SDKs · Updated 2026-07-21

Gemini SDK

Integrate Google Gen AI through the Varsten beta wrapper with conservative direct-to-provider fallback.

Status

The Gemini wrapper is version 0.1.0 beta and intended for founder-supervised pilots. It supports generateContent and generateContentStream. Validate the exact model and request features used by your workload.

Install

bash

npm install @varsten/gemini @google/genai

Node.js 18 or newer and ESM are required.

Create the client

import { VarstenGemini } from "@varsten/gemini";

const client = new VarstenGemini({
  varstenApiKey: process.env.VARSTEN_API_KEY,
  geminiApiKey: process.env.GEMINI_API_KEY,
  onFallback: (event) => console.warn("varsten fallback", event.reasonCode),
});

const response = await client.models.generateContent({
  model: "gemini-3.1-flash-lite",
  contents: "Hello",
});

The Gemini key remains local and is used only for direct fallback.

Conservative fallback

Gemini provider errors do not always expose response headers. The wrapper retries only transport failures and errors positively identified as Varsten-originated. An unattributed provider-like error is surfaced to avoid duplicate billing.