Error when sending second message: "error TypeError: chatMessage._getType is not a function"

[MirzaCickusic]

Whenever I send a second message I always get the: _error TypeError: chatMessage.getType is not a function

I am wondering if this is a project-related or library-related issue.

Full stack trace: error TypeError: chatMessage._getType is not a function at file:///Users/mirzacickusic/Documents/code/projects/gpt4-pdf-chatbot-langchain/node_modules/langchain/dist/chains/conversational_retrieval_chain.js:67:33 at Array.map (<anonymous>) at ConversationalRetrievalQAChain.getChatHistoryString (file:///Users/mirzacickusic/Documents/code/projects/gpt4-pdf-chatbot-langchain/node_modules/langchain/dist/chains/conversational_retrieval_chain.js:66:18) at ConversationalRetrievalQAChain._call (file:///Users/mirzacickusic/Documents/code/projects/gpt4-pdf-chatbot-langchain/node_modules/langchain/dist/chains/conversational_retrieval_chain.js:90:60) at ConversationalRetrievalQAChain.call (file:///Users/mirzacickusic/Documents/code/projects/gpt4-pdf-chatbot-langchain/node_modules/langchain/dist/chains/base.js:65:39) at process.processTicksAndRejections (node:internal/process/task_queues:95:5) at async handler (webpack-internal:///(api)/./pages/api/chat.ts:45:26) at async Object.apiResolver (/Users/mirzacickusic/Documents/code/projects/gpt4-pdf-chatbot-langchain/node_modules/next/dist/server/api-utils/node.js:372:9) at async DevServer.runApi (/Users/mirzacickusic/Documents/code/projects/gpt4-pdf-chatbot-langchain/node_modules/next/dist/server/next-server.js:513:9) at async Object.fn (/Users/mirzacickusic/Documents/code/projects/gpt4-pdf-chatbot-langchain/node_modules/next/dist/server/next-server.js:815:35) at async Router.execute (/Users/mirzacickusic/Documents/code/projects/gpt4-pdf-chatbot-langchain/node_modules/next/dist/server/router.js:243:32) at async DevServer.runImpl (/Users/mirzacickusic/Documents/code/projects/gpt4-pdf-chatbot-langchain/node_modules/next/dist/server/base-server.js:432:29) at async DevServer.run (/Users/mirzacickusic/Documents/code/projects/gpt4-pdf-chatbot-langchain/node_modules/next/dist/server/dev/next-dev-server.js:814:20) at async DevServer.handleRequestImpl (/Users/mirzacickusic/Documents/code/projects/gpt4-pdf-chatbot-langchain/node_modules/next/dist/server/base-server.js:375:20) at async /Users/mirzacickusic/Documents/code/projects/gpt4-pdf-chatbot-langchain/node_modules/next/dist/server/base-server.js:157:99

[josephpconley]

@MirzaCickusic I'm seeing this error as well, what was the resolution?

[rodneysdf]

fyi - I encountered this after upgrading LangChain to a new version. It uses a different format for chat History - an array of strings not an array of string pairs. Or you could use the more complicated BaseChatMessage[]. See https://github.com/hwchase17/langchainjs/blob/c538b228098ee96aed180a1b049cac3f56defb0d/langchain/src/chains/conversational_retrieval_chain.ts?plain=1#L68-L82

[davideuler]

I came across this issue too after upgrade langchain to 0.0.90. In case you have got the same issue. You can checkout my forked version(which uses chromadb as vector database).

gpt4-pdf-chatbot-langchain-chromadb

[rshirani]

I came across this issue too after upgrade langchain to 0.0.90. In case you have got the same issue. You can checkout my forked version(which uses chromadb as vector database).

gpt4-pdf-chatbot-langchain-chromadb

It seems BaseChatMessage, HumanChatMessage, AIChatMessage are deprecated in newer versions. They can be now replaced with BaseMessage, HumanMessage, and AIMessage accordingly.

[mohammadha98]

you should use langchain schema in your code when you wanna create a message to use that in a conversation chain , like this code :

import { ChatMessage } from 'langchain/schema';

let chatHistory: ChatMessage[] = []; const message= new ChatMessage("how can i use langchain to create a chat bot ?","user"); chatHistory.push(message);

await chain.call({ question: initialPrompt, chat_history:chatHistory });