diff --git a/jecs/addons/observers.luau b/jecs/addons/observers.luau
index 0175060..b725e7c 100644
--- a/jecs/addons/observers.luau
+++ b/jecs/addons/observers.luau
@@ -2,15 +2,20 @@ local jecs = require("@jecs")
 
 type Observer = {
 	callback: (jecs.Entity) -> (),
-	query: jecs.Query<...jecs.Id>,
+	query: jecs.Query<...any>,
+}
+
+type Monitor = {
+	callback: (jecs.Entity, jecs.Entity) -> (),
+	queyr: jecs.Query<any>
 }
 
 export type PatchedWorld = jecs.World & {
-	added: <T>(PatchedWorld, jecs.Id<T>, (jecs.Entity, jecs.Id, T) -> ()) -> () -> (),
-	removed: <T>(PatchedWorld, jecs.Id<T>, (jecs.Entity, jecs.Id) -> ()) -> () -> (),
-	changed: <T>(PatchedWorld, jecs.Id<T>, (jecs.Entity, jecs.Id, T) -> ()) -> () -> (),
+	added: <T>(PatchedWorld, jecs.Id<T>, (e: jecs.Entity, id: jecs.Id, value: T) -> ()) -> () -> (),
+	removed: <T>(PatchedWorld, jecs.Id<T>, (e: jecs.Entity, id: jecs.Id) -> ()) -> () -> (),
+	changed: <T>(PatchedWorld, jecs.Id<T>, (e: jecs.Entity, id: jecs.Id, value: T) -> ()) -> () -> (),
 	observer: (PatchedWorld, Observer) -> (),
-	monitor: (PatchedWorld, Observer) -> (),
+	monitor: (PatchedWorld, Monitor) -> (),
 }
 
 local function observers_new(world, description)
@@ -45,7 +50,6 @@ local function observers_new(world, description)
  	end
 end
 
-
 local function join(world, component)
 	local sparse_array = {}
 	local dense_array = {}
@@ -163,16 +167,16 @@ local function observers_add(world: jecs.World): PatchedWorld
 					listener(entity, id, value)
 				end
 			end
-			local idr = world.component_index[component]
-			if idr then
-				local idr_hook_existing = idr.hooks.on_add
-				if idr_hook_existing then
-					table.insert(listeners, idr_hook_existing)
+			local existing_hook = world:get(component, jecs.OnAdd)
+			if existing_hook then
+				table.insert(listeners, existing_hook)
+				local idr = world.component_index[component]
+				if idr then
+					idr.hooks.on_add = on_add
 				end
-				idr.hooks.on_add = on_add :: any
-			else
-				world:set(component, jecs.OnAdd, on_add)
 			end
+
+			world:set(component, jecs.OnAdd, on_add)
 		end
 		table.insert(listeners, fn)
 		return function()
@@ -197,16 +201,15 @@ local function observers_add(world: jecs.World): PatchedWorld
 					listener(entity, id, value)
 				end
 			end
-			local idr = world.component_index[component]
-			if idr then
-				local idr_hook_existing = idr.hooks.on_change
-				if idr_hook_existing then
-					table.insert(listeners, idr_hook_existing)
+			local existing_hook = world:get(component, jecs.OnChange)
+			if existing_hook then
+				table.insert(listeners, existing_hook)
+				local idr = world.component_index[component]
+				if idr then
+					idr.hooks.on_change = on_change
 				end
-				idr.hooks.on_change = on_change :: any
-			else
-				world:set(component, jecs.OnChange, on_change)
 			end
+			world:set(component, jecs.OnChange, on_change)
 		end
 		table.insert(listeners, fn)
 		return function()
@@ -231,16 +234,16 @@ local function observers_add(world: jecs.World): PatchedWorld
 					listener(entity, id, value)
 				end
 			end
-			local idr = world.component_index[component]
-			if idr then
-				local idr_hook_existing = idr.hooks.on_remove
-				if idr_hook_existing then
-					table.insert(listeners, idr_hook_existing)
+			local existing_hook = world:get(component, jecs.OnRemove)
+			if existing_hook then
+				table.insert(listeners, existing_hook)
+				local idr = world.component_index[component]
+				if idr then
+					idr.hooks.on_remove = on_remove
 				end
-				idr.hooks.on_remove = on_remove :: any
-			else
-				world:set(component, jecs.OnRemove, on_remove)
 			end
+
+			world:set(component, jecs.OnRemove, on_remove)
 		end
 		table.insert(listeners, fn)
 		return function()
diff --git a/jecs/build.txt b/jecs/build.txt
index 167581c..1ab250a 100644
--- a/jecs/build.txt
+++ b/jecs/build.txt
@@ -1,2 +1,2 @@
-modified = ["README.md", "jecs.luau"]
-version = "0.6.0-nightly.20250519T001113Z"
+modified = ["addons/observers.luau"]
+version = "0.6.0-nightly.20250520T001101Z"
diff --git a/jecs/pesde-rbx.toml b/jecs/pesde-rbx.toml
index f5a17c4..50592e6 100644
--- a/jecs/pesde-rbx.toml
+++ b/jecs/pesde-rbx.toml
@@ -3,7 +3,7 @@ includes = ["init.luau", "pesde.toml", "README.md", "CHANGELOG.md", "LICENSE", "
 license = "MIT"
 name = "marked/jecs_nightly"
 repository = "https://git.devmarked.win/marked/jecs-nightly"
-version = "0.6.0-nightly.20250519T001113Z"
+version = "0.6.0-nightly.20250520T001101Z"
 
 [indices]
 default = "https://github.com/pesde-pkg/index"
diff --git a/jecs/pesde.toml b/jecs/pesde.toml
index f3ddfa0..fd6740f 100644
--- a/jecs/pesde.toml
+++ b/jecs/pesde.toml
@@ -3,7 +3,7 @@ includes = ["init.luau", "pesde.toml", "README.md", "CHANGELOG.md", "LICENSE", "
 license = "MIT"
 name = "marked/jecs_nightly"
 repository = "https://git.devmarked.win/marked/jecs-nightly"
-version = "0.6.0-nightly.20250519T001113Z"
+version = "0.6.0-nightly.20250520T001101Z"
 
 [indices]
 default = "https://github.com/pesde-pkg/index"
diff --git a/jecs/test.txt b/jecs/test.txt
index f3b008a..aa5cede 100644
--- a/jecs/test.txt
+++ b/jecs/test.txt
@@ -1,2 +1,2 @@
 passed = true
-timestamp = "20250519T001115Z"
+timestamp = "20250521T001102Z"
diff --git a/jecs/test_fulllog.txt b/jecs/test_fulllog.txt
index 2b77688..3edfaca 100644
--- a/jecs/test_fulllog.txt
+++ b/jecs/test_fulllog.txt
@@ -1,6 +1,6 @@
-7.3 us   3 kB│ delete children of entity
-9.2 us   1 kB│ remove friends of entity
-348 ns  10  B│ simple deletion of entity
+7.2 us   3 kB│ delete children of entity
+9.1 us   1 kB│ remove friends of entity
+347 ns  10  B│ simple deletion of entity
 repro
 NONE│ 
 
@@ -121,5 +121,5 @@
 PASS│ #2
 PASS│ #3
 
-74/74 test cases passed in 33.314 ms.
+74/74 test cases passed in 32.770 ms.
 0 fails
diff --git a/jecs/wally.toml b/jecs/wally.toml
index 2a8d02b..d7ffcb9 100644
--- a/jecs/wally.toml
+++ b/jecs/wally.toml
@@ -5,4 +5,4 @@ license = "MIT"
 name = "mark-marks/jecs-nightly"
 realm = "shared"
 registry = "https://github.com/UpliftGames/wally-index"
-version = "0.6.0-nightly.20250519T001113Z"
+version = "0.6.0-nightly.20250520T001101Z"