Anthropic compatible API for Claude, GPT & Gemini

Claude / GPT / Gemini One key reaches multiple model families without separate provider accounts.

USDT / PayPal Prepaid balance, no overseas credit card, no automatic subscription charge.

OpenAI / Anthropic Compatible with common SDKs by changing only base URL and API key.

Start in minutes Register, top up, create an API key, and call your first model.

Quick answer

ClaudeN exposes an Anthropic-compatible and OpenAI-compatible API so you can reach Claude, GPT and Gemini without separate vendor accounts. Reuse the official OpenAI SDK, set a new base URL, and switch models with a single parameter. One prepaid balance funded by USDT or PayPal powers every request.

Why use an Anthropic-compatible gateway

OpenAI SDK works unchanged

Chat Completions requests stay the same. Only base_url and api_key change.

True Anthropic compatibility

Messages API shape for Claude is supported alongside the OpenAI shape.

One key, every model

The same key reaches Claude, GPT and Gemini — switch without new accounts.

Pay with USDT or PayPal

Prepaid balance, no credit card, no per-provider billing.

How to call Claude with an OpenAI SDK

Sign up and get a key — Create a free ClaudeN account. Add credit with USDT or PayPal and copy your API key.
Set base URL and key — Configure your OpenAI client to use https://clauden.ai/v1 and your ClaudeN key.
Choose a model — Use claude-3-5-sonnet-20241022 (or any Claude, GPT or Gemini model name).
Send the request — Call the same Chat Completions or Messages endpoint you already use.

Example: Anthropic-compatible call

Python example using the OpenAI SDK pointed at ClaudeN. Switch models by changing the model string.

OpenAI Python SDK

from openai import OpenAI

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

resp = client.chat.completions.create(
    model="claude-3-5-sonnet",
    messages=[{"role": "user", "content": "Hello from ClaudeN"}],
)
print(resp.choices[0].message.content)

Who it fits / who it does not fit

Good fit

Developers, freelancers and startups that need no-card payments, multi-model access, OpenAI-compatible routing and prepaid USDT/PayPal balance.

Not a fit

If you must use only direct official provider accounts, enterprise private contracts or zero third-party gateway, work directly with model providers.

Ready to connect multiple models with one key?

Claim trial credit, then test Claude, GPT or Gemini through an OpenAI-compatible endpoint.

Create a free account

Resources

USDT AI API — pay for Claude, GPT and Gemini with crypto AI API Without a Credit Card — Claude, GPT & Gemini OpenAI-Compatible API for Claude, GPT & Gemini Anthropic Compatible API — Call Claude with OpenAI SDK Claude vs GPT vs Gemini API Pricing & Comparison Cheap LLM API — Low-Cost Access to Claude, GPT & Gemini LLM API Proxy — One Gateway for Claude, GPT & Gemini LLM API Gateway — One Endpoint for Claude, GPT & Gemini Claude API Proxy — Use Anthropic Claude Without an Account Cursor + Claude API OpenRouter Alternative with USDT — Claude, GPT & Gemini LiteLLM alternative with USDT Cursor GPT API without OpenAI account Quick Start Examples

Anthropic compatible API — frequently asked questions

Is this the official Anthropic API?

No. ClaudeN is an independent gateway that offers an Anthropic-compatible interface to Claude models. It is not operated by Anthropic.

Can I use the official Anthropic SDK?

Yes. Point the Anthropic SDK base URL to https://clauden.ai/v1 and use your ClaudeN key. The request and response shapes match.

Do I still need an Anthropic account?

No. One ClaudeN account and key is enough to call Claude, GPT and Gemini.

How do I pay?

Fund a prepaid balance with USDT or PayPal. You pay per token across every model — no credit card or subscription.