OpenAI Python SDK

Direct SDK with custom base URL

OpenAI Python SDK

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.

Before you start

You need Python 3.10 or newer, a Radium API key, and 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

2. Set your Radium credentials

macOS or Linux

export RADIUM_API_KEY="your-radium-api-key"
export 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, 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

Problem	Fix
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

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.

Next steps

API quickstart

Call Radium directly

Tool calling

The tool_use and tool_result contract