> For the complete documentation index, see [llms.txt](https://docs.tronsave.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.tronsave.io/developers/api-reference/buy-resources/api-key.md).

# API Key

The API-key flow lets you buy resources (Energy and Bandwidth) from a prefunded TronSave internal account. Instead of signing a transaction with your wallet for every order, you authenticate each request with an API key and pay from your internal account balance — so there is no per-order on-chain fee and integration stays simple.

{% hint style="info" %}
Prefer to pay per order directly from your wallet? Use the [Buy with Signed Transaction](/developers/api-reference/buy-resources/signed-tx.md) flow instead.
{% endhint %}

## Before you start

You need a TronSave API key and an internal account with enough balance to cover your orders. There are two ways to create an API key:

* **Option 1:** Generate the API key on the TronSave website.
* **Option 2:** Generate the API key on Telegram.

See [Authentication](/developers/authentication.md) for how to pass the API key on each request.

## Endpoints

Use the API key to call any of the following endpoints:

| Endpoint                                                                                               | Description                                                                 |
| ------------------------------------------------------------------------------------------------------ | --------------------------------------------------------------------------- |
| [Get Internal Account Info](/developers/api-reference/buy-resources/api-key/get-account-info.md)       | Read your internal account balance and details.                             |
| [Get Order Book](/developers/api-reference/buy-resources/api-key/get-order-book.md)                    | Fetch the current order book for resource pricing and availability.         |
| [Estimate TRX](/developers/api-reference/buy-resources/api-key/estimate-trx.md)                        | Calculate the TRX required for a resource amount and rental duration.       |
| [Buy Energy (Create Order)](/developers/api-reference/buy-resources/api-key/create-order.md)           | Place an order to buy Energy or Bandwidth, paid from your internal account. |
| [Get Order Details](/developers/api-reference/buy-resources/api-key/get-order-details.md)              | Look up the details and status of a single order by ID.                     |
| [Get Internal Account Order History](/developers/api-reference/buy-resources/api-key/order-history.md) | List the order history for your internal account.                           |

## Endpoints (TRON Nile Testnet)

{% tabs %}
{% tab title="Testnet" %}

* Estimate TRX: <mark style="color:orange;">`POST`</mark> `https://api-dev.tronsave.io/v2/estimate-buy-resource`
* Create order: <mark style="color:orange;">`POST`</mark> `https://api-dev.tronsave.io/v2/buy-resource`
* Get Internal Account Info: <mark style="color:blue;">`GET`</mark> `https://api-dev.tronsave.io/v2/user-info`
* Get Internal Account Order History: <mark style="color:blue;">`GET`</mark> `https://api-dev.tronsave.io/v2/orders`
* Get the order details: <mark style="color:blue;">`GET`</mark> `https://api-dev.tronsave.io/v2/order/:id`
* Get Order Book: <mark style="color:blue;">`GET`</mark> `https://api-dev.tronsave.io/v2/order-book`
  {% endtab %}
  {% endtabs %}

To integrate with the **Nile Testnet**, replace the base URL with <https://testnet.tronsave.io/> and follow the same steps.

## Next steps

* [Estimate TRX](/developers/api-reference/buy-resources/api-key/estimate-trx.md)
* [Buy Energy (Create Order)](/developers/api-reference/buy-resources/api-key/create-order.md)
* Learn the difference between [Energy and Bandwidth](/concepts/energy-and-bandwidth.md).
* Review the [Order Types](/concepts/order-types.md) before placing orders.