> ## Documentation Index
> Fetch the complete documentation index at: https://java.agentscope.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Gemini

`agentscope-extensions-model-gemini` integrates Google Gemini models through the Gemini API and supports the Vertex AI path through explicit configuration.

## Add the dependency

```xml theme={null}
<dependency>
    <groupId>io.agentscope</groupId>
    <artifactId>agentscope-extensions-model-gemini</artifactId>
    <version>${agentscope.version}</version>
</dependency>
```

## ModelRegistry

Set `GEMINI_API_KEY`, then use the `gemini:<model>` id:

```java theme={null}
ReActAgent agent = ReActAgent.builder()
    .name("assistant")
    .model("gemini:gemini-2.0-flash") // Resolved internally by ModelRegistry.resolve(modelId)
    .build();
```

## Explicit builder

Use the builder when you need custom API settings, Vertex AI credentials, formatter, transport, or generation options:

```java theme={null}
import io.agentscope.extensions.model.gemini.GeminiChatModel;

GeminiChatModel model = GeminiChatModel.builder()
    .apiKey(System.getenv("GEMINI_API_KEY"))
    .modelName("gemini-2.0-flash")
    .streamEnabled(true)
    .build();
```

## Spring Boot

Spring Boot applications can use the Gemini starter:

```xml theme={null}
<dependency>
    <groupId>io.agentscope</groupId>
    <artifactId>agentscope-gemini-spring-boot-starter</artifactId>
    <version>${agentscope.version}</version>
</dependency>
```

Full builder options, formatters, credentials, and registry context details are covered in [Model](/v2/en/docs/building-blocks/model).