从 RetrievalChain javascript 获取流响应时出错

Question

我在 JavaScript 中使用 langchain 创建了管道，当我使用 chain.invoke() 方法时，它工作得很好，但是当我尝试通过 chain.stream() 方法调用链时，我却遇到了问题在控制台上打印。有没有人遇到同样的问题？

    const prompt = ChatPromptTemplate.fromMessages([
      ["system", systemPrompt],
      new MessagesPlaceholder("chat_history"),
      ["user", "{input}"],
      ["user", userPrompt],
    ]);


    // console.log("Prompt is : ");
    // console.log(prompt);

    // Chain creation using prompt and model
    const chain = await createStuffDocumentsChain({
      llm: modelInstance,
      prompt,
    });


    // Initialize retriever with the vector store
    const startTimeInner = Date.now();
    const retriever = vectorStore.asRetriever({
      search_type: "mmr",
      search_kwargs: { k: 3 },
    });


    // console.log(vectorStore);
    const endTimeInner = Date.now();
    console.log(
      "Total time taken by retriever to fetch data from db: ",
      (endTimeInner - startTimeInner) / 1000
    );

    // Create a retrieval chain with the retriever and document chain
    const retrievalChain = await createRetrievalChain({
      retriever,
      combineDocsChain: chain,
    });

调用流响应

const response = await chain.stream({
    chat_history: chatHistory,
    input: question,
    
  });
  let firstResponse = false;
  for await (const chunk of response) {
    console.log(chunk);
    yield chunk.answer;
  }

Answer 1

尝试使用 -

chain.astream

，因为您正在使用

await