# Authentication ## API keys We use basic authentication over secure http (HTTPS). Basic authentication is a method for an HTTP user agent (e.g. a web browser) to provide a user name and password when making a request. In our case, by using basic HTTP authentication, a request contains a header field in the form of `Authorization: Basic ` where `` is the base-64 encoded string of `:`. ## Allowlist domains Customer who has implemented our service as front end, i.e. typically from a website using JavaScript will require API users with allowlisted domains. Allowlisting of the domains ensures that access to our service is not compromised and allows only certain domains to connect to our service. Typically customer who has implemented our service in backend using Java, C#,PHP or Curl etc. will not require any referrer domains to be allowlisted as the back end implementation is already secured enough as the call happens from server side. However some customers may require some additional layer of security to ensure their credentials are not compromised by other internal teams or external third party etc. In such cases domains can be allowlisted so that only the JavaScript code from those domains can make successful calls to our APIs. API users and domain allowlisting can be done by the customer once they sign up for free Trial using [Allowlisting domains](/loqate-harmony-api/guides/console/subscriptions/allowlisting-domains.md) --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.mastersoftgroup.com/loqate-harmony-api/api-specification/authentication.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.