feat(auth): migrate anonymous consent on signUp when cc_consent cookie present

Adds ConsentFactoryProtocol / ConsentGrantMeta / ConsentProtocol to
core-shared/di/bind-protocols so feature binders can wire per-user
consent without a hard dep on the optional @repo/core-consent package.
BindContext gains an optional consentFactory? field following the same
pattern as bus?, auditLog?, etc.

signUpUseCase gains a 4th optional dep (consentFactory). When present
and the input includes a cookieHeader containing cc_consent=<categories>,
the use case calls consent.grant for each category with
method:"signup-migration" and returns a clearCookie payload (Max-Age:0)
so the anonymous cookie is cleared on the HTTP response.

Tests use RecordingConsent from @repo/core-testing to assert migration
call shape and cookie-clear; no-cookie and no-factory branches are also
covered. All coverage bands hold at 100% for use-cases.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

coverage/summary.json

@@ -1,33 +1,33 @@
 {
-  "generatedAt": "2026-05-19T21:36:08.521Z",
-  "commit": "cbe7412",
+  "generatedAt": "2026-05-19T21:51:40.371Z",
+  "commit": "5151454",
   "repo": {
     "statements": 97.38,
-    "branches": 92.08,
-    "functions": 97.09,
+    "branches": 92.19,
+    "functions": 97.1,
     "lines": 97.38,
     "counts": {
-      "lf": 5758,
-      "lh": 5607,
-      "brf": 1149,
-      "brh": 1058,
-      "fnf": 344,
-      "fnh": 334
+      "lf": 5801,
+      "lh": 5649,
+      "brf": 1165,
+      "brh": 1074,
+      "fnf": 345,
+      "fnh": 335
     }
   },
   "byPackage": {
     "@repo/auth": {
-      "statements": 93.81,
-      "branches": 90.82,
+      "statements": 94,
+      "branches": 92.11,
       "functions": 100,
-      "lines": 93.81,
+      "lines": 94,
       "counts": {
-        "lf": 791,
-        "lh": 742,
-        "brf": 98,
-        "brh": 89,
-        "fnf": 44,
-        "fnh": 44
+        "lf": 834,
+        "lh": 784,
+        "brf": 114,
+        "brh": 105,
+        "fnf": 45,
+        "fnh": 45
       }
     },
     "@repo/blog": {

packages/auth/src/application/use-cases/sign-up.use-case.test.ts

@@ -1,6 +1,9 @@
 import { describe, it, expect } from "vitest";
 import { ZodError } from "zod";
-import { RecordingEventBus } from "@repo/core-testing/instrumentation";
+import {
+  RecordingEventBus,
+  RecordingConsent,
+} from "@repo/core-testing/instrumentation";
 import {
   signUpUseCase,
   signUpOutputSchema,
@@ -16,7 +19,7 @@ describe("signUpUseCase", () => {
     const users = new MockUsersRepository([]);
     const auth = new MockAuthenticationService(users);
     const bus = new RecordingEventBus();
-    const useCase = signUpUseCase(users, auth, bus);
+    const useCase = signUpUseCase(users, auth, bus, undefined);
 
     const result = await useCase({
       username: "carol",
@@ -34,7 +37,7 @@ describe("signUpUseCase", () => {
     const bus = new RecordingEventBus();
     await users.createUser(userFactory.build({ username: "alice" }));
 
-    const useCase = signUpUseCase(users, auth, bus);
+    const useCase = signUpUseCase(users, auth, bus, undefined);
     await expect(
       useCase({
         username: "alice",
@@ -48,7 +51,7 @@ describe("signUpUseCase", () => {
     const users = new MockUsersRepository([]);
     const auth = new MockAuthenticationService(users);
     const bus = new RecordingEventBus();
-    const useCase = signUpUseCase(users, auth, bus);
+    const useCase = signUpUseCase(users, auth, bus, undefined);
 
     await useCase({
       username: "dave",
@@ -70,7 +73,7 @@ describe("signUpUseCase", () => {
   it("works without an event bus (welcome email skipped silently)", async () => {
     const users = new MockUsersRepository([]);
     const auth = new MockAuthenticationService(users);
-    const useCase = signUpUseCase(users, auth, undefined);
+    const useCase = signUpUseCase(users, auth, undefined, undefined);
 
     const result = await useCase({
       username: "frank",
@@ -88,7 +91,7 @@ describe("signUpUseCase", () => {
     const bus = new RecordingEventBus();
     await users.createUser(userFactory.build({ username: "eve" }));
 
-    const useCase = signUpUseCase(users, auth, bus);
+    const useCase = signUpUseCase(users, auth, bus, undefined);
     await expect(
       useCase({
         username: "eve",
@@ -98,6 +101,108 @@ describe("signUpUseCase", () => {
     ).rejects.toBeInstanceOf(AuthenticationError);
     expect(bus.published).toHaveLength(0);
   });
+
+  it("migrates anonymous consent when cc_consent cookie is present", async () => {
+    const users = new MockUsersRepository([]);
+    const auth = new MockAuthenticationService(users);
+    const bus = new RecordingEventBus();
+    const consent = new RecordingConsent();
+    const consentFactory = (_userId: string) => Promise.resolve(consent);
+    const useCase = signUpUseCase(users, auth, bus, consentFactory);
+
+    const result = await useCase({
+      username: "grace",
+      password: "secret_password",
+      confirmPassword: "secret_password",
+      cookieHeader: "cc_consent=necessary,analytics; session=xyz",
+    });
+
+    expect(consent.grants).toHaveLength(2);
+    expect(consent.grants[0]).toEqual({
+      category: "necessary",
+      meta: { method: "signup-migration" },
+    });
+    expect(consent.grants[1]).toEqual({
+      category: "analytics",
+      meta: { method: "signup-migration" },
+    });
+    expect(result.clearCookie).toBeDefined();
+    expect(result.clearCookie?.name).toBe("cc_consent");
+    expect(result.clearCookie?.attributes.maxAge).toBe(0);
+  });
+
+  it("does not migrate consent when no cc_consent cookie is present", async () => {
+    const users = new MockUsersRepository([]);
+    const auth = new MockAuthenticationService(users);
+    const bus = new RecordingEventBus();
+    const consent = new RecordingConsent();
+    const consentFactory = (_userId: string) => Promise.resolve(consent);
+    const useCase = signUpUseCase(users, auth, bus, consentFactory);
+
+    const result = await useCase({
+      username: "henry",
+      password: "secret_password",
+      confirmPassword: "secret_password",
+      cookieHeader: "session=xyz",
+    });
+
+    expect(consent.grants).toHaveLength(0);
+    expect(result.clearCookie).toBeUndefined();
+  });
+
+  it("does not migrate consent when consentFactory is absent", async () => {
+    const users = new MockUsersRepository([]);
+    const auth = new MockAuthenticationService(users);
+    const bus = new RecordingEventBus();
+    const useCase = signUpUseCase(users, auth, bus, undefined);
+
+    const result = await useCase({
+      username: "iris",
+      password: "secret_password",
+      confirmPassword: "secret_password",
+      cookieHeader: "cc_consent=analytics",
+    });
+
+    expect(result.clearCookie).toBeUndefined();
+  });
+
+  it("does not migrate consent when cc_consent cookie has no value", async () => {
+    const users = new MockUsersRepository([]);
+    const auth = new MockAuthenticationService(users);
+    const bus = new RecordingEventBus();
+    const consent = new RecordingConsent();
+    const consentFactory = (_userId: string) => Promise.resolve(consent);
+    const useCase = signUpUseCase(users, auth, bus, consentFactory);
+
+    const result = await useCase({
+      username: "jake",
+      password: "secret_password",
+      confirmPassword: "secret_password",
+      cookieHeader: "cc_consent=",
+    });
+
+    expect(consent.grants).toHaveLength(0);
+    expect(result.clearCookie).toBeUndefined();
+  });
+
+  it("parses cookie header with malformed parts (no = sign)", async () => {
+    const users = new MockUsersRepository([]);
+    const auth = new MockAuthenticationService(users);
+    const bus = new RecordingEventBus();
+    const consent = new RecordingConsent();
+    const consentFactory = (_userId: string) => Promise.resolve(consent);
+    const useCase = signUpUseCase(users, auth, bus, consentFactory);
+
+    const result = await useCase({
+      username: "kate",
+      password: "secret_password",
+      confirmPassword: "secret_password",
+      cookieHeader: "malformedcookie; cc_consent=necessary",
+    });
+
+    expect(consent.grants).toHaveLength(1);
+    expect(result.clearCookie).toBeDefined();
+  });
 });
 
 describe("signUpUseCase output validation", () => {
@@ -112,7 +217,7 @@ describe("signUpUseCase output validation", () => {
     } as unknown as IAuthenticationService;
 
     const bus = new RecordingEventBus();
-    const useCase = signUpUseCase(users, auth, bus);
+    const useCase = signUpUseCase(users, auth, bus, undefined);
     await expect(
       useCase({
         username: "carol",

packages/auth/src/application/use-cases/sign-up.use-case.ts

@@ -1,6 +1,9 @@
 import { z } from "zod";
 
-import type { EventBusProtocol } from "@repo/core-shared/di";
+import type {
+  EventBusProtocol,
+  ConsentFactoryProtocol,
+} from "@repo/core-shared/di";
 import { userSignedUpEvent } from "../../events/user-signed-up.event";
 import { AuthenticationError } from "../../entities/errors/auth";
 import { cookieSchema } from "../../entities/models/cookie";
@@ -8,12 +11,32 @@ import { sessionSchema } from "../../entities/models/session";
 import type { IUsersRepository } from "../repositories/users.repository.interface";
 import type { IAuthenticationService } from "../services/authentication.service.interface";
 
+// Cookie name written by the anonymous consent banner (mirrors CONSENT_COOKIE_NAME in @repo/core-consent).
+const ANONYMOUS_CONSENT_COOKIE = "cc_consent";
+
+function extractConsentFromCookieHeader(cookieHeader: string): string[] | null {
+  for (const part of cookieHeader.split(";")) {
+    const eqIdx = part.indexOf("=");
+    if (eqIdx === -1) continue;
+    const name = part.slice(0, eqIdx).trim();
+    if (name !== ANONYMOUS_CONSENT_COOKIE) continue;
+    const value = part.slice(eqIdx + 1).trim();
+    const cats = value
+      .split(",")
+      .map((c) => c.trim())
+      .filter(Boolean);
+    return cats.length > 0 ? cats : null;
+  }
+  return null;
+}
+
 // ── Input ────────────────────────────────────────────────────────────────
 export const signUpInputSchema = z
   .object({
     username: z.string().min(3).max(31),
     password: z.string().min(6).max(255),
     confirmPassword: z.string().min(6).max(255),
+    cookieHeader: z.string().optional(),
   })
   .strict()
   .refine((d) => d.password === d.confirmPassword, {
@@ -26,6 +49,7 @@ export type SignUpInput = z.infer<typeof signUpInputSchema>;
 export const signUpOutputSchema = z.object({
   session: sessionSchema,
   cookie: cookieSchema,
+  clearCookie: cookieSchema.optional(),
 });
 export type SignUpOutput = z.infer<typeof signUpOutputSchema>;
 
@@ -37,6 +61,7 @@ export const signUpUseCase =
     usersRepository: IUsersRepository,
     authenticationService: IAuthenticationService,
     bus: EventBusProtocol | undefined,
+    consentFactory: ConsentFactoryProtocol | undefined,
   ) =>
   async (input: SignUpInput): Promise<SignUpOutput> => {
     const existingUser = await usersRepository.getUserByUsername(
@@ -71,5 +96,24 @@ export const signUpUseCase =
       });
     }
 
-    return signUpOutputSchema.parse({ session, cookie });
+    // Migrate anonymous consent when both a cookie header and a consent factory
+    // are present. consentFactory is optional: absent when core-consent is not wired.
+    const cookieState = input.cookieHeader
+      ? extractConsentFromCookieHeader(input.cookieHeader)
+      : null;
+
+    let clearCookie: z.infer<typeof cookieSchema> | undefined;
+    if (cookieState && consentFactory) {
+      const consent = await consentFactory(newUser.id);
+      for (const category of cookieState) {
+        await consent.grant(category, { method: "signup-migration" });
+      }
+      clearCookie = {
+        name: ANONYMOUS_CONSENT_COOKIE,
+        value: "",
+        attributes: { maxAge: 0, path: "/" },
+      };
+    }
+
+    return signUpOutputSchema.parse({ session, cookie, clearCookie });
   };

packages/auth/src/di/bind-dev-seed.ts

@@ -38,7 +38,15 @@ import type { IAuthenticationService } from "../application/services/authenticat
  * populated repo and rebinds the symbol.
  */
 export async function bindDevSeedAuth(ctx: BindContext): Promise<void> {
-  const { tracer, logger, bus, queue, realtime, realtimeRegistry } = ctx;
+  const {
+    tracer,
+    logger,
+    bus,
+    queue,
+    realtime,
+    realtimeRegistry,
+    consentFactory,
+  } = ctx;
 
   // Bind shared instrumentation into feature container
   if (authContainer.isBound(INSTRUMENTATION_SYMBOLS.TRACER)) {
@@ -88,7 +96,7 @@ export async function bindDevSeedAuth(ctx: BindContext): Promise<void> {
     container: authContainer,
     symbol: AUTH_SYMBOLS.ISignUpUseCase,
     factory: signUpUseCase,
-    deps: [repo, authService, bus],
+    deps: [repo, authService, bus, consentFactory],
     feature: "auth",
     layer: "use-case",
     name: "signUp",

packages/auth/src/di/bind-production.ts

@@ -30,8 +30,16 @@ export function bindProductionAuth(ctx: BindProductionContext): void {
   if (bound) return;
   bound = true;
 
-  const { config, tracer, logger, bus, queue, realtime, realtimeRegistry } =
-    ctx;
+  const {
+    config,
+    tracer,
+    logger,
+    bus,
+    queue,
+    realtime,
+    realtimeRegistry,
+    consentFactory,
+  } = ctx;
 
   // Bind shared instrumentation into feature container
   if (authContainer.isBound(INSTRUMENTATION_SYMBOLS.TRACER)) {
@@ -80,7 +88,7 @@ export function bindProductionAuth(ctx: BindProductionContext): void {
     container: authContainer,
     symbol: AUTH_SYMBOLS.ISignUpUseCase,
     factory: signUpUseCase,
-    deps: [repo, authService, bus],
+    deps: [repo, authService, bus, consentFactory],
     feature: "auth",
     layer: "use-case",
     name: "signUp",

packages/auth/src/di/module.ts

@@ -39,7 +39,9 @@ export const AuthModule = new ContainerModule((bind: interfaces.Bind) => {
   bind<ISignInUseCase>(AUTH_SYMBOLS.ISignInUseCase).toDynamicValue((ctx) =>
     signInUseCase(
       ctx.container.get<IUsersRepository>(AUTH_SYMBOLS.IUsersRepository),
-      ctx.container.get<IAuthenticationService>(AUTH_SYMBOLS.IAuthenticationService),
+      ctx.container.get<IAuthenticationService>(
+        AUTH_SYMBOLS.IAuthenticationService,
+      ),
     ),
   );
 
@@ -49,32 +51,40 @@ export const AuthModule = new ContainerModule((bind: interfaces.Bind) => {
     // bus instance when @repo/core-events is scaffolded.
     signUpUseCase(
       ctx.container.get<IUsersRepository>(AUTH_SYMBOLS.IUsersRepository),
-      ctx.container.get<IAuthenticationService>(AUTH_SYMBOLS.IAuthenticationService),
+      ctx.container.get<IAuthenticationService>(
+        AUTH_SYMBOLS.IAuthenticationService,
+      ),
+      undefined,
       undefined,
     ),
   );
 
   bind<ISignOutUseCase>(AUTH_SYMBOLS.ISignOutUseCase).toDynamicValue((ctx) =>
     signOutUseCase(
-      ctx.container.get<IAuthenticationService>(AUTH_SYMBOLS.IAuthenticationService),
+      ctx.container.get<IAuthenticationService>(
+        AUTH_SYMBOLS.IAuthenticationService,
+      ),
     ),
   );
 
-  bind<ISignInController>(AUTH_SYMBOLS.ISignInController).toDynamicValue((ctx) =>
-    signInController(
-      ctx.container.get<ISignInUseCase>(AUTH_SYMBOLS.ISignInUseCase),
-    ),
+  bind<ISignInController>(AUTH_SYMBOLS.ISignInController).toDynamicValue(
+    (ctx) =>
+      signInController(
+        ctx.container.get<ISignInUseCase>(AUTH_SYMBOLS.ISignInUseCase),
+      ),
   );
 
-  bind<ISignUpController>(AUTH_SYMBOLS.ISignUpController).toDynamicValue((ctx) =>
-    signUpController(
-      ctx.container.get<ISignUpUseCase>(AUTH_SYMBOLS.ISignUpUseCase),
-    ),
+  bind<ISignUpController>(AUTH_SYMBOLS.ISignUpController).toDynamicValue(
+    (ctx) =>
+      signUpController(
+        ctx.container.get<ISignUpUseCase>(AUTH_SYMBOLS.ISignUpUseCase),
+      ),
   );
 
-  bind<ISignOutController>(AUTH_SYMBOLS.ISignOutController).toDynamicValue((ctx) =>
-    signOutController(
-      ctx.container.get<ISignOutUseCase>(AUTH_SYMBOLS.ISignOutUseCase),
-    ),
+  bind<ISignOutController>(AUTH_SYMBOLS.ISignOutController).toDynamicValue(
+    (ctx) =>
+      signOutController(
+        ctx.container.get<ISignOutUseCase>(AUTH_SYMBOLS.ISignOutUseCase),
+      ),
   );
 });

packages/auth/src/interface-adapters/controllers/sign-up.controller.test.ts

@@ -11,7 +11,12 @@ describe("signUpController", () => {
   it("returns a cookie on successful sign-up", async () => {
     const users = new MockUsersRepository([]);
     const auth = new MockAuthenticationService(users);
-    const useCase = signUpUseCase(users, auth, new RecordingEventBus());
+    const useCase = signUpUseCase(
+      users,
+      auth,
+      new RecordingEventBus(),
+      undefined,
+    );
     const controller = signUpController(useCase);
 
     const result = await controller({
@@ -26,7 +31,12 @@ describe("signUpController", () => {
   it("throws InputParseError when passwords do not match", async () => {
     const users = new MockUsersRepository([]);
     const auth = new MockAuthenticationService(users);
-    const useCase = signUpUseCase(users, auth, new RecordingEventBus());
+    const useCase = signUpUseCase(
+      users,
+      auth,
+      new RecordingEventBus(),
+      undefined,
+    );
     const controller = signUpController(useCase);
 
     await expect(
@@ -42,11 +52,20 @@ describe("signUpController", () => {
     const users = new MockUsersRepository([]);
     const auth = new MockAuthenticationService(users);
     await users.createUser(userFactory.build({ username: "alice" }));
-    const useCase = signUpUseCase(users, auth, new RecordingEventBus());
+    const useCase = signUpUseCase(
+      users,
+      auth,
+      new RecordingEventBus(),
+      undefined,
+    );
     const controller = signUpController(useCase);
 
     await expect(
-      controller({ username: "ab", password: "secret_password", confirmPassword: "secret_password" }),
+      controller({
+        username: "ab",
+        password: "secret_password",
+        confirmPassword: "secret_password",
+      }),
     ).rejects.toBeInstanceOf(InputParseError);
   });
 });

packages/auth/tests/sign-in-flow.feature.test.ts

@@ -19,7 +19,9 @@ describe("auth feature: sign-up → sign-in → sign-out", () => {
     const auth = new MockAuthenticationService(users);
 
     const signIn = signInController(signInUseCase(users, auth));
-    const signUp = signUpController(signUpUseCase(users, auth, new RecordingEventBus()));
+    const signUp = signUpController(
+      signUpUseCase(users, auth, new RecordingEventBus(), undefined),
+    );
     const signOut = signOutController(signOutUseCase(auth));
 
     // signUp returns a cookie (presenter shape)

packages/core-shared/src/di/bind-context.ts

@@ -8,6 +8,7 @@ import type {
   MetricsProtocol,
   AuditLogProtocol,
   AnalyticsProtocol,
+  ConsentFactoryProtocol,
 } from "./bind-protocols";
 
 /** Always-present fields. Feature binders rely on these unconditionally. */
@@ -43,6 +44,7 @@ export type BindContext<
   metrics?: Metrics;
   auditLog?: Audit;
   analytics?: Analytics;
+  consentFactory?: ConsentFactoryProtocol;
 };
 
 /** Production binders also receive the resolved Payload config. */

packages/core-shared/src/di/bind-protocols.ts

@@ -80,3 +80,23 @@ export type AnalyticsProtocol = {
     attributes?: Record<string, string | number | boolean>,
   ): void;
 };
+
+/**
+ * Minimal consent protocol surface. `IConsent` (in optional `@repo/core-consent`)
+ * extends this — typechecks fail if narrowed below. Feature binders that
+ * receive `ctx.consentFactory` see only this protocol type.
+ */
+export type ConsentGrantMeta = {
+  method?: string;
+  bannerVersion?: string;
+  policyVersion?: string;
+};
+
+export type ConsentProtocol = {
+  grant(category: string, meta?: ConsentGrantMeta): Promise<void>;
+};
+
+/** Factory that creates a per-user consent instance. Mirrors ConsentFactory in `@repo/core-consent`. */
+export type ConsentFactoryProtocol = (
+  userId: string,
+) => Promise<ConsentProtocol>;