Google Gemini Provider

Two providers for Google's Gemini models:

GoogleProvider — Google AI Studio (Generative AI API) via ApiProtocol::GoogleGenerativeAi
GoogleVertexProvider — Google Cloud Vertex AI via ApiProtocol::GoogleVertex

Google AI Studio

#![allow(unused)]
fn main() {
use phi_core::BasicAgent;
use phi_core::provider::ModelConfig;

let api_key = std::env::var("GOOGLE_API_KEY").unwrap();
let agent = BasicAgent::new(ModelConfig::google(
    "gemini-2.0-flash",
    "Gemini 2.0 Flash",
    &api_key,
));
}

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:

phi-core	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.

#![allow(unused)]
fn main() {
use phi_core::BasicAgent;
use phi_core::provider::{ModelConfig, ApiProtocol};

// Vertex AI uses OAuth2 Bearer tokens as the api_key
let access_token = get_access_token(); // your OAuth2 helper
let agent = BasicAgent::new(ModelConfig {
    id: "gemini-2.0-flash".into(),
    name: "Gemini 2.0 Flash (Vertex)".into(),
    api: ApiProtocol::GoogleVertex,
    provider: "google_vertex".into(),
    base_url: "https://us-central1-aiplatform.googleapis.com".into(),
    api_key: access_token,
    ..Default::default()
});
}