diff --git a/src/ffi/java/buffer.rs b/src/ffi/java/buffer.rs
index c1bdd66..0857118 100644
--- a/src/ffi/java/buffer.rs
+++ b/src/ffi/java/buffer.rs
@@ -7,37 +7,37 @@ use super::null_check;
 
 /// Get the name of the buffer. 
 #[jni(package = "mp.code", class = "BufferController")]
-fn get_name(controller: crate::buffer::Controller) -> String {
+fn get_name(controller: &mut crate::buffer::Controller) -> String {
 	controller.path().to_string() //TODO: &str is built into the newer version
 }
 
 /// Get the contents of the buffers.
 #[jni(package = "mp.code", class = "BufferController")]
-fn get_content(controller: crate::buffer::Controller) -> Result<String, ControllerError> {
+fn get_content(controller: &mut crate::buffer::Controller) -> Result<String, ControllerError> {
 	super::tokio().block_on(controller.content())
 }
 
 /// Try to fetch a [TextChange], or return null if there's nothing.
 #[jni(package = "mp.code", class = "BufferController")]
-fn try_recv(controller: crate::buffer::Controller) -> Result<Option<TextChange>, ControllerError> {
+fn try_recv(controller: &mut crate::buffer::Controller) -> Result<Option<TextChange>, ControllerError> {
 	super::tokio().block_on(controller.try_recv())
 }
 
 /// Block until it receives a [TextChange].
 #[jni(package = "mp.code", class = "BufferController")]
-fn recv(controller: crate::buffer::Controller) -> Result<TextChange, ControllerError> {
+fn recv(controller: &mut crate::buffer::Controller) -> Result<TextChange, ControllerError> {
 	super::tokio().block_on(controller.recv())
 }
 
 /// Send a [TextChange] to the server.
 #[jni(package = "mp.code", class = "BufferController")]
-fn send(controller: crate::buffer::Controller, change: TextChange) -> Result<(), ControllerError> {
+fn send(controller: &mut crate::buffer::Controller, change: TextChange) -> Result<(), ControllerError> {
 	super::tokio().block_on(controller.send(change))
 }
 
 /// Register a callback for buffer changes.
 #[jni(package = "mp.code", class = "BufferController")]
-fn callback<'local>(env: &mut JNIEnv<'local>, controller: crate::buffer::Controller, cb: JObject<'local>) {
+fn callback<'local>(env: &mut JNIEnv<'local>, controller: &mut crate::buffer::Controller, cb: JObject<'local>) {
 	null_check!(env, cb, {});
 	let Ok(cb_ref) = env.new_global_ref(cb) else {
 		env.throw_new("mp/code/exceptions/JNIException", "Failed to pin callback reference!")
@@ -70,19 +70,19 @@ fn callback<'local>(env: &mut JNIEnv<'local>, controller: crate::buffer::Control
 
 /// Clear the callback for buffer changes.
 #[jni(package = "mp.code", class = "BufferController")]
-fn clear_callback(controller: crate::buffer::Controller) {
+fn clear_callback(controller: &mut crate::buffer::Controller) {
 	controller.clear_callback()
 }
 
 /// Block until there is a new value available.
 #[jni(package = "mp.code", class = "BufferController")]
-fn poll(controller: crate::buffer::Controller) -> Result<(), ControllerError> {
+fn poll(controller: &mut crate::buffer::Controller) -> Result<(), ControllerError> {
 	super::tokio().block_on(controller.poll())
 }
 
 /// Stop the controller.
 #[jni(package = "mp.code", class = "BufferController")]
-fn stop(controller: crate::buffer::Controller) -> bool {
+fn stop(controller: &mut crate::buffer::Controller) -> bool {
 	controller.stop()
 }
 
diff --git a/src/ffi/java/client.rs b/src/ffi/java/client.rs
index 624ceba..e420171 100644
--- a/src/ffi/java/client.rs
+++ b/src/ffi/java/client.rs
@@ -9,61 +9,61 @@ fn connect(config: Config) -> Result<Client, ConnectionError> {
 
 /// Gets the current [crate::api::User].
 #[jni(package = "mp.code", class = "Client", ptr)]
-fn get_user(client: Client) -> crate::api::User {
+fn get_user(client: &mut Client) -> crate::api::User {
 	client.user().clone()
 }
 
 /// Join a [Workspace] and return a pointer to it.
 #[jni(package = "mp.code", class = "Client")]
-fn join_workspace(client: Client, workspace: String) -> Result<Workspace, ConnectionError> {
+fn join_workspace(client: &mut Client, workspace: String) -> Result<Workspace, ConnectionError> {
 	super::tokio().block_on(client.join_workspace(workspace))
 }
 
 /// Create a workspace on server, if allowed to.
 #[jni(package = "mp.code", class = "Client")]
-fn create_workspace(client: Client, workspace: String) -> Result<(), RemoteError> {
+fn create_workspace(client: &mut Client, workspace: String) -> Result<(), RemoteError> {
 	super::tokio().block_on(client.create_workspace(workspace))
 }
 
 /// Delete a workspace on server, if allowed to.
 #[jni(package = "mp.code", class = "Client")]
-fn delete_workspace(client: Client, workspace: String) -> Result<(), RemoteError> {
+fn delete_workspace(client: &mut Client, workspace: String) -> Result<(), RemoteError> {
 	super::tokio().block_on(client.delete_workspace(workspace))
 }
 
 /// Invite another user to an owned workspace.
 #[jni(package = "mp.code", class = "Client")]
-fn invite_to_workspace(client: Client, workspace: String, user: String) -> Result<(), RemoteError> {
+fn invite_to_workspace(client: &mut Client, workspace: String, user: String) -> Result<(), RemoteError> {
 	super::tokio().block_on(client.invite_to_workspace(workspace, user))
 }
 
 /// List available workspaces.
 #[jni(package = "mp.code", class = "Client")]
-fn list_workspaces(client: Client, owned: bool, invited: bool) -> Result<Vec<String>, RemoteError> {
+fn list_workspaces(client: &mut Client, owned: bool, invited: bool) -> Result<Vec<String>, RemoteError> {
 	super::tokio().block_on(client.list_workspaces(owned, invited))
 }
 
 /// List available workspaces.
 #[jni(package = "mp.code", class = "Client")]
-fn active_workspaces(client: Client) -> Vec<String> {
+fn active_workspaces(client: &mut Client) -> Vec<String> {
 	client.active_workspaces()
 }
 
 /// Leave a [Workspace] and return whether or not the client was in such workspace.
 #[jni(package = "mp.code", class = "Client")]
-fn leave_workspace(client: Client, workspace: String) -> bool {
+fn leave_workspace(client: &mut Client, workspace: String) -> bool {
 		client.leave_workspace(&workspace)
 }
 
 /// Get a [Workspace] by name and returns a pointer to it.
 #[jni(package = "mp.code", class = "Client")]
-fn get_workspace(client: Client, workspace: String) -> Option<Workspace> {
+fn get_workspace(client: &mut Client, workspace: String) -> Option<Workspace> {
 	client.get_workspace(&workspace)
 }
 
 /// Refresh the client's session token.
 #[jni(package = "mp.code", class = "Client")]
-fn refresh(client: Client) -> Result<(), RemoteError> {
+fn refresh(client: &mut Client) -> Result<(), RemoteError> {
 	super::tokio().block_on(client.refresh())
 }
 
diff --git a/src/ffi/java/cursor.rs b/src/ffi/java/cursor.rs
index c68115c..359ea2b 100644
--- a/src/ffi/java/cursor.rs
+++ b/src/ffi/java/cursor.rs
@@ -6,25 +6,25 @@ use super::null_check;
 
 /// Try to fetch a [Cursor], or returns null if there's nothing.
 #[jni(package = "mp.code", class = "CursorController")]
-fn try_recv(controller: crate::cursor::Controller) -> Result<Option<Cursor>, ControllerError> {
+fn try_recv(controller: &mut crate::cursor::Controller) -> Result<Option<Cursor>, ControllerError> {
 	super::tokio().block_on(controller.try_recv())
 }
 
 /// Block until it receives a [Cursor].
 #[jni(package = "mp.code", class = "CursorController")]
-fn recv(controller: crate::cursor::Controller) -> Result<Cursor, ControllerError> {
+fn recv(controller: &mut crate::cursor::Controller) -> Result<Cursor, ControllerError> {
 	super::tokio().block_on(controller.recv())
 }
 
 /// Receive from Java, converts and sends a [Cursor].
 #[jni(package = "mp.code", class = "CursorController")]
-fn send(controller: crate::cursor::Controller, cursor: Cursor) -> Result<(), ControllerError> {
+fn send(controller: &mut crate::cursor::Controller, cursor: Cursor) -> Result<(), ControllerError> {
 	super::tokio().block_on(controller.send(cursor))
 }
 
 /// Register a callback for cursor changes.
 #[jni(package = "mp.code", class = "CursorController")]
-fn callback<'local>(env: &mut JNIEnv<'local>, controller: crate::cursor::Controller, cb: JObject<'local>) {
+fn callback<'local>(env: &mut JNIEnv<'local>, controller: &mut crate::cursor::Controller, cb: JObject<'local>) {
 	null_check!(env, cb, {});	
 	let Ok(cb_ref) = env.new_global_ref(cb) else {
 		env.throw_new("mp/code/exceptions/JNIException", "Failed to pin callback reference!")
@@ -57,19 +57,19 @@ fn callback<'local>(env: &mut JNIEnv<'local>, controller: crate::cursor::Control
 
 /// Clear the callback for cursor changes.
 #[jni(package = "mp.code", class = "CursorController")]
-fn clear_callback(controller: crate::cursor::Controller) {
+fn clear_callback(controller: &mut crate::cursor::Controller) {
 	controller.clear_callback()	
 }
 
 /// Block until there is a new value available.
 #[jni(package = "mp.code", class = "CursorController")]
-fn poll(controller: crate::cursor::Controller) -> Result<(), ControllerError> {
+fn poll(controller: &mut crate::cursor::Controller) -> Result<(), ControllerError> {
 	super::tokio().block_on(controller.poll())
 }
 
 /// Stop the controller.
 #[jni(package = "mp.code", class = "CursorController")]
-fn stop(controller: crate::cursor::Controller) -> bool {
+fn stop(controller: &mut crate::cursor::Controller) -> bool {
 	controller.stop()	
 }
 
diff --git a/src/ffi/java/mod.rs b/src/ffi/java/mod.rs
index a309599..6e0515a 100644
--- a/src/ffi/java/mod.rs
+++ b/src/ffi/java/mod.rs
@@ -244,11 +244,10 @@ impl<'j> jni_toolbox::IntoJavaObject<'j> for crate::api::Cursor {
 
 macro_rules! from_java_ptr {
 	($type: ty) => {
-		impl<'j> jni_toolbox::FromJava<'j> for $type {
+		impl<'j> jni_toolbox::FromJava<'j> for &mut $type {
 			type From = jni::sys::jobject;
 			fn from_java(_env: &mut jni::JNIEnv<'j>, value: Self::From) -> Result<Self, jni::errors::Error> {
-				let original_ptr = unsafe { Box::leak(Box::from_raw(value as *mut $type)) };
-				Ok(original_ptr.clone())
+				Ok(unsafe { Box::leak(Box::from_raw(value as *mut $type)) })
 			}
 		}
 	};
diff --git a/src/ffi/java/workspace.rs b/src/ffi/java/workspace.rs
index c851fe7..06d8df4 100644
--- a/src/ffi/java/workspace.rs
+++ b/src/ffi/java/workspace.rs
@@ -3,79 +3,79 @@ use crate::{errors::{ConnectionError, ControllerError, RemoteError}, Workspace};
 
 /// Get the workspace id.
 #[jni(package = "mp.code", class = "Workspace")]
-fn get_workspace_id(workspace: Workspace) -> String {
+fn get_workspace_id(workspace: &mut Workspace) -> String {
 	workspace.id()
 }
 
 /// Get a cursor controller by name and returns a pointer to it.
 #[jni(package = "mp.code", class = "Workspace")]
-fn get_cursor(workspace: Workspace) -> crate::cursor::Controller {
+fn get_cursor(workspace: &mut Workspace) -> crate::cursor::Controller {
 	workspace.cursor()
 }
 
 /// Get a buffer controller by name and returns a pointer to it.
 #[jni(package = "mp.code", class = "Workspace")]
-fn get_buffer(workspace: Workspace, path: String) -> Option<crate::buffer::Controller> {
+fn get_buffer(workspace: &mut Workspace, path: String) -> Option<crate::buffer::Controller> {
 	workspace.buffer_by_name(&path)
 }
 
 /// Get the filetree.
 #[jni(package = "mp.code", class = "Workspace")]
-fn get_file_tree(workspace: Workspace, filter: Option<String>, strict: bool) -> Vec<String> {
+fn get_file_tree(workspace: &mut Workspace, filter: Option<String>, strict: bool) -> Vec<String> {
 	workspace.filetree(filter.as_deref(), strict)
 }
 
 /// Gets a list of the active buffers.
 #[jni(package = "mp.code", class = "Workspace")]
-fn active_buffers(workspace: Workspace) -> Vec<String> {
+fn active_buffers(workspace: &mut Workspace) -> Vec<String> {
 	workspace.buffer_list()
 }
 
 /// Create a new buffer.
 #[jni(package = "mp.code", class = "Workspace")]
-fn create_buffer(workspace: Workspace, path: String) -> Result<(), RemoteError> {
+fn create_buffer(workspace: &mut Workspace, path: String) -> Result<(), RemoteError> {
 	super::tokio().block_on(workspace.create(&path))
 }
 
 /// Attach to a buffer and return a pointer to its [crate::buffer::Controller].
 #[jni(package = "mp.code", class = "Workspace")]
-fn attach_to_buffer(workspace: Workspace, path: String) -> Result<crate::buffer::Controller, ConnectionError> {
+fn attach_to_buffer(workspace: &mut Workspace, path: String) -> Result<crate::buffer::Controller, ConnectionError> {
 	super::tokio().block_on(workspace.attach(&path))
 }
 
 /// Detach from a buffer.
 #[jni(package = "mp.code", class = "Workspace")]
-fn detach_from_buffer(workspace: Workspace, path: String) -> crate::workspace::DetachResult {
+fn detach_from_buffer(workspace: &mut Workspace, path: String) -> crate::workspace::DetachResult {
 	workspace.detach(&path)
 }
 
 /// Update the local buffer list.
 #[jni(package = "mp.code", class = "Workspace")]
-fn fetch_buffers(workspace: Workspace) -> Result<(), RemoteError> {
+fn fetch_buffers(workspace: &mut Workspace) -> Result<(), RemoteError> {
 	super::tokio().block_on(workspace.fetch_buffers())
 }
 
 /// Update the local user list.
 #[jni(package = "mp.code", class = "Workspace")]
-fn fetch_users(workspace: Workspace) -> Result<(), RemoteError> {
+fn fetch_users(workspace: &mut Workspace) -> Result<(), RemoteError> {
 	super::tokio().block_on(workspace.fetch_users())
 }
 
 /// List users attached to a buffer.
 #[jni(package = "mp.code", class = "Workspace")]
-fn list_buffer_users(workspace: Workspace, path: String) -> Result<Vec<crate::api::User>, RemoteError> {
+fn list_buffer_users(workspace: &mut Workspace, path: String) -> Result<Vec<crate::api::User>, RemoteError> {
 	super::tokio().block_on(workspace.list_buffer_users(&path))
 }
 
 /// Delete a buffer.
 #[jni(package = "mp.code", class = "Workspace")]
-fn delete_buffer(workspace: Workspace, path: String) -> Result<(), RemoteError> {
+fn delete_buffer(workspace: &mut Workspace, path: String) -> Result<(), RemoteError> {
 	super::tokio().block_on(workspace.delete(&path))
 }
 
 /// Receive a workspace event if present.
 #[jni(package = "mp.code", class = "Workspace")]
-fn event(workspace: Workspace) -> Result<crate::api::Event, ControllerError> {
+fn event(workspace: &mut Workspace) -> Result<crate::api::Event, ControllerError> {
 	super::tokio().block_on(workspace.event())
 }