OpenAI Python SDK

Use the official OpenAI Python SDK with Lightweight.

The official OpenAI Python SDK works with Lightweight by setting a custom base_url. This gives you access to every model in the catalog through the familiar OpenAI Python interface.

Installation

pip install openai

Usage

from openai import OpenAI

client = OpenAI(
    api_key="lw_sk_your-key-here",
    base_url="https://api.lightweight.one/v1"
)

response = client.chat.completions.create(
    model="gpt-5.4",
    messages=[
        {"role": "system", "content": "You are a helpful assistant."},
        {"role": "user", "content": "What is the capital of France?"}
    ]
)

print(response.choices[0].message.content)

Streaming

stream = client.chat.completions.create(
    model="claude-sonnet-4.5",
    messages=[{"role": "user", "content": "Write a haiku about Python."}],
    stream=True
)

for chunk in stream:
    if chunk.choices[0].delta.content:
        print(chunk.choices[0].delta.content, end="")

Using Different Models

Swap the model parameter to use any provider — no other changes needed:

# Anthropic
response = client.chat.completions.create(model="claude-opus-4.6", messages=messages)

# Google
response = client.chat.completions.create(model="gemini-2.5-pro", messages=messages)

# xAI
response = client.chat.completions.create(model="grok-code-fast-1", messages=messages)

See the full Models catalog and Pricing for all available options.