diff --git a/.gitignore b/.gitignore
index 3ad07a5..cca6749 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,6 +1,7 @@
 /*.tar.gz
 /app_packages
 /config
+/data
 /ptth_server.toml
 /ptth_relay.toml
 /ptth_build_L6KLMVS6/
diff --git a/crates/ptth_relay/src/config.rs b/crates/ptth_relay/src/config.rs
index 451d130..9ff2751 100644
--- a/crates/ptth_relay/src/config.rs
+++ b/crates/ptth_relay/src/config.rs
@@ -30,19 +30,31 @@ pub mod machine_editable {
 	
 	use super::file::Server;
 	
-	#[derive (Deserialize, Serialize)]
+	#[derive (Default, Deserialize, Serialize)]
 	pub struct Config {
 		pub servers: Vec <Server>,
+		pub debug_toggle: bool,
 	}
 	
 	impl Config {
-		pub async fn from_file (path: &Path) -> Result <Self, crate::ConfigError>
+		pub fn from_file (path: &Path) -> Result <Self, crate::ConfigError>
 		{
-			let config_s = tokio::fs::read_to_string (path).await?;
+			let config_s = std::fs::read_to_string (path)?;
 			let new_config: Config = toml::from_str (&config_s)?;
 			
 			Ok (new_config)
 		}
+		
+		pub async fn save (&self, path: &Path) -> Result <(), crate::ConfigError> {
+			let s = toml::to_string (self)?;
+			// This is way easier in C++ but also not safe
+			let mut temp_path = path.file_name ().unwrap ().to_os_string ();
+			temp_path.push (".partial");
+			let temp_path = path.with_file_name (temp_path);
+			tokio::fs::write (&temp_path, &s).await?;
+			tokio::fs::rename (&temp_path, path).await?;
+			Ok (())
+		}
 	}
 }
 
diff --git a/crates/ptth_relay/src/errors.rs b/crates/ptth_relay/src/errors.rs
index 9e16573..c25aaca 100644
--- a/crates/ptth_relay/src/errors.rs
+++ b/crates/ptth_relay/src/errors.rs
@@ -20,6 +20,9 @@ pub enum ConfigError {
 	#[error ("Bad server address")]
 	BadServerAddress,
 	
+	#[error (transparent)]
+	TomlSerialization (#[from] toml::ser::Error),
+	
 	#[error ("unknown config error")]
 	Unknown,
 }
diff --git a/crates/ptth_relay/src/lib.rs b/crates/ptth_relay/src/lib.rs
index 7fd0d06..0c1a49a 100644
--- a/crates/ptth_relay/src/lib.rs
+++ b/crates/ptth_relay/src/lib.rs
@@ -542,13 +542,36 @@ async fn handle_all (
 		ClientServerList => handle_server_list (state, handlebars).await?,
 		ClientUnregisteredServers => handle_unregistered_servers (state, handlebars).await?,
 		Debug => {
-			let s = handlebars.render ("debug", &())?;
+			#[derive (Serialize)]
+			struct DebugPage {
+				persistent_toggle: bool,
+			}
+			
+			let page;
+			
+			{
+				let guard = state.me_config.read ().await;
+				page = DebugPage {
+					persistent_toggle: guard.debug_toggle,
+				};
+			}
+			
+			let s = handlebars.render ("debug", &page)?;
 			ok_reply (s)?
 		},
 		DebugEndlessSink => handle_endless_sink (req).await?,
 		DebugEndlessSource (throttle) => handle_endless_source (1, throttle).await?,
 		DebugGenKey => handle_gen_scraper_key (state).await?,
 		DebugMysteriousError => return Err (RequestError::Mysterious),
+		DebugToggle => {
+			trace! ("Toggling debug toggle");
+			{
+				let mut guard = state.me_config.write ().await;
+				guard.debug_toggle = ! guard.debug_toggle;
+				guard.save (Path::new ("data/ptth_relay_me_config.toml")).await.unwrap ();
+			}
+			error_reply (StatusCode::OK, "Toggled.")?
+		},
 		ErrorBadUriFormat => error_reply (StatusCode::BAD_REQUEST, "Bad URI format")?,
 		ErrorCantPost => {
 			error! ("Can't POST {}", path);
@@ -613,7 +636,7 @@ async fn reload_config (
 	let new_config = Config::from_file (config_reload_path).await?;
 	
 	// Reload machine-editable config, if possible
-	let me_config = machine_editable::Config::from_file (Path::new ("data/ptth_relay_me_config.toml")).await.ok ();
+	// let me_config = machine_editable::Config::from_file (Path::new ("data/ptth_relay_me_config.toml")).await.ok ();
 	
 	let mut config = state.config.write ().await;
 	
diff --git a/crates/ptth_relay/src/relay_state.rs b/crates/ptth_relay/src/relay_state.rs
index 037b83c..e639a5c 100644
--- a/crates/ptth_relay/src/relay_state.rs
+++ b/crates/ptth_relay/src/relay_state.rs
@@ -1,6 +1,7 @@
 use std::{
 	collections::HashMap,
 	convert::TryFrom,
+	path::Path,
 	time::Instant,
 };
 
@@ -18,6 +19,7 @@ use crate::{
 	Config,
 	RelayError,
 	ShuttingDownError,
+	config::machine_editable,
 };
 
 use ptth_core::{
@@ -76,6 +78,7 @@ impl Default for ServerStatus {
 
 pub struct Relay {
 	pub (crate) config: RwLock <Config>,
+	pub (crate) me_config: RwLock <machine_editable::Config>,
 	
 	/// The parked clients or parked server, keyed by server
 	
@@ -170,8 +173,20 @@ impl TryFrom <Config> for Relay {
 	fn try_from (config: Config) -> Result <Self, Self::Error> {
 		let (shutdown_watch_tx, shutdown_watch_rx) = watch::channel (false);
 		
+		let me_config = machine_editable::Config::default ();
+		
+		let me_config = match machine_editable::Config::from_file (Path::new ("data/ptth_relay_me_config.toml"))
+		{
+			Err (e) => {
+				error! ("Can't load machine-editable config: {:?}", e);
+				me_config
+			},
+			Ok (x) => x,
+		};
+		
 		Ok (Self {
 			config: config.into (),
+			me_config: me_config.into (),
 			request_rendezvous: Default::default (),
 			server_status: Default::default (),
 			response_rendezvous: Default::default (),
diff --git a/crates/ptth_relay/src/routing.rs b/crates/ptth_relay/src/routing.rs
index 352debb..60b72b4 100644
--- a/crates/ptth_relay/src/routing.rs
+++ b/crates/ptth_relay/src/routing.rs
@@ -15,6 +15,7 @@ pub enum Route <'a> {
 	DebugEndlessSource (Option <usize>),
 	DebugGenKey,
 	DebugMysteriousError,
+	DebugToggle,
 	ErrorBadUriFormat,
 	ErrorCantPost,
 	ErrorMethodNotAllowed,
@@ -41,6 +42,9 @@ pub fn route_url <'a> (method: &Method, path: &'a str) -> Route <'a> {
 		else if path == "/frontend/debug/endless_sink" {
 			Route::DebugEndlessSink
 		}
+		else if path == "/frontend/debug/toggle" {
+			Route::DebugToggle
+		}
 		else {
 			Route::ErrorCantPost
 		}
diff --git a/handlebars/relay/debug.hbs b/handlebars/relay/debug.hbs
index 2b97b3f..f89e422 100644
--- a/handlebars/relay/debug.hbs
+++ b/handlebars/relay/debug.hbs
@@ -52,5 +52,11 @@ Lorem ipsum dolor set amet
 <p>
 <a href="endless_sink">Data sink (POST only)</a>
 
+<p>Persistent toggle is <pre>{{persistent_toggle}}</pre></p>
+
+<form action="toggle" method="post">
+<input type="submit" value="Toggle">
+</form>
+
 </body>
 </html>