1. rpc method exposure

If you want to handle an rpc call from users, you must implement the rpc handler, and annotate the handler with PluginJsonRpcMethod, which is a class that inherits from StreamJsonRpc.JsonRpcMethod It will automatically be exposed as an additional rpc method for c-lightning. The behavior of argument binding etc can be found at StreamJsonRpc's document

IMPORTANT: plugin will use stdin/stdout for communicating with c-lightning, so you must never write naively to stdout in your application's code otherwise json rpc messages will be corrupted.

If you really want to do it, say for logging, use the same synchronized stream for both plugin and your code. i.e.

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let outputStream = Console.OpenStandardOutput() |> Stream.Synchronized
let logger = MyCustomLogger(outputStream) // log to output stream
let plugin =
    MyPlugin().StartAsync(outputStream, Console.OpenStandardInput())

Or just use stderr (e.g. from Console.Error)

2. Subscribing to the topic.

If you want to subscribe to a notification from c-lightning (or other plugins), You must implement it with PluginJsonRpcSubscription instead of PluginJsonRpcMethod. By using it, the response value is ignored by c-lightning, and the method is not exposed to an user.

3. sending notification to c-lightning

plugins can send notification to c-lightning, Use SendNotification method for it. But before that, you must register the notification topics with constructor argument to PluginServerBase, since c-lightning must know the list of possible topics beforehand.

4. other features

For other features, e.g. taking cli options, validating c-lightning init message, etc, see corresponding abstract properties or methods.

If you set ObsoleteAttribute to methods, those will not be shown to users unless they specify "allow-deprecated-apis" to true.

Hooks are currently unsupported since it is a quite advanced feature. Please send a PR if you really want it.