Merge remote-tracking branch 'origin/main' into chord

Prompts sent while a turn is active are queued on the daemon instead of
in the browser's React state. The queue is persisted in the session
sidecar and drained as the next turn when the current one completes.

Fixes the bug where queued messages were delivered to the wrong session
when switching focus in the UI: the client-side queue captured the new
sessionId in its drain closure.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

crates/maestro-cli/src/sessions.rs

@@ -345,6 +345,8 @@ mod tests {
             blocked_work: None,
             last_focused_at: None,
             acp_session_id: None,
+            auto_approve: false,
+            queued_prompts: Vec::new(),
         }
     }
 

crates/maestro-daemon/src/local_api.rs

@@ -483,13 +483,12 @@ async fn structured_prompt(
     Json(body): Json<StructuredPromptRequest>,
 ) -> Response {
     match s.manager.queue_acp_prompt(id, body.prompt).await {
-        Ok(QueueAcpPrompt::Queued) | Ok(QueueAcpPrompt::Pending) => {
-            StatusCode::NO_CONTENT.into_response()
-        }
-        Ok(QueueAcpPrompt::InFlight) => error_response(
-            StatusCode::CONFLICT,
-            "turn_in_flight",
-            "the structured session already has an active turn",
+        Ok(QueueAcpPrompt::Dispatched) => StatusCode::NO_CONTENT.into_response(),
+        Ok(QueueAcpPrompt::Queued) => StatusCode::ACCEPTED.into_response(),
+        Ok(QueueAcpPrompt::Full) => error_response(
+            StatusCode::TOO_MANY_REQUESTS,
+            "queue_full",
+            "the prompt queue has reached its capacity",
         ),
         Ok(QueueAcpPrompt::Unavailable) => error_response(
             StatusCode::CONFLICT,

crates/maestro-daemon/src/session.rs

@@ -5,7 +5,7 @@
 //! single point through which the API handlers and the per-session WS
 //! handler interact with tmux.
 
-use std::collections::{HashMap, HashSet};
+use std::collections::{HashMap, HashSet, VecDeque};
 use std::path::PathBuf;
 use std::sync::atomic::{AtomicBool, AtomicU64, AtomicUsize, Ordering};
 use std::sync::{Arc, Weak};
@@ -15,8 +15,8 @@ use chrono::Utc;
 use maestro_acp::{AcpAdapter, AcpSession, PermissionRequest, SpawnConfig};
 use maestro_protocol::display::command_tool;
 use maestro_protocol::{
-    ActivityState, CatalogEvent, CreateSessionRequest, ErrorInfo, NameSource, Session,
-    SessionStatus, SessionView, StructuredReplayEvent, TranscriptDelta, TranscriptRow,
+    ActivityState, CatalogEvent, CreateSessionRequest, ErrorInfo, NameSource, ReducedState,
+    Session, SessionStatus, SessionView, StructuredReplayEvent, TranscriptDelta, TranscriptRow,
     TranscriptRowKind, WorktreeSpec, NAME_KEY, NAME_SOURCE_KEY,
 };
 use tokio::sync::{broadcast, oneshot, watch, Mutex, Notify};
@@ -122,9 +122,6 @@ pub struct SessionRecord {
     /// When `true`, the permission pump auto-responds `AllowAlways` to every
     /// ACP permission request without surfacing it to clients.
     pub auto_approve: bool,
-    /// A prompt submitted while the adapter was still booting (`Starting`).
-    /// The background handshake task drains this on success.
-    pub pending_prompt: Option<String>,
 }
 
 impl SessionRecord {
@@ -149,6 +146,9 @@ struct StructuredActivityWatermark {
     sequence: u64,
 }
 
+/// Maximum number of prompts that can be queued while a turn is in flight.
+const PROMPT_QUEUE_CAP: usize = 20;
+
 #[derive(Debug)]
 struct AcpEventStream {
     log: EventLog,
@@ -160,6 +160,10 @@ struct AcpEventStream {
     /// claimed: it is queued onto ACP before another operation can proceed.
     operation: Arc<Mutex<()>>,
     dispatch: AcpDispatchState,
+    /// Server-side FIFO of prompts accepted while a turn was in flight or the
+    /// adapter was still booting. Drained as a single concatenated prompt when
+    /// the current turn completes. Persisted to the session sidecar.
+    prompt_queue: VecDeque<String>,
     activity_sequence: u64,
 }
 
@@ -168,6 +172,23 @@ impl AcpEventStream {
         self.activity_sequence += 1;
         (self.activity_sequence, self.projection.activity())
     }
+
+    /// The reduced state with the prompt queue overlaid. Every broadcast and
+    /// snapshot should use this instead of `projection.state()` directly so
+    /// clients always see the current queue.
+    fn state_with_queue(&self) -> ReducedState {
+        let mut state = self.projection.state();
+        state.queued_prompts = self.prompt_queue.iter().cloned().collect();
+        state
+    }
+
+    /// Broadcast a projection update with the prompt queue overlaid into the
+    /// state. Every `projected_live.send` should go through this so clients
+    /// never see a stale queue.
+    fn broadcast(&self, mut update: ProjectionUpdate) {
+        update.state.queued_prompts = self.prompt_queue.iter().cloned().collect();
+        let _ = self.projected_live.send(update);
+    }
 }
 
 #[derive(Debug, Default)]
@@ -235,11 +256,14 @@ pub enum BeginAcpTurn {
 /// Result of serializing a projected turn claim with its ACP prompt enqueue.
 #[derive(Debug)]
 pub enum QueueAcpPrompt {
+    /// The prompt was dispatched to ACP immediately (no turn was in flight).
+    Dispatched,
+    /// The prompt was accepted into the server-side queue and will be
+    /// dispatched when the current turn completes.
     Queued,
-    /// The adapter is still booting; the prompt is held until it is ready.
-    Pending,
-    InFlight,
     Unavailable,
+    /// The prompt queue has reached its capacity.
+    Full,
     Failed(String),
 }
 
@@ -662,7 +686,7 @@ impl SessionManager {
         let live = stream.projected_live.subscribe();
         Ok(Some((
             stream.projection.snapshot(stream.log.last_seq()),
-            stream.projection.state(),
+            stream.state_with_queue(),
             live,
         )))
     }
@@ -692,7 +716,7 @@ impl SessionManager {
             return Ok(false);
         };
         let projected = persist_turn_update(&mut stream, projected);
-        let _ = stream.projected_live.send(projected);
+        stream.broadcast(projected);
         drop(stream);
         sync_structured_activity(&self.inner, id).await;
         Ok(true)
@@ -717,7 +741,7 @@ impl SessionManager {
             return Ok(BeginAcpTurn::InFlight);
         }
         let (turn, update) = stream.projection.begin_turn();
-        let _ = stream.projected_live.send(update);
+        stream.broadcast(update);
         drop(stream);
         sync_structured_activity(&self.inner, id).await;
         Ok(BeginAcpTurn::Started(acp, turn))
@@ -735,13 +759,28 @@ impl SessionManager {
         text: String,
     ) -> Result<QueueAcpPrompt, SessionError> {
         let (acp, stream) = {
-            let mut sessions = self.inner.sessions.lock().await;
-            let record = sessions.get_mut(&id).ok_or(SessionError::NotFound(id))?;
-            // While the adapter is booting, stash the prompt for the
-            // background handshake task to drain on success.
+            let sessions = self.inner.sessions.lock().await;
+            let record = sessions.get(&id).ok_or(SessionError::NotFound(id))?;
             if record.is_starting_structured() {
-                record.pending_prompt = Some(text);
-                return Ok(QueueAcpPrompt::Pending);
+                // Adapter still booting — queue the prompt for drain on boot
+                // success. The AcpEventStream exists, just no ACP handle yet.
+                let stream = record
+                    .acp_events
+                    .clone()
+                    .expect("structured session has events at Starting");
+                let mut stream = stream.lock().await;
+                if stream.prompt_queue.len() >= PROMPT_QUEUE_CAP {
+                    return Ok(QueueAcpPrompt::Full);
+                }
+                stream.prompt_queue.push_back(text);
+                let update = ProjectionUpdate {
+                    transcript: None,
+                    state: stream.projection.state(),
+                };
+                stream.broadcast(update);
+                drop(stream);
+                self.persist_prompt_queue(id).await;
+                return Ok(QueueAcpPrompt::Queued);
             }
             if !record.is_live_structured() {
                 return Ok(QueueAcpPrompt::Unavailable);
@@ -762,12 +801,37 @@ impl SessionManager {
                 }
                 if let Some(turn) = stream.dispatch.queued_turn {
                     if stream.dispatch.cancelled_turn != Some(turn) {
-                        return Ok(QueueAcpPrompt::InFlight);
+                        // Turn is in flight — queue instead of rejecting.
+                        if stream.prompt_queue.len() >= PROMPT_QUEUE_CAP {
+                            return Ok(QueueAcpPrompt::Full);
+                        }
+                        stream.prompt_queue.push_back(text);
+                        let update = ProjectionUpdate {
+                            transcript: None,
+                            state: stream.projection.state(),
+                        };
+                        stream.broadcast(update);
+                        drop(stream);
+                        self.persist_prompt_queue(id).await;
+                        return Ok(QueueAcpPrompt::Queued);
                     }
                     Some((turn, stream.dispatch.settled.clone()))
                 } else {
                     if stream.projection.turn_active() {
-                        return Ok(QueueAcpPrompt::InFlight);
+                        // Projection says active but dispatch says idle —
+                        // queue rather than rejecting.
+                        if stream.prompt_queue.len() >= PROMPT_QUEUE_CAP {
+                            return Ok(QueueAcpPrompt::Full);
+                        }
+                        stream.prompt_queue.push_back(text);
+                        let update = ProjectionUpdate {
+                            transcript: None,
+                            state: stream.projection.state(),
+                        };
+                        stream.broadcast(update);
+                        drop(stream);
+                        self.persist_prompt_queue(id).await;
+                        return Ok(QueueAcpPrompt::Queued);
                     }
                     let row = TranscriptRow {
                         id: format!("user:{}", Uuid::new_v4()),
@@ -789,9 +853,9 @@ impl SessionManager {
                     let logged = LoggedEvent { seq, event };
                     let projected = stream.projection.restore_row(row);
                     let _ = stream.live.send(logged);
-                    let _ = stream.projected_live.send(projected);
+                    stream.broadcast(projected);
                     let (turn, update) = stream.projection.begin_turn();
-                    let _ = stream.projected_live.send(update);
+                    stream.broadcast(update);
                     match acp.prompt(text.clone(), turn) {
                         Ok(done) => {
                             stream.dispatch.queued_turn = Some(turn);
@@ -809,7 +873,7 @@ impl SessionManager {
                             if let Ok(true) = self.claim_autoname(id).await {
                                 crate::autoname::spawn_naming(self.clone(), id, text);
                             }
-                            return Ok(QueueAcpPrompt::Queued);
+                            return Ok(QueueAcpPrompt::Dispatched);
                         }
                         Err(message) => {
                             cancel_pending_approvals(&mut stream);
@@ -820,7 +884,7 @@ impl SessionManager {
                                     "newly claimed turn remains current while stream is locked",
                                 );
                             let projected = persist_turn_update(&mut stream, projected);
-                            let _ = stream.projected_live.send(projected);
+                            stream.broadcast(projected);
                             drop(stream);
                             sync_structured_activity(&self.inner, id).await;
                             return Ok(QueueAcpPrompt::Failed(message));
@@ -840,6 +904,27 @@ impl SessionManager {
         }
     }
 
+    /// Persist the current prompt queue to the session sidecar.
+    async fn persist_prompt_queue(&self, id: Uuid) {
+        let stream_arc = {
+            let sessions = self.inner.sessions.lock().await;
+            sessions.get(&id).and_then(|r| r.acp_events.clone())
+        };
+        let Some(stream_arc) = stream_arc else { return };
+        let queue: Vec<String> = stream_arc
+            .lock()
+            .await
+            .prompt_queue
+            .iter()
+            .cloned()
+            .collect();
+        let mut sessions = self.inner.sessions.lock().await;
+        if let Some(record) = sessions.get_mut(&id) {
+            record.session.queued_prompts = queue;
+            let _ = self.inner.sidecar.write(&record.session);
+        }
+    }
+
     async fn finish_queued_acp_turn(&self, id: Uuid, turn: u64, lifecycle: TurnLifecycle) {
         let stream = self
             .inner
@@ -860,16 +945,33 @@ impl SessionManager {
             stream.dispatch.cancelled_turn = None;
         }
         stream.dispatch.settled.notify_waiters();
-        if stream.projection.active_turn() != Some(turn) {
-            return;
-        }
-        cancel_pending_approvals(&mut stream);
-        if let Some(projected) = stream.projection.turn_lifecycle(lifecycle, turn) {
-            let projected = persist_turn_update(&mut stream, projected);
-            let _ = stream.projected_live.send(projected);
+        if stream.projection.active_turn() == Some(turn) {
+            cancel_pending_approvals(&mut stream);
+            if let Some(projected) = stream.projection.turn_lifecycle(lifecycle, turn) {
+                let projected = persist_turn_update(&mut stream, projected);
+                stream.broadcast(projected);
+            }
         }
+        // Drain the prompt queue: concatenate all queued prompts into a single
+        // prompt and dispatch as the next turn.  This must run even when the
+        // projection already ended the turn (e.g. cancel settled via the event
+        // stream before this function ran).
+        let queued_text = if stream.prompt_queue.is_empty() {
+            None
+        } else {
+            let texts: Vec<String> = stream.prompt_queue.drain(..).collect();
+            Some(texts.join("\n\n"))
+        };
         drop(stream);
         sync_structured_activity(&self.inner, id).await;
+        if let Some(text) = queued_text {
+            self.persist_prompt_queue(id).await;
+            // Cannot call queue_acp_prompt here (async cycle via the spawn
+            // inside queue_acp_prompt → finish_queued_acp_turn → here).
+            // Spawn an independent task instead.
+            let manager = self.clone();
+            drain_prompt_queue(manager, id, text);
+        }
     }
 
     async fn fail_cancelled_acp_turn(
@@ -983,7 +1085,7 @@ impl SessionManager {
             .turn_lifecycle(TurnLifecycle::Cancel, turn)
             .expect("active turn remains current while stream is locked");
         let projected = persist_turn_update(&mut stream, projected);
-        let _ = stream.projected_live.send(projected);
+        stream.broadcast(projected);
         drop(stream);
         sync_structured_activity(&self.inner, id).await;
         if let Some(turn) = cancelled_queued_turn {
@@ -1032,7 +1134,7 @@ impl SessionManager {
         let outcome = permission_outcome(decision, &pending.options);
         let _ = pending.response.send(outcome);
         if let Some(update) = stream.projection.resolve_approval(nonce) {
-            let _ = stream.projected_live.send(update);
+            stream.broadcast(update);
         }
         drop(stream);
         sync_structured_activity(&self.inner, id).await;
@@ -1340,6 +1442,7 @@ impl SessionManager {
                             pending_approvals: HashMap::new(),
                             operation: Arc::new(Mutex::new(())),
                             dispatch: AcpDispatchState::default(),
+                            prompt_queue: VecDeque::new(),
                             activity_sequence: 0,
                         }))
                     }
@@ -1404,6 +1507,8 @@ impl SessionManager {
             last_focused_at: None,
             acp_session_id: None,
             view: req.view,
+            auto_approve: req.auto_approve,
+            queued_prompts: Vec::new(),
         };
 
         if let Err(e) = self.inner.sidecar.write(&session) {
@@ -1435,7 +1540,6 @@ impl SessionManager {
                     structured_activity_watermark: None,
                     acp_event_pump: None,
                     auto_approve: req.auto_approve,
-                    pending_prompt: None,
                 },
             );
         }
@@ -1489,8 +1593,8 @@ impl SessionManager {
                         let acp = Arc::new(acp_session);
                         let done = start_acp_event_pump(&inner, id, &acp, events.clone());
                         start_acp_permission_pump(&inner, id, &acp, events.clone(), auto_approve);
-                        // Drain any prompt submitted while Starting.
-                        let pending_prompt = {
+                        // Drain any prompts queued while the adapter was Starting.
+                        let queued_text = {
                             let mut sessions = inner.sessions.lock().await;
                             let Some(record) = sessions.get_mut(&id) else {
                                 // Session was killed while we were booting.
@@ -1504,17 +1608,30 @@ impl SessionManager {
                             record.session.acp_session_id = Some(acp.session_id().to_string());
                             record.session.activity = ActivityState::Idle;
                             record.session.activity_since = Utc::now();
+                            let queued = if let Some(ref stream) = record.acp_events {
+                                let mut stream = stream.lock().await;
+                                if stream.prompt_queue.is_empty() {
+                                    None
+                                } else {
+                                    let texts: Vec<String> =
+                                        stream.prompt_queue.drain(..).collect();
+                                    Some(texts.join("\n\n"))
+                                }
+                            } else {
+                                None
+                            };
+                            record.session.queued_prompts.clear();
                             let _ = inner.sidecar.write(&record.session);
                             let _ = inner.events.send(CatalogEvent::SessionUpdated {
                                 session: record.session.clone(),
                             });
-                            record.pending_prompt.take()
+                            queued
                         };
-                        if let Some(prompt) = pending_prompt {
+                        if let Some(text) = queued_text {
                             let manager = SessionManager {
                                 inner: inner.clone(),
                             };
-                            let _ = manager.queue_acp_prompt(id, prompt).await;
+                            let _ = manager.queue_acp_prompt(id, text).await;
                         }
                     }
                     Err(e) => {
@@ -1678,6 +1795,8 @@ impl SessionManager {
                     // Unknown on adoption without a sidecar; matches every
                     // other field's forward-compat default.
                     view: maestro_protocol::SessionView::Terminal,
+                    auto_approve: false,
+                    queued_prompts: Vec::new(),
                 },
             };
             let fifo_path = self.inner.fifo_dir.join(format!("{id}.fifo"));
@@ -1715,8 +1834,7 @@ impl SessionManager {
                     acp_events: None,
                     structured_activity_watermark: None,
                     acp_event_pump: None,
-                    auto_approve: false,
-                    pending_prompt: None,
+                    auto_approve: session.auto_approve,
                 },
             );
             let _ = self
@@ -1844,6 +1962,7 @@ impl SessionManager {
                             pending_approvals: HashMap::new(),
                             operation: Arc::new(Mutex::new(())),
                             dispatch: AcpDispatchState::default(),
+                            prompt_queue: session.queued_prompts.drain(..).collect(),
                             activity_sequence: 0,
                         })))
                     }
@@ -1891,21 +2010,35 @@ impl SessionManager {
                     focused_since: None,
                     awaiting_suppressed: false,
                     acp,
-                    acp_events,
+                    acp_events: acp_events.clone(),
                     structured_activity_watermark: None,
                     acp_event_pump: None,
-                    // Recovery cannot know the original preset's flag; the
-                    // operator re-enables it by restarting with the preset.
-                    auto_approve: false,
-                    pending_prompt: None,
+                    auto_approve: session.auto_approve,
                 },
             );
             if let Some((acp, events)) = event_pump {
                 let done = start_acp_event_pump(&self.inner, id, &acp, events.clone());
-                start_acp_permission_pump(&self.inner, id, &acp, events, false);
+                start_acp_permission_pump(&self.inner, id, &acp, events, session.auto_approve);
                 if let Some(record) = self.inner.sessions.lock().await.get_mut(&id) {
                     record.acp_event_pump = Some(done);
                 }
+                // Drain any prompts that were queued before the daemon restarted.
+                let queued_text = {
+                    let stream = acp_events
+                        .as_ref()
+                        .expect("recovery with acp implies acp_events");
+                    let mut stream = stream.lock().await;
+                    if stream.prompt_queue.is_empty() {
+                        None
+                    } else {
+                        let texts: Vec<String> = stream.prompt_queue.drain(..).collect();
+                        Some(texts.join("\n\n"))
+                    }
+                };
+                if let Some(text) = queued_text {
+                    self.persist_prompt_queue(id).await;
+                    let _ = self.queue_acp_prompt(id, text).await;
+                }
             }
             let _ = self
                 .inner
@@ -2264,7 +2397,7 @@ fn start_acp_event_pump(
                         };
                         let projected = apply_persisted_event(&mut events.projection, &logged);
                         let _ = events.live.send(logged);
-                        let _ = events.projected_live.send(projected);
+                        events.broadcast(projected);
                         None
                     }
                     Err(error) => Some(error),
@@ -2434,7 +2567,7 @@ fn start_acp_permission_pump(
             let outcome = record_permission_request(&mut events, request, response);
             let fatal = matches!(outcome, RecordOutcome::Fatal);
             if let RecordOutcome::Live(update) = outcome {
-                let _ = events.projected_live.send(*update);
+                events.broadcast(*update);
             }
             drop(events);
             if fatal {
@@ -2527,7 +2660,7 @@ fn cancel_pending_approvals(events: &mut AcpEventStream) {
             .send(maestro_acp::schema::RequestPermissionOutcome::Cancelled);
     }
     if let Some(update) = events.projection.clear_approval() {
-        let _ = events.projected_live.send(update);
+        events.broadcast(update);
     }
 }
 
@@ -2877,6 +3010,18 @@ async fn run_blocked_work_pass(inner: &Arc<Inner>) {
 /// Terminal sessions that die naturally do not survive a daemon restart:
 /// [`SessionManager::recover`] adopts only what tmux still holds. Structured
 /// sessions stopped for daemon shutdown retain their sidecars for ACP recovery.
+/// Spawn an independent task to dispatch the next prompt from the drained
+/// queue. Free function with an explicit `Box::pin` future to break the
+/// compiler's async-cycle check: `queue_acp_prompt` → spawn →
+/// `finish_queued_acp_turn` → here → `queue_acp_prompt`.
+fn drain_prompt_queue(manager: SessionManager, id: Uuid, text: String) {
+    let fut: std::pin::Pin<Box<dyn std::future::Future<Output = ()> + Send>> =
+        Box::pin(async move {
+            let _ = manager.queue_acp_prompt(id, text).await;
+        });
+    tokio::spawn(fut);
+}
+
 async fn mark_session_dead(inner: &Arc<Inner>, id: Uuid) {
     if inner.shutting_down.load(Ordering::Acquire) {
         return;
@@ -2930,7 +3075,9 @@ async fn mark_session_dead_with_worktree_settlement(
         .get(&id)
         .and_then(|record| record.acp_events.clone());
     if let Some(stream) = stream {
-        cancel_pending_approvals(&mut *stream.lock().await);
+        let mut stream = stream.lock().await;
+        cancel_pending_approvals(&mut stream);
+        stream.prompt_queue.clear();
     }
     tracing::info!(%id, "session process gone — marking dead");
 
@@ -2957,6 +3104,7 @@ async fn mark_session_dead_with_worktree_settlement(
             return false;
         };
         record.settled = true;
+        record.session.queued_prompts.clear();
         record.session.clone()
     };
 
@@ -3023,12 +3171,7 @@ async fn settle_worktree_on_exit(
 /// gone from the authoritative in-memory map, so a stray FIFO or sidecar can't
 /// resurrect it. `kill_tmux` is `true` for an explicit kill and `false` for the
 /// liveness reaper (tmux already lost the session).
-async fn cleanup_record(
-    inner: &Arc<Inner>,
-    id: Uuid,
-    record: SessionRecord,
-    kill_tmux: bool,
-) {
+async fn cleanup_record(inner: &Arc<Inner>, id: Uuid, record: SessionRecord, kill_tmux: bool) {
     if kill_tmux {
         let tmux = inner.tmux.clone();
         let _ = tmux_blocking(move || tmux.kill_session(id)).await;
@@ -3125,6 +3268,7 @@ mod tests {
             pending_approvals: std::collections::HashMap::new(),
             operation: std::sync::Arc::new(tokio::sync::Mutex::new(())),
             dispatch: AcpDispatchState::default(),
+            prompt_queue: std::collections::VecDeque::new(),
             activity_sequence: 0,
         }
     }

crates/maestro-daemon/tests/acp.rs

@@ -262,7 +262,7 @@ async fn structured_activity_tracks_turn_completion_and_failure() {
             .queue_acp_prompt(session.id, "fail".into())
             .await
             .unwrap(),
-        maestro_daemon::session::QueueAcpPrompt::Queued
+        maestro_daemon::session::QueueAcpPrompt::Dispatched
     ));
     assert_eq!(
         fx.manager
@@ -289,7 +289,7 @@ async fn structured_activity_tracks_turn_completion_and_failure() {
             .queue_acp_prompt(session.id, "succeed".into())
             .await
             .unwrap(),
-        maestro_daemon::session::QueueAcpPrompt::Queued
+        maestro_daemon::session::QueueAcpPrompt::Dispatched
     ));
     assert_eq!(
         fx.manager
@@ -429,7 +429,7 @@ async fn queued_prompt_is_a_durable_user_transcript_row() {
             .queue_acp_prompt(session.id, "show my prompt".into())
             .await
             .expect("queue prompt"),
-        maestro_daemon::session::QueueAcpPrompt::Queued
+        maestro_daemon::session::QueueAcpPrompt::Dispatched
     ));
 
     let (snapshot, _, _) = fx
@@ -519,7 +519,7 @@ async fn cancelled_prompt_that_never_settles_fails_the_session() {
             .queue_acp_prompt(session.id, "first".into())
             .await
             .unwrap(),
-        maestro_daemon::session::QueueAcpPrompt::Queued
+        maestro_daemon::session::QueueAcpPrompt::Dispatched
     ));
     assert!(fx.manager.cancel_acp_turn(session.id).await.unwrap());
     let second = fx
@@ -558,7 +558,7 @@ async fn cancellation_settlement_allows_the_next_prompt_permission() {
             .queue_acp_prompt(session.id, "first".into())
             .await
             .unwrap(),
-        maestro_daemon::session::QueueAcpPrompt::Queued
+        maestro_daemon::session::QueueAcpPrompt::Dispatched
     ));
     assert!(fx.manager.cancel_acp_turn(session.id).await.unwrap());
     assert!(matches!(
@@ -566,7 +566,7 @@ async fn cancellation_settlement_allows_the_next_prompt_permission() {
             .queue_acp_prompt(session.id, "second".into())
             .await
             .unwrap(),
-        maestro_daemon::session::QueueAcpPrompt::Queued
+        maestro_daemon::session::QueueAcpPrompt::Dispatched
     ));
 
     let nonce = tokio::time::timeout(Duration::from_secs(2), async {

crates/maestro-daemon/tests/local_api.rs

@@ -293,7 +293,7 @@ async fn structured_attachments_preserve_bytes_and_reject_paths() {
 }
 
 #[tokio::test]
-async fn structured_prompt_rejects_a_second_in_flight_turn_and_cancel_clears_it() {
+async fn structured_prompt_queues_during_active_turn_and_cancel_clears_it() {
     let h = spawn("naps-laptop").await;
     let fake = FakeAcp::new();
     let mut env = fake.env();
@@ -310,6 +310,7 @@ async fn structured_prompt_rejects_a_second_in_flight_turn_and_cancel_clears_it(
         .await
         .unwrap();
     assert_eq!(first.status(), reqwest::StatusCode::NO_CONTENT);
+    // A second prompt while a turn is active is accepted into the queue.
     let second = client
         .post(url(
             h.addr,
@@ -319,9 +320,7 @@ async fn structured_prompt_rejects_a_second_in_flight_turn_and_cancel_clears_it(
         .send()
         .await
         .unwrap();
-    assert_eq!(second.status(), reqwest::StatusCode::CONFLICT);
-    let error: ApiError = second.json().await.unwrap();
-    assert_eq!(error.error.code, "turn_in_flight");
+    assert_eq!(second.status(), reqwest::StatusCode::ACCEPTED);
 
     let cancel = client
         .post(url(
@@ -332,16 +331,8 @@ async fn structured_prompt_rejects_a_second_in_flight_turn_and_cancel_clears_it(
         .await
         .unwrap();
     assert_eq!(cancel.status(), reqwest::StatusCode::NO_CONTENT);
-    let next = client
-        .post(url(
-            h.addr,
-            &format!("/api/sessions/{id}/structured/prompt"),
-        ))
-        .json(&serde_json::json!({"prompt": "next"}))
-        .send()
-        .await
-        .unwrap();
-    assert_eq!(next.status(), reqwest::StatusCode::NO_CONTENT);
+    // After cancel + settlement, the queued "second" prompt drains. Wait for
+    // both the first and the drained prompt to reach ACP.
     tokio::time::timeout(Duration::from_secs(2), async {
         loop {
             if fake.log().matches("recv session/prompt").count() == 2 {
@@ -351,7 +342,7 @@ async fn structured_prompt_rejects_a_second_in_flight_turn_and_cancel_clears_it(
         }
     })
     .await
-    .expect("both prompt commands reach ACP");
+    .expect("first and drained queued prompt both reach ACP");
     let log = fake.log();
     let first_prompt = log.find("recv session/prompt").unwrap();
     let cancel = log.find("recv session/cancel").unwrap();

crates/maestro-daemon/tests/sidecar.rs

@@ -34,6 +34,8 @@ fn sample(id: Uuid) -> Session {
         last_focused_at: None,
         acp_session_id: None,
         view: SessionView::Terminal,
+        auto_approve: false,
+        queued_prompts: Vec::new(),
     }
 }
 

crates/maestro-protocol/src/display.rs

@@ -744,6 +744,8 @@ mod tests {
             blocked_work: None,
             last_focused_at: None,
             acp_session_id: None,
+            auto_approve: false,
+            queued_prompts: Vec::new(),
         }
     }
 

crates/maestro-protocol/src/lib.rs

@@ -132,6 +132,16 @@ pub struct Session {
     /// the two are minted by different processes with different lifetimes.
     #[serde(default, skip_serializing_if = "Option::is_none")]
     pub acp_session_id: Option<String>,
+    /// When `true` the daemon auto-approves every ACP permission request for
+    /// this session instead of surfacing them to the client. Set at spawn time
+    /// from the preset or the `CreateSessionRequest`; persisted so it survives
+    /// a daemon restart.
+    #[serde(default)]
+    pub auto_approve: bool,
+    /// Prompts queued on the daemon while a turn was in flight or the adapter
+    /// was still booting. Persisted so the queue survives a daemon restart.
+    #[serde(default, skip_serializing_if = "Vec::is_empty")]
+    pub queued_prompts: Vec<String>,
 }
 
 /// A session's process shape (#133): a plain terminal, or a structured agent
@@ -872,6 +882,10 @@ pub struct ReducedState {
     pub mode: Option<String>,
     #[serde(default, skip_serializing_if = "Option::is_none")]
     pub config_options: Option<Value>,
+    /// Prompts queued on the daemon while a turn is in flight. Drained as
+    /// a single concatenated prompt when the current turn completes.
+    #[serde(default, skip_serializing_if = "Vec::is_empty")]
+    pub queued_prompts: Vec<String>,
 }
 
 /// Server messages sent over a structured-session WebSocket.
@@ -1054,6 +1068,8 @@ mod tests {
             last_focused_at: None,
             view: SessionView::Terminal,
             acp_session_id: None,
+            auto_approve: false,
+            queued_prompts: Vec::new(),
         }
     }
 

crates/maestro-testing/src/lib.rs

@@ -50,6 +50,8 @@ pub fn session(id: Uuid, cwd: &str, command: &str) -> Session {
         blocked_work: None,
         last_focused_at: None,
         acp_session_id: None,
+        auto_approve: false,
+        queued_prompts: Vec::new(),
     }
 }
 

crates/maestro-tui/src/app.rs

@@ -2216,6 +2216,8 @@ mod tests {
                     blocked_work: None,
                     last_focused_at: None,
                     acp_session_id: None,
+                    auto_approve: false,
+                    queued_prompts: Vec::new(),
                 })
                 .collect(),
         });
@@ -2399,6 +2401,8 @@ mod tests {
                 blocked_work: None,
                 last_focused_at: None,
                 acp_session_id: None,
+                auto_approve: false,
+                queued_prompts: Vec::new(),
             }],
         });
         app.dispatch(Action::SidebarNext);
@@ -2428,6 +2432,8 @@ mod tests {
             blocked_work: None,
             last_focused_at: None,
             acp_session_id: None,
+            auto_approve: false,
+            queued_prompts: Vec::new(),
         }
     }
 
@@ -3590,6 +3596,8 @@ mod tests {
             blocked_work: None,
             last_focused_at: focused,
             acp_session_id: None,
+            auto_approve: false,
+            queued_prompts: Vec::new(),
         };
         let older = Utc::now() - chrono::Duration::seconds(60);
         app.catalog.apply_event(CatalogEvent::Snapshot {
@@ -3870,6 +3878,8 @@ mod tests {
                 blocked_work: None,
                 last_focused_at: None,
                 acp_session_id: None,
+                auto_approve: false,
+                queued_prompts: Vec::new(),
             }],
         });
         app.dispatch(Action::KillHighlighted);
@@ -3907,6 +3917,8 @@ mod tests {
                 blocked_work: None,
                 last_focused_at: None,
                 acp_session_id: None,
+                auto_approve: false,
+                queued_prompts: Vec::new(),
             }],
         });
     }

crates/maestro-tui/src/catalog.rs

@@ -225,6 +225,8 @@ mod tests {
             blocked_work: None,
             last_focused_at: None,
             acp_session_id: None,
+            auto_approve: false,
+            queued_prompts: Vec::new(),
         }
     }
 

crates/maestro-tui/src/command_bar.rs

@@ -811,6 +811,8 @@ mod tests {
             blocked_work: None,
             last_focused_at: None,
             acp_session_id: None,
+            auto_approve: false,
+            queued_prompts: Vec::new(),
         }
     }
 

crates/maestro-tui/src/sidebar.rs

@@ -502,6 +502,8 @@ mod tests {
             blocked_work: None,
             last_focused_at: None,
             acp_session_id: None,
+            auto_approve: false,
+            queued_prompts: Vec::new(),
         }
     }
 
@@ -1272,6 +1274,8 @@ mod tests {
             blocked_work: None,
             last_focused_at: None,
             acp_session_id: None,
+            auto_approve: false,
+            queued_prompts: Vec::new(),
         };
         let sb = Sidebar {
             sessions: vec![s],

docs/STRUCTURED-VIEW.md

@@ -353,21 +353,26 @@ thing a callback can be attributed to, so at most one turn may ever be
 in flight, and a cancelled turn must fully settle before the next prompt is
 allowed to claim the daemon's idea of "the active turn."
 
-- Web clients may collect a visible FIFO of operator messages while a turn is
-  active. They submit each queued message only after the projected turn becomes
-  idle; the queue is client-local and unsent messages do not survive a reload.
+- Prompts are accepted at any time: if the session is idle the daemon dispatches
+  immediately (`204`); if a turn is active the prompt is appended to a
+  server-side FIFO (`202 Accepted`, capped at 20 entries, `429` when full).
+  When the active turn completes, all queued prompts are concatenated with
+  `\n\n` and dispatched as the next turn. The queue is persisted in the session
+  sidecar and survives daemon restarts — clients never queue locally.
+  `ReducedState.queued_prompts` contains the current queue so every connected
+  client can render the pending messages.
 - A submitted prompt is appended as a durable `User` row before it claims the turn and
   dispatches to ACP, so the transcript never depends on an adapter echoing the
-  operator's input. If that append fails, the prompt is not dispatched. While a
-  turn is active, a second prompt gets `409 turn_in_flight` rather than
-  queuing in the daemon — one active turn per session, never a hidden
-  server-side queue of prompts.
+  operator's input. If that append fails, the prompt is not dispatched.
 - Cancel sends `session/cancel`, clears any pending approval as `Cancelled`,
-  and ends the turn's client-visible lifecycle immediately. If the cancelled
-  turn was still *dispatched* to ACP (waiting on its response), the daemon
-  cannot simply forget it: ACP has not confirmed the cancel yet, and a new
-  prompt claiming "the active turn" while the old one is still outstanding
-  would make the next permission callback ambiguous between the two.
+  and ends the turn's client-visible lifecycle immediately. The prompt queue
+  is preserved: after the cancelled turn settles, the queued prompts drain as
+  the next turn. If the session dies instead (settlement timeout), the queue
+  is cleared. If the cancelled turn was still *dispatched* to ACP (waiting on
+  its response), the daemon cannot simply forget it: ACP has not confirmed the
+  cancel yet, and a new prompt claiming "the active turn" while the old one is
+  still outstanding would make the next permission callback ambiguous between
+  the two.
 - So a cancelled-but-still-dispatched turn must **settle within
   `CANCEL_GRACE` (500ms)** — either ACP acknowledges the prompt (however it
   resolves) or that grace period runs out. If it settles in time, the next

web/src/components/structured/StructuredPane.test.tsx

@@ -308,7 +308,7 @@ describe("prompt and cancel", () => {
     );
   });
 
-  it("queues a second message while a turn is in flight, and sends it when the turn ends", async () => {
+  it("always POSTs a prompt even while a turn is active (server queues it)", async () => {
     const { socket } = mount();
     snapshot(socket, [], busy);
     fireEvent.change(document.querySelector<HTMLTextAreaElement>(".structured-input")!, {
@@ -316,31 +316,17 @@ describe("prompt and cancel", () => {
     });
     fireEvent.submit(document.querySelector("form.structured-composer")!);
 
-    expect(sendStructuredPrompt).not.toHaveBeenCalled();
-    expect(document.querySelector(".st-row-queued")?.textContent).toBe("next up");
-
-    socket.emit({ type: "reduced_state", state: idle });
     await waitFor(() => expect(sendStructuredPrompt).toHaveBeenCalledWith("s1", "next up"));
   });
 
-  it("concatenates multiple queued messages into a single prompt", async () => {
+  it("renders server-side queued prompts from state", () => {
     const { socket } = mount();
-    snapshot(socket, [], busy);
-    const input = document.querySelector<HTMLTextAreaElement>(".structured-input")!;
-    const form = document.querySelector("form.structured-composer")!;
+    snapshot(socket, [], { ...busy, queued_prompts: ["first", "second"] });
 
-    fireEvent.change(input, { target: { value: "first" } });
-    fireEvent.submit(form);
-    fireEvent.change(input, { target: { value: "second" } });
-    fireEvent.submit(form);
-
-    expect(sendStructuredPrompt).not.toHaveBeenCalled();
     const queued = document.querySelectorAll(".st-row-queued");
     expect(queued).toHaveLength(2);
-
-    socket.emit({ type: "reduced_state", state: idle });
-    await waitFor(() => expect(sendStructuredPrompt).toHaveBeenCalledWith("s1", "first\n\nsecond"));
-    expect(sendStructuredPrompt).toHaveBeenCalledTimes(1);
+    expect(queued[0].textContent).toBe("first");
+    expect(queued[1].textContent).toBe("second");
   });
 
   it("hands a failed send's draft back to the operator", async () => {

web/src/components/structured/StructuredPane.tsx

@@ -48,11 +48,6 @@ import "./structured.css";
  *  count as following. */
 const FOLLOW_BOTTOM_THRESHOLD_PX = 64;
 
-interface QueuedPrompt {
-  text: string;
-  attachments: File[];
-}
-
 export interface StructuredPaneProps {
   sessionId: Uuid;
   /** Grabs the composer once mounted. A sidebar preview passes `false`. */
@@ -85,7 +80,6 @@ export const StructuredPane = forwardRef<StructuredPaneHandle, StructuredPanePro
   const [expandedGroups, setExpandedGroups] = useState<ReadonlySet<string>>(new Set());
   const [draft, setDraft] = useState("");
   const [attachments, setAttachments] = useState<File[]>([]);
-  const [queue, setQueue] = useState<QueuedPrompt[]>([]);
   const [uploading, setUploading] = useState(false);
   const [configBusy, setConfigBusy] = useState(false);
   const [error, setError] = useState<string | null>(null);
@@ -100,7 +94,6 @@ export const StructuredPane = forwardRef<StructuredPaneHandle, StructuredPanePro
   const submission = useRef(0);
   const accepted = useRef<{ generation: number; socketGeneration: number } | null>(null);
   const optimisticStart = useRef<number | null>(null);
-  const promptPending = useRef(false);
   const [awaitingBegin, setAwaitingBegin] = useState<number | null>(null);
 
   useImperativeHandle(
@@ -166,7 +159,7 @@ export const StructuredPane = forwardRef<StructuredPaneHandle, StructuredPanePro
     const el = scrollRef.current;
     if (!el || !followingBottom.current) return;
     el.scrollTop = Math.max(0, el.scrollHeight - el.clientHeight);
-  }, [items, active, queue]);
+  }, [items, active, state.queued_prompts]);
 
   useEffect(() => {
     if (!active) return;
@@ -207,7 +200,7 @@ export const StructuredPane = forwardRef<StructuredPaneHandle, StructuredPanePro
       setAwaitingBegin(generation);
       optimisticStart.current = Date.now();
       accepted.current = null;
-      promptPending.current = true;
+
       setUploading(files.length > 0);
       setDraft("");
       setError(null);
@@ -224,7 +217,6 @@ export const StructuredPane = forwardRef<StructuredPaneHandle, StructuredPanePro
 
       void send().then(
         () => {
-          promptPending.current = false;
           if (generation !== submission.current) return;
           setUploading(false);
           setAttachments((current) => (current === files ? [] : current));
@@ -235,7 +227,6 @@ export const StructuredPane = forwardRef<StructuredPaneHandle, StructuredPanePro
           if (socketGeneration > submissionSocket) session.reconnect();
         },
         (e: unknown) => {
-          promptPending.current = false;
           if (generation !== submission.current) return;
           setAwaitingBegin((current) => (current === generation ? null : current));
           optimisticStart.current = null;
@@ -251,26 +242,10 @@ export const StructuredPane = forwardRef<StructuredPaneHandle, StructuredPanePro
     [sessionId, socketGeneration, session],
   );
 
-  // Queued messages are concatenated into a single prompt so the agent sees
-  // one user turn instead of N back-to-back turns. The daemon rejects a
-  // second prompt while a turn is in flight (`409 turn_in_flight`), so the
-  // queue is client-local (docs/STRUCTURED-VIEW.md).
-  useEffect(() => {
-    if (active || promptPending.current || queue.length === 0) return;
-    const text = queue.map((q) => q.text).join("\n\n");
-    const files = queue.flatMap((q) => q.attachments);
-    setQueue([]);
-    dispatchPrompt(text, files);
-  }, [active, queue, dispatchPrompt]);
-
+  // The server accepts prompts at any time: if a turn is active the prompt is
+  // queued server-side and drained when the turn completes.  The client always
+  // POSTs immediately — no local queue.
   const submit = (text: string, files: File[]) => {
-    if (active || queue.length > 0) {
-      setQueue((current) => [...current, { text, attachments: files }]);
-      setAttachments([]);
-      setDraft("");
-      setError(null);
-      return;
-    }
     dispatchPrompt(text, files);
   };
 
@@ -365,10 +340,10 @@ export const StructuredPane = forwardRef<StructuredPaneHandle, StructuredPanePro
                   </ToolGroup>
                 ),
               )}
-              {queue.map((queued, index) => (
+              {(state.queued_prompts ?? []).map((text, index) => (
                 <div key={`queued-${index}`} className="st-row st-row-queued">
                   <div className="st-body">
-                    <div className="st-user-text">{queued.text}</div>
+                    <div className="st-user-text">{text}</div>
                   </div>
                 </div>
               ))}

web/src/components/structured/structured.css

@@ -726,7 +726,11 @@
 }
 
 .st-tool-group-title {
-  flex: 0 0 auto;
+  flex: 1 1 0;
+  min-width: 0;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
   font-weight: 500;
 }
 

web/src/types.ts

@@ -441,6 +441,7 @@ export interface ReducedState {
   model?: string | null;
   mode?: string | null;
   config_options?: { configOptions: AcpSessionConfigOption[] } | null;
+  queued_prompts?: string[];
 }
 
 /** Server messages on `WS /api/structured/:id`. */