A pray for help - TypeError: stream is not async iterable

Gemini API
,
1

Hello, I have tried to set up GitHub - google-gemini/example-chat-app: Get up and running with the Gemini API using Node.js and Python and have got the chat working, but the stream keeps coming back with the current error: Error during /stream: TypeError: stream is not async iterable.

I would be very grateful for any help?
require(‘dotenv’).config({ path: ‘./.env’ });
/** Package to enable CORS to handle requests from all domains. */
const cors = require(‘cors’);

/** Framework for building RESTful APIs. */
const express = require(‘express’);

/** Initialize the Express app. */
const app = express();
app.use(express.json());

/** Apply the CORS middleware. */
app.use(cors());

/** Enable and listen to port 9000. */
const PORT = process.env.PORT || 9000;
app.listen(PORT, () => {
console.log(‘Server Listening on PORT:’, PORT);
});
// Hard-coded API key

/**

  • POST method route for normal chat (complete response, no streaming).
  • A chat message and the history of the conversation are sent to the Gemini
  • model. The complete response generated by the model to the posted message
  • will be returned in the API’s response.
    */

/** Package to use the Gemini API. */
const { GoogleGenerativeAI } = require(‘@google/generative-ai’);

const genAI = new GoogleGenerativeAI({apiKey: GEMINI_API_KEY });

/**

  • Initialize the Gemini model that will generate responses based on the
  • user’s queries. */
    const model = genAI.getGenerativeModel({ model: “gemini-2.0-flash” });

/**

  • POST method route for normal chat(complete response, no streaming).

  • A chat message and the history of the conversation are send to the Gemini

  • model. The complete response generated by the model to the posted message

  • will be returned in the API’s response.

  • Expects a JSON payload in the request with the following format:

  • Request:

  • chat: string,

  • history: Array

  • Returns a JSON payload containing the model response with the

  • following format:

  • Response:

  • text: string
    /
    app.post(“/chat”, async (req, res) => {
    /    * Read the request data. */
    const chatHistory = req.body.history || ;
    const msg = req.body.chat;

    /** Initialize the chat with the given history. */
    const chat = model.startChat({
    history: chatHistory
    });

    /**

    • Send the message posted by the user to the Gemini model and read the
    • response generated by the model.
      */
      const result = await chat.sendMessage(msg);
      const response = await result.response;
      const text = response.text();

    /** Send the response returned by the model as the API’s response. */
    res.send({“text”:text});
    });

/**

  • POST method route for streaming response.
  • A chat message and the history of the conversation are send to the Gemini
  • model. The response generated by the model will be streamed to handle
  • partial results.
  • Expects a JSON payload in the request with the following format:
  • Request:
  • chat: string,
  • history: Array
  • Returns a partial result of the model response with the
  • following format:
  • Response:

/
app.post(“/stream”, async (req, res) => {
/* Read the request data. */
const chatHistory = req.body.history || ;
const msg = req.body.chat;

/** Initialize the chat with history. */
const chat = model.startChat({
  history: chatHistory
});

/** 
 * Send a new user message and read the response.
 * Send the chunk of text result back to the client 
 * as soon as you receive it.
 */
const result = await chat.sendMessageStream(msg);
for await (const chunk of result.stream) {
  const chunkText = chunk.text();
  res.write(chunkText);
}
res.end();

});