Gemini Adapter (Google)

Use Commerce Gateway with Gemini 1.5 Pro and Flash via Google's function_declarations format.

1 min read · LLM Adapters

Gemini function declarations

Gemini uses functionDeclarations and functionCall/functionResponse parts. GeminiAdapter handles translation from universal schema to Gemini declaration format.

Installation

bash

npm install @commerce-gateway/sdk @google/generative-ai

Usage example

import { GeminiAdapter } from "@betterdata/commerce-gateway/adapters";

const adapter = new GeminiAdapter({
  apiKey: process.env.GOOGLE_API_KEY!,
  model: "gemini-1.5-pro",
  maxToolIterations: 10,
  tools: ["search_products", "get_recommendations"],
});

const response = await adapter.handleRequest({
  messages: [{ role: "user", content: "Recommend skincare bundles under $80" }],
});

Model compatibility

Tested against Gemini 1.5 Pro, Gemini 1.5 Flash, and Gemini 2.x function-calling variants.

Differences vs OpenAI/Claude

Uses functionCall parts instead of OpenAI tool_calls or Claude tool_use
Supports richer nested parameter conversion via Gemini type enums (OBJECT, STRING, ARRAY)
Response assembly can include inline and function response parts in one candidate payload

Commerce Registry

To discover gateway endpoints for brands or GTINs before invoking tools, see Registry overview and .well-known File.