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/realtime

Use this to loadbalance across Azure + OpenAI + xAI and more.

Supported Providers:

  • OpenAI
  • Azure
  • xAI (see full docs)
  • Google AI Studio (Gemini)
  • Vertex AI
  • Bedrock

Proxy Usage​

Add model to config​

model_list:
- model_name: openai-gpt-4o-realtime-audio
litellm_params:
model: openai/gpt-4o-realtime-preview-2024-10-01
api_key: os.environ/OPENAI_API_KEY
model_info:
mode: realtime

Start proxy​

litellm --config /path/to/config.yaml 

# RUNNING on http://0.0.0.0:8000

Test​

Run this script using node - node test.js

// test.js
const WebSocket = require("ws");

const url = "ws://0.0.0.0:4000/v1/realtime?model=openai-gpt-4o-realtime-audio";
// const url = "wss://my-endpoint-sweden-berri992.openai.azure.com/openai/realtime?api-version=2024-10-01-preview&deployment=gpt-4o-realtime-preview";
const ws = new WebSocket(url, {
headers: {
"api-key": `sk-1234`,
"OpenAI-Beta": "realtime=v1",
},
});

ws.on("open", function open() {
console.log("Connected to server.");
ws.send(JSON.stringify({
type: "response.create",
response: {
modalities: ["text"],
instructions: "Please assist the user.",
}
}));
});

ws.on("message", function incoming(message) {
console.log(JSON.parse(message.toString()));
});

ws.on("error", function handleError(error) {
console.error("Error: ", error);
});

Guardrails​

You can apply LiteLLM guardrails to realtime sessions.

Set guardrails on a key or team​

The easiest production setup — attach guardrails to a virtual key or team so they always apply automatically, without any client-side changes.

See Virtual Keys → Guardrails and Teams → Guardrails.

Pass guardrails dynamically (easy testing)​

Pass guardrails as a query param when opening the WebSocket. Useful for testing guardrails without modifying key/team config.

// node test.js
const WebSocket = require("ws");

const guardrails = ["your-guardrail-name"]; // comma-separated list
const url = `ws://0.0.0.0:4000/v1/realtime?model=openai-gpt-4o-realtime-audio&guardrails=${guardrails.join(",")}`;

const ws = new WebSocket(url, {
headers: {
"Authorization": "Bearer sk-1234",
},
});

ws.on("open", function open() {
console.log("Connected — guardrails active:", guardrails);
});

ws.on("message", function incoming(message) {
const data = JSON.parse(message);
if (data.type === "error") {
// Guardrail block is sent as an error event before the connection closes
console.error("Guardrail error:", data.error.message);
}
});

ws.on("close", function close(code, reason) {
console.log("Closed:", code, reason.toString());
// code 1011 = blocked by guardrail at pre_call
});

Or with Python:

import asyncio
import websockets

async def main():
url = "ws://0.0.0.0:4000/v1/realtime?model=openai-gpt-4o-realtime-audio&guardrails=your-guardrail-name"
async with websockets.connect(
url,
additional_headers={"Authorization": "Bearer sk-1234"},
) as ws:
print("Connected — guardrail active")
async for msg in ws:
import json
data = json.loads(msg)
if data["type"] == "error":
print("Guardrail blocked:", data["error"]["message"])
break

asyncio.run(main())

When a guardrail blocks the request, the proxy sends an error event over the WebSocket and then closes the connection:

{
"type": "error",
"error": {
"type": "guardrail_error",
"message": "Guardrail blocked this request: <reason>"
}
}

Logging​

To prevent requests from being dropped, by default LiteLLM just logs these event types:

  • session.created
  • response.create
  • response.done

You can override this by setting the logged_real_time_event_types parameter in the config. For example:

litellm_settings:
logged_real_time_event_types: "*" # Log all events
## OR ##
logged_real_time_event_types: ["session.created", "response.create", "response.done"] # Log only these event types