> ## Documentation Index
> Fetch the complete documentation index at: https://docs.layerswap.io/llms.txt
> Use this file to discover all available pages before exploring further.

# API keys & environments

> Create a Layerswap API key, select an environment, and authenticate API and Widget requests.

## Create a key

1. Register in the [Partner Dashboard](https://layerswap.io/dashboard).
2. Create an organization, then create an app inside it.
3. Open the app and copy its mainnet or testnet API key.

## Select an environment

Layerswap uses the same API base URL for both environments:

```text theme={null}
https://api.layerswap.io/api/v2
```

The API key selects the environment. A testnet key returns testnet networks and routes; a mainnet key returns mainnet data. In the Widget, the `config.version` value must match the key's environment.

## Authenticate an API request

Send the key in the `X-LS-APIKEY` header:

```bash theme={null}
curl 'https://api.layerswap.io/api/v2/limits?source_network=ETHEREUM_MAINNET&source_token=USDC&destination_network=ARBITRUM_MAINNET&destination_token=USDC' \
  --header 'accept: application/json' \
  --header 'X-LS-APIKEY: YOUR_API_KEY'
```

## Use a key with the Widget

```tsx theme={null}
const config = {
  apiKey: "YOUR_API_KEY",
  version: "mainnet",
}
```

Pass the object to `LayerswapWidget` or `LayerswapDepositWidget`. See the [Swap Widget quickstart](/widget/quickstart) for a complete example.

## Related resources

* [Choose your integration](/get-started/choose-your-integration) — compare the Widget, Hosted Page, and API.
* [Swap Widget quickstart](/widget/quickstart) — add the swap flow to your app.
* [Build your first API swap](/api/quickstart) — quote, create, fund, and track a swap.
* [Partner Dashboard reference](/resources/partner-dashboard) — manage apps, API keys, and webhooks.