Honor bread.command.lock.unlock via loginctl unlock-session

Subscribe the same locker and breadlock listen handlers. Already
unlocked is bread.lock.unlock.done; otherwise run loginctl
unlock-session and emit done / failed. Do not call compositor
unlock() — PAM stays the compositor path (fail-secure). Document
in EVENTS.md and README; drop the "Not implemented: unlock"
paragraph. pin/blur stay unimplemented.

EVENTS.md

@@ -14,8 +14,8 @@ Commands are received on a `BreadClient::subscribe` background thread
 (reconnect/backoff) from two places:
 
 - the locker process itself, while the session is locked
-- `breadlock listen`, a tiny long-running subscriber so the command
+- `breadlock listen`, a tiny long-running subscriber so lock/unlock
-  works while unlocked
+  work while unlocked
 
 `breadgreet` is not wired to the bus. It runs under greetd (typically as
 the dedicated greeter user, before a user session exists), so breadd is
@@ -30,29 +30,38 @@ from session lock/unlock.
 | `bread.lock.unlocked` | `{}` | PAM authenticated successfully and breadlock sent `unlock` to the compositor. Not emitted on a compositor-ended lock (`finished`), a dispatch-error exit (fail-secure: the session stays locked), or a failed/typo password. |
 | `bread.lock.lock.done` | `{}` | `bread.command.lock.lock` was honored: the locker was already running, or a locker process was started (same no-args invocation as hypridle's `lock_cmd = breadlock`). This is the command confirmation, not compositor proof — wait on `bread.lock.locked` if you need the session-lock protocol to have completed. |
 | `bread.lock.lock.failed` | `{ "error": "<message>" }` | `bread.command.lock.lock` was received but the locker could not be started (e.g. this binary is missing from disk). |
+| `bread.lock.unlock.done` | `{}` | `bread.command.lock.unlock` was honored: no locker was running (already unlocked), or `loginctl unlock-session` was invoked for this session. This is the command confirmation, not compositor proof — wait on `bread.lock.unlocked` if you need PAM + `ext-session-lock-v1` unlock. |
+| `bread.lock.unlock.failed` | `{ "error": "<message>" }` | `bread.command.lock.unlock` was received but `loginctl unlock-session` could not be run (binary missing, non-zero exit). |
 
 ## Commands honored (`bread.command.lock.*`)
 
 | Verb | Effect |
 |------|--------|
 | `lock` | If a locker is already running, emit `bread.lock.lock.done` and do nothing else. Otherwise start `breadlock` the same way hypridle does (`lock_cmd = breadlock`: this binary, no args) and emit `done` or `failed`. |
+| `unlock` | If no locker is running, emit `bread.lock.unlock.done` (already unlocked). Otherwise run `loginctl unlock-session` on the caller's session and emit `done` or `failed`. This is session-level (logind), not a passwordless PAM bypass: breadlock does not call compositor `unlock()` for this verb. |
 
 A Lua workflow that wants the session locked should `bread.wait` /
 `bread.wait_any` on `bread.lock.lock.done` (or `.failed`) with a timeout.
 To know the compositor actually locked, wait on `bread.lock.locked`.
+The same pattern applies to unlock: wait on `bread.lock.unlock.done` /
+`.failed` for the command, and on `bread.lock.unlocked` for PAM +
+compositor unlock.
 
 ### Who is listening
 
-`bread.command.lock.lock` is a silent no-op if nobody is subscribed
+`bread.command.lock.lock` / `bread.command.lock.unlock` are a silent
-(bread's usual "no listener, no-op" rule). Two subscribers exist:
+no-op if nobody is subscribed (bread's usual "no listener, no-op"
+rule). Two subscribers exist:
 
 1. **`breadlock listen`** — run this for the unlocked path (Hyprland
    `exec-once = breadlock listen`, a bread module, or equivalent).
    Without it, a command sent while the session is unlocked has no
-   process to receive it.
+   process to receive it. Unlock while already unlocked is an
+   idempotent `done`.
 2. **The locker process** — always subscribes once the lock screen is
-   up, so a command received during an active lock is an idempotent
+   up, so `lock` during an active lock is an idempotent `done`, and
-   `done`.
+   `unlock` runs `loginctl unlock-session` rather than compositor
+   `unlock()`.
 
 ### Session-level equivalent
 
@@ -63,13 +72,18 @@ bread command bus. It is the session-level equivalent of
 same `ext-session-lock-v1` request. Prefer `loginctl lock-session`
 from a keybind; prefer the bus command from a Lua workflow.
 
-### Not implemented: `unlock` / `pin` / `blur`
+`loginctl unlock-session` is the matching session-level unlock. The
+bus verb invokes that same command. Compositor unlock after a typed
+password is still PAM on this process (`bread.lock.unlocked`); a
+dispatch-error or crash path still does **not** call compositor
+`unlock()` (fail-secure).
 
-Unlock is PAM on this process only — there is no `bread.command.lock.unlock`
+### Not implemented: `pin` / `blur`
-and none is stubbed. `background.blur` in `breadlock.toml` remains a
+
-documented locker no-op (accepted, warned, surface drawn unblurred).
+`background.blur` in `breadlock.toml` remains a documented locker
-That is appearance config, not a bus command — do not invent
+no-op (accepted, warned, surface drawn unblurred). That is appearance
-`bread.command.lock.blur` for it.
+config, not a bus command — do not invent `bread.command.lock.blur`
+for it.
 
 ## Fail-safe behavior
 

README.md

@@ -13,13 +13,15 @@ Both use [`bread-theme`](https://git.breadway.dev/Breadway/bread-ecosystem) for
 
 `breadlock` works the same with or without `breadd`. When `breadd` is
 running, it publishes `bread.lock.locked` / `bread.lock.unlocked` and
-honors `bread.command.lock.lock` (emits `bread.lock.lock.done` /
+honors `bread.command.lock.lock` / `bread.command.lock.unlock` (emits
-`.failed`). Run `breadlock listen` so the command works while unlocked;
+`bread.lock.lock.done` / `.failed` and `bread.lock.unlock.done` /
-the locker also subscribes while the session is locked. Super+L remains
+`.failed`). Run `breadlock listen` so both commands work while
-`loginctl lock-session` (hypridle then runs `breadlock`) — that is the
+unlocked; the locker also subscribes while the session is locked.
-session-level equivalent, not a bus command. See [EVENTS.md](EVENTS.md).
+Unlock is `loginctl unlock-session` at the session level — not a
-`breadgreet` is not on the bus. There is no `bakery.toml` (PAM / pacman
+passwordless compositor `unlock()`. Super+L remains
-exception).
+`loginctl lock-session` (hypridle then runs `breadlock`). See
+[EVENTS.md](EVENTS.md). `breadgreet` is not on the bus. There is no
+`bakery.toml` (PAM / pacman exception).
 
 ## Architecture
 
@@ -82,9 +84,11 @@ lock_cmd = breadlock
 ```
 
 `breadlock listen` is the unlocked-path subscriber for
-`bread.command.lock.lock`. It is not started by hypridle; add it to
+`bread.command.lock.lock` and `bread.command.lock.unlock`. It is not
-session startup (`exec-once = breadlock listen`) if a Lua workflow
+started by hypridle; add it to session startup
-should be able to lock the session while it is unlocked.
+(`exec-once = breadlock listen`) if a Lua workflow should be able to
+lock or unlock the session while it is unlocked. Session-level unlock
+is `loginctl unlock-session` (the bus verb runs that).
 
 ## Verification (why this is safe to test without a lockout risk)
 

breadlock/src/bread_events.rs

@@ -5,12 +5,14 @@
 //! process) so a missing or restarting breadd never affects locking
 //! itself.
 //!
-//! `bread.command.lock.lock` is the one verb this process honors. The
+//! `bread.command.lock.lock` and `bread.command.lock.unlock` are the
-//! locker subscribes while the session is locked (already-locked is
+//! verbs this process honors. The locker subscribes while the session is
-//! `bread.lock.lock.done`). `breadlock listen` is the unlocked-path
+//! locked (already-locked is `bread.lock.lock.done`). `breadlock listen`
-//! subscriber: it starts this same binary the way hypridle's
+//! is the unlocked-path subscriber: it starts this same binary the way
-//! `lock_cmd = breadlock` does. Session-level equivalent of Super+L is
+//! hypridle's `lock_cmd = breadlock` does, and treats unlock as already
-//! `loginctl lock-session`.
+//! unlocked (`bread.lock.unlock.done`). Session-level equivalents are
+//! `loginctl lock-session` / `loginctl unlock-session`. Unlock never
+//! calls compositor `unlock()` — that stays on the PAM path.
 
 use std::process::{Command, Stdio};
 use std::thread;
@@ -46,6 +48,17 @@ pub fn emit_lock_failed(error: &str) {
     );
 }
 
+pub fn emit_unlock_done() {
+    BreadClient::connect(APP_ID).emit("bread.lock.unlock.done", serde_json::json!({}));
+}
+
+pub fn emit_unlock_failed(error: &str) {
+    BreadClient::connect(APP_ID).emit(
+        "bread.lock.unlock.failed",
+        serde_json::json!({ "error": error }),
+    );
+}
+
 /// True when another process holds the locker singleton — i.e. breadlock
 /// is already locking this session. A `try_acquire` that succeeds is
 /// released immediately; this is a check, not a claim.
@@ -84,6 +97,31 @@ pub fn honor_lock_command() {
     honor_lock_command_with(start_locker);
 }
 
+/// Session-level unlock (`loginctl unlock-session` on the caller's
+/// session). Does not send compositor `unlock` and does not skip PAM —
+/// that stays on the typed-password path. `done` means the command was
+/// acted on (or the session was already unlocked), not that
+/// `ext-session-lock-v1` has been released — wait on
+/// `bread.lock.unlocked` for the compositor confirmation.
+fn unlock_session() -> Result<(), String> {
+    let status = Command::new("loginctl")
+        .arg("unlock-session")
+        .stdin(Stdio::null())
+        .status()
+        .map_err(|e| format!("failed to run loginctl unlock-session: {e}"))?;
+    if status.success() {
+        Ok(())
+    } else {
+        Err(format!("loginctl unlock-session exited with {status}"))
+    }
+}
+
+/// Honor `bread.command.lock.unlock`: already unlocked is success;
+/// otherwise ask logind to unlock this session.
+pub fn honor_unlock_command() {
+    honor_unlock_command_with(locker_is_running(), unlock_session);
+}
+
 fn honor_lock_command_with(start: impl FnOnce() -> Result<(), String>) {
     if locker_is_running() {
         tracing::info!("bread.command.lock.lock: already locked");
@@ -102,6 +140,24 @@ fn honor_lock_command_with(start: impl FnOnce() -> Result<(), String>) {
     }
 }
 
+fn honor_unlock_command_with(locked: bool, unlock: impl FnOnce() -> Result<(), String>) {
+    if !locked {
+        tracing::info!("bread.command.lock.unlock: already unlocked");
+        emit_unlock_done();
+        return;
+    }
+    match unlock() {
+        Ok(()) => {
+            tracing::info!("bread.command.lock.unlock: loginctl unlock-session");
+            emit_unlock_done();
+        }
+        Err(error) => {
+            tracing::error!(%error, "bread.command.lock.unlock: failed");
+            emit_unlock_failed(&error);
+        }
+    }
+}
+
 /// Reacts to `bread.command.lock.*`. Unknown verbs are ignored, not stubbed.
 pub fn handle_command(event: &BreadEvent) {
     let Some(verb) = event.event.strip_prefix("bread.command.lock.") else {
@@ -109,6 +165,7 @@ pub fn handle_command(event: &BreadEvent) {
     };
     match verb {
         "lock" => honor_lock_command(),
+        "unlock" => honor_unlock_command(),
         other => tracing::info!(verb = other, "ignoring unknown bread.command.lock verb"),
     }
 }
@@ -135,7 +192,6 @@ mod tests {
 
     #[test]
     fn handle_command_ignores_unrecognized_verb() {
-        handle_command(&event("bread.command.lock.unlock"));
         handle_command(&event("bread.command.lock.pin"));
         handle_command(&event("bread.command.clip.clear"));
         handle_command(&event("bread.lock.locked"));
@@ -168,4 +224,24 @@ mod tests {
     fn honor_lock_command_with_successful_start_does_not_panic() {
         honor_lock_command_with(|| Ok(()));
     }
+
+    #[test]
+    fn honor_unlock_command_already_unlocked_does_not_call_loginctl() {
+        let called = std::cell::Cell::new(false);
+        honor_unlock_command_with(false, || {
+            called.set(true);
+            Err("should not run".into())
+        });
+        assert!(!called.get());
+    }
+
+    #[test]
+    fn honor_unlock_command_with_failed_loginctl_does_not_panic() {
+        honor_unlock_command_with(true, || Err("boom".into()));
+    }
+
+    #[test]
+    fn honor_unlock_command_with_successful_loginctl_does_not_panic() {
+        honor_unlock_command_with(true, || Ok(()));
+    }
 }

breadlock/src/main.rs

@@ -51,9 +51,9 @@ fn print_usage() {
         "Usage: breadlock [listen]\n\
          \n\
          (no args)   lock this session — hypridle lock_cmd / Super+L via loginctl lock-session\n\
-         listen      subscribe to bread.command.lock.lock so the command works while unlocked\n\
+         listen      subscribe to bread.command.lock.lock / unlock so both work while unlocked\n\
          \n\
-         Session-level equivalent of Super+L: loginctl lock-session (hypridle then runs breadlock).\n\
+         Session-level: loginctl lock-session / unlock-session.\n\
          See EVENTS.md for the bus contract."
     );
 }
@@ -75,10 +75,11 @@ fn main() {
     }
 }
 
-/// Long-running subscriber so `bread.command.lock.lock` works while the
+/// Long-running subscriber so `bread.command.lock.lock` / `.unlock` work
-/// session is unlocked. The locker process also subscribes; this path is
+/// while the session is unlocked. The locker process also subscribes;
-/// what actually starts breadlock (the same no-args invocation hypridle
+/// this path is what actually starts breadlock (the same no-args
-/// uses). One listen process per session.
+/// invocation hypridle uses) and what runs `loginctl unlock-session`
+/// when a locker is up. One listen process per session.
 fn run_listen() {
     let _guard = match try_acquire(bread_events::LISTEN_APP) {
         Ok(Acquire::Acquired(g)) => g,
@@ -106,7 +107,7 @@ fn run_listen() {
     }
 
     let _commands = bread_events::subscribe_commands();
-    tracing::info!("listening for bread.command.lock.lock");
+    tracing::info!("listening for bread.command.lock.lock / unlock");
     loop {
         std::thread::sleep(Duration::from_secs(3600));
     }
@@ -127,8 +128,9 @@ fn run_lock() {
         }
     };
 
-    // Honor bread.command.lock.lock while this locker is up (already-locked
+    // Honor bread.command.lock.lock / unlock while this locker is up
-    // is bread.lock.lock.done). Unlocked commands need `breadlock listen`.
+    // (already-locked is bread.lock.lock.done; unlock is loginctl, not
+    // compositor unlock()). Unlocked-path commands need `breadlock listen`.
     let _commands = bread_events::subscribe_commands();
 
     let username = std::env::var("USER")