I’m using the @ai-sdk/google integration in the Vercel AI SDK with the gemini-2.0-flash. I’m trying to use the streamText with tools and experimental_output option.

code:

import { createGoogleGenerativeAI } from "@ai-sdk/google";
import { Output, smoothStream, streamText, tool } from "ai";
import { z } from "zod";

const model = createGoogleGenerativeAI({
  apiKey: EncodedVideoChunk.GEMINI_API_KEY,
});

const Schema = z.object({
  response: z.string(),
});

const getWeatherInformation = tool({
  description: "show the weather in a given city to the user",
  parameters: z.object({ city: z.string() }),
  execute: async ({ city }) => {
    console.log(`Getting weather information for ${city}`);
    return `The weather in ${city} is sunny`;
  },
});

export const tools = {
  getWeatherInformation,
};

const result = streamText({
  model: model("gemini-2.0-flash-001"),
  messages: [
    { role: "system", content: "You are a helpful assistant." },
    { role: "user", content: "Give me weather of gujarat" },
  ],
  tools,
  maxSteps: 2,
  onError: (error) => {
    console.error("Error while streaming:", JSON.stringify(error, null, 2));
  },
  onFinish: (result) => {
    console.info("Output: " + JSON.stringify(result.object, null, 2));
    console.info("Tool calling: " + JSON.stringify(result.toolCalls, null, 2));
  },
  experimental_transform: smoothStream(),
  experimental_output: Output.object({
    schema: Schema,
  }),
});

for await (const delta of result.textStream) {
  console.info("------------------->", delta);
  console.info("\n\n");
}

Getting the following error:

For controlled generation of only function calls (forced function calling), please set 'tool_config.function_calling_config.mode' field to ANY instead of populating 'response_mime_type' and 'response_schema' fields. For more details, see: https://cloud.google.com/vertex-ai/generative-ai/docs/multimodal/function-calling#tool-config

It is working with OpenAI.