One API Key for Claude, GPT and Gemini: A Developer's Guide

## Why one API key matters

As an individual developer, the worst part of building with large language models is not the code — it is the operational overhead. You sign up for OpenAI, then Anthropic, then Google. Three dashboards, three invoices, three rate-limit policies, and at least two different SDKs to learn.

ClaudeN AI collapses all of that into a single, OpenAI/Anthropic-compatible endpoint. You keep the SDK you already know, change one base URL, and suddenly Claude, GPT and Gemini are all reachable with the same key.

## How it works

The gateway speaks the OpenAI Chat Completions format and the Anthropic Messages format. Point your client at our base URL and pass the model name you want:

``python
from openai import OpenAI

client = OpenAI(
api_key="YOUR_CLAUDEN_KEY",
base_url="https://clauden.ai/v1",
)

resp = client.chat.completions.create(
model="claude-3-5-sonnet",
messages=[{"role": "user", "content": "Explain async/await in one paragraph."}],
)
print(resp.choices[0].message.content)
`

Switch model to gpt-4o or gemini-1.5-pro` and nothing else changes. That is the whole point.

## Pay only for what you use

There is no monthly subscription. You top up with USDT — no overseas credit card required — and every request is billed per token at a transparent rate. New accounts get a trial credit so you can ship something before spending a cent.

## When you should use a relay

- You are prototyping and want to compare models quickly.
- You live in a region where the official billing methods are painful.
- You want one usage log instead of three.

If that sounds like you, create an account, grab your key, and make your first call in under five minutes.