Type 'ChatAnthropic' is not assignable to type 'LLMType'.

[AdiletBekmuratov]

Hello! Today after updating langchain package I encountered such error:

Type 'ChatAnthropic' is not assignable to type 'LLMType'. Type 'ChatAnthropic' is not assignable to type 'LLMType'. Type 'ChatAnthropicMessages' is not assignable to type 'Runnable<BaseLanguageModelInput, BaseMessage, RunnableConfig>'. Property 'lc_runnable' is protected but type 'Runnable<RunInput, RunOutput, CallOptions>' is not a class derived from 'Runnable<RunInput, RunOutput, CallOptions>'.ts(2322)

Example code:

...

 const model = new ChatAnthropic();
 const chain = new LLMChain({
    prompt: ChatPromptTemplate.fromMessages(messages),
    llm: model
 });

...

Packages versions: "langchain": "^0.1.3", "@langchain/anthropic": "^0.0.9", "@langchain/community": "^0.0.17", "@langchain/core": "^0.1.15", "@langchain/openai": "^0.0.12",

[dosubot[bot]]

🤖

Hello @AdiletBekmuratov! 👋

I'm Dosu, a friendly bot here to assist you with your LangChainJS questions and issues while you're waiting for a human maintainer to chime in. I'm here to help you solve bugs, answer questions, and even guide you on your journey to becoming a contributor. So feel free to ask anything, and let's work on this together! 😊

Based on the error message you provided, it seems like there's a type mismatch between the ChatAnthropic class and the expected LLMType. The LLMType is likely a type or interface that the ChatAnthropic class should implement or extend.

In your code snippet, you're trying to pass an instance of ChatAnthropic to the LLMChain constructor. The LLMChain constructor expects an object that matches the LLMType interface. If ChatAnthropic doesn't implement or extend LLMType, TypeScript will throw a type error.

To resolve this issue, you should ensure that ChatAnthropic either implements or extends LLMType. If ChatAnthropic is a class, you can do this by adding implements LLMType to the class declaration. If ChatAnthropic is an interface, you can extend LLMType by adding extends LLMType to the interface declaration.

Here's an example of how you can modify the ChatAnthropic class:

class ChatAnthropic implements LLMType {
  // ChatAnthropic class implementation
}

Or if ChatAnthropic is an interface:

interface ChatAnthropic extends LLMType {
  // ChatAnthropic interface definition
}

Please note that when you implement or extend LLMType, you need to ensure that ChatAnthropic includes all the properties and methods defined in LLMType.

If ChatAnthropic is coming from a third-party library and you can't modify it directly, you might need to create a wrapper class that implements LLMType and uses ChatAnthropic under the hood.

If the error persists, could you please provide the specific part of the code that's causing the error? This would help me provide a more accurate solution.

Sources

• langchain/src/agents/chat/index.ts

---

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[jacoblee93]

Will have a look at this today, thanks for reporting!

Did you lock core to a specific version as shown here?

https://js.langchain.com/docs/get_started/installation#installing-integration-packages

[AdiletBekmuratov]

@jacoblee93 Thank you very much! If someone encounters the same issues with types, they should follow the instructions from that link. Even after that, if there is still an error, try deleting the node_modules directory (and even the *.lock file) and reinstalling the packages. These steps helped me 🙌

Will have a look at this today, thanks for reporting!

Did you lock core to a specific version as shown here?

https://js.langchain.com/docs/get_started/installation#installing-integration-packages