Tool calls not working with streamText

[AdiPat]

Hi everyone,

I'm facing an issue with tool calls using streamText.

interface StreamingAnswerGeneratorOptions {
  query: string;
  system?: string;
  temperature?: number;
  references: string[];
}

async function* streamingAnswerGenerator(
  options: StreamingAnswerGeneratorOptions
): AsyncGenerator<string, void, unknown> {
  const { query, references } = options;
  let { system, temperature } = options;

  if (!query) {
    yield "Please provide a query.";
    return;
  }

  if (!system) {
    console.warn("System prompt not provided. Using default. ");
    system = Constants.ANSWER_ENGINE_API.DEFAULT_SYSTEM_PROMPT;
  }

  if (!temperature || temperature < 0 || temperature > 1) {
    temperature = Constants.ANSWER_ENGINE_API.DEFAULT_TEMPERATURE;
  }

  console.log("streamingAnswerGenerator: query =", query);
  const { textStream: result, toolResults } = await streamText({
    model: Utils.AI_MODEL, // this is openai('gpt-4o')
    prompt: `Query: ${query}
            ${
              references.length > 0 ? `Context: ${references.join("\n")}` : ""
            }`,
    system,
    temperature,
    maxSteps: Constants.ANSWER_ENGINE_API.MAX_STEPS, // this is 10
    tools: {
      getWeather: {
        description:
          "Get the weather for a location given latitude and longitude. ",
        parameters: z.object({
          latitude: z.number(),
          longitude: z.number(),
        }),
        execute: async ({ latitude, longitude }) => {
          const weather = await getWeather({ latitude, longitude });

          if (!weather) {
            return "Failed to fetch weather. ";
          }

          return JSON.stringify(weather.current);
        },
      },
    },
  });

  const _toolResults = await toolResults;

  console.log("toolResults: ", _toolResults); // this line doesn't execute

  for await (const textPart of result) {
    yield textPart;
  }
}

What essentially happens is that the streamText call gets stuck and the console log for toolResults doesn't execute. What am I doing wrong here? Any help would be appreciated!

If max steps is not set then I can see the result of toolResults being printed. If max steps is set, then I don't see it. Also, either way I can see that getWeather is being called. So I'm not sure if I'm doing something incorrectly here.

I'm currently using Vercel AI 3.4.9 and OpenAI SDK 0.0.66 and NextJS 14.

[lgrammel]

await toolResults blocks further processing, so the stream never gets consumed.