# LlamaIndex Integration
> Use the Helicone LLM for LlamaIndex to route OpenAI-compatible requests through the Helicone AI Gateway with full observability.
import Star from "/snippets/star.mdx";
import RequestIntegration from "/snippets/request-integration.mdx";
## Introduction
The Helicone LLM for LlamaIndex lets you send OpenAI‑compatible requests through the Helicone AI Gateway — no provider keys needed. Gain centralized routing, observability, and control across many models and providers.
This integration uses a dedicated LlamaIndex package: llama-index-llms-helicone.
## Install
```bash
pip install llama-index-llms-helicone
```
## Usage
```python
from llama_index.llms.helicone import Helicone
from llama_index.llms.openai_like.base import ChatMessage
llm = Helicone(
api_key="",
model="gpt-4o-mini", # works across providers
is_chat_model=True,
)
message: ChatMessage = ChatMessage(role="user", content="Hello world!")
response = llm.chat(messages=[message])
print(str(response))
```
### Parameters
- model: OpenAI‑compatible model name routed via Helicone. See the
model registry.
- api_base (optional): Base URL for Helicone AI Gateway (defaults to the package’s `DEFAULT_API_BASE`). Can also be set via `HELICONE_API_BASE`.
- api_key: Your Helicone API key. You can set via constructor or `HELICONE_API_KEY`.
- default_headers (optional): Add additional headers; the `Authorization: Bearer ` header is set automatically.
## Environment Variables
```bash
export HELICONE_API_KEY=sk-helicone-...
# Optional override
export HELICONE_API_BASE=https://ai-gateway.helicone.ai/v1
```
## Advanced Configuration
```python
from llama_index.llms.helicone import Helicone
llm = Helicone(
model="gpt-4.1-mini",
api_key="",
api_base="https://ai-gateway.helicone.ai/v1",
default_headers={
"Helicone-Session-Id": "demo-session",
"Helicone-User-Id": "user-123",
"Helicone-Property-Environment": "production",
},
temperature=0.2,
max_tokens=256,
)
```
## Notes
- Authentication uses your Helicone API key; provider keys are not required when using the AI Gateway.
- All requests appear in the Helicone dashboard with full request/response visibility and cost tracking.
- Learn more about routing and model coverage:
- Provider routing
- Model registry