diff --git a/src/automation/compact_prompt.rs b/src/automation/compact_prompt.rs
index ee8cd54b..bfa80ee5 100644
--- a/src/automation/compact_prompt.rs
+++ b/src/automation/compact_prompt.rs
@@ -84,11 +84,14 @@ async fn compact_prompt_for_bot(
     let config_manager = ConfigManager::new(Arc::clone(&state.conn));
     let compact_threshold = config_manager
         .get_config(&automation.bot_id, "prompt-compact", None)?
-        .parse::<usize>()
+        .parse::<i32>()
         .unwrap_or(0);
 
+    // Compact if threshold is negative (always compact) or positive (conditional)
     if compact_threshold == 0 {
         return Ok(());
+    } else if compact_threshold < 0 {
+        info!("Compaction forced for bot {} (threshold = {})", automation.bot_id, compact_threshold);
     }
 
     // Get sessions without holding lock
@@ -153,17 +156,13 @@ async fn compact_prompt_for_bot(
                 history.len()
             );
 
-            // Remove all old messages and save only the summary
-            {
-                let mut session_manager = state.session_manager.lock().await;
-                // First delete all existing messages for this session
-                if let Err(e) = session_manager.clear_messages(session.id) {
-                    error!("Failed to clear messages for session {}: {}", session.id, e);
-                    return Err(e);
-                }
-                // Then save just the summary
-                session_manager.save_message(session.id, session.user_id, 3, &summarized, 1)?;
-            }
+    // Instead of clearing messages, insert a compacted marker message
+    {
+        let mut session_manager = state.session_manager.lock().await;
+        // Save a special compacted message type (9)
+        session_manager.save_message(session.id, session.user_id, 9, &summarized, 1)?;
+        trace!("Inserted compacted message for session {}", session.id);
+    }
     }
 
     Ok(())
diff --git a/src/bot/mod.rs b/src/bot/mod.rs
index a97382fe..210c4562 100644
--- a/src/bot/mod.rs
+++ b/src/bot/mod.rs
@@ -405,15 +405,23 @@ impl BotOrchestrator {
         };
 
         // Acquire lock briefly for history retrieval with configurable limit
-        let history = {
-            let mut sm = self.state.session_manager.lock().await;
-            let mut history = sm.get_conversation_history(session.id, user_id)?;
-            if history_limit > 0 && history.len() > history_limit as usize {
-                let start = history.len() - history_limit as usize;
-                history.drain(0..start);
-            }
-            history
-        };
+let history = {
+    let mut sm = self.state.session_manager.lock().await;
+    let mut history = sm.get_conversation_history(session.id, user_id)?;
+
+    // Skip all messages before the most recent compacted message (type 9)
+    if let Some(last_compacted_index) = history.iter().rposition(|(role, content)| {
+        role == "COMPACTED" || content.starts_with("SUMMARY:")
+    }) {
+        history = history.split_off(last_compacted_index);
+    }
+
+    if history_limit > 0 && history.len() > history_limit as usize {
+        let start = history.len() - history_limit as usize;
+        history.drain(0..start);
+    }
+    history
+};
 
         let mut prompt = String::new();
         if !system_prompt.is_empty() {