Multi-LLM Router API docs
One API, many AI models. Route prompts to GPT, Claude, Gemini, Llama, Mistral and more. Auto-fallback and cost optimization built in.
Authentication
All Multi-LLM Router API requests authenticate via two headers. Get your API key from your RapidAPI dashboard after subscribing on the Basic (free) tier or higher.
X-RapidAPI-Key: YOUR_API_KEY X-RapidAPI-Host: multi-llm-router-by-helix-api.p.rapidapi.com
Base URL
https://multi-llm-router-by-helix-api.p.rapidapi.com
Endpoints
POST
/chatSend chat completion request
GET
/modelsList available models
POST
/compareSame prompt to multiple models
Code Examples
Python
import requests
url = "https://multi-llm-router-by-helix-api.p.rapidapi.com/chat"
headers = {
"X-RapidAPI-Key": "YOUR_API_KEY",
"X-RapidAPI-Host": "multi-llm-router-by-helix-api.p.rapidapi.com",
}
response = requests.post(url, headers=headers)
print(response.json())JavaScript
const response = await fetch(
"https://multi-llm-router-by-helix-api.p.rapidapi.com/chat",
{
method: "POST",
headers: {
"X-RapidAPI-Key": "YOUR_API_KEY",
"X-RapidAPI-Host": "multi-llm-router-by-helix-api.p.rapidapi.com"
}
}
);
const data = await response.json();cURL
curl -X POST "https://multi-llm-router-by-helix-api.p.rapidapi.com/chat" \ -H "X-RapidAPI-Key: YOUR_API_KEY" \ -H "X-RapidAPI-Host: multi-llm-router-by-helix-api.p.rapidapi.com"
Response Format
All endpoints return JSON in this consistent envelope:
{
"status": "ok",
"data": { /* endpoint-specific payload */ },
"meta": {
"cached": false,
"latency_ms": 142,
"request_id": "req_abc123"
},
"timestamp": "2026-05-21T12:00:00Z"
}Error Codes
| HTTP | Code | Meaning |
|---|---|---|
| 400 | BAD_REQUEST | Missing or invalid parameter |
| 401 | UNAUTHORIZED | Invalid or missing API key |
| 403 | FORBIDDEN | Your plan doesn't include this endpoint |
| 429 | RATE_LIMIT_EXCEEDED | Too many requests — back off and retry |
| 500 | INTERNAL_ERROR | Something went wrong on our side |
| 503 | UPSTREAM_UNAVAILABLE | A third-party data source is down |
Common Use Cases
AI app backends
Model comparison
Cost optimization
Failover routing
A/B testing models
Chatbot with multi-provider fallback
AI customer support agent
Content moderation pipeline
Code review assistant
AI writing assistant
Prompt testing dashboard
Multi-model consensus scoring
AI-powered search engine
Document Q&A system
AI tutor platform
Sentiment analysis service
Email draft generation
Product description generator
AI translation service
Compliance checking automation