# Extending Supervisor’s XML-RPC API

Supervisor can be extended with new XML-RPC APIs. Several third-party plugins already exist that can be wired into your Supervisor configuration. You may additionally write your own. Extensible XML-RPC interfaces is an advanced feature, introduced in version 3.0. You needn’t understand it unless you wish to use an existing third-party RPC interface plugin or if you wish to write your own RPC interface plugin.

## Configuring XML-RPC Interface Factories

An additional RPC interface is configured into a supervisor installation by adding a `[rpcinterface:x]` section in the Supervisor configuration file.

In the sample config file, there is a section which is named `[rpcinterface:supervisor]`. By default it looks like this:

    [rpcinterface:supervisor]
    supervisor.rpcinterface_factory = supervisor.rpcinterface:make_main_rpcinterface

This section must remain in the configuration for the standard setup of supervisor to work properly. If you don’t want supervisor to do anything it doesn’t already do out of the box, this is all you need to know about this type of section.

However, if you wish to add additional XML-RPC interface namespaces to a configuration of supervisor, you may add additional `[rpcinterface:foo]` sections, where “foo” represents the namespace of the interface (from the web root), and the value named by `supervisor.rpcinterface_factory` is a factory callable written in Python which should have a function signature that accepts a single positional argument `supervisord` and as many keyword arguments as required to perform configuration. Any key/value pairs defined within the `rpcinterface:foo` section will be passed as keyword arguments to the factory. Here’s an example of a factory function, created in the package `my.package`.

    def make_another_rpcinterface(supervisord, **config):
        retries = int(config.get('retries', 0))
        another_rpc_interface = AnotherRPCInterface(supervisord, retries)
        return another_rpc_interface

And a section in the config file meant to configure it.

    [rpcinterface:another]
    supervisor.rpcinterface_factory = my.package:make_another_rpcinterface
    retries = 1