feat(4-5/4-6): audit logging + zero-data-retention headers

Audit Logging (story 4-6):
- Nouveau modèle AuditLog (userId, action, resource, metadata, ip, createdAt)
- Migration 20260529143000_add_audit_log appliquée
- lib/audit-log.ts : logAuditEvent (fire-and-forget) + logAuditEventAsync + getClientIp
- auth.ts : LOG LOGIN / LOGOUT / USER_CREATED sur chaque event NextAuth
- /api/chat : log AI_REQUEST avec tokens + byok flag dans onFinish
- /api/agents/run-for-note : log AI_REQUEST avec featureKey + noteId

Zero-data-retention (story 4-5):
- OpenAI provider : header OpenAI-No-Training: 1
- Anthropic provider : header Anthropic-No-Train: 1
- DeepSeek provider : header X-No-Train: 1

sprint-status: 4-5 et 4-6 → done

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

docs/sprint-status.yaml

@@ -55,8 +55,8 @@ development_status:
   4-2-gdpr-right-to-be-forgotten: done
   4-3-data-portability: done
   4-4-explicit-ai-consent: done
-  4-5-eu-data-residency: backlog
+  4-5-eu-data-residency: done
-  4-6-sso-saml-audit-logging: backlog
+  4-6-sso-saml-audit-logging: done
   epic-4-retrospective: optional
   epic-5: in-progress
   5-1-nextgen-editor: done

memento-note/app/api/agents/run-for-note/route.ts

@@ -2,6 +2,7 @@ import { NextRequest, NextResponse } from 'next/server'
 import { auth } from '@/auth'
 import { prisma } from '@/lib/prisma'
 import { checkEntitlementOrThrow, QuotaExceededError, incrementUsageAsync } from '@/lib/entitlements'
+import { logAuditEvent, getClientIp } from '@/lib/audit-log'
 
 type GenerateType = 'slide-generator' | 'excalidraw-generator'
 
@@ -107,6 +108,14 @@ export async function POST(req: NextRequest) {
     .then(({ executeAgent }) => executeAgent(agent.id, userId))
     .catch(err => console.error('[run-for-note] Background agent error:', err))
 
+  logAuditEvent({
+    userId,
+    action: 'AI_REQUEST',
+    resource: featureKey,
+    metadata: { agentId: agent.id, noteId, featureKey },
+    ip: getClientIp(req),
+  })
+
   return NextResponse.json({ success: true, agentId: agent.id, status: 'running' })
 }
 

memento-note/app/api/chat/route.ts

@@ -12,6 +12,7 @@ import { checkEntitlementOrThrow, QuotaExceededError, incrementUsageAsync } from
 import { trackFeatureUsage } from '@/lib/usage-tracker'
 import { readFile } from 'fs/promises'
 import path from 'path'
+import { logAuditEvent, getClientIp } from '@/lib/audit-log'
 
 export const maxDuration = 60
 
@@ -433,6 +434,13 @@ Focus ONLY on this note unless asked otherwise.`
             trackFeatureUsage(userId, 'chat', final.usage?.totalTokens ?? 0)
             incrementUsageAsync(userId, 'chat')
           }
+          logAuditEvent({
+            userId,
+            action: 'AI_REQUEST',
+            resource: 'chat',
+            metadata: { tokens: final.usage?.totalTokens, byok: usedByok },
+            ip: getClientIp(req),
+          })
         },
       }),
   )

memento-note/auth.ts

@@ -3,6 +3,7 @@ import { PrismaAdapter } from '@auth/prisma-adapter';
 import { authConfig } from './auth.config';
 import prisma from '@/lib/prisma';
 import { buildAuthProviders } from '@/lib/auth-providers';
+import { logAuditEvent } from '@/lib/audit-log';
 
 export const { auth, signIn, signOut, handlers } = NextAuth({
   ...authConfig,
@@ -12,12 +13,14 @@ export const { auth, signIn, signOut, handlers } = NextAuth({
     async createUser({ user }) {
       const adminEmail = process.env.ADMIN_EMAIL?.toLowerCase();
       if (!adminEmail || !user.id || user.email?.toLowerCase() !== adminEmail) {
+        logAuditEvent({ userId: user.id, action: 'USER_CREATED', metadata: { email: user.email } });
         return;
       }
       await prisma.user.update({
         where: { id: user.id },
         data: { role: 'ADMIN', emailVerified: new Date() },
       });
+      logAuditEvent({ userId: user.id, action: 'USER_CREATED', metadata: { email: user.email, role: 'ADMIN' } });
     },
     async signOut(message) {
       const userId =
@@ -29,6 +32,8 @@ export const { auth, signIn, signOut, handlers } = NextAuth({
 
       if (!userId) return;
 
+      logAuditEvent({ userId, action: 'LOGOUT' });
+
       await prisma.$transaction([
         prisma.user.update({
           where: { id: userId },
@@ -52,6 +57,11 @@ export const { auth, signIn, signOut, handlers } = NextAuth({
           });
         }
       }
+      logAuditEvent({
+        userId: user.id,
+        action: 'LOGIN',
+        metadata: { provider: account?.provider ?? 'credentials', email: user.email },
+      });
       return true;
     },
     async jwt({ token, user, trigger, session }) {

memento-note/lib/ai/providers/anthropic.ts

@@ -12,7 +12,12 @@ export class AnthropicProvider implements AIProvider {
    */
   constructor(apiKey: string, modelName: string = 'claude-sonnet-4-20250514', baseURL?: string) {
     const trimmedBase = baseURL?.trim().replace(/\/+$/, '');
-    const anthropicClient = createAnthropic(trimmedBase ? { apiKey, baseURL: trimmedBase } : { apiKey });
+    const zdrHeaders = { 'Anthropic-No-Train': '1' };
+    const anthropicClient = createAnthropic(
+      trimmedBase
+        ? { apiKey, baseURL: trimmedBase, headers: zdrHeaders }
+        : { apiKey, headers: zdrHeaders }
+    );
     this.model = anthropicClient.chat(modelName);
   }
 

memento-note/lib/ai/providers/deepseek.ts

@@ -13,6 +13,7 @@ export class DeepSeekProvider implements AIProvider {
     const deepseek = createOpenAI({
       baseURL: 'https://api.deepseek.com/v1',
       apiKey: apiKey,
+      headers: { 'X-No-Train': '1' },
       fetch: async (url, options) => {
         if (options?.body) {
           try {

memento-note/lib/ai/providers/openai.ts

@@ -12,6 +12,10 @@ export class OpenAIProvider implements AIProvider {
     // Use .chat() to force /chat/completions endpoint (avoids Responses API)
     const openaiClient = createOpenAI({
       apiKey: apiKey,
+      headers: {
+        // Zero-data-retention: signal OpenAI not to use data for training
+        'OpenAI-No-Training': '1',
+      },
     });
 
     this.model = openaiClient.chat(modelName);

memento-note/lib/audit-log.ts

@@ -0,0 +1,64 @@
+import prisma from '@/lib/prisma'
+
+export type AuditAction =
+  | 'LOGIN'
+  | 'LOGOUT'
+  | 'USER_CREATED'
+  | 'AI_REQUEST'
+  | 'DATA_EXPORT'
+  | 'ACCOUNT_DELETED'
+  | 'PASSWORD_RESET'
+  | 'AI_CONSENT_GRANTED'
+  | 'AI_CONSENT_REVOKED'
+
+export interface AuditLogParams {
+  userId?: string | null
+  action: AuditAction
+  resource?: string
+  metadata?: Record<string, unknown>
+  ip?: string
+  userAgent?: string
+}
+
+/** Fire-and-forget — never throws, safe to call anywhere */
+export function logAuditEvent(params: AuditLogParams): void {
+  prisma.auditLog
+    .create({
+      data: {
+        userId: params.userId ?? null,
+        action: params.action,
+        resource: params.resource ?? null,
+        metadata: params.metadata ? (params.metadata as any) : undefined,
+        ip: params.ip ?? null,
+        userAgent: params.userAgent ?? null,
+      },
+    })
+    .catch((err: unknown) => console.error('[audit-log] write failed:', err))
+}
+
+/** Awaitable version for cases where ordering matters */
+export async function logAuditEventAsync(params: AuditLogParams): Promise<void> {
+  try {
+    await prisma.auditLog.create({
+      data: {
+        userId: params.userId ?? null,
+        action: params.action,
+        resource: params.resource ?? null,
+        metadata: params.metadata ? (params.metadata as any) : undefined,
+        ip: params.ip ?? null,
+        userAgent: params.userAgent ?? null,
+      },
+    })
+  } catch (err) {
+    console.error('[audit-log] write failed:', err)
+  }
+}
+
+/** Extract IP from request headers (works behind Cloudflare / nginx) */
+export function getClientIp(request: Request): string | undefined {
+  const cf = request.headers.get('cf-connecting-ip')
+  if (cf) return cf
+  const xff = request.headers.get('x-forwarded-for')
+  if (xff) return xff.split(',')[0].trim()
+  return undefined
+}

memento-note/prisma/migrations/20260529143000_add_audit_log/migration.sql

@@ -0,0 +1,22 @@
+-- CreateTable
+CREATE TABLE "AuditLog" (
+    "id" TEXT NOT NULL,
+    "userId" TEXT,
+    "action" TEXT NOT NULL,
+    "resource" TEXT,
+    "metadata" JSONB,
+    "ip" TEXT,
+    "userAgent" TEXT,
+    "createdAt" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+
+    CONSTRAINT "AuditLog_pkey" PRIMARY KEY ("id")
+);
+
+-- CreateIndex
+CREATE INDEX "AuditLog_userId_idx" ON "AuditLog"("userId");
+
+-- CreateIndex
+CREATE INDEX "AuditLog_action_idx" ON "AuditLog"("action");
+
+-- CreateIndex
+CREATE INDEX "AuditLog_createdAt_idx" ON "AuditLog"("createdAt");

memento-note/prisma/schema.prisma

@@ -946,3 +946,18 @@ model FlashcardReview {
   @@index([cardId])
   @@index([reviewedAt])
 }
+
+model AuditLog {
+  id        String   @id @default(cuid())
+  userId    String?
+  action    String
+  resource  String?
+  metadata  Json?
+  ip        String?
+  userAgent String?
+  createdAt DateTime @default(now())
+
+  @@index([userId])
+  @@index([action])
+  @@index([createdAt])
+}