diff --git a/Source/Mods/JecsTools.cs b/Source/Mods/JecsTools.cs
new file mode 100644
index 00000000..894f198f
--- /dev/null
+++ b/Source/Mods/JecsTools.cs
@@ -0,0 +1,143 @@
+using System.Collections;
+using System.Linq;
+using HarmonyLib;
+using Multiplayer.API;
+using Verse;
+
+namespace Multiplayer.Compat
+{
+    /// <summary>JecsTools by jecrell and contributors</summary>
+    /// <see href="https://github.com/jecrell/JecsTools"/>
+    /// <see href="https://steamcommunity.com/sharedfiles/filedetails/?id=932008009"/>
+    [MpCompatFor("jecrell.jecstools")]
+    public class JecsTools
+    {
+        #region Main patch
+
+        public JecsTools(ModContentPack mod)
+        {
+            // AbilityUser
+            PatchAbilities();
+
+            // CompActivatableEffect
+            {
+                // Deactivate/Activate gizmo
+                MpCompat.RegisterLambdaMethod("CompActivatableEffect.CompActivatableEffect", "EquippedGizmos", 0, 1);
+            }
+
+            // CompInstalledPart
+            {
+                MpCompat.RegisterLambdaDelegate("CompInstalledPart.InstalledPartFloatMenuPatch", "GetFloatMenus", 3);
+                // Looking at the code, it seems there's no built-in way to uninstall those?
+            }
+
+            // CompSlotLoadable
+            {
+                var type = AccessTools.TypeByName("CompSlotLoadable.CompSlotLoadable");
+                MP.RegisterSyncMethod(type, "TryCancel"); // Gizmo -> cancel
+                MP.RegisterSyncMethod(type, "TryGiveLoadSlotJob"); // Gizmo -> float menu -> load option
+                MP.RegisterSyncMethod(type, "TryEmptySlot"); // Gizmo -> float menu -> empty option
+                MpCompat.RegisterLambdaDelegate("CompSlotLoadable.SloatLoadbleFloatMenuPatch", "GetFloatMenus", 1);
+            }
+
+            // CompToggleDef
+            {
+                MP.RegisterSyncMethod(AccessTools.Method("CompToggleDef.ToggleDefCardUtility:SwapThing")).SetContext(SyncContext.MapSelected);
+            }
+        }
+
+        #endregion
+
+        #region Abilities
+
+        // PawnAbility
+        private static AccessTools.FieldRef<object, ThingComp> pawnAbilityUserField;
+
+        // CompAbilityUser
+        private static AccessTools.FieldRef<object, object> compAbilityUserAbilityDataField;
+
+        // AbilityData
+        private static FastInvokeHandler abilityDataAllPowersGetter;
+
+        // AbilityUserUtility
+        private static FastInvokeHandler abilityUserUtilityGetCompsMethod;
+
+        private static void PatchAbilities()
+        {
+            // PawnAbility
+            var type = AccessTools.TypeByName("AbilityUser.PawnAbility");
+            pawnAbilityUserField = AccessTools.FieldRefAccess<ThingComp>(type, "abilityUser");
+
+            MP.RegisterSyncMethod(type, "UseAbility").SetPostInvoke(StopTargeting);
+            MP.RegisterSyncWorker<object>(SyncPawnAbility, type);
+
+            // CompAbilityUser
+            compAbilityUserAbilityDataField = AccessTools.FieldRefAccess<object>("AbilityUser.CompAbilityUser:abilityData");
+
+            // AbilityData
+            abilityDataAllPowersGetter = MethodInvoker.GetHandler(AccessTools.PropertyGetter("AbilityUser.AbilityData:AllPowers"));
+
+            // AbilityUserUtility
+            abilityUserUtilityGetCompsMethod = MethodInvoker.GetHandler(AccessTools.Method("AbilityUser.AbilityUserUtility:GetCompAbilityUsers"));
+        }
+
+        private static void StopTargeting(object instance, object[] args)
+        {
+            // The job driver is assigning Find.Targeter.targetingSource, starting targeting again.
+            // We need to stop targeting after casting or we'll start targeting again after casting.
+            if (MP.IsExecutingSyncCommandIssuedBySelf)
+                Find.Targeter.StopTargeting();
+        }
+
+        private static void SyncPawnAbility(SyncWorker sync, ref object ability)
+        {
+            if (sync.isWriting)
+            {
+                // The comp.props seems null, at least in some cases - which is what MP sync worker uses for syncing.
+                // We need to sync it differently.
+                var abilityUserComp = pawnAbilityUserField(ability);
+                var comps = ((IEnumerable)abilityUserUtilityGetCompsMethod(null, abilityUserComp.parent)).Cast<ThingComp>().ToArray();
+
+                var foundMatch = false;
+                for (var index = 0; index < comps.Length; index++)
+                {
+                    var comp = comps[index];
+                    var data = compAbilityUserAbilityDataField(comp);
+                    var allPowers = (IList)abilityDataAllPowersGetter(data);
+                    var innerIndex = allPowers.IndexOf(ability);
+
+                    if (innerIndex >= 0)
+                    {
+                        foundMatch = true;
+                        sync.Write(index);
+                        sync.Write(innerIndex);
+                        sync.Write(abilityUserComp.parent); // Parent pawn
+                        break;
+                    }
+                }
+
+                if (!foundMatch)
+                    sync.Write(-1);
+            }
+            else
+            {
+                var index = sync.Read<int>();
+
+                if (index < 0)
+                    return;
+
+                var innerIndex = sync.Read<int>();
+                var pawn = sync.Read<Pawn>();
+
+                var allComps = ((IEnumerable)abilityUserUtilityGetCompsMethod(null, pawn)).Cast<ThingComp>().ToArray();
+                var comp = allComps[index];
+                var data = compAbilityUserAbilityDataField(comp);
+                var all = (IList)abilityDataAllPowersGetter(data);
+
+                ability = all[innerIndex];
+            }
+        }
+
+        #endregion
+    }
+}
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