application. For more examples on collecting feedback using LangSmith, consult the [documentation](https://docs.smith.langchain.com/cookbook/feedback-examples).

## Implementation

Feedback collection occurs within a custom `RunEvaluator`. This evaluator is called using the `EvaluatorCallbackHandler`, which run it in a separate thread to avoid interfering with the chat bot's runtime.

The evaluator instructs an LLM, specifically `gpt-3.5-turbo`, to evaluate the AI's most recent chat message based on the user's followup response. It generates a score and accompanying reasoning that is converted to feedback in LangSmith, applied to the value provided as the `last_run_id`.

The prompt used within the LLM [is available on the hub](https://smith.langchain.com/hub/wfh/response-effectiveness). Feel free to customize it with things like additional app context (such as the goal of the app or the types of questions it should respond to) or "symptoms" you'd like the LLM to focus on. This evaluator also utilizes OpenAI's function-calling API to ensure a more consistent, structured output for the grade.

## Environment Variables

Ensure that `OPENAI_API_KEY` is set to use OpenAI models. Also, configure LangSmith by setting your `LANGSMITH_API_KEY`.

```bash
export OPENAI_API_KEY=sk-...
export LANGSMITH_API_KEY=...
export LANGCHAIN_TRACING_V2=true
```

## Usage

If deploying via `LangServe`, we recommend configuring the server to return callback events as well. This will ensure the backend traces are included in whatever traces you generate using the `RemoteRunnable`.

```python
from conversational_feedback.chain import chain

add_routes(app, chain, path="/conversational-feedback", include_callback_events=True)
```

With the server running, you can use the following code snippet to stream the chat bot responses for a 2 turn conversation.

```python
from functools import partial
from typing import Dict, Optional, Callable, List
from langserve import RemoteRunnable
from langchain.callbacks.manager import tracing_v2_enabled
from langchain.schema import BaseMessage, AIMessage, HumanMessage

# Update with the URL provided by your LangServe server
chain = RemoteRunnable("http://127.0.0.1:8031/conversational-feedback")

def stream_content(
text: str,
chat_history: Optional[List[BaseMessage]] = None,
last_run_id: Optional[str] = None,
on_chunk: Callable = None,
):
results = []
with tracing_v2_enabled() as cb:
for chunk in chain.stream(
{"text": text, "chat_history": chat_history, "last_run_id": last_run_id},
):
on_chunk(chunk)
results.append(chunk)
last_run_id = cb.latest_run.id if cb.latest_run else None
return last_run_id, "".join(results)

chat_history = []
text = "Where are my keys?"
last_run_id, response_message = stream_content(text, on_chunk=partial(print, end=""))
print()
chat_history.extend([HumanMessage(content=text), AIMessage(content=response_message)])
text = "I CAN'T FIND THEM ANYWHERE" # The previous response will likely receive a low score,
# as the user's frustration appears to be escalating.
last_run_id, response_message = stream_content(
text,
chat_history=chat_history,
last_run_id=str(last_run_id),
on_chunk=partial(print, end=""),
)
print()
chat_history.extend([HumanMessage(content=text), AIMessage(content=response_message)])
```

This uses the `tracing_v2_enabled` callback manager to get the run ID of the call, which we provide in subsequent calls in the same chat thread, so the evaluator can assign feedback to the appropriate trace.
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from conversational_feedback.chain import chain

__all__ = ["chain"]
166 changes: 166 additions & 0 deletions templates/conversational-feedback/conversational_feedback/chain.py
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from __future__ import annotations

from typing import List, Optional

from langchain import hub
from langchain.callbacks.tracers.evaluation import EvaluatorCallbackHandler
from langchain.callbacks.tracers.schemas import Run
from langchain.chains.openai_functions.base import convert_to_openai_function
from langchain.chat_models import ChatOpenAI
from langchain.output_parsers.openai_functions import JsonOutputFunctionsParser
from langchain.prompts import ChatPromptTemplate, MessagesPlaceholder
from langchain.schema import (
AIMessage,
BaseMessage,
HumanMessage,
StrOutputParser,
get_buffer_string,
)
from langchain.schema.runnable import Runnable
from langsmith.evaluation import EvaluationResult, RunEvaluator
from langsmith.schemas import Example
from pydantic import BaseModel, Field

### The feedback model used for the "function definition" provided to OpenAI
# For use with open source models, you can add the schema directly,
# but some modifications to the prompt and parser will be needed


class ResponseEffectiveness(BaseModel):
"""Score the effectiveness of the AI chat bot response."""

reasoning: str = Field(
...,
description="Explanation for the score.",
)
score: int = Field(
...,
min=0,
max=5,
description="Effectiveness of AI's final response.",
)


def format_messages(input: dict) -> List[BaseMessage]:
"""Format the messages for the evaluator."""
chat_history = input.get("chat_history") or []
results = []
for message in chat_history:
if message["type"] == "human":
results.append(HumanMessage.parse_obj(message))
else:
results.append(AIMessage.parse_obj(message))
return results


def format_dialog(input: dict) -> dict:
"""Format the dialog for the evaluator."""
chat_history = format_messages(input)
formatted_dialog = get_buffer_string(chat_history) # + f"\nhuman: {input['text']}"
return {"dialog": formatted_dialog}


def normalize_score(response: dict) -> dict:
"""Normalize the score to be between 0 and 1."""
response["score"] = int(response["score"]) / 5
return response


evaluation_prompt = hub.pull("wfh/response-effectiveness")
evaluate_response_effectiveness = (
# format_messages is a function that takes a dict and returns a dict
format_dialog
| evaluation_prompt
# bind() provides the requested schemas to the model for structured prediction
| ChatOpenAI(model="gpt-3.5-turbo").bind(
functions=[convert_to_openai_function(ResponseEffectiveness)],
function_call={"name": "ResponseEffectiveness"},
)
# Convert the model's output to a dict
| JsonOutputFunctionsParser(args_only=True)
| normalize_score
)


class ResponseEffectivenessEvaluator(RunEvaluator):
def __init__(self, evaluator_runnable: Runnable) -> None:
super().__init__()
self.runnable = evaluator_runnable

def evaluate_run(
self, run: Run, example: Optional[Example] = None
) -> EvaluationResult:
# This particular evaluator is configured to evaluate the previous
# AI response. It uses the user's followup question or comment as
# additional grounding for its grade.
if not run.inputs.get("chat_history"):
return EvaluationResult(
key="response_effectiveness", comment="No chat history present."
)
elif "last_run_id" not in run.inputs:
return EvaluationResult(
key="response_effectiveness", comment="No last run ID present."
)
eval_grade: Optional[dict] = self.runnable.invoke(run.inputs)
target_run_id = run.inputs["last_run_id"]
return EvaluationResult(
**eval_grade,
key="response_effectiveness",
target_run_id=target_run_id,
)


### The actual deployed chain (we are keeping it simple for this example)
# The main focus of this template is the evaluator above, not the chain itself.


class ChainInput(BaseModel):
chat_history: Optional[List[BaseMessage]] = Field(
description="Previous chat messages."
)
text: str = Field(..., description="User's latest query.")
last_run_id: Optional[str] = Field("", description="ID of the last run.")


_prompt = ChatPromptTemplate.from_messages(
[
(
"system",
"You are a helpful assistant who speaks like a pirate",
),
MessagesPlaceholder(variable_name="chat_history"),
("user", "{text}"),
]
)
_model = ChatOpenAI()


def format_chat_history(chain_input: ChainInput) -> dict:
# This is a hack to get the chat history into the prompt
messages = format_messages(chain_input)

return {
"chat_history": messages,
"text": chain_input.get("text"),
}


# if you update the name of this, you MUST also update ../pyproject.toml
# with the new `tool.langserve.export_attr`
chain = (
(format_chat_history | _prompt | _model | StrOutputParser())
# This is to populate the openapi spec for LangServe
.with_types(input_type=ChainInput)
# This is to add the evluators as "listeners"
# and to customize the name of the chain
.with_config(
run_name="ChatBot",
callbacks=[
EvaluatorCallbackHandler(
evaluators=[
ResponseEffectivenessEvaluator(evaluate_response_effectiveness)
]
)
],
)
)
26 changes: 26 additions & 0 deletions templates/conversational-feedback/pyproject.toml
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[tool.poetry]
name = "chat_feedback"
version = "0.0.1"
description = ""
authors = []
readme = "README.md"

[tool.poetry.dependencies]
python = ">=3.8.1,<4.0"
langchain = ">=0.0.325, <0.1"
openai = "^0.28.1"
langsmith = ">=0.0.54"
langchainhub = ">=0.1.13"

[tool.poetry.group.dev.dependencies]
langchain-cli = ">=0.0.4"
fastapi = "^0.104.0"
sse-starlette = "^1.6.5"

[tool.langserve]
export_module = "chat_feedback.chain"
export_attr = "chain"

[build-system]
requires = ["poetry-core"]
build-backend = "poetry.core.masonry.api"
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