diff --git a/signal-gateway-assistant/claude/src/lib.rs b/signal-gateway-assistant/claude/src/lib.rs
index f92ec3f..ecd556f 100644
--- a/signal-gateway-assistant/claude/src/lib.rs
+++ b/signal-gateway-assistant/claude/src/lib.rs
@@ -175,7 +175,7 @@ impl ClaudeAssistant {
         };
 
         if can_compact {
-            self.do_compact(true).await;
+            self.do_compact(true, None).await;
         } else {
             self.drop_oldest_messages();
         }
@@ -216,7 +216,9 @@ impl ClaudeAssistant {
     }
 
     /// Perform compaction by summarizing messages and storing the result.
-    async fn do_compact(&mut self, is_automatic: bool) {
+    ///
+    /// If `cancel` is provided, the operation can be interrupted.
+    async fn do_compact(&mut self, is_automatic: bool, cancel: Option<&CancellationToken>) {
         if self.messages.is_empty() {
             return;
         }
@@ -257,15 +259,26 @@ impl ClaudeAssistant {
             tools: Vec::new(),
         };
 
-        let result = self
+        let http_fut = self
             .client
             .post(&self.config.claude_api_url)
             .header("x-api-key", &self.api_key)
             .header("anthropic-version", ANTHROPIC_API_VERSION)
             .header("content-type", "application/json")
             .json(&request_body)
-            .send()
-            .await;
+            .send();
+
+        let result = if let Some(cancel) = cancel {
+            tokio::select! {
+                result = http_fut => result,
+                _ = cancel.cancelled() => {
+                    info!("Compaction cancelled");
+                    return;
+                }
+            }
+        } else {
+            http_fut.await
+        };
 
         match result {
             Ok(response) if response.status().is_success() => {
@@ -469,9 +482,9 @@ impl Assistant for ClaudeAssistant {
         Ok(self.handle_request(&cancel).await?)
     }
 
-    async fn compact(&mut self) {
+    async fn compact(&mut self, cancel: CancellationToken) {
         // Manual compaction always runs (is_automatic = false)
-        self.do_compact(false).await;
+        self.do_compact(false, Some(&cancel)).await;
     }
 
     fn debug_log(&mut self) {
diff --git a/signal-gateway-assistant/src/assistant.rs b/signal-gateway-assistant/src/assistant.rs
index 66e0aca..9dadcb2 100644
--- a/signal-gateway-assistant/src/assistant.rs
+++ b/signal-gateway-assistant/src/assistant.rs
@@ -25,7 +25,9 @@ pub trait Assistant: Send {
     ///
     /// This is called when the user explicitly requests compaction.
     /// Automatic compaction is an internal implementation detail.
-    async fn compact(&mut self);
+    ///
+    /// The cancellation token can be used to interrupt the operation.
+    async fn compact(&mut self, cancel: CancellationToken);
 
     /// Log the assistant's current state for debugging.
     fn debug_log(&mut self);
diff --git a/signal-gateway/src/assistant/worker.rs b/signal-gateway/src/assistant/worker.rs
index 1cb237a..fcaf1b5 100644
--- a/signal-gateway/src/assistant/worker.rs
+++ b/signal-gateway/src/assistant/worker.rs
@@ -117,7 +117,17 @@ impl AssistantWorker {
                 false
             }
             Input::Compact => {
-                self.assistant.compact().await;
+                let cancel_token = self.cancellation_token.child_token();
+                let mut compact_fut = self.assistant.compact(cancel_token.clone());
+
+                tokio::select! {
+                    _ = &mut compact_fut => {},
+                    _ = self.stop_rx.recv() => {
+                        cancel_token.cancel();
+                        compact_fut.await;
+                        return true;
+                    }
+                };
                 false
             }
             Input::Debug => {