# Core concepts

> Tchavi is a secure gateway that gives you access to multiple AI providers through one API key and one credit balance.

- Canonical: https://tchavi.com/en/docs/principles

---


Tchavi is a secure gateway (a proxy) that sits between your application and multiple AI providers — OpenAI, Anthropic, Google, and more. Instead of managing a separate account, key, and bill for each provider, you use **one Tchavi API key** and **one credit balance** to reach every model.

## OpenAI API compatibility

Tchavi is **100% compatible with the OpenAI API format**. The request and response shapes are the same, and the response is a transparent pass-through of the provider's format. If you already use the OpenAI SDK or any OpenAI-compatible library, you only change two things: the base URL and the API key — the rest of your code stays the same.

```bash
https://tchavi.com/api/v1
```

See [Base URL](/en/docs/base-url) for full SDK examples and [Authentication](/en/docs/authentication) for how to pass your key.

## Credit-based billing

There is no subscription. Tchavi is pay-as-you-go: each API request consumes credits based on the model used and the number of tokens processed. You start with **500 free credits** on signup, and recharge whenever you want — credits never expire into a monthly plan.

Every API response carries metadata headers so you can track usage in real time:

- `X-Credits-Used` — credits consumed by this request
- `X-Credits-Remaining` — your current credit balance
- `X-RateLimit-RPM-Limit` / `X-RateLimit-RPM-Remaining` — your requests-per-minute budget
- `X-RateLimit-TPM-Limit` / `X-RateLimit-TPM-Remaining` — your tokens-per-minute budget
- `X-Request-Id` — unique request ID for support and debugging

See [Credits & Billing](/en/docs/credits) for how credits are calculated.

## Account levels

Rate limits depend on your **account level**, which is unlocked automatically based on your lifetime spend on the platform — there is no plan to choose. The levels are Free, Builder, Growth, and Pro, each raising your requests-per-minute (RPM) and tokens-per-minute (TPM) budgets and the number of API keys you can create.

See [Rate Limits](/en/docs/rate-limits) for the full table.

## Mobile-money recharge

Buy credit packs from your [billing dashboard](/billing) using Wave, Orange Money, MTN MoMo, and 30+ mobile money operators. Credits are added instantly after payment.