# Gemini Elixir Client
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[](https://hex.pm/packages/gemini_ex)
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A comprehensive Elixir client for Google's Gemini AI API with dual authentication support, advanced streaming capabilities, type safety, and built-in telemetry.
## โจ Features
- **๐ค Automatic Tool Calling**: A seamless, Python-SDK-like experience that automates the entire multi-turn tool-calling loop
- **๐ Dual Authentication**: Seamless support for both Gemini API keys and Vertex AI OAuth/Service Accounts
- **โก Advanced Streaming**: Production-grade Server-Sent Events streaming with real-time processing
- **๐ก๏ธ Type Safety**: Complete type definitions with runtime validation
- **๐ Built-in Telemetry**: Comprehensive observability and metrics out of the box
- **๐ฌ Chat Sessions**: Multi-turn conversation management with state persistence
- **๐ญ Multimodal**: Full support for text, image, audio, and video content
- **โ๏ธ Complete Generation Config**: Full support for all 12 generation config options including structured output
- **๏ฟฝ Producltion Ready**: Robust error handling, retry logic, and performance optimizations
- **๐ง Flexible Configuration**: Environment variables, application config, and per-request overrides
## ๐ฆ Installation
Add `gemini` to your list of dependencies in `mix.exs`:
```elixir
def deps do
[
{:gemini_ex, "~> 0.1.1"}
]
end
```
## ๐ Quick Start
### Basic Configuration
Configure your API key in `config/runtime.exs`:
```elixir
import Config
config :gemini_ex,
api_key: System.get_env("GEMINI_API_KEY")
```
Or set the environment variable:
```bash
export GEMINI_API_KEY="your_api_key_here"
```
### Simple Content Generation
```elixir
# 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-2.0-flash-lite",
temperature: 0.7,
max_output_tokens: 1000
])
# Advanced generation config with structured output
{:ok, response} = Gemini.generate("Analyze this topic and provide a summary", [
response_schema: %{
"type" => "object",
"properties" => %{
"summary" => %{"type" => "string"},
"key_points" => %{"type" => "array", "items" => %{"type" => "string"}},
"confidence" => %{"type" => "number"}
}
},
response_mime_type: "application/json",
temperature: 0.3
])
```
### Simple Tool Calling
```elixir
# Define a simple tool
defmodule WeatherTool do
def get_weather(%{"location" => location}) do
%{location: location, temperature: 22, condition: "sunny"}
end
end
# Create and register the tool
{:ok, weather_declaration} = Altar.ADM.new_function_declaration(%{
name: "get_weather",
description: "Gets weather for a location",
parameters: %{
type: "object",
properties: %{location: %{type: "string", description: "City name"}},
required: ["location"]
}
})
Gemini.Tools.register(weather_declaration, &WeatherTool.get_weather/1)
# Use the tool automatically - the model will call it as needed
{:ok, response} = Gemini.generate_content_with_auto_tools(
"What's the weather like in Tokyo?",
tools: [weather_declaration]
)
{:ok, text} = Gemini.extract_text(response)
IO.puts(text) # "The weather in Tokyo is sunny with a temperature of 22ยฐC."
```
### Advanced Streaming
```elixir
# Start a streaming session
{:ok, stream_id} = Gemini.stream_generate("Write a long story about AI", [
on_chunk: fn chunk -> IO.write(chunk) end,
on_complete: fn -> IO.puts("\nโ
Stream complete!") end,
on_error: fn error -> IO.puts("โ Error: #{inspect(error)}") end
])
# Stream management
Gemini.Streaming.pause_stream(stream_id)
Gemini.Streaming.resume_stream(stream_id)
Gemini.Streaming.stop_stream(stream_id)
```
### Advanced Generation Configuration
```elixir
# Using GenerationConfig struct for complex configurations
config = %Gemini.Types.GenerationConfig{
temperature: 0.7,
max_output_tokens: 2000,
response_schema: %{
"type" => "object",
"properties" => %{
"analysis" => %{"type" => "string"},
"recommendations" => %{"type" => "array", "items" => %{"type" => "string"}}
}
},
response_mime_type: "application/json",
stop_sequences: ["END", "COMPLETE"],
presence_penalty: 0.5,
frequency_penalty: 0.3
}
{:ok, response} = Gemini.generate("Analyze market trends", generation_config: config)
# All generation config options are supported:
{:ok, response} = Gemini.generate("Creative writing task", [
temperature: 0.9, # Creativity level
top_p: 0.8, # Nucleus sampling
top_k: 40, # Top-k sampling
candidate_count: 3, # Multiple responses
response_logprobs: true, # Include probabilities
logprobs: 5 # Token probabilities
])
```
### Multi-turn Conversations
```elixir
# Create a chat session
{:ok, session} = Gemini.create_chat_session([
model: "gemini-2.0-flash-lite",
system_instruction: "You are a helpful programming assistant."
])
# Send messages
{:ok, response1} = Gemini.send_message(session, "What is functional programming?")
{:ok, response2} = Gemini.send_message(session, "Show me an example in Elixir")
# Get conversation history
history = Gemini.get_conversation_history(session)
```
## ๐ ๏ธ Tool Calling (Function Calling)
Tool calling enables the Gemini model to interact with external functions and APIs, making it possible to build powerful agents that can perform actions, retrieve real-time data, and integrate with your systems. This transforms the model from a text generator into an intelligent agent capable of complex workflows.
### Automatic Execution (Recommended)
The automatic tool calling system provides the easiest and most robust way to use tools. It handles the entire multi-turn conversation loop automatically, executing tool calls and managing the conversation state behind the scenes.
#### Step 1: Define & Register Your Tools
```elixir
# Define your tool functions
defmodule DemoTools do
def get_weather(%{"location" => location}) do
# Your weather API integration here
%{
location: location,
temperature: 22,
condition: "sunny",
humidity: 65
}
end
def calculate(%{"operation" => op, "a" => a, "b" => b}) do
result = case op do
"add" -> a + b
"multiply" -> a * b
"divide" when b != 0 -> a / b
_ -> {:error, "Invalid operation"}
end
%{operation: op, result: result}
end
end
# Create function declarations
{:ok, weather_declaration} = Altar.ADM.new_function_declaration(%{
name: "get_weather",
description: "Gets current weather information for a specified location",
parameters: %{
type: "object",
properties: %{
location: %{
type: "string",
description: "The location to get weather for (e.g., 'San Francisco')"
}
},
required: ["location"]
}
})
{:ok, calc_declaration} = Altar.ADM.new_function_declaration(%{
name: "calculate",
description: "Performs basic mathematical calculations",
parameters: %{
type: "object",
properties: %{
operation: %{type: "string", enum: ["add", "multiply", "divide"]},
a: %{type: "number", description: "First operand"},
b: %{type: "number", description: "Second operand"}
},
required: ["operation", "a", "b"]
}
})
# Register the tools
Gemini.Tools.register(weather_declaration, &DemoTools.get_weather/1)
Gemini.Tools.register(calc_declaration, &DemoTools.calculate/1)
```
#### Step 2: Call the Model
```elixir
# Single call with automatic tool execution
{:ok, response} = Gemini.generate_content_with_auto_tools(
"What's the weather like in Tokyo? Also calculate 15 * 23.",
tools: [weather_declaration, calc_declaration],
model: "gemini-2.0-flash-lite",
temperature: 0.1
)
```
#### Step 3: Get the Final Result
```elixir
# Extract the final text response
{:ok, text} = Gemini.extract_text(response)
IO.puts(text)
# Output: "The weather in Tokyo is sunny with 22ยฐC and 65% humidity.
# The calculation of 15 * 23 equals 345."
```
The model automatically:
- Determines which tools to call based on your prompt
- Executes the necessary function calls
- Processes the results
- Provides a natural language response incorporating all the data
#### Streaming with Automatic Execution
For real-time responses with tool calling:
```elixir
# Start streaming with automatic tool execution
{:ok, stream_id} = Gemini.stream_generate_with_auto_tools(
"Check the weather in London and calculate the tip for a $50 meal",
tools: [weather_declaration, calc_declaration],
model: "gemini-2.0-flash-lite"
)
# Subscribe to the stream
:ok = Gemini.subscribe_stream(stream_id)
# The subscriber will only receive the final text chunks
# All tool execution happens automatically in the background
receive do
{:stream_chunk, ^stream_id, chunk} -> IO.write(chunk)
{:stream_complete, ^stream_id} -> IO.puts("\nโ
Complete!")
end
```
### Manual Execution (Advanced)
For advanced use cases requiring full control over the conversation loop, custom state management, or detailed logging of tool executions:
```elixir
# Step 1: Generate content with tool declarations
{:ok, response} = Gemini.generate_content(
"What's the weather in Paris?",
tools: [weather_declaration],
model: "gemini-2.0-flash-lite"
)
# Step 2: Check for function calls in the response
case response.candidates do
[%{content: %{parts: parts}}] ->
function_calls = Enum.filter(parts, &match?(%{function_call: _}, &1))
if function_calls != [] do
# Step 3: Execute the function calls
{:ok, tool_results} = Gemini.Tools.execute_calls(function_calls)
# Step 4: Create content from tool results
tool_content = Gemini.Types.Content.from_tool_results(tool_results)
# Step 5: Continue the conversation with results
conversation_history = [
%{role: "user", parts: [%{text: "What's the weather in Paris?"}]},
response.candidates |> hd() |> Map.get(:content),
tool_content
]
{:ok, final_response} = Gemini.generate_content(
conversation_history,
model: "gemini-2.0-flash-lite"
)
{:ok, text} = Gemini.extract_text(final_response)
IO.puts(text)
end
end
```
This manual approach gives you complete visibility and control over each step of the tool calling process, which can be valuable for debugging, logging, or implementing custom conversation management logic.
## ๐ฏ Examples
The repository includes comprehensive examples demonstrating all library features. All examples are ready to run and include proper error handling.
### Running Examples
All examples use the same execution method:
```bash
mix run examples/[example_name].exs
```
### Available Examples
#### 1. **`demo.exs`** - Comprehensive Feature Showcase
**The main library demonstration covering all core features.**
```bash
mix run examples/demo.exs
```
**Features demonstrated:**
- Model listing and information retrieval
- Simple text generation with various prompts
- Configured generation (creative vs precise modes)
- Multi-turn chat sessions with context
- Token counting for different text lengths
**Requirements:** `GEMINI_API_KEY` environment variable
---
#### 2. **`streaming_demo.exs`** - Real-time Streaming
**Live demonstration of Server-Sent Events streaming with progressive text delivery.**
```bash
mix run examples/streaming_demo.exs
```
**Features demonstrated:**
- Real-time progressive text streaming
- Stream subscription and event handling
- Authentication detection (Gemini API or Vertex AI)
- Stream status monitoring
**Requirements:** `GEMINI_API_KEY` or Vertex AI credentials
---
#### 3. **`demo_unified.exs`** - Multi-Auth Architecture
**Showcases the unified architecture supporting multiple authentication methods.**
```bash
mix run examples/demo_unified.exs
```
**Features demonstrated:**
- Configuration system and auth detection
- Authentication strategy switching
- Streaming manager capabilities
- Backward compatibility verification
**Requirements:** None (works with or without credentials)
---
#### 4. **`multi_auth_demo.exs`** - Concurrent Authentication
**Demonstrates concurrent usage of multiple authentication strategies.**
```bash
mix run examples/multi_auth_demo.exs
```
**Features demonstrated:**
- Concurrent Gemini API and Vertex AI requests
- Authentication failure handling
- Per-request auth strategy selection
- Error handling for invalid credentials
**Requirements:** `GEMINI_API_KEY` recommended (demonstrates Vertex AI auth failure)
---
#### 5. **`telemetry_showcase.exs`** - Comprehensive Telemetry System
**Complete demonstration of the built-in telemetry and observability features.**
```bash
mix run examples/telemetry_showcase.exs
```
**Features demonstrated:**
- Real-time telemetry event monitoring
- 7 event types: request start/stop/exception, stream start/chunk/stop/exception
- Telemetry helper functions (stream IDs, content classification, metadata)
- Live performance measurement and analysis
- Configuration management for telemetry
**Requirements:** `GEMINI_API_KEY` for live telemetry (works without for utilities demo)
---
#### 6. **`auto_tool_calling_demo.exs`** - Automatic Tool Execution (Recommended)
**Demonstrates the powerful automatic tool calling system for building intelligent agents.**
```bash
mix run examples/auto_tool_calling_demo.exs
```
**Features demonstrated:**
- Tool function definition and registration
- Automatic multi-turn tool execution
- Multiple tool types (weather, calculator, time)
- Function declaration creation with JSON schemas
- Streaming with automatic tool execution
**Requirements:** `GEMINI_API_KEY` for live tool execution
---
#### 7. **`tool_calling_demo.exs`** - Manual Tool Execution
**Shows manual control over the tool calling conversation loop for advanced use cases.**
```bash
mix run examples/tool_calling_demo.exs
```
**Features demonstrated:**
- Manual tool execution workflow
- Step-by-step conversation management
- Custom tool result processing
- Advanced debugging and logging capabilities
**Requirements:** `GEMINI_API_KEY` for live tool execution
---
#### 8. **`manual_tool_calling_demo.exs`** - Advanced Manual Tool Control
**Comprehensive manual tool calling patterns for complex agent workflows.**
```bash
mix run examples/manual_tool_calling_demo.exs
```
**Features demonstrated:**
- Complex multi-step tool workflows
- Custom conversation state management
- Error handling in tool execution
- Integration patterns for external APIs
**Requirements:** `GEMINI_API_KEY` for live tool execution
---
#### 9. **`live_auto_tool_test.exs`** - Live End-to-End Tool Calling Test โก **LIVE EXAMPLE**
**A comprehensive live test demonstrating real automatic tool execution with the Gemini API.**
```bash
elixir examples/live_auto_tool_test.exs
```
**Features demonstrated:**
- **Real Elixir module introspection** using `Code.ensure_loaded/1` and `Code.fetch_docs/1`
- **Live automatic tool execution** with the actual Gemini API
- **End-to-end workflow validation** from tool registration to final response
- **Comprehensive error handling** and debug output
- **Self-contained execution** with `Mix.install` dependency management
- **Professional output formatting** with step-by-step progress indicators
**What makes this special:**
- โ
**Actually calls the Gemini API** - not a mock or simulation
- โ
**Executes real Elixir code** - introspects modules like `Enum`, `String`, `GenServer`
- โ
**Demonstrates the complete pipeline** - tool registration โ API call โ tool execution โ response synthesis
- โ
**Self-contained** - runs independently with just an API key
- โ
**Comprehensive logging** - shows exactly what's happening at each step
**Requirements:** `GEMINI_API_KEY` environment variable (this is a live API test)
**Example output:**
```
๐ SUCCESS! Final Response from Gemini:
The `Enum` module in Elixir is a powerful tool for working with collections...
Based on the information retrieved using `get_elixir_module_info`, here's a breakdown:
1. Main Purpose: Provides consistent iteration over enumerables (lists, maps, ranges)
2. Common Functions: map/2, filter/2, reduce/3, sum/1, sort/1...
3. Usefulness: Unified interface, functional programming, high performance...
```
---
#### 10. **`live_api_test.exs`** - API Testing and Validation
**Comprehensive testing utility for validating both authentication methods.**
```bash
mix run examples/live_api_test.exs
```
**Features demonstrated:**
- Full API testing suite for both auth methods
- Configuration detection and validation
- Model operations (listing, details, existence checks)
- Streaming functionality testing
- Performance monitoring
**Requirements:** `GEMINI_API_KEY` and/or Vertex AI credentials
### Example Output
Each example provides detailed output with:
- โ
Success indicators for working features
- โ Error messages with clear explanations
- ๐ Performance metrics and timing information
- ๐ง Configuration details and detected settings
- ๐ก Live telemetry events (in telemetry showcase)
### Setting Up Authentication
For the examples to work with live API calls, set up authentication:
```bash
# For Gemini API (recommended for examples)
export GEMINI_API_KEY="your_gemini_api_key"
# For Vertex AI (optional, for multi-auth demos)
export VERTEX_JSON_FILE="/path/to/service-account.json"
export VERTEX_PROJECT_ID="your-gcp-project-id"
```
### Example Development Pattern
The examples follow a consistent pattern:
- **Self-contained**: Each example runs independently
- **Well-documented**: Clear inline comments and descriptions
- **Error-resilient**: Graceful handling of missing credentials
- **Informative output**: Detailed logging of operations and results
## ๐ Authentication
### Gemini API Key (Recommended for Development)
```elixir
# Environment variable (recommended)
export GEMINI_API_KEY="your_api_key"
# Application config
config :gemini_ex, api_key: "your_api_key"
# Per-request override
Gemini.generate("Hello", api_key: "specific_key")
```
### Vertex AI (Recommended for Production)
```elixir
# 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_ex, :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"
}
```
## ๐ Documentation
- **[API Reference](https://hexdocs.pm/gemini_ex)** - Complete function documentation
- **[Architecture Guide](https://hexdocs.pm/gemini_ex/architecture.html)** - System design and components
- **[Authentication System](https://hexdocs.pm/gemini_ex/authentication_system.html)** - Detailed auth configuration
- **[Examples](https://github.com/nshkrdotcom/gemini_ex/tree/main/examples)** - Working code examples
## ๐๏ธ Architecture
The library features a modular, layered architecture:
- **Authentication Layer**: Multi-strategy auth with automatic credential resolution
- **Coordination Layer**: Unified API coordinator for all operations
- **Streaming Layer**: Advanced SSE processing with state management
- **HTTP Layer**: Dual client system for standard and streaming requests
- **Type Layer**: Comprehensive schemas with runtime validation
## ๐ง Advanced Usage
### Complete Generation Configuration Support
All 12 generation config options are fully supported across all API entry points:
```elixir
# Structured output with JSON schema
{:ok, response} = Gemini.generate("Analyze this data", [
response_schema: %{
"type" => "object",
"properties" => %{
"summary" => %{"type" => "string"},
"insights" => %{"type" => "array", "items" => %{"type" => "string"}}
}
},
response_mime_type: "application/json"
])
# Creative writing with advanced controls
{:ok, response} = Gemini.generate("Write a story", [
temperature: 0.9,
top_p: 0.8,
top_k: 40,
presence_penalty: 0.6,
frequency_penalty: 0.4,
stop_sequences: ["THE END", "EPILOGUE"]
])
```
### Custom Model Configuration
```elixir
# List available models
{:ok, models} = Gemini.list_models()
# Get model details
{:ok, model_info} = Gemini.get_model("gemini-2.0-flash-lite")
# Count tokens
{:ok, token_count} = Gemini.count_tokens("Your text here", model: "gemini-2.0-flash-lite")
```
### Multimodal Content
```elixir
# Text with images
content = [
%{type: "text", text: "What's in this image?"},
%{type: "image", source: %{type: "base64", data: base64_image}}
]
{:ok, response} = Gemini.generate(content)
```
### Error Handling
```elixir
case Gemini.generate("Hello world") do
{:ok, response} ->
# Handle success
{:ok, text} = Gemini.extract_text(response)
{:error, %Gemini.Error{type: :rate_limit} = error} ->
# Handle rate limiting
IO.puts("Rate limited. Retry after: #{error.retry_after}")
{:error, %Gemini.Error{type: :authentication} = error} ->
# Handle auth errors
IO.puts("Auth error: #{error.message}")
{:error, error} ->
# Handle other errors
IO.puts("Unexpected error: #{inspect(error)}")
end
```
## ๐งช Testing
```bash
# Run all tests
mix test
# Run with coverage
mix test --cover
# Run integration tests (requires API key)
GEMINI_API_KEY="your_key" mix test --only integration
```
## ๐ค Contributing
1. Fork the repository
2. Create your feature branch (`git checkout -b feature/amazing-feature`)
3. Commit your changes (`git commit -m 'Add amazing feature'`)
4. Push to the branch (`git push origin feature/amazing-feature`)
5. Open a Pull Request
## ๐ License
This project is licensed under the MIT License - see the [LICENSE](https://github.com/nshkrdotcom/gemini_ex/blob/main/LICENSE) file for details.
## ๐ Acknowledgments
- Google AI team for the Gemini API
- Elixir community for excellent tooling and libraries
- Contributors and maintainers
