<a id="api"></a>

# API

The `smtpd` process is controlled via an API, which in turn is used by
management tools such as the [command line interface](cli.html.md), [Visual Studio Code integration](vscode.html.md),
and [web administration](web.html.md).
Those tools can be installed on either a central location (controlling an entire cluster)
or on the MTA hosts themselves.

* [Endpoint](api_endpoints.html.md)
  * [Monitor](api_monitor.html.md)
    * [Endpoints](api_monitor.html.md#endpoints)
      * [/metrics](api_monitor.html.md#metrics)
      * [/ready](api_monitor.html.md#ready)
      * [/healthy](api_monitor.html.md#healthy)
  * [Control socket](api_control_sockets.html.md)
  * [HTTP/JSON](api_http_json.html.md)
    * [Installation](api_install.html.md)
      * [Distributions](api_install.html.md#distributions)
        * [Ubuntu](api_install.html.md#ubuntu)
        * [RHEL](api_install.html.md#rhel)
        * [Azure Linux](api_install.html.md#azure-linux)
      * [Startup](api_install.html.md#startup)
    * [Upgrade](api_upgrade.html.md)
    * [Configuration](api_config.html.md)
      * [Authentication directives](api_config.html.md#authentication-directives)
      * [Listener directives](api_config.html.md#listener-directives)
      * [Other directives](api_config.html.md#other-directives)
      * [Environment directives](api_config.html.md#environment-directives)
    * [Examples](api_examples.html.md)
* [API reference](api_reference.html.md)
  * [Command list](api_reference.html.md#command-list)
* [Version compatibility](api_reference.html.md#version-compatibility)
* [HTTP submission](http_submission.html.md)
  * [Endpoint reference](http_submission.html.md#endpoint-reference)
    * [Authentication](http_submission.html.md#authentication)
    * [HTTP request format](http_submission.html.md#http-request-format)
    * [HTTP response format](http_submission.html.md#http-response-format)
  * [Examples](http_submission.html.md#examples)