Guide·7 min read

How to Call GPT, Claude & Gemini With One API Key

Stop juggling provider SDKs. Route prompts to every major LLM through a single endpoint and switch models with one parameter.

If you build with AI, you have probably wired up OpenAI, then added Anthropic, then wanted to try Gemini — each with its own SDK, auth, and response shape. A multi-LLM router collapses all of that into one endpoint.

The problem with provider lock-in

  • Every provider has a different SDK and request format
  • Switching models means rewriting client code
  • Outages take your whole feature down with no failover
  • Comparing models for cost and quality is tedious

One endpoint, every model

The Helix-API Multi-LLM Router exposes a single chat endpoint. You pick the model with a parameter:

bash
curl -X POST "https://multi-llm-router-by-helix-api.p.rapidapi.com/chat" \
  -H "X-RapidAPI-Key: YOUR_KEY" \
  -H "X-RapidAPI-Host: multi-llm-router-by-helix-api.p.rapidapi.com" \
  -H "Content-Type: application/json" \
  -d '{"model":"auto","messages":[{"role":"user","content":"Explain APIs in one sentence."}]}'

Set model to auto to let the router pick the best available option, or name a specific model. Your client code never changes.

Why route through one API

  • A/B test models without touching client code
  • Cost-optimize — send simple requests to cheaper models
  • Stay vendor-neutral — no lock-in, swap providers freely
  • One bill instead of three provider invoices

Build smarter AI features

Combine the router with AI Embeddings for retrieval-augmented generation, or AI Summarization for long-document workflows — all under the same key.

Try the Multi-LLM Router live, then see the full API catalog.

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