Use LlamaIndex with Radium
LlamaIndex provides OpenAILike for third-party OpenAI-compatible APIs. Use it to connect a LlamaIndex application to Radium.
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 LlamaIndex
macOS or Linux:
mkdir radium-llamaindex
cd radium-llamaindex
python3 -m venv .venv
source .venv/bin/activate
python -m pip install llama-index-llms-openai-like
Windows PowerShell:
mkdir radium-llamaindex
cd radium-llamaindex
py -m venv .venv
.venv\Scripts\Activate.ps1
python -m pip install llama-index-llms-openai-like
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"
3. Create main.py
import os
from llama_index.core.llms import ChatMessage
from llama_index.llms.openai_like import OpenAILike
api_key = os.getenv("RADIUM_API_KEY")
if not api_key:
raise SystemExit("Set RADIUM_API_KEY before running this program.")
llm = OpenAILike(
model=os.getenv("RADIUM_MODEL", "hal-1.0"),
api_key=api_key,
api_base="https://api.radium.cloud/v1",
is_chat_model=True,
max_tokens=512,
temperature=0,
timeout=90,
)
response = llm.chat(
[
ChatMessage(role="system", content="Follow the user's instruction exactly."),
ChatMessage(role="user", content="Reply with exactly: Radium connected."),
]
)
content = response.message.content
if not content or not content.strip():
raise RuntimeError("Radium returned no visible text.")
print(f"RADIUM_RESPONSE: {content.strip()}")
LlamaIndex calls the endpoint setting api_base, not base_url.
4. Run it
python main.py
Expected output:
RADIUM_RESPONSE: Radium connected.
Choose a model
export RADIUM_MODEL="clarke-1.0" # or hal-1.0 or tycho-1.0
python main.py
Migrate an existing LlamaIndex app
Replace its current LLM object:
llm = OpenAILike(
model="hal-1.0",
api_key=os.environ["RADIUM_API_KEY"],
api_base="https://api.radium.cloud/v1",
is_chat_model=True,
max_tokens=512,
)
Pass llm to the existing index, query engine, workflow, or agent. A RAG application still needs a separate embedding model; do not use these chat model IDs as embedding model IDs.
Troubleshooting
- Authentication errors: check
RADIUM_API_KEYin the active terminal. 404: keep/v1inapi_baseand use an exact Radium model ID.- Empty output: use at least 512 output tokens.
- Import errors: activate
.venvand reinstall the pinned package.
Validation
Version note: these instructions were verified with Python 3.12.7 and llama-index-llms-openai-like==0.7.2 on August 20, 2026. You do not need that exact package version. Text generation and FunctionAgent tool calling passed with hal-1.0, clarke-1.0, and tycho-1.0.
Reference: LlamaIndex OpenAILike integration.
Next
- API quickstart, for calling Radium directly
- Tool calling, for the
tool_useandtool_resultcontract