diff --git a/.idea/dictionaries/ericf.xml b/.idea/dictionaries/ericf.xml
index 18caaff6..b388fb62 100644
--- a/.idea/dictionaries/ericf.xml
+++ b/.idea/dictionaries/ericf.xml
@@ -1598,6 +1598,7 @@
       <w>outpath</w>
       <w>outputter</w>
       <w>outval</w>
+      <w>outvals</w>
       <w>outvalue</w>
       <w>ouya</w>
       <w>overloadsigs</w>
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 723fde22..1e5b7d87 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,4 +1,5 @@
 ### 1.6.5 (20388)
+- Added co-op support to server builds (thanks Dliwk!)
 
 ### 1.6.4 (20382)
 - Some cleanups in the Favorites tab of the gather window.
diff --git a/assets/src/ba_data/python/ba/_activity.py b/assets/src/ba_data/python/ba/_activity.py
index b19a2e40..4c9190ba 100644
--- a/assets/src/ba_data/python/ba/_activity.py
+++ b/assets/src/ba_data/python/ba/_activity.py
@@ -112,8 +112,9 @@ class Activity(DependencyComponent, Generic[PlayerType, TeamType]):
     # transitions).
     inherits_tint = False
 
-    # Whether players should be allowed to join in the middle of
-    # activity.
+    # Whether players should be allowed to join in the middle of this
+    # activity. Note that Sessions may not allow mid-activity-joins even
+    # if the activity says its ok.
     allow_mid_activity_joins: bool = True
 
     # If the activity fades or transitions in, it should set the length of
diff --git a/assets/src/ba_data/python/ba/_coopsession.py b/assets/src/ba_data/python/ba/_coopsession.py
index bb85a4b0..021142a9 100644
--- a/assets/src/ba_data/python/ba/_coopsession.py
+++ b/assets/src/ba_data/python/ba/_coopsession.py
@@ -166,51 +166,44 @@ class CoopSession(Session):
         from ba._general import WeakCall
         super().on_player_leave(sessionplayer)
 
-        _ba.timer(2.0, WeakCall(self._check_end_game))
+        _ba.timer(2.0, WeakCall(self._handle_empty_activity))
 
-    def _check_end_game(self) -> None:
-        if not _ba.app.server:
-            self._end_session_if_empty()
+    def _handle_empty_activity(self) -> None:
+        """Handle cases where all players have left the current activity."""
 
-        activity = self.getactivity()
-        if activity is None:
-            return  # Probably everything is already broken, why do something?
-
-        if [player for player in activity.players if player.is_alive()]:
-            return
-
-        with _ba.Context(activity):
-            from ba._gameactivity import GameActivity
-
-            if isinstance(activity, GameActivity):
-                activity.end_game()
-
-    def _end_session_if_empty(self) -> None:
+        from ba._gameactivity import GameActivity
         activity = self.getactivity()
         if activity is None:
             return  # Hmm what should we do in this case?
 
-        # If there's still players in the current activity, we're good.
+        # If there are still players in the current activity, we're good.
         if activity.players:
             return
 
-        # If there's *no* players left in the current activity but there *is*
-        # in the session, restart the activity to pull them into the game
-        # (or quit if they're just in the lobby).
+        # If there are *not* players in the current activity but there
+        # *are* in the session:
         if not activity.players and self.sessionplayers:
 
-            # Special exception for tourney games; don't auto-restart these.
-            if self.tournament_id is not None:
-                self.end()
-            else:
-                # Don't restart joining activities; this probably means there's
-                # someone with a chooser up in that case.
-                if not activity.is_joining_activity:
+            # If we're in a game, we should restart to pull in players
+            # currently waiting in the session.
+            if isinstance(activity, GameActivity):
+
+                # Never restart tourney games however; just end the session
+                # if all players are gone.
+                if self.tournament_id is not None:
+                    self.end()
+                else:
                     self.restart()
 
-        # Hmm; no players anywhere. lets just end the session.
+        # Hmm; no players anywhere. Let's end the entire session if we're
+        # running a GUI (or just the current game if we're running headless).
         else:
-            self.end()
+            if not _ba.app.headless_mode:
+                self.end()
+            else:
+                if isinstance(activity, GameActivity):
+                    with _ba.Context(activity):
+                        activity.end_game()
 
     def _on_tournament_restart_menu_press(
             self, resume_callback: Callable[[], Any]) -> None:
@@ -274,9 +267,10 @@ class CoopSession(Session):
         else:
             outcome = '' if results is None else results.get('outcome', '')
 
-        # If at any point we have no in-game players, quit out of the session
-        # (this can happen if someone leaves in the tutorial for instance).
-        if isinstance(activity, TutorialActivity):
+        # If we're running with a gui and at any point we have no
+        # in-game players, quit out of the session (this can happen if
+        # someone leaves in the tutorial for instance).
+        if not _ba.app.headless_mode:
             active_players = [p for p in self.sessionplayers if p.in_game]
             if not active_players:
                 self.end()
diff --git a/assets/src/ba_data/python/ba/_level.py b/assets/src/ba_data/python/ba/_level.py
index c45f7156..ad764b15 100644
--- a/assets/src/ba_data/python/ba/_level.py
+++ b/assets/src/ba_data/python/ba/_level.py
@@ -36,6 +36,10 @@ class Level:
         self._index: Optional[int] = None
         self._score_version_string: Optional[str] = None
 
+    def __repr__(self) -> str:
+        cls = type(self)
+        return f"<{cls.__module__}.{cls.__name__} '{self._name}'>"
+
     @property
     def name(self) -> str:
         """The unique name for this Level."""
diff --git a/assets/src/ba_data/python/ba/_servermode.py b/assets/src/ba_data/python/ba/_servermode.py
index 0f03d4c5..7f06ddaa 100644
--- a/assets/src/ba_data/python/ba/_servermode.py
+++ b/assets/src/ba_data/python/ba/_servermode.py
@@ -98,8 +98,6 @@ class ServerController:
         self._playlist_fetch_got_response = False
         self._playlist_fetch_code = -1
 
-        self._coop_game_name = self._config.coop_game_name
-
         # Now sit around doing any pre-launch prep such as waiting for
         # account sign-in or fetching playlists; this will kick off the
         # session once done.
@@ -349,11 +347,9 @@ class ServerController:
             appcfg['Team Tournament Playlist Randomize'] = (
                 self._config.playlist_shuffle)
         elif sessiontype is CoopSession:
-            gamename = self._coop_game_name or 'Default:Onslaught Training'
-            campaignname, levelname = gamename.split(':')
             app.coop_session_args = {
-                'campaign': campaignname,
-                'level': levelname,
+                'campaign': self._config.coop_campaign,
+                'level': self._config.coop_level,
             }
         else:
             raise RuntimeError(f'Unknown session type {sessiontype}')
diff --git a/assets/src/ba_data/python/ba/_session.py b/assets/src/ba_data/python/ba/_session.py
index 618e9d00..c3f0c632 100644
--- a/assets/src/ba_data/python/ba/_session.py
+++ b/assets/src/ba_data/python/ba/_session.py
@@ -206,11 +206,12 @@ class Session:
         return node
 
     def should_allow_mid_activity_joins(self, activity: ba.Activity) -> bool:
-        """Returned value is used by the Session to determine
-        whether to allow players to join in the middle of activity.
+        """Ask ourself if we should allow joins during an Activity.
 
-        Activity.allow_mid_activity_joins is also required to allow these
-        joins."""
+        Note that for a join to be allowed, both the Session and Activity
+        have to be ok with it (via this function and the
+        Activity.allow_mid_activity_joins property.
+        """
         del activity  # Unused.
         return True
 
diff --git a/assets/src/ba_data/python/bastd/game/runaround.py b/assets/src/ba_data/python/bastd/game/runaround.py
index 711ee463..3607ecbd 100644
--- a/assets/src/ba_data/python/bastd/game/runaround.py
+++ b/assets/src/ba_data/python/bastd/game/runaround.py
@@ -561,7 +561,7 @@ class RunaroundGame(ba.CoopGameActivity[Player, Team]):
             fail_message = None
         else:
             score = None
-            fail_message = 'Reach wave 2 to rank.'
+            fail_message = ba.Lstr(resource='reachWave2Text')
 
         self.end(delay=delay,
                  results={
diff --git a/ballisticacore-cmake/.idea/dictionaries/ericf.xml b/ballisticacore-cmake/.idea/dictionaries/ericf.xml
index 36dd41ab..b4e73a88 100644
--- a/ballisticacore-cmake/.idea/dictionaries/ericf.xml
+++ b/ballisticacore-cmake/.idea/dictionaries/ericf.xml
@@ -766,6 +766,7 @@
       <w>outpath</w>
       <w>outputter</w>
       <w>outval</w>
+      <w>outvals</w>
       <w>outvalue</w>
       <w>ouya</w>
       <w>ovld</w>
diff --git a/docs/ba_module.md b/docs/ba_module.md
index f1ef308a..4d96634f 100644
--- a/docs/ba_module.md
+++ b/docs/ba_module.md
@@ -1837,11 +1837,11 @@ is pressed.</p>
 <dt><h4><a name="method_ba_CoopSession__should_allow_mid_activity_joins">should_allow_mid_activity_joins()</a></dt></h4><dd>
 <p><span>should_allow_mid_activity_joins(self, activity: <a href="#class_ba_Activity">ba.Activity</a>) -&gt; bool</span></p>
 
-<p>Returned value is used by the Session to determine
-whether to allow players to join in the middle of activity.</p>
+<p>Ask ourself if we should allow joins during an Activity.</p>
 
-<p>Activity.allow_mid_activity_joins is also required to allow these
-joins.</p>
+<p>Note that for a join to be allowed, both the Session and Activity
+have to be ok with it (via this function and the
+Activity.allow_mid_activity_joins property.</p>
 
 </dd>
 </dl>
@@ -5263,11 +5263,11 @@ session.setactivity(foo) and then <a href="#function_ba_newnode">ba.newnode</a>(
 <dt><h4><a name="method_ba_Session__should_allow_mid_activity_joins">should_allow_mid_activity_joins()</a></dt></h4><dd>
 <p><span>should_allow_mid_activity_joins(self, activity: <a href="#class_ba_Activity">ba.Activity</a>) -&gt; bool</span></p>
 
-<p>Returned value is used by the Session to determine
-whether to allow players to join in the middle of activity.</p>
+<p>Ask ourself if we should allow joins during an Activity.</p>
 
-<p>Activity.allow_mid_activity_joins is also required to allow these
-joins.</p>
+<p>Note that for a join to be allowed, both the Session and Activity
+have to be ok with it (via this function and the
+Activity.allow_mid_activity_joins property.</p>
 
 </dd>
 </dl>
diff --git a/tools/bacommon/servermanager.py b/tools/bacommon/servermanager.py
index 128d5090..0ae3005c 100644
--- a/tools/bacommon/servermanager.py
+++ b/tools/bacommon/servermanager.py
@@ -55,10 +55,7 @@ class ServerConfig:
     # This value is ignored if you supply a playlist_code (see below).
     session_type: str = 'ffa'
 
-    # There are unavailable co-op playlists now, so if you want to host a co-op
-    # game, pass level name here.
-    coop_game_name: Optional[str] = None
-
+    # Playlist-code for teams or free-for-all mode sessions.
     # To host your own custom playlists, use the 'share' functionality in the
     # playlist editor in the regular version of the game.
     # This will give you a numeric code you can enter here to host that
@@ -76,6 +73,15 @@ class ServerConfig:
     # (teams mode only).
     auto_balance_teams: bool = True
 
+    # The campaign used when in co-op session mode.
+    # Do print(ba.app.campaigns) to see available campaign names.
+    coop_campaign: str = 'Easy'
+
+    # The level name within the campaign used in co-op session mode.
+    # For campaign name FOO, do print(ba.app.campaigns['FOO'].levels) to see
+    # available level names.
+    coop_level: str = 'Onslaught Training'
+
     # Whether to enable telnet access.
     # IMPORTANT: This option is no longer available, as it was being used
     # for exploits. Live access to the running server is still possible through
diff --git a/tools/batools/build.py b/tools/batools/build.py
index 18b3be97..7c914573 100644
--- a/tools/batools/build.py
+++ b/tools/batools/build.py
@@ -742,10 +742,14 @@ def _get_server_config_template_yaml(projroot: str) -> str:
             continue
 
         if line != '' and not line.startswith('#'):
-            vname, _vtype, veq, vval_raw = line.split()
+            before_equal_sign, vval_raw = line.split('=', 1)
+            before_equal_sign = before_equal_sign.strip()
+            vval_raw = vval_raw.strip()
+            # vname, _vtype, veq, vval_raw = line.split()
+            vname, _vtype = before_equal_sign.split()
             assert vname.endswith(':')
             vname = vname[:-1]
-            assert veq == '='
+            # assert veq == '='
             vval: Any
             if vval_raw == 'field(default_factory=list)':
                 vval = []