To authenticate with our API, you'll need to use Authorization headers.
Both Shops and Partners are given API keys to authenticate with our API. For Partners, you'll use your API token in the Authorization header and an individual Shop's API token in the X-Postscript-Shop-Token header (if making API calls that require a Shop's authorization). For Shops, you'll just use your API token in the Authorization header. This will allow you to perform API calls on your shop's behalf. It does not require you to have a Partner API Token too. Both Shops and Partners should use your API Private Key in the requests and not your Public Key.
For more on Authentication, check out our Authentication guide.