Authentication

All communication with the Cost+ API requires TLS 1.2 or higher and HTTP Basic Authentication.

How Basic Auth Works

Authenticate by using your API key as the username with an empty password. Base64-encode the string \{api_key\}: (note the trailing colon — the password is empty).

The resulting Authorization header looks like this:

Authorization: Basic aHVudGVyMjo=

[!WARNING] Never expose your API key in client-side code or public repositories. Keep it server-side only.

Using cURL

Out-of-the-box (recommended)

cURL natively supports Basic Auth with the -u flag. Pass your API key followed by a colon:

curl -u YOUR_API_KEY: https://api.costplus.online/v1/orders/

Manual Base64 encoding

If you prefer to construct the header yourself, first encode the key:

echo -n "YOUR_API_KEY:" | base64

Then pass the encoded value in the Authorization header:

curl -H "Authorization: Basic YOUR_BASE64_ENCODED_KEY" https://api.costplus.online/v1/orders/

[!TIP] The trailing colon after the API key is required — it separates the username from the (empty) password in the Basic Auth scheme.

HTTP Status Codes

The API uses standard HTTP status codes to indicate the result of a request.