LangChainAdapter

Copilot Runtime adapter for LangChain.

Example

import { CopilotRuntime, LangChainAdapter } from "@copilotkit/runtime";
import { ChatOpenAI } from "@langchain/openai";
 
const copilotKit = new CopilotRuntime();
 
const model = new ChatOpenAI({
  model: "gpt-4o",
  apiKey: "<your-api-key>",
});
 
return new LangChainAdapter({
  chainFn: async ({ messages, tools }) => {
    return model.bindTools(tools).stream(messages);
    // or optionally enable strict mode
    // return model.bindTools(tools, { strict: true }).stream(messages);
  }
});

The asynchronous handler function (chainFn) can return any of the following:

• A simple string response
• A LangChain stream (IterableReadableStream)
• A LangChain BaseMessageChunk object
• A LangChain AIMessage object

Constructor Parameters