diff --git a/hive-c0re/src/broker.rs b/hive-c0re/src/broker.rs
index 0d16b1a6..e28a698e 100644
--- a/hive-c0re/src/broker.rs
+++ b/hive-c0re/src/broker.rs
@@ -263,6 +263,27 @@ impl Broker {
         Ok(u64::try_from(n.max(0)).unwrap_or(0))
     }
 
+    /// Returns true when the recipient already has at least one
+    /// undelivered message from `sender` with exactly `body` in the
+    /// broker. Used by the scheduler to skip re-delivery of the same
+    /// scheduled prompt without blocking distinct schedules whose
+    /// bodies differ.
+    pub fn has_pending_with_body(
+        &self,
+        recipient: &str,
+        sender: &str,
+        body: &str,
+    ) -> Result<bool> {
+        let conn = self.conn.lock().unwrap();
+        let n: i64 = conn.query_row(
+            "SELECT COUNT(*) FROM messages
+              WHERE recipient = ?1 AND sender = ?2 AND body = ?3 AND delivered_at IS NULL",
+            params![recipient, sender, body],
+            |row| row.get(0),
+        )?;
+        Ok(n > 0)
+    }
+
     /// Long-poll variant of `recv_batch`: returns immediately if any
     /// row is pending (popping up to `max`); otherwise waits up to
     /// `timeout` for the broker to emit a `Sent { to: recipient }`
@@ -1254,3 +1275,4 @@ mod tests {
         assert!(pop_one(broker, "bob").is_none());
     }
 }
+
diff --git a/hive-c0re/src/scheduled_prompts_worker.rs b/hive-c0re/src/scheduled_prompts_worker.rs
index 611a57d4..a37f363a 100644
--- a/hive-c0re/src/scheduled_prompts_worker.rs
+++ b/hive-c0re/src/scheduled_prompts_worker.rs
@@ -96,6 +96,31 @@ fn fire_schedule(coord: &Arc<Coordinator>, schedule: &Schedule, now: i64) {
             notify_operator_missing_target(coord, schedule, target);
             continue;
         }
+        // Skip delivery if there is already an unread message from
+        // "scheduled" waiting in this target's inbox. Prevents the same
+        // scheduled prompt from stacking up when an agent is slow or
+        // briefly offline, while still allowing distinct scheduled
+        // messages (different body) to enqueue independently.
+        match coord.broker.has_pending_with_body(target, "scheduled", &schedule.body) {
+            Ok(true) => {
+                tracing::debug!(
+                    schedule = schedule.id,
+                    %target,
+                    "scheduled_prompts: skipping — same body already pending for target"
+                );
+                let _ = coord.scheduled_prompts.record_target_result(
+                    schedule.id,
+                    target,
+                    now,
+                    "skipped: already pending",
+                );
+                continue;
+            }
+            Err(e) => {
+                tracing::warn!(schedule = schedule.id, %target, error = ?e, "has_pending_with_body failed");
+            }
+            Ok(false) => {}
+        }
         let msg = Message {
             from: "scheduled".to_owned(),
             to: target.clone(),
@@ -359,3 +384,4 @@ async fn known_agents_async() -> std::collections::HashSet<String> {
     }
     out
 }
+