doc: update channel_state_changed notification

doc/PLUGINS.md

@@ -325,8 +325,8 @@ into a block.
 ### `channel_state_changed`
 
 A notification for topic `channel_state_changed` is sent every time a channel
-changes its state. The notification includes the peer and channel ids as well
-as the old and the new channel states.
+changes its state. The notification includes the `peer_id` and `channel_id`, the
+old and new channel states, the type of `cause` and a `message`.
 
 ```json
 {
@@ -335,11 +335,35 @@ as the old and the new channel states.
         "channel_id": "a2d0851832f0e30a0cf778a826d72f077ca86b69f72677e0267f23f63a0599b4",
         "short_channel_id" : "561820x1020x1",
         "old_state": "CHANNELD_NORMAL",
-        "new_state": "CHANNELD_SHUTTING_DOWN"
+        "new_state": "CHANNELD_SHUTTING_DOWN",
+        "cause" : "remote",
+        "message" : "Peer closes channel"
     }
 }
 ```
 
+A `cause` can have the following values:
+ - "unknown"   Anything other than the reasons below. Should not happen.
+ - "local"     Unconscious internal reasons, e.g. dev fail of a channel.
+ - "user"      The operator or a plugin opened or closed a channel by intention.
+ - "remote"    The remote closed or funded a channel with us by intention.
+ - "protocol"  We need to close a channel because of bad signatures and such.
+ - "onchain"   A channel was closed onchain, while we were offline.
+
+Most state changes are caused subsequentially for a prior state change, e.g.
+"CLOSINGD_COMPLETE" is followed by "FUNDING_SPEND_SEEN". Because of this, the
+`cause` reflects the last known reason in terms of local or remote user
+interaction, protocol reasons, etc. More specifically, a `new_state`
+"FUNDING_SPEND_SEEN" will likely _not_ have "onchain" as a `cause` but some
+value such as "REMOTE" or "LOCAL" depending on who initiated the closing of a
+channel.
+
+Note: If the channel is not closed or being closed yet, the `cause` will reflect
+which side "remote" or "local" opened the channel.
+
+Note: If the cause is "onchain" this was very likely a conscious decision of the
+remote peer, but we have been offline.
+
 ### `connect`
 
 A notification for topic `connect` is sent every time a new connection

doc/lightning-listpeers.7

@@ -114,6 +114,14 @@ The channel will eventually be removed from this array\.
 
 .RE
 
+.IP \[bu]
+\fIstate_changes\fR: An array of objects describing prior state change events\.
+.IP \[bu]
+\fIopener\fR: A string \fB"local"\fR or \fB"remote\fR" describing which side opened this
+channel\.
+.IP \[bu]
+\fIcloser\fR: A string \fB"local"\fR or \fB"remote\fR" describing which side
+closed this channel or \fBnull\fR if the channel is not (being) closed yet\.
 .IP \[bu]
 \fIstatus\fR: An array of strings containing the most important log messages
 relevant to this channel\.
@@ -319,4 +327,4 @@ Main web site: \fIhttps://github.com/ElementsProject/lightning\fR Lightning
 RFC site (BOLT #9):
 \fIhttps://github.com/lightningnetwork/lightning-rfc/blob/master/09-features.md\fR
 
-\" SHA256STAMP:c1ed65bd0e15a1056e3785cf8162ae11d4817fef3c1c12a85c46bab82ab32d0e
+\" SHA256STAMP:8f6fbdc92e59d5efb2e9e8fa113651badb8aacddaea29d81798ecb598fbaad01

doc/lightning-listpeers.7.md

@@ -84,6 +84,11 @@ The objects in the *channels* array will have at least these fields:
     peer, or a theft attempt).
   * `"CLOSED"`: The channel closure has been confirmed deeply.
     The channel will eventually be removed from this array.
+* *state_changes*: An array of objects describing prior state change events.
+* *opener*: A string `"local"` or `"remote`" describing which side opened this
+  channel.
+* *closer*: A string `"local"` or `"remote`" describing which side
+  closed this channel or `null` if the channel is not (being) closed yet.
 * *status*: An array of strings containing the most important log messages
   relevant to this channel.
   Also known as the "billboard".