Google Gemini Provider

Two providers for Google's Gemini models:

GoogleProvider — Google AI Studio (Generative AI API)
GoogleVertexProvider — Google Cloud Vertex AI

Google AI Studio

#![allow(unused)]
fn main() {
use yoagent::provider::GoogleProvider;

let agent = Agent::new(GoogleProvider)
    .with_model("gemini-2.0-flash")
    .with_api_key(std::env::var("GOOGLE_API_KEY").unwrap());
}

API Details

Endpoint: {base_url}/v1beta/models/{model}:streamGenerateContent?alt=sse&key={api_key}
Auth: API key as query parameter
Default base URL: https://generativelanguage.googleapis.com
Default context window: 1,000,000 tokens

Message Format

Google uses a different message format than OpenAI/Anthropic:

yoagent	Google API
`user` role	`user` role
`assistant` role	`model` role
`Content::Text`	`{"text": "..."}`
`Content::Image`	`{"inlineData": {...}}`
`Content::ToolCall`	`{"functionCall": {...}}`
`Message::ToolResult`	`{"functionResponse": {...}}`
System prompt	`systemInstruction` field
Tools	`tools[].functionDeclarations[]`

Streaming

Uses SSE format (alt=sse). Each chunk contains candidates with content.parts and optional usageMetadata.

Google Vertex AI

GoogleVertexProvider uses the same message format but with Vertex AI authentication and endpoints.