如何为聊天机器人添加检索功能

检索是聊天机器人用来增强其响应的常见技术，利用聊天模型训练数据之外的数据。本节将介绍如何在聊天机器人的上下文中实现检索，但值得注意的是，检索是一个非常微妙和深奥的话题 - 我们鼓励您探索文档的其他部分，以获得更深入的了解！

设置

您需要安装一些软件包，并将您的 OpenAI API 密钥设置为名为 OPENAI_API_KEY 的环境变量：

%pip install -qU langchain langchain-openai langchain-chroma beautifulsoup4

# Set env var OPENAI_API_KEY or load from a .env file:
import dotenv

dotenv.load_dotenv()

WARNING: You are using pip version 22.0.4; however, version 23.3.2 is available.
You should consider upgrading via the '/Users/jacoblee/.pyenv/versions/3.10.5/bin/python -m pip install --upgrade pip' command.
Note: you may need to restart the kernel to use updated packages.

True

我们还要设置一个聊天模型，用于下面的示例。

<!--IMPORTS:[{"imported": "ChatOpenAI", "source": "langchain_openai", "docs": "https://python.langchain.com/api_reference/openai/chat_models/langchain_openai.chat_models.base.ChatOpenAI.html", "title": "How to add retrieval to chatbots"}]-->
from langchain_openai import ChatOpenAI

chat = ChatOpenAI(model="gpt-4o-mini", temperature=0.2)

创建检索器

我们将使用LangSmith文档作为源材料，并将内容存储在向量存储中以便后续检索。请注意，这个示例将略过一些关于解析和存储数据源的细节 - 你可以在这里查看更深入的创建检索系统文档。

我们使用文档加载器从文档中提取文本：

<!--IMPORTS:[{"imported": "WebBaseLoader", "source": "langchain_community.document_loaders", "docs": "https://python.langchain.com/api_reference/community/document_loaders/langchain_community.document_loaders.web_base.WebBaseLoader.html", "title": "How to add retrieval to chatbots"}]-->
from langchain_community.document_loaders import WebBaseLoader

loader = WebBaseLoader("https://docs.smith.langchain.com/overview")
data = loader.load()

接下来，我们将其拆分为LLM的上下文窗口可以处理的较小块，并将其存储在向量数据库中：

<!--IMPORTS:[{"imported": "RecursiveCharacterTextSplitter", "source": "langchain_text_splitters", "docs": "https://python.langchain.com/api_reference/text_splitters/character/langchain_text_splitters.character.RecursiveCharacterTextSplitter.html", "title": "How to add retrieval to chatbots"}]-->
from langchain_text_splitters import RecursiveCharacterTextSplitter

text_splitter = RecursiveCharacterTextSplitter(chunk_size=500, chunk_overlap=0)
all_splits = text_splitter.split_documents(data)

然后我们将这些块嵌入并存储在向量数据库中：

<!--IMPORTS:[{"imported": "Chroma", "source": "langchain_chroma", "docs": "https://python.langchain.com/api_reference/chroma/vectorstores/langchain_chroma.vectorstores.Chroma.html", "title": "How to add retrieval to chatbots"}, {"imported": "OpenAIEmbeddings", "source": "langchain_openai", "docs": "https://python.langchain.com/api_reference/openai/embeddings/langchain_openai.embeddings.base.OpenAIEmbeddings.html", "title": "How to add retrieval to chatbots"}]-->
from langchain_chroma import Chroma
from langchain_openai import OpenAIEmbeddings

vectorstore = Chroma.from_documents(documents=all_splits, embedding=OpenAIEmbeddings())

最后，让我们从初始化的向量存储中创建一个检索器：

# k is the number of chunks to retrieve
retriever = vectorstore.as_retriever(k=4)

docs = retriever.invoke("Can LangSmith help test my LLM applications?")

docs

[Document(page_content='Skip to main content🦜️🛠️ LangSmith DocsPython DocsJS/TS DocsSearchGo to AppLangSmithOverviewTracingTesting & EvaluationOrganizationsHubLangSmith CookbookOverviewOn this pageLangSmith Overview and User GuideBuilding reliable LLM applications can be challenging. LangChain simplifies the initial setup, but there is still work needed to bring the performance of prompts, chains and agents up the level where they are reliable enough to be used in production.Over the past two months, we at LangChain', metadata={'description': 'Building reliable LLM applications can be challenging. LangChain simplifies the initial setup, but there is still work needed to bring the performance of prompts, chains and agents up the level where they are reliable enough to be used in production.', 'language': 'en', 'source': 'https://docs.smith.langchain.com/overview', 'title': 'LangSmith Overview and User Guide | 🦜️🛠️ LangSmith'}),
 Document(page_content='LangSmith Overview and User Guide | 🦜️🛠️ LangSmith', metadata={'description': 'Building reliable LLM applications can be challenging. LangChain simplifies the initial setup, but there is still work needed to bring the performance of prompts, chains and agents up the level where they are reliable enough to be used in production.', 'language': 'en', 'source': 'https://docs.smith.langchain.com/overview', 'title': 'LangSmith Overview and User Guide | 🦜️🛠️ LangSmith'}),
 Document(page_content='You can also quickly edit examples and add them to datasets to expand the surface area of your evaluation sets or to fine-tune a model for improved quality or reduced costs.Monitoring\u200bAfter all this, your app might finally ready to go in production. LangSmith can also be used to monitor your application in much the same way that you used for debugging. You can log all traces, visualize latency and token usage statistics, and troubleshoot specific issues as they arise. Each run can also be', metadata={'description': 'Building reliable LLM applications can be challenging. LangChain simplifies the initial setup, but there is still work needed to bring the performance of prompts, chains and agents up the level where they are reliable enough to be used in production.', 'language': 'en', 'source': 'https://docs.smith.langchain.com/overview', 'title': 'LangSmith Overview and User Guide | 🦜️🛠️ LangSmith'}),
 Document(page_content="does that affect the output?\u200bSo you notice a bad output, and you go into LangSmith to see what's going on. You find the faulty LLM call and are now looking at the exact input. You want to try changing a word or a phrase to see what happens -- what do you do?We constantly ran into this issue. Initially, we copied the prompt to a playground of sorts. But this got annoying, so we built a playground of our own! When examining an LLM call, you can click the Open in Playground button to access this", metadata={'description': 'Building reliable LLM applications can be challenging. LangChain simplifies the initial setup, but there is still work needed to bring the performance of prompts, chains and agents up the level where they are reliable enough to be used in production.', 'language': 'en', 'source': 'https://docs.smith.langchain.com/overview', 'title': 'LangSmith Overview and User Guide | 🦜️🛠️ LangSmith'})]

我们可以看到，上述检索器的调用结果是LangSmith文档中包含关于测试的信息，这些信息可以作为我们的聊天机器人回答问题时的上下文。现在我们有了一个可以从LangSmith文档中返回相关数据的检索器！

文档链

现在我们有了一个可以返回LangChain文档的检索器，让我们创建一个链，可以使用它们作为上下文来回答问题。我们将使用create_stuff_documents_chain辅助函数将所有输入文档“填充”到提示中。它还将处理将文档格式化为字符串。

除了聊天模型，该函数还期望一个包含 context 变量的提示，以及一个名为 messages 的聊天历史消息占位符。我们将创建一个合适的提示并按如下所示传递它：

<!--IMPORTS:[{"imported": "create_stuff_documents_chain", "source": "langchain.chains.combine_documents", "docs": "https://python.langchain.com/api_reference/langchain/chains/langchain.chains.combine_documents.stuff.create_stuff_documents_chain.html", "title": "How to add retrieval to chatbots"}, {"imported": "ChatPromptTemplate", "source": "langchain_core.prompts", "docs": "https://python.langchain.com/api_reference/core/prompts/langchain_core.prompts.chat.ChatPromptTemplate.html", "title": "How to add retrieval to chatbots"}, {"imported": "MessagesPlaceholder", "source": "langchain_core.prompts", "docs": "https://python.langchain.com/api_reference/core/prompts/langchain_core.prompts.chat.MessagesPlaceholder.html", "title": "How to add retrieval to chatbots"}]-->
from langchain.chains.combine_documents import create_stuff_documents_chain
from langchain_core.prompts import ChatPromptTemplate, MessagesPlaceholder

SYSTEM_TEMPLATE = """
Answer the user's questions based on the below context. 
If the context doesn't contain any relevant information to the question, don't make something up and just say "I don't know":

<context>
{context}
</context>
"""

question_answering_prompt = ChatPromptTemplate.from_messages(
    [
        (
            "system",
            SYSTEM_TEMPLATE,
        ),
        MessagesPlaceholder(variable_name="messages"),
    ]
)

document_chain = create_stuff_documents_chain(chat, question_answering_prompt)

我们可以单独调用这个 document_chain 来回答问题。让我们使用上面检索到的文档和相同的问题，langsmith 如何帮助测试？：

<!--IMPORTS:[{"imported": "HumanMessage", "source": "langchain_core.messages", "docs": "https://python.langchain.com/api_reference/core/messages/langchain_core.messages.human.HumanMessage.html", "title": "How to add retrieval to chatbots"}]-->
from langchain_core.messages import HumanMessage

document_chain.invoke(
    {
        "context": docs,
        "messages": [
            HumanMessage(content="Can LangSmith help test my LLM applications?")
        ],
    }
)

'Yes, LangSmith can help test and evaluate your LLM applications. It simplifies the initial setup, and you can use it to monitor your application, log all traces, visualize latency and token usage statistics, and troubleshoot specific issues as they arise.'

看起来不错！为了比较，我们可以尝试不使用上下文文档并比较结果：

document_chain.invoke(
    {
        "context": [],
        "messages": [
            HumanMessage(content="Can LangSmith help test my LLM applications?")
        ],
    }
)

"I don't know about LangSmith's specific capabilities for testing LLM applications. It's best to reach out to LangSmith directly to inquire about their services and how they can assist with testing your LLM applications."

我们可以看到 LLM 没有返回任何结果。

检索链

让我们将这个文档链与检索器结合起来。这是一个可能的实现方式：

<!--IMPORTS:[{"imported": "RunnablePassthrough", "source": "langchain_core.runnables", "docs": "https://python.langchain.com/api_reference/core/runnables/langchain_core.runnables.passthrough.RunnablePassthrough.html", "title": "How to add retrieval to chatbots"}]-->
from typing import Dict

from langchain_core.runnables import RunnablePassthrough


def parse_retriever_input(params: Dict):
    return params["messages"][-1].content


retrieval_chain = RunnablePassthrough.assign(
    context=parse_retriever_input | retriever,
).assign(
    answer=document_chain,
)

给定一组输入消息，我们提取列表中最后一条消息的内容，并将其传递给检索器以获取一些文档。然后，我们将这些文档作为上下文传递给我们的文档链以生成最终响应。

调用这个链结合了上述两个步骤：

retrieval_chain.invoke(
    {
        "messages": [
            HumanMessage(content="Can LangSmith help test my LLM applications?")
        ],
    }
)

{'messages': [HumanMessage(content='Can LangSmith help test my LLM applications?')],
 'context': [Document(page_content='Skip to main content🦜️🛠️ LangSmith DocsPython DocsJS/TS DocsSearchGo to AppLangSmithOverviewTracingTesting & EvaluationOrganizationsHubLangSmith CookbookOverviewOn this pageLangSmith Overview and User GuideBuilding reliable LLM applications can be challenging. LangChain simplifies the initial setup, but there is still work needed to bring the performance of prompts, chains and agents up the level where they are reliable enough to be used in production.Over the past two months, we at LangChain', metadata={'description': 'Building reliable LLM applications can be challenging. LangChain simplifies the initial setup, but there is still work needed to bring the performance of prompts, chains and agents up the level where they are reliable enough to be used in production.', 'language': 'en', 'source': 'https://docs.smith.langchain.com/overview', 'title': 'LangSmith Overview and User Guide | 🦜️🛠️ LangSmith'}),
  Document(page_content='LangSmith Overview and User Guide | 🦜️🛠️ LangSmith', metadata={'description': 'Building reliable LLM applications can be challenging. LangChain simplifies the initial setup, but there is still work needed to bring the performance of prompts, chains and agents up the level where they are reliable enough to be used in production.', 'language': 'en', 'source': 'https://docs.smith.langchain.com/overview', 'title': 'LangSmith Overview and User Guide | 🦜️🛠️ LangSmith'}),
  Document(page_content='You can also quickly edit examples and add them to datasets to expand the surface area of your evaluation sets or to fine-tune a model for improved quality or reduced costs.Monitoring\u200bAfter all this, your app might finally ready to go in production. LangSmith can also be used to monitor your application in much the same way that you used for debugging. You can log all traces, visualize latency and token usage statistics, and troubleshoot specific issues as they arise. Each run can also be', metadata={'description': 'Building reliable LLM applications can be challenging. LangChain simplifies the initial setup, but there is still work needed to bring the performance of prompts, chains and agents up the level where they are reliable enough to be used in production.', 'language': 'en', 'source': 'https://docs.smith.langchain.com/overview', 'title': 'LangSmith Overview and User Guide | 🦜️🛠️ LangSmith'}),
  Document(page_content="does that affect the output?\u200bSo you notice a bad output, and you go into LangSmith to see what's going on. You find the faulty LLM call and are now looking at the exact input. You want to try changing a word or a phrase to see what happens -- what do you do?We constantly ran into this issue. Initially, we copied the prompt to a playground of sorts. But this got annoying, so we built a playground of our own! When examining an LLM call, you can click the Open in Playground button to access this", metadata={'description': 'Building reliable LLM applications can be challenging. LangChain simplifies the initial setup, but there is still work needed to bring the performance of prompts, chains and agents up the level where they are reliable enough to be used in production.', 'language': 'en', 'source': 'https://docs.smith.langchain.com/overview', 'title': 'LangSmith Overview and User Guide | 🦜️🛠️ LangSmith'})],
 'answer': 'Yes, LangSmith can help test and evaluate your LLM applications. It simplifies the initial setup, and you can use it to monitor your application, log all traces, visualize latency and token usage statistics, and troubleshoot specific issues as they arise.'}

看起来不错！

查询转换

我们的检索链能够回答关于LangSmith的问题，但存在一个问题 - 聊天机器人与用户的互动是对话式的，因此必须处理后续问题。

当前形式的链在这方面会遇到困难。考虑一个对我们原始问题的后续问题，比如告诉我更多！。如果我们直接用这个查询调用检索器，我们会得到与LLM应用测试无关的文档：

retriever.invoke("Tell me more!")

[Document(page_content='You can also quickly edit examples and add them to datasets to expand the surface area of your evaluation sets or to fine-tune a model for improved quality or reduced costs.Monitoring\u200bAfter all this, your app might finally ready to go in production. LangSmith can also be used to monitor your application in much the same way that you used for debugging. You can log all traces, visualize latency and token usage statistics, and troubleshoot specific issues as they arise. Each run can also be', metadata={'description': 'Building reliable LLM applications can be challenging. LangChain simplifies the initial setup, but there is still work needed to bring the performance of prompts, chains and agents up the level where they are reliable enough to be used in production.', 'language': 'en', 'source': 'https://docs.smith.langchain.com/overview', 'title': 'LangSmith Overview and User Guide | 🦜️🛠️ LangSmith'}),
 Document(page_content='playground. Here, you can modify the prompt and re-run it to observe the resulting changes to the output - as many times as needed!Currently, this feature supports only OpenAI and Anthropic models and works for LLM and Chat Model calls. We plan to extend its functionality to more LLM types, chains, agents, and retrievers in the future.What is the exact sequence of events?\u200bIn complicated chains and agents, it can often be hard to understand what is going on under the hood. What calls are being', metadata={'description': 'Building reliable LLM applications can be challenging. LangChain simplifies the initial setup, but there is still work needed to bring the performance of prompts, chains and agents up the level where they are reliable enough to be used in production.', 'language': 'en', 'source': 'https://docs.smith.langchain.com/overview', 'title': 'LangSmith Overview and User Guide | 🦜️🛠️ LangSmith'}),
 Document(page_content='however, there is still no complete substitute for human review to get the utmost quality and reliability from your application.', metadata={'description': 'Building reliable LLM applications can be challenging. LangChain simplifies the initial setup, but there is still work needed to bring the performance of prompts, chains and agents up the level where they are reliable enough to be used in production.', 'language': 'en', 'source': 'https://docs.smith.langchain.com/overview', 'title': 'LangSmith Overview and User Guide | 🦜️🛠️ LangSmith'}),
 Document(page_content='Skip to main content🦜️🛠️ LangSmith DocsPython DocsJS/TS DocsSearchGo to AppLangSmithOverviewTracingTesting & EvaluationOrganizationsHubLangSmith CookbookOverviewOn this pageLangSmith Overview and User GuideBuilding reliable LLM applications can be challenging. LangChain simplifies the initial setup, but there is still work needed to bring the performance of prompts, chains and agents up the level where they are reliable enough to be used in production.Over the past two months, we at LangChain', metadata={'description': 'Building reliable LLM applications can be challenging. LangChain simplifies the initial setup, but there is still work needed to bring the performance of prompts, chains and agents up the level where they are reliable enough to be used in production.', 'language': 'en', 'source': 'https://docs.smith.langchain.com/overview', 'title': 'LangSmith Overview and User Guide | 🦜️🛠️ LangSmith'})]

这是因为检索器没有内在的状态概念，只会提取与给定查询最相似的文档。为了解决这个问题，我们可以将查询转换为一个独立的查询，而不依赖于任何外部参考的LLM。

这是一个例子：

<!--IMPORTS:[{"imported": "AIMessage", "source": "langchain_core.messages", "docs": "https://python.langchain.com/api_reference/core/messages/langchain_core.messages.ai.AIMessage.html", "title": "How to add retrieval to chatbots"}, {"imported": "HumanMessage", "source": "langchain_core.messages", "docs": "https://python.langchain.com/api_reference/core/messages/langchain_core.messages.human.HumanMessage.html", "title": "How to add retrieval to chatbots"}]-->
from langchain_core.messages import AIMessage, HumanMessage

query_transform_prompt = ChatPromptTemplate.from_messages(
    [
        MessagesPlaceholder(variable_name="messages"),
        (
            "user",
            "Given the above conversation, generate a search query to look up in order to get information relevant to the conversation. Only respond with the query, nothing else.",
        ),
    ]
)

query_transformation_chain = query_transform_prompt | chat

query_transformation_chain.invoke(
    {
        "messages": [
            HumanMessage(content="Can LangSmith help test my LLM applications?"),
            AIMessage(
                content="Yes, LangSmith can help test and evaluate your LLM applications. It allows you to quickly edit examples and add them to datasets to expand the surface area of your evaluation sets or to fine-tune a model for improved quality or reduced costs. Additionally, LangSmith can be used to monitor your application, log all traces, visualize latency and token usage statistics, and troubleshoot specific issues as they arise."
            ),
            HumanMessage(content="Tell me more!"),
        ],
    }
)

AIMessage(content='"LangSmith LLM application testing and evaluation"')

太棒了！那个转换后的查询将提取与LLM应用测试相关的上下文文档。

让我们将其添加到我们的检索链中。我们可以如下包装我们的检索器：

<!--IMPORTS:[{"imported": "StrOutputParser", "source": "langchain_core.output_parsers", "docs": "https://python.langchain.com/api_reference/core/output_parsers/langchain_core.output_parsers.string.StrOutputParser.html", "title": "How to add retrieval to chatbots"}, {"imported": "RunnableBranch", "source": "langchain_core.runnables", "docs": "https://python.langchain.com/api_reference/core/runnables/langchain_core.runnables.branch.RunnableBranch.html", "title": "How to add retrieval to chatbots"}]-->
from langchain_core.output_parsers import StrOutputParser
from langchain_core.runnables import RunnableBranch

query_transforming_retriever_chain = RunnableBranch(
    (
        lambda x: len(x.get("messages", [])) == 1,
        # If only one message, then we just pass that message's content to retriever
        (lambda x: x["messages"][-1].content) | retriever,
    ),
    # If messages, then we pass inputs to LLM chain to transform the query, then pass to retriever
    query_transform_prompt | chat | StrOutputParser() | retriever,
).with_config(run_name="chat_retriever_chain")

然后，我们可以使用这个查询转换链，使我们的检索链更好地处理此类后续问题：

SYSTEM_TEMPLATE = """
Answer the user's questions based on the below context. 
If the context doesn't contain any relevant information to the question, don't make something up and just say "I don't know":

<context>
{context}
</context>
"""

question_answering_prompt = ChatPromptTemplate.from_messages(
    [
        (
            "system",
            SYSTEM_TEMPLATE,
        ),
        MessagesPlaceholder(variable_name="messages"),
    ]
)

document_chain = create_stuff_documents_chain(chat, question_answering_prompt)

conversational_retrieval_chain = RunnablePassthrough.assign(
    context=query_transforming_retriever_chain,
).assign(
    answer=document_chain,
)

太棒了！让我们用与之前相同的输入调用这个新链：

conversational_retrieval_chain.invoke(
    {
        "messages": [
            HumanMessage(content="Can LangSmith help test my LLM applications?"),
        ]
    }
)

{'messages': [HumanMessage(content='Can LangSmith help test my LLM applications?')],
 'context': [Document(page_content='Skip to main content🦜️🛠️ LangSmith DocsPython DocsJS/TS DocsSearchGo to AppLangSmithOverviewTracingTesting & EvaluationOrganizationsHubLangSmith CookbookOverviewOn this pageLangSmith Overview and User GuideBuilding reliable LLM applications can be challenging. LangChain simplifies the initial setup, but there is still work needed to bring the performance of prompts, chains and agents up the level where they are reliable enough to be used in production.Over the past two months, we at LangChain', metadata={'description': 'Building reliable LLM applications can be challenging. LangChain simplifies the initial setup, but there is still work needed to bring the performance of prompts, chains and agents up the level where they are reliable enough to be used in production.', 'language': 'en', 'source': 'https://docs.smith.langchain.com/overview', 'title': 'LangSmith Overview and User Guide | 🦜️🛠️ LangSmith'}),
  Document(page_content='LangSmith Overview and User Guide | 🦜️🛠️ LangSmith', metadata={'description': 'Building reliable LLM applications can be challenging. LangChain simplifies the initial setup, but there is still work needed to bring the performance of prompts, chains and agents up the level where they are reliable enough to be used in production.', 'language': 'en', 'source': 'https://docs.smith.langchain.com/overview', 'title': 'LangSmith Overview and User Guide | 🦜️🛠️ LangSmith'}),
  Document(page_content='You can also quickly edit examples and add them to datasets to expand the surface area of your evaluation sets or to fine-tune a model for improved quality or reduced costs.Monitoring\u200bAfter all this, your app might finally ready to go in production. LangSmith can also be used to monitor your application in much the same way that you used for debugging. You can log all traces, visualize latency and token usage statistics, and troubleshoot specific issues as they arise. Each run can also be', metadata={'description': 'Building reliable LLM applications can be challenging. LangChain simplifies the initial setup, but there is still work needed to bring the performance of prompts, chains and agents up the level where they are reliable enough to be used in production.', 'language': 'en', 'source': 'https://docs.smith.langchain.com/overview', 'title': 'LangSmith Overview and User Guide | 🦜️🛠️ LangSmith'}),
  Document(page_content="does that affect the output?\u200bSo you notice a bad output, and you go into LangSmith to see what's going on. You find the faulty LLM call and are now looking at the exact input. You want to try changing a word or a phrase to see what happens -- what do you do?We constantly ran into this issue. Initially, we copied the prompt to a playground of sorts. But this got annoying, so we built a playground of our own! When examining an LLM call, you can click the Open in Playground button to access this", metadata={'description': 'Building reliable LLM applications can be challenging. LangChain simplifies the initial setup, but there is still work needed to bring the performance of prompts, chains and agents up the level where they are reliable enough to be used in production.', 'language': 'en', 'source': 'https://docs.smith.langchain.com/overview', 'title': 'LangSmith Overview and User Guide | 🦜️🛠️ LangSmith'})],
 'answer': 'Yes, LangSmith can help test and evaluate LLM (Language Model) applications. It simplifies the initial setup, and you can use it to monitor your application, log all traces, visualize latency and token usage statistics, and troubleshoot specific issues as they arise.'}

conversational_retrieval_chain.invoke(
    {
        "messages": [
            HumanMessage(content="Can LangSmith help test my LLM applications?"),
            AIMessage(
                content="Yes, LangSmith can help test and evaluate your LLM applications. It allows you to quickly edit examples and add them to datasets to expand the surface area of your evaluation sets or to fine-tune a model for improved quality or reduced costs. Additionally, LangSmith can be used to monitor your application, log all traces, visualize latency and token usage statistics, and troubleshoot specific issues as they arise."
            ),
            HumanMessage(content="Tell me more!"),
        ],
    }
)

{'messages': [HumanMessage(content='Can LangSmith help test my LLM applications?'),
  AIMessage(content='Yes, LangSmith can help test and evaluate your LLM applications. It allows you to quickly edit examples and add them to datasets to expand the surface area of your evaluation sets or to fine-tune a model for improved quality or reduced costs. Additionally, LangSmith can be used to monitor your application, log all traces, visualize latency and token usage statistics, and troubleshoot specific issues as they arise.'),
  HumanMessage(content='Tell me more!')],
 'context': [Document(page_content='LangSmith Overview and User Guide | 🦜️🛠️ LangSmith', metadata={'description': 'Building reliable LLM applications can be challenging. LangChain simplifies the initial setup, but there is still work needed to bring the performance of prompts, chains and agents up the level where they are reliable enough to be used in production.', 'language': 'en', 'source': 'https://docs.smith.langchain.com/overview', 'title': 'LangSmith Overview and User Guide | 🦜️🛠️ LangSmith'}),
  Document(page_content='You can also quickly edit examples and add them to datasets to expand the surface area of your evaluation sets or to fine-tune a model for improved quality or reduced costs.Monitoring\u200bAfter all this, your app might finally ready to go in production. LangSmith can also be used to monitor your application in much the same way that you used for debugging. You can log all traces, visualize latency and token usage statistics, and troubleshoot specific issues as they arise. Each run can also be', metadata={'description': 'Building reliable LLM applications can be challenging. LangChain simplifies the initial setup, but there is still work needed to bring the performance of prompts, chains and agents up the level where they are reliable enough to be used in production.', 'language': 'en', 'source': 'https://docs.smith.langchain.com/overview', 'title': 'LangSmith Overview and User Guide | 🦜️🛠️ LangSmith'}),
  Document(page_content='Skip to main content🦜️🛠️ LangSmith DocsPython DocsJS/TS DocsSearchGo to AppLangSmithOverviewTracingTesting & EvaluationOrganizationsHubLangSmith CookbookOverviewOn this pageLangSmith Overview and User GuideBuilding reliable LLM applications can be challenging. LangChain simplifies the initial setup, but there is still work needed to bring the performance of prompts, chains and agents up the level where they are reliable enough to be used in production.Over the past two months, we at LangChain', metadata={'description': 'Building reliable LLM applications can be challenging. LangChain simplifies the initial setup, but there is still work needed to bring the performance of prompts, chains and agents up the level where they are reliable enough to be used in production.', 'language': 'en', 'source': 'https://docs.smith.langchain.com/overview', 'title': 'LangSmith Overview and User Guide | 🦜️🛠️ LangSmith'}),
  Document(page_content='LangSmith makes it easy to manually review and annotate runs through annotation queues.These queues allow you to select any runs based on criteria like model type or automatic evaluation scores, and queue them up for human review. As a reviewer, you can then quickly step through the runs, viewing the input, output, and any existing tags before adding your own feedback.We often use this for a couple of reasons:To assess subjective qualities that automatic evaluators struggle with, like', metadata={'description': 'Building reliable LLM applications can be challenging. LangChain simplifies the initial setup, but there is still work needed to bring the performance of prompts, chains and agents up the level where they are reliable enough to be used in production.', 'language': 'en', 'source': 'https://docs.smith.langchain.com/overview', 'title': 'LangSmith Overview and User Guide | 🦜️🛠️ LangSmith'})],
 'answer': 'LangSmith simplifies the initial setup for building reliable LLM applications, but it acknowledges that there is still work needed to bring the performance of prompts, chains, and agents up to the level where they are reliable enough to be used in production. It also provides the capability to manually review and annotate runs through annotation queues, allowing you to select runs based on criteria like model type or automatic evaluation scores for human review. This feature is particularly useful for assessing subjective qualities that automatic evaluators struggle with.'}

您可以查看这个LangSmith追踪，亲自查看内部查询转换步骤。

流式处理

因为这个链是用LCEL构建的，你可以像使用.stream()这样的熟悉方法:

stream = conversational_retrieval_chain.stream(
    {
        "messages": [
            HumanMessage(content="Can LangSmith help test my LLM applications?"),
            AIMessage(
                content="Yes, LangSmith can help test and evaluate your LLM applications. It allows you to quickly edit examples and add them to datasets to expand the surface area of your evaluation sets or to fine-tune a model for improved quality or reduced costs. Additionally, LangSmith can be used to monitor your application, log all traces, visualize latency and token usage statistics, and troubleshoot specific issues as they arise."
            ),
            HumanMessage(content="Tell me more!"),
        ],
    }
)

for chunk in stream:
    print(chunk)

{'messages': [HumanMessage(content='Can LangSmith help test my LLM applications?'), AIMessage(content='Yes, LangSmith can help test and evaluate your LLM applications. It allows you to quickly edit examples and add them to datasets to expand the surface area of your evaluation sets or to fine-tune a model for improved quality or reduced costs. Additionally, LangSmith can be used to monitor your application, log all traces, visualize latency and token usage statistics, and troubleshoot specific issues as they arise.'), HumanMessage(content='Tell me more!')]}
{'context': [Document(page_content='LangSmith Overview and User Guide | 🦜️🛠️ LangSmith', metadata={'description': 'Building reliable LLM applications can be challenging. LangChain simplifies the initial setup, but there is still work needed to bring the performance of prompts, chains and agents up the level where they are reliable enough to be used in production.', 'language': 'en', 'source': 'https://docs.smith.langchain.com/overview', 'title': 'LangSmith Overview and User Guide | 🦜️🛠️ LangSmith'}), Document(page_content='You can also quickly edit examples and add them to datasets to expand the surface area of your evaluation sets or to fine-tune a model for improved quality or reduced costs.Monitoring\u200bAfter all this, your app might finally ready to go in production. LangSmith can also be used to monitor your application in much the same way that you used for debugging. You can log all traces, visualize latency and token usage statistics, and troubleshoot specific issues as they arise. Each run can also be', metadata={'description': 'Building reliable LLM applications can be challenging. LangChain simplifies the initial setup, but there is still work needed to bring the performance of prompts, chains and agents up the level where they are reliable enough to be used in production.', 'language': 'en', 'source': 'https://docs.smith.langchain.com/overview', 'title': 'LangSmith Overview and User Guide | 🦜️🛠️ LangSmith'}), Document(page_content='Skip to main content🦜️🛠️ LangSmith DocsPython DocsJS/TS DocsSearchGo to AppLangSmithOverviewTracingTesting & EvaluationOrganizationsHubLangSmith CookbookOverviewOn this pageLangSmith Overview and User GuideBuilding reliable LLM applications can be challenging. LangChain simplifies the initial setup, but there is still work needed to bring the performance of prompts, chains and agents up the level where they are reliable enough to be used in production.Over the past two months, we at LangChain', metadata={'description': 'Building reliable LLM applications can be challenging. LangChain simplifies the initial setup, but there is still work needed to bring the performance of prompts, chains and agents up the level where they are reliable enough to be used in production.', 'language': 'en', 'source': 'https://docs.smith.langchain.com/overview', 'title': 'LangSmith Overview and User Guide | 🦜️🛠️ LangSmith'}), Document(page_content='LangSmith makes it easy to manually review and annotate runs through annotation queues.These queues allow you to select any runs based on criteria like model type or automatic evaluation scores, and queue them up for human review. As a reviewer, you can then quickly step through the runs, viewing the input, output, and any existing tags before adding your own feedback.We often use this for a couple of reasons:To assess subjective qualities that automatic evaluators struggle with, like', metadata={'description': 'Building reliable LLM applications can be challenging. LangChain simplifies the initial setup, but there is still work needed to bring the performance of prompts, chains and agents up the level where they are reliable enough to be used in production.', 'language': 'en', 'source': 'https://docs.smith.langchain.com/overview', 'title': 'LangSmith Overview and User Guide | 🦜️🛠️ LangSmith'})]}
{'answer': ''}
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进一步阅读

本指南仅仅触及了检索技术的表面。有关不同方式的摄取、准备和检索最相关数据的更多信息，请查看相关的使用手册这里。