@shayan-builds/use-every-llm/index.js

A unified API wrapper to use multiple LLMs like OpenAI and Gemini with ease.

import {
  GoogleGenAI,
  createUserContent,
  createPartFromUri,
} from "@google/genai";
import OpenAI from "openai";
import * as fs from "node:fs";

const gemini = new GoogleGenAI({
  apiKey: "AIzaSyDvKrElDZVDsdHVILCiHP7gswHZRF2a8sc",
});

const gpt = new OpenAI({
  baseURL: "https://models.github.ai/inference",
  apiKey: "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",
});

async function useLLM({ model, prompt, systemPrompt = "", image = "" }) {
  if (model.includes("gpt")) {
    const response = await gpt.chat.completions.create({
      messages: [
        { role: "system", content: systemPrompt },
        { role: "user", content: prompt },
      ],
      model,
    });

    console.log(response.choices[0].message.content);
  } else if (model.includes("gemini")) {
    const contents = [
      image
        ? {
            inlineData: {
              mimeType: "image/jpeg",
              data: fs.readFileSync(image, {
                encoding: "base64",
              }),
            },
          }
        : "",
      { text: prompt },
    ];

    const config = systemPrompt
      ? { systemInstruction: systemPrompt }
      : undefined;

    const response = await gemini.models.generateContent({
      model,
      contents,
      ...(config ? { config } : {}), // only add config if it exists
    });

    console.log(response.text);
  }
}

await useLLM({
  model: "gemini-2.5-flash",
  prompt: "describe the image",
  image: "Screenshot 2025-07-17 at 5.35.40 PM.png",
});

// await useLLM("gpt-4.1", "What model is it?")