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Use the OpenAI Python SDK with Radium

Radium exposes an OpenAI-compatible Chat Completions API. If your application already uses the OpenAI Python SDK, you only need to change the API key, base URL, and model name.

This guide creates a small program that sends one request and prints the response.

Before you start

You need:

  • Python 3.10 or newer
  • A Radium API key
  • A terminal or PowerShell window

1. Create a project and install the SDK

macOS or Linux:

mkdir radium-openai-python
cd radium-openai-python
python3 -m venv .venv
source .venv/bin/activate
python -m pip install openai

Windows PowerShell:

mkdir radium-openai-python
cd radium-openai-python
py -m venv .venv
.venv\Scripts\Activate.ps1
python -m pip install openai

2. Set your Radium credentials

macOS or Linux:

export RADIUM_API_KEY="your-radium-api-key"
export RADIUM_MODEL="hal-1.0"

Windows PowerShell:

$env:RADIUM_API_KEY = "your-radium-api-key"
$env:RADIUM_MODEL = "hal-1.0"

Keep the key on the server. Do not paste it into main.py, commit it, or expose it in browser code.

3. Create main.py

import os

from openai import OpenAI


api_key = os.getenv("RADIUM_API_KEY")
if not api_key:
    raise SystemExit("Set RADIUM_API_KEY before running this program.")

model = os.getenv("RADIUM_MODEL", "hal-1.0")
client = OpenAI(
    api_key=api_key,
    base_url="https://api.radium.cloud/v1",
    timeout=90,
    max_retries=0,
)

response = client.chat.completions.create(
    model=model,
    messages=[
        {"role": "system", "content": "Follow the user's instruction exactly."},
        {"role": "user", "content": "Reply with exactly: Radium connected."},
    ],
    max_tokens=512,
    temperature=0,
)

content = response.choices[0].message.content
if not content or not content.strip():
    raise RuntimeError("Radium returned no visible text.")
print(f"RADIUM_RESPONSE: {content.strip()}")

The base URL must include /v1. Do not append /chat/completions; the SDK adds that path.

4. Run it

python main.py

Expected output:

RADIUM_RESPONSE: Radium connected.

Choose a model

Set RADIUM_MODEL to any validated model before running the program:

export RADIUM_MODEL="hal-1.0"
# or: clarke-1.0
# or: tycho-1.0
python main.py

Migrate an existing OpenAI client

Before:

client = OpenAI(api_key=os.environ["OPENAI_API_KEY"])

After:

client = OpenAI(
    api_key=os.environ["RADIUM_API_KEY"],
    base_url="https://api.radium.cloud/v1",
)

Keep your existing messages and response parsing. Replace the old model ID with hal-1.0, clarke-1.0, or tycho-1.0.

Troubleshooting

  • 401 or 403: verify that RADIUM_API_KEY is set in the same terminal running Python.
  • 404: verify the base URL and use one of the model IDs listed above.
  • Empty output: keep max_tokens at 512 or higher so model reasoning does not consume the visible response allowance.
  • ModuleNotFoundError: activate .venv and rerun the installation command.

Validation

Version note: these instructions were verified with Python 3.12.7 and openai==2.54.0 on August 20, 2026. You do not need that exact package version. Text generation and a complete function-calling loop passed with hal-1.0, clarke-1.0, and tycho-1.0.

Reference: OpenAI Python library.

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