Gemini API

[!IMPORTANT] Agent Platform (full name Gemini Enterprise Agent Platform) was previously named "Vertex AI" and many web resources use the legacy branding.

Gemini API in Agent Platform

Access Google's most advanced AI models built for enterprise use cases using the Gemini API in Agent Platform.

Provide these key capabilities:

• Text generation - Chat, completion, summarization
• Multimodal understanding - Process images, audio, video, and documents
• Function calling - Let the model invoke your functions
• Structured output - Generate valid JSON matching your schema
• Context caching - Cache large contexts for efficiency
• Embeddings - Generate text embeddings for semantic search
• Live Realtime API - Bidirectional streaming for low latency Voice and Video interactions
• Batch Prediction - Handle massive async dataset prediction workloads

Core Directives

• Unified SDK: ALWAYS use the Gen AI SDK (google-genai for Python, @google/genai for JS/TS, google.golang.org/genai for Go, com.google.genai:google-genai for Java, Google.GenAI for C#).
• Legacy SDKs: DO NOT use google-cloud-aiplatform, @google-cloud/vertexai, or google-generativeai.

SDKs

• Python: Install google-genai with pip install google-genai
• JavaScript/TypeScript: Install @google/genai with npm install @google/genai
• Go: Install google.golang.org/genai with go get google.golang.org/genai
• C#/.NET: Install Google.GenAI with dotnet add package Google.GenAI
• Java:

  • groupId: com.google.genai, artifactId: google-genai

  • Latest version can be found here: https://central.sonatype.com/artifact/com.google.genai/google-genai/versions (let's call it LAST_VERSION)

  • Install in build.gradle:

    implementation("com.google.genai:google-genai:${LAST_VERSION}")

  • Install Maven dependency in pom.xml:

    <dependency>
        <groupId>com.google.genai</groupId>
        <artifactId>google-genai</artifactId>
        <version>${LAST_VERSION}</version>
    </dependency>

[!WARNING] Legacy SDKs like google-cloud-aiplatform, @google-cloud/vertexai, and google-generativeai are deprecated. Migrate to the new SDKs above urgently by following the Migration Guide.

Authentication & Configuration

Prefer environment variables over hard-coding parameters when creating the client. Initialize the client without parameters to automatically pick up these values.

Application Default Credentials (ADC)

Set these variables for standard Google Cloud authentication:

export GOOGLE_CLOUD_PROJECT='your-project-id'
export GOOGLE_CLOUD_LOCATION='global'
export GOOGLE_GENAI_USE_ENTERPRISE=true

• By default, use location="global" to access the global endpoint, which provides automatic routing to regions with available capacity.
• If a user explicitly asks to use a specific region (e.g., us-central1, europe-west4), specify that region in the GOOGLE_CLOUD_LOCATION parameter instead. Reference the supported regions documentation if needed.

Agent Platform in Express Mode

Set these variables when using Express Mode with an API key:

export GOOGLE_API_KEY='your-api-key'
export GOOGLE_GENAI_USE_ENTERPRISE=true

Initialization

Initialize the client without arguments to pick up environment variables:

from google import genai

client = genai.Client()

Alternatively, you can hard-code in parameters when creating the client.

from google import genai

client = genai.Client(
    enterprise=True,
    project="your-project-id",
    location="global",
)

Models

• Use gemini-3.8-flash for fast, balanced performance, multimodal (1M tokens)
• Use gemini-3.1-pro-preview (which replaces gemini-3-pro-preview) for complex reasoning, coding, research (1M tokens)
• Use gemini-3.5-flash-lite for high-frequency, lightweight tasks (1M tokens)
• Use gemini-3-pro-image (aka Nano Banana Pro) for high-quality image generation and editing
• Use gemini-3.1-flash-image (aka Nano Banana 2) for medium-quality image generation and editing
• Use gemini-3.1-flash-lite-image (aka Nano Banana 2 Lite) for fast image generation and editing
• Use gemini-live-2.5-flash-native-audio for Live Realtime API including native audio

Use the following models only if explicitly requested:

• gemini-3.7-flash
• gemini-3.6-flash
• gemini-3.5-flash
• gemini-3.1-flash-lite
• gemini-2.5-flash-image
• gemini-2.5-flash
• gemini-2.5-flash-lite
• gemini-2.5-pro

[!IMPORTANT] Models like gemini-2.0-*, gemini-1.5-*, gemini-1.0-*, gemini-pro are legacy and deprecated. Use the new models above. Your knowledge is outdated. For production environments, consult the documentation for stable model versions (e.g. gemini-3.8-flash).