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

# Authentication

Every request to the ezInvoice API requires a valid access token. You get this token by calling the Auth endpoint once with your credentials, then include it in every subsequent request.

## How it works

```text theme={null}
1. POST /v1/e-invoicing/auth  →  get token
2. Include token in Authorization header on every API call
```

## Getting your token

Call the Auth endpoint with your registered credentials:

```bash theme={null}
curl -X POST https://api.einvoice.sa.com/v1/e-invoicing/auth \
  -H "Content-Type: application/json" \
  -d '{
    "vat_number": "YOUR_VAT_NUMBER",
    "username": "YOUR_USERNAME",
    "secret": "YOUR_SECRET"
  }'
```

You'll receive a token in the response. Copy it — you'll need it for every request.

## Using your token

Include the token in the `Authorization` header on every call:

```bash theme={null}
Authorization: Bearer YOUR_TOKEN_HERE
```

## Important notes

<Warning>
  Never share your secret or commit it to source code. Store credentials in environment variables.
</Warning>

<Info>
  Your credentials (VAT number, username, secret) are provided by ezInvoice during account setup. Contact [support@einvoice.sa.com](mailto:support@einvoice.sa.com) if you need them.
</Info>