Gemini Elixir Client

A comprehensive Elixir client for Google's Gemini AI API with dual authentication support, advanced streaming capabilities, type safety, and built-in telemetry.

Features

• 🔐 Dual Authentication: Seamless support for both Gemini API keys and Vertex AI OAuth/Service Accounts
• ⚡ Advanced Streaming: Production-grade Server-Sent Events streaming with real-time processing
• 🛡️ Type Safety: Complete type definitions with runtime validation
• 📊 Built-in Telemetry: Comprehensive observability and metrics out of the box
• 💬 Chat Sessions: Multi-turn conversation management with state persistence
• 🎭 Multimodal: Full support for text, image, audio, and video content
• 🚀 Production Ready: Robust error handling, retry logic, and performance optimizations

Quick Start

Installation

Add to your mix.exs:

def deps do
  [
    {:gemini, "~> 0.0.1"}
  ]
end

Basic Configuration

Configure your API key in config/runtime.exs:

import Config

config :gemini,
  api_key: System.get_env("GEMINI_API_KEY")

Or set the environment variable:

export GEMINI_API_KEY="your_api_key_here"

Simple Usage

# Basic text generation
{:ok, response} = Gemini.generate("Tell me about Elixir programming")
{:ok, text} = Gemini.extract_text(response)
IO.puts(text)

# With options
{:ok, response} = Gemini.generate("Explain quantum computing", [
  model: Gemini.Config.get_model(:flash_2_0_lite),
  temperature: 0.7,
  max_output_tokens: 1000
])

Streaming

# Start a streaming session
{:ok, stream_id} = Gemini.stream_generate("Write a long story", [
  on_chunk: fn chunk -> IO.write(chunk) end,
  on_complete: fn -> IO.puts("\n✅ Complete!") end
])

Authentication

This client supports two authentication methods:

1. Gemini API Key (Simple)

Best for development and simple applications:

# Environment variable (recommended)
export GEMINI_API_KEY="your_api_key"

# Application config
config :gemini, api_key: "your_api_key"

# Per-request override
Gemini.generate("Hello", api_key: "specific_key")

2. Vertex AI (Production)

Best for production Google Cloud applications:

# Service Account JSON file
export VERTEX_SERVICE_ACCOUNT="/path/to/service-account.json"
export VERTEX_PROJECT_ID="your-gcp-project"
export VERTEX_LOCATION="us-central1"

# Application config
config :gemini, :auth,
  type: :vertex_ai,
  credentials: %{
    service_account_key: System.get_env("VERTEX_SERVICE_ACCOUNT"),
    project_id: System.get_env("VERTEX_PROJECT_ID"),
    location: "us-central1"
  }

Error Handling

The client provides detailed error information with recovery suggestions:

case Gemini.generate("Hello world") do
  {:ok, response} ->
    {:ok, text} = Gemini.extract_text(response)

  {:error, %Gemini.Error{type: :rate_limit} = error} ->
    IO.puts("Rate limited. Retry after: #{error.retry_after}")

  {:error, %Gemini.Error{type: :authentication} = error} ->
    IO.puts("Auth error: #{error.message}")

  {:error, error} ->
    IO.puts("Unexpected error: #{inspect(error)}")
end

Advanced Features

Multimodal Content

content = [
  %{type: "text", text: "What's in this image?"},
  %{type: "image", source: %{type: "base64", data: base64_image}}
]

{:ok, response} = Gemini.generate(content)

Model Management

# List available models
{:ok, models} = Gemini.list_models()

# Get model details
{:ok, model_info} = Gemini.get_model(Gemini.Config.get_model(:flash_2_0_lite))

# Count tokens
{:ok, token_count} = Gemini.count_tokens("Your text", model: Gemini.Config.get_model(:flash_2_0_lite))

This module provides backward-compatible access to the Gemini API while routing requests through the unified coordinator for maximum flexibility and performance.