From ff53c03952462fc89492c8b806fba42e8c0969b3 Mon Sep 17 00:00:00 2001
From: Karl Nilsson <kjnilsson@gmail.com>
Date: Wed, 7 Feb 2024 12:23:23 +0000
Subject: [PATCH] potential new callback sig

readme.md
---
 README.md          |  2 +-
 src/ra_machine.erl | 14 ++++++++++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 48eaf44f..3c464a88 100644
--- a/README.md
+++ b/README.md
@@ -440,7 +440,7 @@ Ra attempts to follow [Semantic Versioning](https://semver.org/).
 
 The modules that form part of the public API are:
 * `ra`
-* `ra_machine`
+* `ra_machine` (behaviour callbacks only)
 * `ra_system`
 * `ra_counters`
 * `ra_leaderboard`
diff --git a/src/ra_machine.erl b/src/ra_machine.erl
index ba54092a..3213272d 100644
--- a/src/ra_machine.erl
+++ b/src/ra_machine.erl
@@ -232,6 +232,20 @@
 
 -callback init_aux(Name :: atom()) -> term().
 
+-callback handle_aux(ra_server:ra_state(),
+                     {call, From :: from()} | cast,
+                     Command :: term(),
+                     AuxState,
+                     State) ->
+    {reply, Reply :: term(), AuxState, State} |
+    {reply, Reply :: term(), AuxState, State,
+     [{monitor, process, aux, pid()}]} |
+    {no_reply, AuxState, State} |
+    {no_reply, AuxState, State,
+     [{monitor, process, aux, pid()}]}
+      when AuxState :: term(),
+           State :: ra_aux:state().
+
 -callback handle_aux(ra_server:ra_state(),
                      {call, From :: from()} | cast,
                      Command :: term(),