# Beacon node authentication

## HTTP Basic Access Authentication

If you want to use Charon with an [HTTP basic access authentication](https://en.wikipedia.org/wiki/Basic_access_authentication) protected beacon node, then you can supply `charon run` with the `--beacon-node-headers` flag. The flag's value should be set like: `Authorization=Basic <credentials>` where `Authorization` will be the header key and `Basic <credentials>` will be the header value. The `<credentials>` are a [Base64](https://en.wikipedia.org/wiki/Base64) encoding of the username and password joined by a single colon `:`.

{% hint style="warning" %}
These headers will be sent in every request to every beacon node. This could leak your credentials to the other beacon nodes. Make sure you trust every listed beacon node.
{% endhint %}

## Usage example

Suppose we have an HTTP Basic access protected beacon node with username `john` and password `doe`. To access it we would construct the credentials by running the following command:

```
echo -n "john:doe" | base64
```

Then you could pass the flag to your Charon instance like this:

```
charon run --beacon-node-headers="Authorization=Basic am9objpkb2U="
```

Or you could specify it as an environment variable like this:

```
CHARON_BEACON_NODE_HEADERS="Authorization=Basic am9objpkb2U="
```

{% hint style="info" %}
Note that 'Authorization' is followed with an `=` rather than the usual `:`.
{% endhint %}


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