diff --git a/src/app/models/assistant.ts b/src/app/models/assistant.ts
index 2cc3c96..88d0163 100644
--- a/src/app/models/assistant.ts
+++ b/src/app/models/assistant.ts
@@ -46,7 +46,7 @@ export type AssistantConfig = {
   availableModelsRetrieverUrl: string;
 };
 
-export type AssistantCallStatus = 'QUEUED' | 'RUNNING' | 'COMPLETED' | 'FAILED';
+export type AssistantCallStatus = 'QUEUED' | 'RUNNING' | 'COMPLETED' | 'FAILED' | 'CANCELLED';
 
 export type AssistantCallPhase =
   | 'queued'
@@ -58,7 +58,8 @@ export type AssistantCallPhase =
   | 'fixing'
   | 'explaining'
   | 'completed'
-  | 'failed';
+  | 'failed'
+  | 'cancelled';
 
 export type AssistantCallState = {
   id: string;
diff --git a/src/app/services/assistant/assistant-call.base.ts b/src/app/services/assistant/assistant-call.base.ts
index 6fb37e7..20eaf61 100644
--- a/src/app/services/assistant/assistant-call.base.ts
+++ b/src/app/services/assistant/assistant-call.base.ts
@@ -19,5 +19,7 @@ export abstract class AssistantCallServiceBase {
 
   abstract getCall(callId: string): Observable<AssistantCallState>;
 
+  abstract cancelCall(callId: string): Observable<AssistantCallState>;
+
   abstract getSession(sessionId: string): Observable<AssistantSessionState>;
 }
diff --git a/src/app/services/assistant/assistant-call.fake.ts b/src/app/services/assistant/assistant-call.fake.ts
index 4826eb4..1b5511c 100644
--- a/src/app/services/assistant/assistant-call.fake.ts
+++ b/src/app/services/assistant/assistant-call.fake.ts
@@ -20,6 +20,7 @@ type FakeCallRecord = {
   phases: AssistantCallPhase[];
   completed: boolean;
   failed: boolean;
+  cancelled: boolean;
 };
 
 export class AssistantCallServiceFake extends AssistantCallServiceBase {
@@ -83,7 +84,8 @@ export class AssistantCallServiceFake extends AssistantCallServiceBase {
       phaseIndex: 0,
       phases,
       completed: false,
-      failed: false
+      failed: false,
+      cancelled: false
     });
     session.lastCallId = callId;
 
@@ -96,7 +98,7 @@ export class AssistantCallServiceFake extends AssistantCallServiceBase {
       throw new Error(`Assistant call ${callId} not found`);
     }
 
-    if (!call.completed && !call.failed) {
+    if (!call.completed && !call.failed && !call.cancelled) {
       if (call.phaseIndex < call.phases.length - 1) {
         call.phaseIndex += 1;
       } else {
@@ -109,23 +111,44 @@ export class AssistantCallServiceFake extends AssistantCallServiceBase {
       ? 'completed'
       : call.failed
         ? 'failed'
-        : call.phases[call.phaseIndex];
+        : call.cancelled
+          ? 'cancelled'
+          : call.phases[call.phaseIndex];
 
     return of({
       id: call.id,
       sessionId: call.sessionId,
       status: call.failed
         ? 'FAILED'
+        : call.cancelled
+          ? 'CANCELLED'
         : call.completed
           ? 'COMPLETED'
           : call.phaseIndex === 0
             ? 'QUEUED'
             : 'RUNNING',
       phase,
+      progressMessage: call.cancelled ? 'Assistant request cancelled' : undefined,
       errorMessage: call.failed ? 'Fake assistant call failed.' : undefined
     });
   }
 
+  override cancelCall(callId: string): Observable<AssistantCallState> {
+    const call = this.calls.get(callId);
+    if (!call) {
+      throw new Error(`Assistant call ${callId} not found`);
+    }
+
+    call.cancelled = true;
+    return of({
+      id: call.id,
+      sessionId: call.sessionId,
+      status: 'CANCELLED',
+      phase: 'cancelled',
+      progressMessage: 'Assistant request cancelled'
+    });
+  }
+
   override getSession(sessionId: string): Observable<AssistantSessionState> {
     const session = this.sessions.get(sessionId);
     if (!session) {
diff --git a/src/app/services/assistant/assistant-call.ts b/src/app/services/assistant/assistant-call.ts
index 3a5131c..3560045 100644
--- a/src/app/services/assistant/assistant-call.ts
+++ b/src/app/services/assistant/assistant-call.ts
@@ -55,6 +55,13 @@ export class AssistantCallService extends AssistantCallServiceBase {
       .pipe(map((raw) => mapAssistantCallState(raw)));
   }
 
+  override cancelCall(callId: string): Observable<AssistantCallState> {
+    const encodedId = encodeURIComponent(callId);
+    return this.http
+      .put<unknown>(`${environment.apiUrl}/assistant/calls/${encodedId}/cancel`, {})
+      .pipe(map((raw) => mapAssistantCallState(raw)));
+  }
+
   override getSession(sessionId: string): Observable<AssistantSessionState> {
     const encodedId = encodeURIComponent(sessionId);
     return this.http
@@ -222,7 +229,7 @@ function mapValidationIssues(raw: unknown): AssistantValidationIssue[] {
 
 function mapCallStatus(raw: unknown): AssistantCallStatus {
   const normalized = typeof raw === 'string' ? raw.toUpperCase() : '';
-  if (normalized === 'QUEUED' || normalized === 'RUNNING' || normalized === 'FAILED') return normalized;
+  if (normalized === 'QUEUED' || normalized === 'RUNNING' || normalized === 'FAILED' || normalized === 'CANCELLED') return normalized;
   return 'COMPLETED';
 }
 
@@ -239,6 +246,7 @@ function mapCallPhase(raw: unknown): AssistantCallPhase {
     case 'explaining':
     case 'completed':
     case 'failed':
+    case 'cancelled':
       return normalized;
     default:
       return 'queued';
diff --git a/src/app/services/assistant/assistant.ts b/src/app/services/assistant/assistant.ts
index 6f0a9b9..400a262 100644
--- a/src/app/services/assistant/assistant.ts
+++ b/src/app/services/assistant/assistant.ts
@@ -29,6 +29,10 @@ export class AssistantService {
     return this.assistantCall.getCall(callId);
   }
 
+  cancelCall(callId: string) {
+    return this.assistantCall.cancelCall(callId);
+  }
+
   getSession(sessionId: string) {
     return this.assistantCall.getSession(sessionId);
   }
diff --git a/src/app/stores/assistant-session-store.ts b/src/app/stores/assistant-session-store.ts
index c03e67f..ec86e8f 100644
--- a/src/app/stores/assistant-session-store.ts
+++ b/src/app/stores/assistant-session-store.ts
@@ -10,10 +10,14 @@ export type AssistantSessionSnapshot = {
   localMessages: AssistantChatMessage[];
   currentCall: AssistantCallState | null;
   sessionState: AssistantSessionState | null;
+  assistantErrorMessage: string | null;
+  lastFailedPrompt: string | null;
+  lastSubmittedPrompt: string;
 };
 
 @Injectable({ providedIn: 'root' })
 export class AssistantSessionStore {
+  static readonly CREATE_MODAL_FLOW_KEY = '__assistant:create-modal';
   private static readonly NO_FLOW_KEY = '__assistant:no-flow__';
   private static readonly STORAGE_KEY = 'assistant-session-store:v1';
   private static readonly STORAGE_TARGETS: Array<'localStorage' | 'sessionStorage'> = ['localStorage', 'sessionStorage'];
@@ -32,6 +36,10 @@ export class AssistantSessionStore {
     return snapshot ? structuredClone(snapshot) : null;
   }
 
+  hasSnapshot(flowKey: string): boolean {
+    return this.snapshots.has(flowKey);
+  }
+
   setSnapshot(flowKey: string, snapshot: AssistantSessionSnapshot) {
     this.snapshots.set(flowKey, structuredClone(snapshot));
     this.persistToStorage();
@@ -44,6 +52,11 @@ export class AssistantSessionStore {
     this.persistToStorage();
   }
 
+  clearSnapshot(flowKey: string) {
+    if (!this.snapshots.delete(flowKey)) return;
+    this.persistToStorage();
+  }
+
   private hydrateFromStorage() {
     const raw = this.readStoredPayload();
     if (!raw) return;
@@ -83,7 +96,16 @@ export class AssistantSessionStore {
         : null,
       sessionState: snapshot['sessionState'] && typeof snapshot['sessionState'] === 'object'
         ? this.normalizeSessionState(snapshot['sessionState'])
-        : null
+        : null,
+      assistantErrorMessage: typeof snapshot['assistantErrorMessage'] === 'string'
+        ? snapshot['assistantErrorMessage']
+        : null,
+      lastFailedPrompt: typeof snapshot['lastFailedPrompt'] === 'string'
+        ? snapshot['lastFailedPrompt']
+        : null,
+      lastSubmittedPrompt: typeof snapshot['lastSubmittedPrompt'] === 'string'
+        ? snapshot['lastSubmittedPrompt']
+        : ''
     };
   }