request-raw-gemini.ts

import { GoogleAuth } from "google-auth-library";

const projectId = "pokutuna-playground";
const location = "us-central1";
const model = "gemini-1.5-pro-preview-0409";
const [temperature, topK, topP, maxOutputTokens] = [0, 1, 0, 1028];

// en: List as many Japanese proverbs as possible.
const prompt = "日本のことわざをできるだけたくさん挙げて";

const token = await new GoogleAuth({ projectId }).getAccessToken();
const url = `https://us-central1-aiplatform.googleapis.com/v1/projects/${projectId}/locations/${location}/publishers/google/models/${model}:streamGenerateContent`;
const params = {
  contents: [{ role: "user", parts: [{ text: prompt }] }],
  generationConfig: { temperature, topK, topP, maxOutputTokens },
};

fetch(url, {
  method: "POST",
  headers: {
    "Content-Type": "application/json",
    Authorization: `Bearer ${token}`,
  },
  body: JSON.stringify(params),
}).then(async (res) => {
  if (!res.body) throw new Error("No body");

  const reader = res.body.getReader();
  const decoder = new TextDecoder();
  let isDone = false;
  while (!isDone) {
    const { value, done } = await reader.read();
    console.log(`--- [chunk] ---\n${decoder.decode(value)}\n`);
    isDone = done;
  }
});