diff --git a/src/ffi/js/buffer.rs b/src/ffi/js/buffer.rs
index 5fc72d3..9e141c7 100644
--- a/src/ffi/js/buffer.rs
+++ b/src/ffi/js/buffer.rs
@@ -7,8 +7,8 @@ use crate::buffer::controller::BufferController;
 
 #[napi]
 impl BufferController {
-	#[napi(ts_args_type = "fun: (event: TextChange) => void")]
-	pub fn callback(&self, fun: napi::JsFunction) -> napi::Result<()>{ 
+	#[napi(js_name = "callback", ts_args_type = "fun: (event: TextChange) => void")]
+	pub fn jscallback(&self, fun: napi::JsFunction) -> napi::Result<()>{ 
 		let tsfn : ThreadsafeFunction<crate::api::TextChange, Fatal> = 
 		fun.create_threadsafe_function(0,
 			|ctx : ThreadSafeCallContext<crate::api::TextChange>| {
@@ -41,4 +41,4 @@ impl BufferController {
 	pub async fn js_send(&self, op: TextChange) -> napi::Result<()> {
 		Ok(self.send(op).await?)
 	}
-}
\ No newline at end of file
+}
diff --git a/src/ffi/js/cursor.rs b/src/ffi/js/cursor.rs
index a0d4c28..c84d90d 100644
--- a/src/ffi/js/cursor.rs
+++ b/src/ffi/js/cursor.rs
@@ -42,8 +42,8 @@ impl From<crate::api::Cursor> for JsCursor {
 
 #[napi]
 impl CursorController {
-	#[napi(ts_args_type = "fun: (event: Cursor) => void")]
-	pub fn callback(&self, fun: napi::JsFunction) -> napi::Result<()>{ 
+	#[napi(js_name = "callback", ts_args_type = "fun: (event: Cursor) => void")]
+	pub fn jscallback(&self, fun: napi::JsFunction) -> napi::Result<()>{ 
 		let tsfn : ThreadsafeFunction<JsCursor, ErrorStrategy::Fatal> = 
 		fun.create_threadsafe_function(0,
 			|ctx : ThreadSafeCallContext<JsCursor>| {
diff --git a/src/ffi/js/workspace.rs b/src/ffi/js/workspace.rs
index 3aa552e..0711beb 100644
--- a/src/ffi/js/workspace.rs
+++ b/src/ffi/js/workspace.rs
@@ -12,8 +12,8 @@ impl Workspace {
 	}
 	
 	#[napi(js_name = "filetree")]
-	pub fn js_filetree(&self) -> Vec<String> {
-		self.filetree()
+	pub fn js_filetree(&self, filter: Option<&str>) -> Vec<String> {
+		self.filetree(filter)
 	}
 
 	#[napi(js_name = "cursor")]
@@ -41,4 +41,4 @@ impl Workspace {
 		Ok(self.delete(&path).await?)
 	}
 
-}
\ No newline at end of file
+}
diff --git a/src/ffi/lua.rs b/src/ffi/lua.rs
index d0967fd..da72d26 100644
--- a/src/ffi/lua.rs
+++ b/src/ffi/lua.rs
@@ -166,12 +166,15 @@ impl LuaUserData for CodempWorkspace {
 			});
 			Ok(())
 		});
+
+		methods.add_method("filetree", |_, this, (filter,):(Option<String>,)|
+			Ok(this.filetree(filter.as_deref()))
+		);
 	}
 
 	fn add_fields<'lua, F: LuaUserDataFields<'lua, Self>>(fields: &mut F) {
 		fields.add_field_method_get("id", |_, this| Ok(this.id()));
 		fields.add_field_method_get("cursor", |_, this| Ok(this.cursor()));
-		fields.add_field_method_get("filetree", |_, this| Ok(this.filetree()));
 		fields.add_field_method_get("active_buffers", |_, this| Ok(this.buffer_list()));
 		// fields.add_field_method_get("users", |_, this| Ok(this.0.users())); // TODO
 	}
diff --git a/src/ffi/python/workspace.rs b/src/ffi/python/workspace.rs
index 425301d..263704f 100644
--- a/src/ffi/python/workspace.rs
+++ b/src/ffi/python/workspace.rs
@@ -72,7 +72,7 @@ impl Workspace {
 				.list_buffer_users(path.as_str())
 				.await?
 				.into_iter()
-				.map(|e| e.id)
+				.map(|e| e.id.to_string())
 				.collect();
 
 			Ok(usrlist)
@@ -118,8 +118,8 @@ impl Workspace {
 	}
 
 	#[pyo3(name = "filetree")]
-	fn pyfiletree(&self) -> Vec<String> {
-		self.filetree()
+	fn pyfiletree(&self, filter: Option<&str>) -> Vec<String> {
+		self.filetree(filter)
 	}
 }
 
diff --git a/src/workspace/worker.rs b/src/workspace/worker.rs
index 7e83dd7..b3aa61c 100644
--- a/src/workspace/worker.rs
+++ b/src/workspace/worker.rs
@@ -332,8 +332,11 @@ impl Workspace {
 
 	/// get the currently cached "filetree"
 	// #[cfg_attr(feature = "js", napi)] // https://github.com/napi-rs/napi-rs/issues/1120
-	pub fn filetree(&self) -> Vec<String> {
-		self.0.filetree.iter().map(|f| f.clone()).collect()
+	pub fn filetree(&self, filter: Option<&str>) -> Vec<String> {
+		self.0.filetree.iter()
+			.filter(|f| filter.map_or(true, |flt| f.starts_with(flt)))
+			.map(|f| f.clone())
+			.collect()
 	}
 }