Installation

Complete installation and configuration guide for Lunar SDK

Installation

Requirements

• Python 3.10+ (recommended) — also supports 3.9, 3.11, 3.12
• pip package manager

Install

pip install lunar

Configuration

Environment Variables

Variable	Description	Required
LUNAR_API_KEY	API key for authentication	Yes

Set your API key:

export LUNAR_API_KEY="your-api-key"

Client Initialization

Basic usage with environment variable:

from lunar import Lunar

client = Lunar()  # Uses LUNAR_API_KEY from environment

With explicit API key:

client = Lunar(api_key="your-api-key")

Full configuration:

client = Lunar(
    api_key="your-api-key",
    timeout=60.0,                 # Request timeout in seconds
    num_retries=2,                # Retry attempts for failed requests
    max_connections=100,          # Max concurrent connections
    fallbacks={                   # Global fallback configuration
        "gpt-4o-mini": ["claude-3-haiku", "llama-3.1-8b"],
        "gpt-4": ["claude-3-opus"]
    }
)

Configuration Parameters

Parameter	Type	Default	Description
api_key	str	None	API key for authentication
base_url	str	None	Custom API URL
timeout	float	60.0	Request timeout in seconds
num_retries	int	2	Number of retry attempts
max_connections	int	100	Maximum concurrent connections
fallbacks	dict	None	Model fallback configuration

Using Context Manager

The client supports context managers for automatic resource cleanup:

Synchronous:

from lunar import Lunar

with Lunar(api_key="your-api-key") as client:
    response = client.chat.completions.create(
        model="gpt-4o-mini",
        messages=[{"role": "user", "content": "Hello!"}]
    )
# Resources automatically cleaned up

Asynchronous:

from lunar import AsyncLunar

async with AsyncLunar(api_key="your-api-key") as client:
    response = await client.chat.completions.create(
        model="gpt-4o-mini",
        messages=[{"role": "user", "content": "Hello!"}]
    )
# Resources automatically cleaned up

Verify Installation

Run this script to verify your installation:

from lunar import Lunar

try:
    client = Lunar()
    response = client.chat.completions.create(
        model="gpt-4o-mini",
        messages=[{"role": "user", "content": "Say 'Hello from Lunar!'"}],
        max_tokens=20
    )
    print("Success:", response.choices[0].message.content)
    print(f"Cost: ${response.usage.total_cost_usd}")
except Exception as e:
    print(f"Error: {e}")

Next Steps

Authentication

Learn more about API Key authentication

Chat Completions

Make chat completion requests