Using writer in workflow step with agent

export const advocateStep = createStep({
  id: "advocate",
  description: "Decide next action and draft external or ask user",
  stateSchema,
  inputSchema: messageSchema,
  outputSchema: advocateOutputSchema,
  execute: async ({
    writer,
    state,
    setState,
    inputData: { message, source },
  }) => {
    const { threadId, resourceId } = state;

    const prompt = `
      New message from ${source}: ${message}
    `;

    const stream = await consumerSupportAgent.stream(prompt, {
      structuredOutput: {
        schema: advocateOutputSchema,
      },
      maxSteps: 1,
      memory: {
        thread: threadId,
        resource: resourceId,
      },
    });

    await stream!.textStream.pipeTo(writer!);

    const response = await stream.getFullOutput();

    console.log("**", response);

    const { responseToUser, responseToThirdParty, status, awaiting } =
      response.object;

    setState({ ...state, status, awaiting });

    return { status, responseToUser, responseToThirdParty, awaiting };
  },
});