Use Google Generative AI SDK for Gemini AI service chats with Kong AI Gateway

Deployment Platform
Tags
#ai
Minimum Version
Kong Gateway - 3.10
TL;DR

Configure the AI Proxy Advanced plugin with llm_format set to gemini, then use the Google Generative AI SDK to send requests through Kong AI Gateway.

Prerequisites

This is a Konnect tutorial and requires a Konnect personal access token.

  1. Create a new personal access token by opening the Konnect PAT page and selecting Generate Token.

  2. Export your token to an environment variable:

     export KONNECT_TOKEN='YOUR_KONNECT_PAT'
    
  3. Run the quickstart script to automatically provision a Control Plane and Data Plane, and configure your environment:

     curl -Ls https://get.konghq.com/quickstart | bash -s -- -k $KONNECT_TOKEN --deck-output
    

    This sets up a Konnect Control Plane named quickstart, provisions a local Data Plane, and prints out the following environment variable exports:

     export DECK_KONNECT_TOKEN=$KONNECT_TOKEN
     export DECK_KONNECT_CONTROL_PLANE_NAME=quickstart
     export KONNECT_CONTROL_PLANE_URL=https://us.api.konghq.com
     export KONNECT_PROXY_URL='http://localhost:8000'
    

    Copy and paste these into your terminal to configure your session.

This tutorial requires Kong Gateway Enterprise. If you don’t have Kong Gateway set up yet, you can use the quickstart script with an enterprise license to get an instance of Kong Gateway running almost instantly.

  1. Export your license to an environment variable:

     export KONG_LICENSE_DATA='LICENSE-CONTENTS-GO-HERE'
    
  2. Run the quickstart script:

    curl -Ls https://get.konghq.com/quickstart | bash -s -- -e KONG_LICENSE_DATA 
    

    Once Kong Gateway is ready, you will see the following message:

     Kong Gateway Ready
    

decK is a CLI tool for managing Kong Gateway declaratively with state files. To complete this tutorial, install decK version 1.43 or later.

This guide uses deck gateway apply, which directly applies entity configuration to your Gateway instance. We recommend upgrading your decK installation to take advantage of this tool.

You can check your current decK version with deck version.

For this tutorial, you’ll need Kong Gateway entities, like Gateway Services and Routes, pre-configured. These entities are essential for Kong Gateway to function but installing them isn’t the focus of this guide. Follow these steps to pre-configure them:

  1. Run the following command:

    echo '
    _format_version: "3.0"
    services:
      - name: gemini-service
        url: http://httpbin.konghq.com/
    routes:
      - name: gemini-route
        paths:
        - "/gemini"
        service:
          name: gemini-service
    ' | deck gateway apply -
    

To learn more about entities, you can read our entities documentation.

Before you begin, you must get the Gemini API key from Google Cloud:

  1. Go to the Google Cloud Console.
  2. Select or create a project.
  3. Enable the Generative Language API:
    • Navigate to APIs & Services > Library.
    • Search for “Generative Language API”.
    • Click Enable.
  4. Create an API key:
    • Navigate to APIs & Services > Credentials.
    • Click Create Credentials > API Key.
    • Copy the generated API key.

Export the API key as an environment variable:

export DECK_GEMINI_API_KEY="<your_gemini_api_key>"

To complete this tutorial, you’ll need Python (version 3.7 or later) and pip installed on your machine. You can verify it by running:

python3
python3 -m pip --version
  1. Create a virtual env:

    python3 -m venv myenv
    
  2. Activate it:

    source myenv/bin/activate
    

Install the Google Generative AI SDK:

pip install google-generativeai

Configure the AI Proxy plugin

The AI Proxy plugin supports Google’s Gemini models and works with the Google Generative AI SDK. This configuration allows you to use the standard Gemini SDK. Apply the plugin configuration with your GCP service account credentials:

echo '
_format_version: "3.0"
plugins:
  - name: ai-proxy
    service: gemini-service
    config:
      route_type: llm/v1/chat
      llm_format: gemini
      auth:
        param_name: key
        param_value: "${{ env "DECK_GEMINI_API_KEY" }}"
        param_location: query
      model:
        provider: gemini
        name: gemini-2.0-flash-exp
' | deck gateway apply -

Test with Google Generative AI SDK

Create a test script that uses the Google Generative AI SDK. The script initializes a client with a dummy API key because Kong AI Gateway handles authentication, then sends a generation request through the gateway:

cat << 'EOF' > gemini.py
#!/usr/bin/env python3
import os
from google import genai

BASE_URL = "http://localhost:8000/gemini"

def gemini_chat():

    try:
        print(f"Connecting to: {BASE_URL}")

        client = genai.Client(
            api_key=os.environ.get("DECK_GEMINI_API_KEY"),
            vertexai=False,
            http_options={
                "base_url": BASE_URL
            }
        )

        print("Sending message...")
        response = client.models.generate_content(
            model="gemini-2.0-flash-exp",
            contents="Hello! How are you?"
        )

        print(f"Response: {response.text}")

    except Exception as e:
        print(f"Error: {e}")
        import traceback
        traceback.print_exc()

if __name__ == "__main__":
    gemini_chat()
EOF    

Run the script:

python3 gemini.py

Expected output:

Connecting to: http://localhost:8000/gemini
Sending message...
Response: Hello! I'm doing well, thank you for asking. As a large language model, I don't experience feelings or emotions in the way humans do, but I'm functioning properly and ready to assist you. How can I help you today?

Cleanup

If you created a new control plane and want to conserve your free trial credits or avoid unnecessary charges, delete the new control plane used in this tutorial.

curl -Ls https://get.konghq.com/quickstart | bash -s -- -d
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