> For the complete documentation index, see [llms.txt](https://circular-protocol.gitbook.io/standard-apis/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://circular-protocol.gitbook.io/standard-apis/api-docs/javascript-old/setnagkey-and-setnagurl.md).

# SetNAGKey & SetNAGURL

After successfully including the library, it's time to configure the URL and key of the Network Access Gateway (NAG) for interacting with Circular.

```javascript
Circular.SetNAGKey([your key]);
Circular.SetNAGURL([NAG URL]);
```

You can find the URLs for native NAGs in our SDK documentation, while a list of third-party NAGs will be provided in the future. 

**If you plan to use the SandBox blockchain for testing, you can use an empty ("") NAG key.**