> For the complete documentation index, see [llms.txt](https://coingecko-api.gitbook.io/coingecko-api-guide/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://coingecko-api.gitbook.io/coingecko-api-guide/getting-started/authentication.md).

# Authentication

{% hint style="info" %}
**Pro API key** is only available for [CoinGecko API paid plan](https://www.coingecko.com/en/api/pricing) subscribers, all Pro API key requests should target this root URL: <mark style="color:yellow;">**<https://pro-api.coingecko.com/api/v3/>**</mark> \
\
You are recommended to store the API key securely in your own backend and use a proxy to insert the key into the request URL.
{% endhint %}

You can send API calls directly in your web browser, using cURL from a command line, or with your programming language of choice. You may also check some of the unofficial clients [here](/coingecko-api-guide/others/clients-unofficial.md).

## **You can supply your API key in one of two ways:**

1. Header: **x-cg-pro-api-key**
2. Query string parameter: **x\_cg\_pro\_api\_key**

**You may try to use this ping endpoint to check CoinGecko API status:**

{% code overflow="wrap" %}

```markup
https://pro-api.coingecko.com/api/v3/ping?x_cg_pro_api_key=YOUR_API_KEY
```

{% endcode %}

**Tips:** you can also check the API status here: <https://status.coingecko.com/>

### API Key Usage Credits

* 1 call = 1 credit. Calling any endpoint will only count as 1 call for every request made.
* Your monthly credit & rate limit is subject to the [paid plan](https://www.coingecko.com/en/api/pricing) that you subscribed to.&#x20;