feat(ai): persist user preferences across chat sessions

Tasks.md

@@ -18,6 +18,7 @@ Last updated: 2026-02-24
 | T-010 | Chat history persistence and simple direct-query handling | Complete | `apps/client/src/app/pages/portfolio/analysis/ai-chat-panel/ai-chat-panel.component.spec.ts`, `apps/api/src/app/endpoints/ai/ai-agent.utils.spec.ts`, `apps/api/src/app/endpoints/ai/ai.service.spec.ts` | Local implementation |
 | T-011 | Per-LLM LangSmith invocation tracing + production tracing env enablement | Complete | `apps/api/src/app/endpoints/ai/ai-observability.service.spec.ts`, `apps/api/src/app/endpoints/ai/ai.service.spec.ts`, `apps/api/src/app/endpoints/ai/ai-performance.spec.ts`, `apps/api/src/app/endpoints/ai/evals/mvp-eval.runner.spec.ts`, `apps/api/src/app/endpoints/ai/evals/ai-quality-eval.spec.ts` | Local implementation + Railway variable update |
 | T-012 | LangChain wrapper enforcement for provider calls + arithmetic direct-response correction | Complete | `apps/api/src/app/endpoints/ai/ai.service.spec.ts`, `apps/api/src/app/endpoints/ai/ai-agent.utils.spec.ts`, `npm run test:ai` | Local implementation |
+| T-013 | Cross-session user preference memory (persisted by user, independent of chat session) | Complete | `apps/api/src/app/endpoints/ai/ai-agent.chat.helpers.spec.ts`, `apps/api/src/app/endpoints/ai/ai.service.spec.ts`, `npm run test:ai`, `npx nx run api:lint` | Local implementation |
 
 ## Notes
 
@@ -39,3 +40,4 @@ Last updated: 2026-02-24
 - Chat persistence + simple direct-query handling (2026-02-24): client chat panel now restores/persists session + bounded message history via localStorage and policy no-tool prompts now return assistant capability guidance for queries like "Who are you?".
 - Per-LLM LangSmith invocation tracing (2026-02-24): each provider call now records an explicit LangSmith `llm` run (provider/model/query/session/response metadata), and production Railway env now has tracing variables enabled.
 - Direct arithmetic no-tool behavior fix (2026-02-24): simple arithmetic prompts now return computed answers (for example `2+2 = 4`) instead of generic capability guidance.
+- Cross-session preference memory (2026-02-24): AI now persists explicit user response-style preferences in Redis by `userId`, recalls them across different `sessionId`s, and applies them to later AI responses.

apps/api/src/app/endpoints/ai/ai-agent.chat.helpers.spec.ts

@@ -1,6 +1,12 @@
 import { DataSource } from '@prisma/client';
 
-import { buildAnswer } from './ai-agent.chat.helpers';
+import {
+  buildAnswer,
+  createPreferenceSummaryResponse,
+  getUserPreferences,
+  isPreferenceRecallQuery,
+  resolvePreferenceUpdate
+} from './ai-agent.chat.helpers';
 
 describe('AiAgentChatHelpers', () => {
   const originalLlmTimeout = process.env.AI_AGENT_LLM_TIMEOUT_IN_MS;
@@ -66,4 +72,40 @@ describe('AiAgentChatHelpers', () => {
 
     expect(answer).toBe(generatedText);
   });
+
+  it('parses and persists concise response-style preference updates', () => {
+    const result = resolvePreferenceUpdate({
+      query: 'Remember to keep responses concise.',
+      userPreferences: {}
+    });
+
+    expect(result.shouldPersist).toBe(true);
+    expect(result.userPreferences.responseStyle).toBe('concise');
+    expect(result.acknowledgement).toContain('Saved preference');
+  });
+
+  it('recognizes preference recall queries and renders deterministic summary', () => {
+    expect(isPreferenceRecallQuery('What do you remember about me?')).toBe(true);
+    expect(
+      createPreferenceSummaryResponse({
+        userPreferences: {
+          responseStyle: 'concise',
+          updatedAt: '2026-02-24T10:00:00.000Z'
+        }
+      })
+    ).toContain('response style: concise');
+  });
+
+  it('returns empty preferences for malformed user preference payload', async () => {
+    const redisCacheService = {
+      get: jest.fn().mockResolvedValue('{bad-json')
+    };
+
+    const result = await getUserPreferences({
+      redisCacheService: redisCacheService as never,
+      userId: 'user-1'
+    });
+
+    expect(result).toEqual({});
+  });
 });

apps/api/src/app/endpoints/ai/ai-agent.chat.helpers.ts

@@ -7,6 +7,7 @@ import ms from 'ms';
 
 import {
   AiAgentMemoryState,
+  AiAgentUserPreferenceState,
   MarketDataLookupResult,
   PortfolioAnalysisResult,
   RebalancePlanResult,
@@ -19,7 +20,16 @@ import {
 } from './ai-agent.utils';
 
 const AI_AGENT_MEMORY_TTL = ms('24 hours');
+const AI_AGENT_USER_PREFERENCES_TTL = ms('90 days');
 const DEFAULT_LLM_TIMEOUT_IN_MS = 3_500;
+const CLEAR_PREFERENCES_PATTERN =
+  /\b(?:clear|forget|reset)\s+(?:all\s+)?(?:my\s+)?(?:saved\s+)?preferences?\b/i;
+const CONCISE_RESPONSE_STYLE_PATTERN =
+  /\b(?:(?:concise|brief|short)\s+(?:answers?|responses?|replies?)|(?:answers?|responses?|replies?)\s+(?:concise|brief|short)|(?:answer|reply)\s+(?:briefly|concisely)|keep (?:the )?(?:answers?|responses?|replies?) (?:short|brief|concise))\b/i;
+const DETAILED_RESPONSE_STYLE_PATTERN =
+  /\b(?:(?:detailed|verbose|longer)\s+(?:answers?|responses?|replies?)|(?:answers?|responses?|replies?)\s+(?:detailed|verbose|longer)|(?:answer|reply)\s+(?:in detail|verbosely)|(?:more|extra)\s+detail)\b/i;
+const PREFERENCE_RECALL_PATTERN =
+  /\b(?:what do you remember about me|show (?:my )?preferences?|what are my preferences?|which preferences (?:do|did) you (?:remember|save))\b/i;
 
 export const AI_AGENT_MEMORY_MAX_TURNS = 10;
 
@@ -31,6 +41,122 @@ function getLlmTimeoutInMs() {
     : DEFAULT_LLM_TIMEOUT_IN_MS;
 }
 
+function sanitizeUserPreferences(
+  preferences?: AiAgentUserPreferenceState
+): AiAgentUserPreferenceState {
+  if (!preferences || typeof preferences !== 'object') {
+    return {};
+  }
+
+  return {
+    responseStyle:
+      preferences.responseStyle === 'concise' || preferences.responseStyle === 'detailed'
+        ? preferences.responseStyle
+        : undefined,
+    updatedAt:
+      typeof preferences.updatedAt === 'string' ? preferences.updatedAt : undefined
+  };
+}
+
+function hasStoredPreferences(preferences: AiAgentUserPreferenceState) {
+  return Boolean(preferences.responseStyle);
+}
+
+function getResponseInstruction({
+  userPreferences
+}: {
+  userPreferences?: AiAgentUserPreferenceState;
+}) {
+  if (userPreferences?.responseStyle === 'concise') {
+    return `User preference: keep the response concise in 1-3 short sentences and avoid speculation.`;
+  }
+
+  if (userPreferences?.responseStyle === 'detailed') {
+    return `User preference: provide a detailed structured response with clear steps and avoid speculation.`;
+  }
+
+  return `Write a concise response with actionable insight and avoid speculation.`;
+}
+
+export function isPreferenceRecallQuery(query: string) {
+  return PREFERENCE_RECALL_PATTERN.test(query.trim().toLowerCase());
+}
+
+export function createPreferenceSummaryResponse({
+  userPreferences
+}: {
+  userPreferences: AiAgentUserPreferenceState;
+}) {
+  if (!hasStoredPreferences(userPreferences)) {
+    return 'I have no saved cross-session preferences yet.';
+  }
+
+  const sections: string[] = ['Saved cross-session preferences:'];
+
+  if (userPreferences.responseStyle) {
+    sections.push(`- response style: ${userPreferences.responseStyle}`);
+  }
+
+  return sections.join('\n');
+}
+
+export function resolvePreferenceUpdate({
+  query,
+  userPreferences
+}: {
+  query: string;
+  userPreferences: AiAgentUserPreferenceState;
+}): {
+  acknowledgement?: string;
+  shouldPersist: boolean;
+  userPreferences: AiAgentUserPreferenceState;
+} {
+  const normalizedPreferences = sanitizeUserPreferences(userPreferences);
+  const normalizedQuery = query.trim();
+
+  if (CLEAR_PREFERENCES_PATTERN.test(normalizedQuery)) {
+    return {
+      acknowledgement: hasStoredPreferences(normalizedPreferences)
+        ? 'Cleared your saved cross-session preferences.'
+        : 'No saved cross-session preferences were found.',
+      shouldPersist: hasStoredPreferences(normalizedPreferences),
+      userPreferences: {}
+    };
+  }
+
+  const wantsConcise = CONCISE_RESPONSE_STYLE_PATTERN.test(normalizedQuery);
+  const wantsDetailed = DETAILED_RESPONSE_STYLE_PATTERN.test(normalizedQuery);
+
+  if (wantsConcise === wantsDetailed) {
+    return {
+      shouldPersist: false,
+      userPreferences: normalizedPreferences
+    };
+  }
+
+  const responseStyle: AiAgentUserPreferenceState['responseStyle'] = wantsConcise
+    ? 'concise'
+    : 'detailed';
+
+  if (normalizedPreferences.responseStyle === responseStyle) {
+    return {
+      acknowledgement: `Preference already saved: response style is ${responseStyle}.`,
+      shouldPersist: false,
+      userPreferences: normalizedPreferences
+    };
+  }
+
+  return {
+    acknowledgement: `Saved preference: I will keep responses ${responseStyle} across sessions.`,
+    shouldPersist: true,
+    userPreferences: {
+      ...normalizedPreferences,
+      responseStyle,
+      updatedAt: new Date().toISOString()
+    }
+  };
+}
+
 export async function buildAnswer({
   generateText,
   languageCode,
@@ -41,6 +167,7 @@ export async function buildAnswer({
   rebalancePlan,
   riskAssessment,
   stressTest,
+  userPreferences,
   userCurrency
 }: {
   generateText: ({
@@ -58,6 +185,7 @@ export async function buildAnswer({
   rebalancePlan?: RebalancePlanResult;
   riskAssessment?: RiskAssessmentResult;
   stressTest?: StressTestResult;
+  userPreferences?: AiAgentUserPreferenceState;
   userCurrency: string;
 }) {
   const fallbackSections: string[] = [];
@@ -169,7 +297,9 @@ export async function buildAnswer({
     );
   }
 
-  const fallbackAnswer = fallbackSections.join('\n');
+  const fallbackAnswer = userPreferences?.responseStyle === 'concise'
+    ? fallbackSections.slice(0, 2).join('\n')
+    : fallbackSections.join('\n');
   const llmPrompt = [
     `You are a neutral financial assistant.`,
     `User currency: ${userCurrency}`,
@@ -177,7 +307,7 @@ export async function buildAnswer({
     `Query: ${query}`,
     `Context summary:`,
     fallbackAnswer,
-    `Write a concise response with actionable insight and avoid speculation.`
+    getResponseInstruction({ userPreferences })
   ].join('\n');
   const llmTimeoutInMs = getLlmTimeoutInMs();
   const abortController = new AbortController();
@@ -255,6 +385,30 @@ export async function getMemory({
   }
 }
 
+export async function getUserPreferences({
+  redisCacheService,
+  userId
+}: {
+  redisCacheService: RedisCacheService;
+  userId: string;
+}): Promise<AiAgentUserPreferenceState> {
+  const rawPreferences = await redisCacheService.get(
+    getUserPreferencesKey({ userId })
+  );
+
+  if (!rawPreferences) {
+    return {};
+  }
+
+  try {
+    const parsed = JSON.parse(rawPreferences) as AiAgentUserPreferenceState;
+
+    return sanitizeUserPreferences(parsed);
+  } catch {
+    return {};
+  }
+}
+
 export function getMemoryKey({
   sessionId,
   userId
@@ -265,6 +419,10 @@ export function getMemoryKey({
   return `ai-agent-memory-${userId}-${sessionId}`;
 }
 
+export function getUserPreferencesKey({ userId }: { userId: string }) {
+  return `ai-agent-preferences-${userId}`;
+}
+
 export function resolveSymbols({
   portfolioAnalysis,
   query,
@@ -434,3 +592,19 @@ export async function setMemory({
     AI_AGENT_MEMORY_TTL
   );
 }
+
+export async function setUserPreferences({
+  redisCacheService,
+  userId,
+  userPreferences
+}: {
+  redisCacheService: RedisCacheService;
+  userId: string;
+  userPreferences: AiAgentUserPreferenceState;
+}) {
+  await redisCacheService.set(
+    getUserPreferencesKey({ userId }),
+    JSON.stringify(sanitizeUserPreferences(userPreferences)),
+    AI_AGENT_USER_PREFERENCES_TTL
+  );
+}

apps/api/src/app/endpoints/ai/ai-agent.chat.interfaces.ts

@@ -11,6 +11,13 @@ export interface AiAgentMemoryState {
   }[];
 }
 
+export type AiAgentResponseStylePreference = 'concise' | 'detailed';
+
+export interface AiAgentUserPreferenceState {
+  responseStyle?: AiAgentResponseStylePreference;
+  updatedAt?: string;
+}
+
 export interface PortfolioAnalysisResult {
   allocationSum: number;
   holdings: {

apps/api/src/app/endpoints/ai/ai.service.spec.ts

@@ -291,6 +291,93 @@ describe('AiService', () => {
     expect(generateTextSpy).not.toHaveBeenCalled();
   });
 
+  it('persists and recalls cross-session user preferences for the same user', async () => {
+    const redisStore = new Map<string, string>();
+    redisCacheService.get.mockImplementation(async (key: string) => {
+      return redisStore.get(key);
+    });
+    redisCacheService.set.mockImplementation(
+      async (key: string, value: string) => {
+        redisStore.set(key, value);
+      }
+    );
+
+    const savePreferenceResult = await subject.chat({
+      languageCode: 'en',
+      query: 'Remember to keep responses concise.',
+      sessionId: 'session-pref-1',
+      userCurrency: 'USD',
+      userId: 'user-pref'
+    });
+
+    expect(savePreferenceResult.answer).toContain('Saved preference');
+    expect(redisStore.get('ai-agent-preferences-user-pref')).toContain('concise');
+
+    const recallPreferenceResult = await subject.chat({
+      languageCode: 'en',
+      query: 'What do you remember about me?',
+      sessionId: 'session-pref-2',
+      userCurrency: 'USD',
+      userId: 'user-pref'
+    });
+
+    expect(recallPreferenceResult.answer).toContain(
+      'Saved cross-session preferences'
+    );
+    expect(recallPreferenceResult.answer).toContain('response style: concise');
+  });
+
+  it('applies persisted response-style preferences to LLM prompt generation', async () => {
+    const redisStore = new Map<string, string>();
+    redisCacheService.get.mockImplementation(async (key: string) => {
+      return redisStore.get(key);
+    });
+    redisCacheService.set.mockImplementation(
+      async (key: string, value: string) => {
+        redisStore.set(key, value);
+      }
+    );
+    portfolioService.getDetails.mockResolvedValue({
+      holdings: {
+        AAPL: {
+          allocationInPercentage: 1,
+          dataSource: DataSource.YAHOO,
+          symbol: 'AAPL',
+          valueInBaseCurrency: 1000
+        }
+      }
+    });
+    const generateTextSpy = jest.spyOn(subject, 'generateText');
+    generateTextSpy.mockResolvedValue({
+      text: 'Portfolio concentration is high.'
+    } as never);
+
+    await subject.chat({
+      languageCode: 'en',
+      query: 'Keep responses concise.',
+      sessionId: 'session-pref-tools-1',
+      userCurrency: 'USD',
+      userId: 'user-pref-tools'
+    });
+
+    const result = await subject.chat({
+      languageCode: 'en',
+      query: 'Show my portfolio allocation',
+      sessionId: 'session-pref-tools-2',
+      userCurrency: 'USD',
+      userId: 'user-pref-tools'
+    });
+
+    expect(result.answer.length).toBeGreaterThan(0);
+    expect(generateTextSpy).toHaveBeenCalledWith(
+      expect.objectContaining({
+        prompt: expect.stringContaining(
+          'User preference: keep the response concise in 1-3 short sentences and avoid speculation.'
+        )
+      })
+    );
+  });
+
   it('runs rebalance and stress test tools for portfolio scenario prompts', async () => {
     portfolioService.getDetails.mockResolvedValue({
       holdings: {

apps/api/src/app/endpoints/ai/ai.service.ts

@@ -20,12 +20,17 @@ import {
 import {
   AI_AGENT_MEMORY_MAX_TURNS,
   buildAnswer,
+  createPreferenceSummaryResponse,
   getMemory,
+  getUserPreferences,
+  isPreferenceRecallQuery,
+  resolvePreferenceUpdate,
   resolveSymbols,
   runMarketDataLookup,
   runPortfolioAnalysis,
   runRiskAssessment,
-  setMemory
+  setMemory,
+  setUserPreferences
 } from './ai-agent.chat.helpers';
 import { addVerificationChecks } from './ai-agent.verification.helpers';
 import {
@@ -247,11 +252,17 @@ export class AiService {
 
     try {
       const memoryReadStartedAt = Date.now();
-      const memory = await getMemory({
+      const [memory, userPreferences] = await Promise.all([
+        getMemory({
           redisCacheService: this.redisCacheService,
           sessionId: resolvedSessionId,
           userId
-      });
+        }),
+        getUserPreferences({
+          redisCacheService: this.redisCacheService,
+          userId
+        })
+      ]);
       memoryReadInMs = Date.now() - memoryReadStartedAt;
 
       const plannedTools = determineToolPlan({
@@ -262,6 +273,11 @@ export class AiService {
         plannedTools,
         query: normalizedQuery
       });
+      const preferenceUpdate = resolvePreferenceUpdate({
+        query: normalizedQuery,
+        userPreferences
+      });
+      const effectiveUserPreferences = preferenceUpdate.userPreferences;
       const toolCalls: AiAgentToolCall[] = [];
       const citations: AiAgentChatResponse['citations'] = [];
       const verification: AiAgentChatResponse['verification'] = [];
@@ -438,6 +454,19 @@ export class AiService {
         query: normalizedQuery
       });
 
+      if (
+        policyDecision.route === 'direct' &&
+        policyDecision.blockReason === 'no_tool_query'
+      ) {
+        if (isPreferenceRecallQuery(normalizedQuery)) {
+          answer = createPreferenceSummaryResponse({
+            userPreferences: effectiveUserPreferences
+          });
+        } else if (preferenceUpdate.acknowledgement) {
+          answer = preferenceUpdate.acknowledgement;
+        }
+      }
+
       if (policyDecision.route === 'tools') {
         const llmGenerationStartedAt = Date.now();
         answer = await buildAnswer({
@@ -458,6 +487,7 @@ export class AiService {
           rebalancePlan,
           riskAssessment,
           stressTest,
+          userPreferences: effectiveUserPreferences,
           userCurrency
         });
         llmGenerationInMs = Date.now() - llmGenerationStartedAt;
@@ -525,6 +555,13 @@ export class AiService {
         sessionId: resolvedSessionId,
         userId
       });
+      if (preferenceUpdate.shouldPersist) {
+        await setUserPreferences({
+          redisCacheService: this.redisCacheService,
+          userId,
+          userPreferences: effectiveUserPreferences
+        });
+      }
       memoryWriteInMs = Date.now() - memoryWriteStartedAt;
 
       const response: AiAgentChatResponse = {

tasks/lessons.md

@@ -35,3 +35,7 @@ Updated: 2026-02-24
 8. Context: Open-source submission strategy after publish constraints
    Mistake: Treated npm publication as the only completion path for contribution evidence
    Rule: When package publication is blocked, ship the tool in-repo and open upstream PRs in high-signal repositories to preserve external contribution progress.
+
+9. Context: Memory feature validation after chat/session persistence rollout
+   Mistake: Session-scoped memory shipped without an explicit user-scoped preference path for cross-session continuity.
+   Rule: When memory requirements mention user preferences, implement and test both session memory and user-level memory keyed independently from session IDs.

tasks/tasks.md

@@ -216,6 +216,22 @@ Last updated: 2026-02-24
 - [x] Add/update unit tests for arithmetic direct replies and provider tracing/fallback behavior.
 - [x] Run focused verification (`test:ai` and `api:lint`) and update tracker notes.
 
+## Session Plan (2026-02-24, Cross-Session User Preference Memory)
+
+- [x] Add Redis-backed user preference storage keyed by `userId` (independent of `sessionId`).
+- [x] Parse explicit preference update prompts and persist preference changes across sessions.
+- [x] Apply persisted preference context to AI answer generation and direct-route responses where relevant.
+- [x] Add/update AI unit tests to verify cross-session preference continuity and deterministic behavior.
+- [x] Run focused verification (`test:ai`) and update tracker notes.
+
+## Session Plan (2026-02-24, Chat Details Popover UX)
+
+- [ ] Audit current AI chat response rendering and identify diagnostics shown inline.
+- [ ] Move diagnostics (confidence, citations, verification, observability) behind an info-triggered popover per assistant message.
+- [ ] Keep main assistant response focused on user-facing answer and retain feedback controls in primary view.
+- [ ] Update chat panel tests to assert info-trigger behavior and diagnostics visibility expectations.
+- [ ] Run focused frontend verification and update trackers (`Tasks.md`, `tasks/tasks.md`, `tasks/lessons.md`).
+
 ## Verification Notes
 
 - `nx run api:lint` completed successfully (existing workspace warnings only).
@@ -293,3 +309,6 @@ Last updated: 2026-02-24
   - `npx jest apps/api/src/app/endpoints/ai/ai-agent.utils.spec.ts apps/api/src/app/endpoints/ai/ai.service.spec.ts apps/api/src/app/endpoints/ai/ai-observability.service.spec.ts --config apps/api/jest.config.ts` (36/36 tests passed)
   - `npm run test:ai` (9/9 suites passed, 49/49 tests)
   - `npx nx run api:lint --verbose` (passes with existing workspace warnings)
+- Cross-session user preference memory verification (local, 2026-02-24):
+  - `npm run test:ai` (9/9 suites passed, 54/54 tests)
+  - `npx nx run api:lint` (passes with existing workspace warnings)