.gitignore

@@ -31,6 +31,10 @@ pnpm-debug.log*
 *.pem
 *.key
 
+# Tenant-private Entra group GUIDs per ADR-0025 (commit only the .example.json)
+infra/*-tenant.entra.json
+!infra/*-tenant.entra.example.json
+
 # OS / editor scrap
 .DS_Store
 Thumbs.db

apps/portal-bff/.env.example

@@ -72,6 +72,18 @@ ENTRA_POST_LOGOUT_REDIRECT_URI=http://localhost:4200/
 ENTRA_ADMIN_REDIRECT_URI=http://localhost:3000/api/admin/auth/callback
 ENTRA_ADMIN_POST_LOGOUT_REDIRECT_URI=http://localhost:4300/
 
+# Authorization model (per ADR-0025). Points at the JSON file that
+# maps tenant-private Entra security-group GUIDs to the closed
+# catalogue of `apf-role-*` slugs. The BFF loads it at boot through
+# `EntraGroupToRoleResolver` (libs/shared/auth). Unset means the
+# resolver runs empty — sign-in still succeeds but every user gets
+# zero functional roles (no `apf-role-*` UI). A WARN is logged at
+# boot so an operator can spot the missing config. See
+# `infra/test-tenant.entra.example.json` for the schema; copy to
+# `infra/test-tenant.entra.json` (gitignored) and fill in the real
+# GUIDs from the Entra admin centre.
+ENTRA_GROUP_MAP_PATH=infra/test-tenant.entra.json
+
 # Cookie signing secret (per ADR-0009 §"Cookies"). Used to sign the
 # transient pre-auth cookie that carries the OIDC `state` + PKCE
 # verifier between the /auth/login redirect and the /auth/callback

apps/portal-bff/src/auth/auth.controller.spec.ts

@@ -150,11 +150,30 @@ function makeController(opts?: { completeAuthCodeFlow?: jest.Mock }): Controller
   // Real SessionEstablisher with the same mocks the legacy tests
   // already wire — keeps the behavioural assertions on session
   // fields / audit calls untouched after the controller refactor.
+  const principalBuilder = {
+    // The auth.controller specs do not assert on the principal
+    // shape; the resolved value just has to be a valid `Principal`
+    // so SessionEstablisher persists it without throwing.
+    build: jest.fn().mockResolvedValue({
+      user: {
+        id: 'oid',
+        personId: 'oid',
+        entraOid: 'oid',
+        tenantId: 'tid',
+        displayName: 'Jane',
+      },
+      privileges: [],
+      roles: [],
+      scopes: [{ kind: 'unrestricted' }],
+      amr: [],
+    }),
+  };
   const sessionEstablisher = new SessionEstablisher(
     logger as unknown as Logger,
     userSessionIndex as unknown as UserSessionIndexService,
     audit as unknown as AuditWriter,
     userDirectory as unknown as UserDirectoryService,
+    principalBuilder as unknown as import('./principal-builder').PrincipalBuilder,
   );
   return {
     controller: new AuthController(

apps/portal-bff/src/auth/auth.module.ts

@@ -2,12 +2,16 @@ import { ConfidentialClientApplication, LogLevel } from '@azure/msal-node';
 import { Module } from '@nestjs/common';
 import { Logger } from 'nestjs-pino';
 import { assertEntraConfig } from '../config/check-entra-config';
+import { loadEntraGroupToRoleResolver } from '../config/load-entra-group-map';
 import { SessionModule } from '../session/session.module';
 import { AuthController } from './auth.controller';
 import { AuthService } from './auth.service';
 import { ENTRA_CONFIG, type EntraConfig } from './entra-config.token';
+import { ENTRA_GROUP_TO_ROLE_RESOLVER } from './entra-group-to-role.token';
 import { MSAL_CLIENT } from './msal-client.token';
+import { PrincipalBuilder } from './principal-builder';
 import { RequireMfaGuard } from './require-mfa.guard';
+import { ScopeResolver, StubScopeResolver } from './scope-resolver';
 import { SessionEstablisher } from './session-establisher.service';
 
 /**
@@ -47,10 +51,35 @@ import { SessionEstablisher } from './session-establisher.service';
     AuthService,
     RequireMfaGuard,
     SessionEstablisher,
+    PrincipalBuilder,
+    { provide: ScopeResolver, useClass: StubScopeResolver },
     {
       provide: ENTRA_CONFIG,
       useFactory: () => assertEntraConfig(),
     },
+    {
+      provide: ENTRA_GROUP_TO_ROLE_RESOLVER,
+      inject: [Logger],
+      useFactory: (logger: Logger) => {
+        const { resolver, sourcePath } = loadEntraGroupToRoleResolver({
+          onWarn: (event, payload) => logger.warn({ event, ...payload }, 'AuthModule'),
+        });
+        // Log the post-load summary unconditionally so an operator
+        // grepping the boot log can confirm how many functional
+        // roles are wired without inspecting the JSON file. The
+        // file path (if any) helps diagnose env-var / cwd mismatches.
+        logger.log(
+          {
+            event: 'auth.entra_group_map_loaded',
+            sourcePath,
+            mappingCount: resolver.size,
+            coveredRoles: resolver.coveredRoles(),
+          },
+          'AuthModule',
+        );
+        return resolver;
+      },
+    },
     {
       provide: MSAL_CLIENT,
       inject: [ENTRA_CONFIG, Logger],
@@ -92,6 +121,15 @@ import { SessionEstablisher } from './session-establisher.service';
         }),
     },
   ],
-  exports: [ENTRA_CONFIG, MSAL_CLIENT, RequireMfaGuard, AuthService, SessionEstablisher],
+  exports: [
+    ENTRA_CONFIG,
+    ENTRA_GROUP_TO_ROLE_RESOLVER,
+    MSAL_CLIENT,
+    RequireMfaGuard,
+    AuthService,
+    PrincipalBuilder,
+    ScopeResolver,
+    SessionEstablisher,
+  ],
 })
 export class AuthModule {}

apps/portal-bff/src/auth/auth.service.spec.ts

@@ -38,6 +38,7 @@ function makeAuthResult(
   claims: Partial<{
     amr: string[];
     roles: unknown;
+    groups: unknown;
     oid: string;
     tid: string;
     name: string;
@@ -58,6 +59,12 @@ function makeAuthResult(
   if (Object.prototype.hasOwnProperty.call(claims, 'roles')) {
     idTokenClaims['roles'] = claims.roles;
   }
+  // Same opt-in pattern for `groups` — Entra emits it only when
+  // the app registration sets `groupMembershipClaims: 'SecurityGroup'`
+  // and the user is in at least one group.
+  if (Object.prototype.hasOwnProperty.call(claims, 'groups')) {
+    idTokenClaims['groups'] = claims.groups;
+  }
   return {
     idTokenClaims,
     account: { username: 'jane.doe@apf.example', name: 'Jane Doe' },
@@ -124,6 +131,7 @@ describe('AuthService.completeAuthCodeFlow', () => {
       displayName: 'Jane Doe',
       amr: ['pwd', 'mfa'],
       roles: [],
+      groups: [],
     });
   });
 
@@ -220,6 +228,80 @@ describe('AuthService.completeAuthCodeFlow', () => {
     expect(user.roles).toEqual(['admin', 'editor']);
   });
 
+  // `groups` claim — extracted identically to `roles`. The raw
+  // GUIDs are surfaced here; resolution to `apf-role-*` slugs
+  // happens downstream in `PrincipalBuilder` per ADR-0025.
+  it('surfaces the `groups` claim when Entra includes it (security-group member)', async () => {
+    const acquireTokenByCode = jest.fn().mockResolvedValue(
+      makeAuthResult({
+        groups: ['11111111-1111-1111-1111-111111111111', '22222222-2222-2222-2222-222222222222'],
+      }),
+    );
+    const { service } = makeService({ acquireTokenByCode });
+    const user = await service.completeAuthCodeFlow(
+      'code',
+      PRE_AUTH_OK.state,
+      PRE_AUTH_OK,
+      ENTRA.redirectUri,
+      PRE_AUTH_OK.createdAt,
+    );
+    expect(user.groups).toEqual([
+      '11111111-1111-1111-1111-111111111111',
+      '22222222-2222-2222-2222-222222222222',
+    ]);
+  });
+
+  it('returns an empty `groups` array when the claim is absent (no group membership)', async () => {
+    const acquireTokenByCode = jest.fn().mockResolvedValue(makeAuthResult({}));
+    const { service } = makeService({ acquireTokenByCode });
+    const user = await service.completeAuthCodeFlow(
+      'code',
+      PRE_AUTH_OK.state,
+      PRE_AUTH_OK,
+      ENTRA.redirectUri,
+      PRE_AUTH_OK.createdAt,
+    );
+    expect(user.groups).toEqual([]);
+  });
+
+  it('returns an empty `groups` array when the claim is non-array (defensive)', async () => {
+    const acquireTokenByCode = jest.fn().mockResolvedValue(makeAuthResult({ groups: 'oops' }));
+    const { service } = makeService({ acquireTokenByCode });
+    const user = await service.completeAuthCodeFlow(
+      'code',
+      PRE_AUTH_OK.state,
+      PRE_AUTH_OK,
+      ENTRA.redirectUri,
+      PRE_AUTH_OK.createdAt,
+    );
+    expect(user.groups).toEqual([]);
+  });
+
+  it('drops non-string entries from `groups` (defensive)', async () => {
+    const acquireTokenByCode = jest.fn().mockResolvedValue(
+      makeAuthResult({
+        groups: [
+          '11111111-1111-1111-1111-111111111111',
+          42,
+          null,
+          '22222222-2222-2222-2222-222222222222',
+        ],
+      }),
+    );
+    const { service } = makeService({ acquireTokenByCode });
+    const user = await service.completeAuthCodeFlow(
+      'code',
+      PRE_AUTH_OK.state,
+      PRE_AUTH_OK,
+      ENTRA.redirectUri,
+      PRE_AUTH_OK.createdAt,
+    );
+    expect(user.groups).toEqual([
+      '11111111-1111-1111-1111-111111111111',
+      '22222222-2222-2222-2222-222222222222',
+    ]);
+  });
+
   it('throws token-exchange-failed when MSAL throws', async () => {
     const acquireTokenByCode = jest.fn().mockRejectedValue(new Error('AADSTS70008'));
     const { service } = makeService({ acquireTokenByCode });

apps/portal-bff/src/auth/auth.service.ts

@@ -38,11 +38,23 @@ export interface AuthCodeFlowStart {
  *     the BFF's MFA sanity-check (ADR-0011) and by `@RequireMfa`
  *     freshness checks once the session lands.
  *   - `roles`: Entra app roles assigned to this user on the BFF's
- *     app registration. Surfaced for the future `@RequireAdmin` /
+ *     app registration. These are the four `Portal.*` *privileges*
- *     `@RequireRole(...)` guards (ADR-0020 admin module). Always
+ *     per ADR-0025 (`Portal.Admin`, `Portal.Auditor`,
- *     present in the shape — an empty array means the user has no
+ *     `Portal.SecurityOfficer`, `Portal.DPO`). Surfaced for the
- *     app role on this app registration, not that the claim was
+ *     existing `@RequireAdmin()` guard and the upcoming
- *     unparseable.
+ *     `@RequirePrivilege()` decorator. Always present in the shape
+ *     — an empty array means the user has no app role on this app
+ *     registration, not that the claim was unparseable.
+ *   - `groups`: Entra security-group GUIDs the user belongs to.
+ *     Emitted by the `groups` claim once the app registration sets
+ *     `groupMembershipClaims: 'SecurityGroup'` (per ADR-0025
+ *     §"Sources of truth — Entra-side configuration"). The
+ *     `PrincipalBuilder` resolves these GUIDs to `apf-role-*` slugs
+ *     via the `EntraGroupToRoleResolver`. Always present — empty
+ *     means either the user has no group membership or the claim
+ *     was not configured on the app registration. Unknown GUIDs
+ *     are dropped at resolve time, not at extraction time, so an
+ *     audit reader still sees the raw claim.
  */
 export interface AuthenticatedUser {
   readonly oid: string;
@@ -51,6 +63,7 @@ export interface AuthenticatedUser {
   readonly displayName: string;
   readonly amr: readonly string[];
   readonly roles: readonly string[];
+  readonly groups: readonly string[];
 }
 
 /**
@@ -212,6 +225,18 @@ export class AuthService {
       ? (claims['roles'] as unknown[]).filter((v): v is string => typeof v === 'string')
       : [];
 
+    // `groups` is an optional claim (per ADR-0025 §"Sources of truth
+    // — Entra-side configuration"). Present only when the app
+    // registration sets `groupMembershipClaims: 'SecurityGroup'`.
+    // Empty array if the user is in zero security groups or the
+    // claim is not configured — both are valid "no functional
+    // roles" states the rest of the BFF must tolerate. Same
+    // string-filter as `roles` to defend against a non-string value
+    // smuggled in via a malformed token.
+    const groups = Array.isArray(claims['groups'])
+      ? (claims['groups'] as unknown[]).filter((v): v is string => typeof v === 'string')
+      : [];
+
     return {
       oid: requireString(claims['oid'], 'oid'),
       tid: requireString(claims['tid'], 'tid'),
@@ -225,6 +250,7 @@ export class AuthService {
           : (result.account?.name ?? ''),
       amr,
       roles,
+      groups,
     };
   }
 }

apps/portal-bff/src/auth/entra-group-to-role.token.ts

@@ -0,0 +1,12 @@
+/**
+ * DI token for the lazily-loaded `EntraGroupToRoleResolver`.
+ *
+ * The resolver wraps a `Map<groupGuid, FunctionalRole>` parsed
+ * once at boot from `infra/<env>-tenant.entra.json` (per ADR-0025
+ * §"Sources of truth — Entra-side configuration"). The token is
+ * separate from the class import so the BFF can swap the
+ * implementation (an empty-map stub when no file is configured,
+ * a real one when `ENTRA_GROUP_MAP_PATH` resolves) without the
+ * consumers caring.
+ */
+export const ENTRA_GROUP_TO_ROLE_RESOLVER = Symbol('ENTRA_GROUP_TO_ROLE_RESOLVER');

apps/portal-bff/src/auth/principal-builder.spec.ts

@@ -0,0 +1,340 @@
+import type { Logger } from 'nestjs-pino';
+import {
+  EntraGroupToRoleResolver,
+  parseEntraGroupMap,
+  type FunctionalRole,
+  type Scope,
+} from 'shared-auth';
+import type { AuthenticatedUser } from './auth.service';
+import { PrincipalBuilder } from './principal-builder';
+import type { ScopeResolver } from './scope-resolver';
+
+/**
+ * Mirrors the 24-entry `apf-role-*` catalogue: one synthetic GUID
+ * per slug, in catalogue order. The exact GUIDs do not matter to
+ * any assertion below — what matters is that the test resolver
+ * maps them deterministically so a persona's `groups` claim can
+ * be assembled by slug.
+ */
+const ROLE_GUID: Record<FunctionalRole, string> = {
+  collaborateur: '00000000-0000-0000-0000-000000000101',
+  'chef-equipe': '00000000-0000-0000-0000-000000000102',
+  'chef-service': '00000000-0000-0000-0000-000000000103',
+  'directeur-etablissement': '00000000-0000-0000-0000-000000000104',
+  'directeur-territorial': '00000000-0000-0000-0000-000000000105',
+  rh: '00000000-0000-0000-0000-000000000106',
+  'responsable-paie': '00000000-0000-0000-0000-000000000107',
+  comptable: '00000000-0000-0000-0000-000000000108',
+  juriste: '00000000-0000-0000-0000-000000000109',
+  dpo: '00000000-0000-0000-0000-00000000010a',
+  rssi: '00000000-0000-0000-0000-00000000010b',
+  it: '00000000-0000-0000-0000-00000000010c',
+  formation: '00000000-0000-0000-0000-00000000010d',
+  qualite: '00000000-0000-0000-0000-00000000010e',
+  communication: '00000000-0000-0000-0000-00000000010f',
+  'elu-ca': '00000000-0000-0000-0000-000000000110',
+  'elu-cd': '00000000-0000-0000-0000-000000000111',
+  'elu-cd-president': '00000000-0000-0000-0000-000000000112',
+  'elu-cd-tresorier': '00000000-0000-0000-0000-000000000113',
+  'elu-cd-secretaire': '00000000-0000-0000-0000-000000000114',
+  delegue: '00000000-0000-0000-0000-000000000115',
+  benevole: '00000000-0000-0000-0000-000000000116',
+  'benevole-responsable': '00000000-0000-0000-0000-000000000117',
+  partenaire: '00000000-0000-0000-0000-000000000118',
+};
+
+/**
+ * The 19 personas provisioned in the `apfrd.onmicrosoft.com` test
+ * tenant on 2026-05-20, transcribed from
+ * `notes/test-tenant-role-assignments.md` (reverse view). The
+ * builder's contract is that these inputs round-trip to the
+ * expected `(privileges, roles, scopes)` triple — when the spec
+ * passes, every persona we documented in the ADR is exercised
+ * end-to-end.
+ *
+ * Scopes are stubbed to `[{ kind: 'unrestricted' }]` for every
+ * persona in v1 per ADR-0025 §"Sources of truth — apf_portal-side
+ * `user_scopes` table". The intended per-persona scopes
+ * (`etablissement:…`, `delegation:33`, …) land with the Prisma
+ * `user_scopes` table — the next PR after this skeleton.
+ */
+interface Persona {
+  readonly label: string;
+  readonly username: string;
+  readonly privileges: readonly string[]; // raw `roles` claim values
+  readonly roles: readonly FunctionalRole[];
+}
+
+const PERSONAS: readonly Persona[] = [
+  {
+    label: 'admin',
+    username: 'admin@apfrd.onmicrosoft.com',
+    privileges: ['Portal.Admin'],
+    roles: ['collaborateur', 'rh'],
+  },
+  {
+    label: 'directeur-bordeaux',
+    username: 'directeur-bordeaux@apfrd.onmicrosoft.com',
+    privileges: [],
+    roles: ['collaborateur', 'directeur-etablissement'],
+  },
+  {
+    label: 'directeur-complexe',
+    username: 'directeur-complexe@apfrd.onmicrosoft.com',
+    privileges: [],
+    roles: ['collaborateur', 'directeur-etablissement'],
+  },
+  {
+    label: 'rh-aquitaine',
+    username: 'rh-aquitaine@apfrd.onmicrosoft.com',
+    privileges: [],
+    roles: ['collaborateur', 'rh', 'formation'],
+  },
+  {
+    label: 'rh-siege',
+    username: 'rh-siege@apfrd.onmicrosoft.com',
+    privileges: [],
+    roles: ['collaborateur', 'rh', 'responsable-paie', 'comptable'],
+  },
+  {
+    label: 'collaborateur-simple',
+    username: 'collaborateur-simple@apfrd.onmicrosoft.com',
+    privileges: [],
+    roles: ['collaborateur'],
+  },
+  {
+    label: 'tresorier-bordeaux',
+    username: 'tresorier-bordeaux@apfrd.onmicrosoft.com',
+    privileges: [],
+    roles: ['elu-cd', 'elu-cd-tresorier'],
+  },
+  {
+    label: 'dpo',
+    username: 'dpo@apfrd.onmicrosoft.com',
+    privileges: ['Portal.DPO', 'Portal.Auditor'],
+    roles: ['collaborateur', 'dpo', 'qualite'],
+  },
+  {
+    label: 'it',
+    username: 'it@apfrd.onmicrosoft.com',
+    privileges: [],
+    roles: ['collaborateur', 'it'],
+  },
+  {
+    label: 'benevole-aquitaine',
+    username: 'benevole-aquitaine@apfrd.onmicrosoft.com',
+    privileges: [],
+    // Catalogue order: delegue (governance) precedes benevole +
+    // benevole-responsable (volunteer). The resolver re-sorts on
+    // catalogue order regardless of the Entra claim's order.
+    roles: ['delegue', 'benevole', 'benevole-responsable'],
+  },
+  {
+    label: 'chef-equipe-bordeaux',
+    username: 'chef-equipe-bordeaux@apfrd.onmicrosoft.com',
+    privileges: [],
+    roles: ['collaborateur', 'chef-equipe'],
+  },
+  {
+    label: 'chef-service-bordeaux',
+    username: 'chef-service-bordeaux@apfrd.onmicrosoft.com',
+    privileges: [],
+    roles: ['collaborateur', 'chef-service'],
+  },
+  {
+    label: 'directeur-territorial-aquitaine',
+    username: 'directeur-territorial-aquitaine@apfrd.onmicrosoft.com',
+    privileges: [],
+    roles: ['collaborateur', 'directeur-territorial'],
+  },
+  {
+    label: 'juriste-siege',
+    username: 'juriste-siege@apfrd.onmicrosoft.com',
+    privileges: [],
+    roles: ['collaborateur', 'juriste'],
+  },
+  {
+    label: 'rssi',
+    username: 'rssi@apfrd.onmicrosoft.com',
+    privileges: ['Portal.SecurityOfficer'],
+    roles: ['collaborateur', 'rssi'],
+  },
+  {
+    label: 'communication-siege',
+    username: 'communication-siege@apfrd.onmicrosoft.com',
+    privileges: [],
+    roles: ['collaborateur', 'communication'],
+  },
+  {
+    label: 'elu-ca-national',
+    username: 'elu-ca-national@apfrd.onmicrosoft.com',
+    privileges: [],
+    roles: ['elu-ca'],
+  },
+  {
+    label: 'president-cd-aquitaine',
+    username: 'president-cd-aquitaine@apfrd.onmicrosoft.com',
+    privileges: [],
+    roles: ['elu-cd', 'elu-cd-president'],
+  },
+  {
+    label: 'secretaire-cd-aquitaine',
+    username: 'secretaire-cd-aquitaine@apfrd.onmicrosoft.com',
+    privileges: [],
+    roles: ['elu-cd', 'elu-cd-secretaire'],
+  },
+];
+
+function makeUser(p: Persona): AuthenticatedUser {
+  return {
+    oid: `oid-${p.label}`,
+    tid: 'tenant-1',
+    username: p.username,
+    displayName: p.label,
+    amr: ['pwd', 'mfa'],
+    roles: [...p.privileges],
+    groups: p.roles.map((slug) => ROLE_GUID[slug]),
+  };
+}
+
+function makeBuilder(): {
+  builder: PrincipalBuilder;
+  scopeResolver: { resolve: jest.Mock };
+  logger: { log: jest.Mock; warn: jest.Mock; error: jest.Mock };
+} {
+  const rawMap: Record<string, FunctionalRole> = {};
+  for (const [slug, guid] of Object.entries(ROLE_GUID) as Array<[FunctionalRole, string]>) {
+    rawMap[guid] = slug;
+  }
+  const resolver = new EntraGroupToRoleResolver(parseEntraGroupMap(rawMap));
+  const scopeResolver = {
+    resolve: jest.fn().mockResolvedValue([{ kind: 'unrestricted' } as Scope]),
+  };
+  const logger = { log: jest.fn(), warn: jest.fn(), error: jest.fn() };
+  const builder = new PrincipalBuilder(
+    resolver,
+    scopeResolver as unknown as ScopeResolver,
+    logger as unknown as Logger,
+  );
+  return { builder, scopeResolver, logger };
+}
+
+describe('PrincipalBuilder — 19 test-tenant personas', () => {
+  for (const persona of PERSONAS) {
+    it(`builds the principal for ${persona.label}`, async () => {
+      const { builder } = makeBuilder();
+      const principal = await builder.build(makeUser(persona));
+      expect(principal.privileges).toEqual(persona.privileges);
+      expect(principal.roles).toEqual(persona.roles);
+      expect(principal.scopes).toEqual([{ kind: 'unrestricted' }]);
+      expect(principal.user.entraOid).toBe(`oid-${persona.label}`);
+      expect(principal.user.tenantId).toBe('tenant-1');
+      // amr passes through verbatim — MFA freshness checks read it
+      // off the principal per ADR-0011.
+      expect(principal.amr).toEqual(['pwd', 'mfa']);
+    });
+  }
+
+  it('asserts the 19 personas cover all 4 privileges + 23 of 24 functional roles', () => {
+    // Coverage check baked into the spec so a regression that
+    // drops a role from a persona is caught here, not at PR review.
+    // The intentional gap is `partenaire` (placeholder per ADR-0025).
+    const privilegesUsed = new Set(PERSONAS.flatMap((p) => p.privileges));
+    expect(privilegesUsed).toEqual(
+      new Set(['Portal.Admin', 'Portal.Auditor', 'Portal.SecurityOfficer', 'Portal.DPO']),
+    );
+    const rolesUsed = new Set(PERSONAS.flatMap((p) => p.roles));
+    expect(rolesUsed.size).toBe(23);
+    expect(rolesUsed.has('partenaire')).toBe(false);
+  });
+});
+
+describe('PrincipalBuilder — edge cases', () => {
+  it('returns an empty privileges array when the user has no app role assignment', async () => {
+    const { builder } = makeBuilder();
+    const user = makeUser({
+      label: 'anon',
+      username: 'anon@example',
+      privileges: [],
+      roles: ['collaborateur'],
+    });
+    const principal = await builder.build(user);
+    expect(principal.privileges).toEqual([]);
+  });
+
+  it('drops + warns on a claim value that is not a known privilege', async () => {
+    const { builder, logger } = makeBuilder();
+    const user = makeUser({
+      label: 'stale',
+      username: 'stale@example',
+      privileges: [],
+      roles: [],
+    });
+    // Force in a non-catalogue value the way an old assignment would.
+    const userWithDrift: AuthenticatedUser = {
+      ...user,
+      roles: ['Portal.Admin', 'Portal.GhostRole'],
+    };
+    const principal = await builder.build(userWithDrift);
+    expect(principal.privileges).toEqual(['Portal.Admin']);
+    expect(logger.warn).toHaveBeenCalledWith(
+      expect.objectContaining({
+        event: 'auth.unknown_privilege_claim',
+        value: 'Portal.GhostRole',
+      }),
+      'PrincipalBuilder',
+    );
+  });
+
+  it('drops + warns on an unknown group GUID (tenant misconfiguration)', async () => {
+    const { builder, logger } = makeBuilder();
+    const user = makeUser({
+      label: 'ghost-group',
+      username: 'ghost-group@example',
+      privileges: [],
+      roles: ['collaborateur'],
+    });
+    const userWithUnknownGroup: AuthenticatedUser = {
+      ...user,
+      groups: [...user.groups, 'ffffffff-ffff-ffff-ffff-ffffffffffff'],
+    };
+    const principal = await builder.build(userWithUnknownGroup);
+    expect(principal.roles).toEqual(['collaborateur']);
+    expect(logger.warn).toHaveBeenCalledWith(
+      expect.objectContaining({
+        event: 'auth.unknown_group_claim',
+        groupId: 'ffffffff-ffff-ffff-ffff-ffffffffffff',
+      }),
+      'PrincipalBuilder',
+    );
+  });
+
+  it('builds an empty-permissions principal when the user has no groups or roles', async () => {
+    const { builder } = makeBuilder();
+    const user = makeUser({
+      label: 'empty',
+      username: 'empty@example',
+      privileges: [],
+      roles: [],
+    });
+    const principal = await builder.build(user);
+    expect(principal.privileges).toEqual([]);
+    expect(principal.roles).toEqual([]);
+    // Scope resolver stub returns unrestricted — the v1 behaviour
+    // per ADR-0025 §331 until the user_scopes table lands.
+    expect(principal.scopes).toEqual([{ kind: 'unrestricted' }]);
+  });
+
+  it('asks the scope resolver to resolve by entraOid', async () => {
+    const { builder, scopeResolver } = makeBuilder();
+    await builder.build(
+      makeUser({
+        label: 'sr',
+        username: 'sr@example',
+        privileges: [],
+        roles: ['collaborateur'],
+      }),
+    );
+    expect(scopeResolver.resolve).toHaveBeenCalledWith({ entraOid: 'oid-sr' });
+  });
+});

apps/portal-bff/src/auth/principal-builder.ts

@@ -0,0 +1,107 @@
+import { Inject, Injectable } from '@nestjs/common';
+import { Logger } from 'nestjs-pino';
+import { EntraGroupToRoleResolver, isPrivilege, type Principal, type Privilege } from 'shared-auth';
+import { ENTRA_GROUP_TO_ROLE_RESOLVER } from './entra-group-to-role.token';
+import { ScopeResolver } from './scope-resolver';
+import type { AuthenticatedUser } from './auth.service';
+
+/**
+ * Builds the session-resident `Principal` per
+ * [ADR-0025 §"Principal shape"](../../../../docs/decisions/0025-authorization-model-privileges-roles-scopes.md).
+ *
+ * Composes the three orthogonal axes once at sign-in:
+ *   - **Privileges** — pulled from the `roles` claim, filtered to
+ *     the closed `PRIVILEGES` catalogue. Unknown values are
+ *     dropped (with a WARN) rather than honoured: the BFF only
+ *     reasons about catalogue privileges, anything else is
+ *     either a tenant misconfiguration or a leftover from a v1+1
+ *     experiment that should not silently grant access.
+ *   - **Functional roles** — resolved from the `groups` claim via
+ *     `EntraGroupToRoleResolver`. Unknown GUIDs are logged at
+ *     WARN (per ADR-0025 §"Sources of truth — Entra-side
+ *     configuration") and ignored.
+ *   - **Scopes** — resolved by `ScopeResolver` from the portal-side
+ *     `user_scopes` table once ADR-0026 lands. v1 stubs to
+ *     `[{ kind: 'unrestricted' }]`.
+ *
+ * Built once per sign-in, not per request: the session payload
+ * carries the resolved `Principal` so guards can read it without
+ * re-doing the GUID lookup on every API call.
+ *
+ * `user.id` and `user.personId` are placeholders (= `entraOid`)
+ * until the `User` + `Person` schema (proposed ADR-0026) lands.
+ * The seam is here so the next PR populates the real UUIDs in one
+ * place, not in every guard.
+ */
+@Injectable()
+export class PrincipalBuilder {
+  constructor(
+    @Inject(ENTRA_GROUP_TO_ROLE_RESOLVER)
+    private readonly groupToRole: EntraGroupToRoleResolver,
+    private readonly scopes: ScopeResolver,
+    private readonly logger: Logger,
+  ) {}
+
+  async build(user: AuthenticatedUser): Promise<Principal> {
+    const privileges = filterPrivileges(user.roles, user.oid, this.logger);
+
+    const roles = this.groupToRole.resolve(user.groups, (groupId: string) => {
+      this.logger.warn(
+        {
+          event: 'auth.unknown_group_claim',
+          oid: user.oid,
+          groupId,
+        },
+        'PrincipalBuilder',
+      );
+    });
+
+    const scopes = await this.scopes.resolve({ entraOid: user.oid });
+
+    return {
+      user: {
+        // Real UUIDs land with ADR-0026's User + Person schema.
+        // Until then `entraOid` is the closest thing to a stable
+        // portal identity, so callers that key on `principal.user.id`
+        // get a usable value today and a real one later.
+        id: user.oid,
+        personId: user.oid,
+        entraOid: user.oid,
+        tenantId: user.tid,
+        displayName: user.displayName,
+      },
+      privileges,
+      roles,
+      scopes,
+      amr: user.amr,
+    };
+  }
+}
+
+function filterPrivileges(
+  rawRoles: readonly string[],
+  oid: string,
+  logger: Logger,
+): ReadonlyArray<Privilege> {
+  const out: Privilege[] = [];
+  for (const value of rawRoles) {
+    if (isPrivilege(value)) {
+      out.push(value);
+    } else {
+      // A value in the `roles` claim that is not a known privilege
+      // is either a leftover from a different app registration, a
+      // typo in the Entra manifest, or a future privilege not yet
+      // in the catalogue. None of those should silently grant
+      // access — drop with a WARN so an operator can investigate.
+      logger.warn(
+        {
+          event: 'auth.unknown_privilege_claim',
+          oid,
+          value,
+        },
+        'PrincipalBuilder',
+      );
+    }
+  }
+  return out;
+}

apps/portal-bff/src/auth/require-mfa.guard.spec.ts

@@ -53,6 +53,7 @@ const USER = {
   displayName: 'Jane',
   amr: ['pwd', 'mfa'],
   roles: ['admin'],
+  groups: [],
 };
 
 describe('RequireMfaGuard', () => {

apps/portal-bff/src/auth/scope-resolver.ts

@@ -0,0 +1,47 @@
+import { Injectable } from '@nestjs/common';
+import type { Scope } from 'shared-auth';
+
+/**
+ * Resolves the portal-side scopes for a user being signed in.
+ *
+ * Per [ADR-0025 §"Sources of truth — apf_portal-side `user_scopes`
+ * table"](../../../../docs/decisions/0025-authorization-model-privileges-roles-scopes.md),
+ * scopes are *not* carried by Entra: they will live in a portal
+ * `user_scopes` Prisma table (proposed ADR-0026), queried by Entra
+ * `oid` at sign-in. Each row materialises one `Scope` entry on the
+ * session principal.
+ *
+ * The seam is here in v1 so the next PR replaces only the
+ * implementation, leaving the call-site in `PrincipalBuilder`
+ * untouched. The v1 implementation (`StubScopeResolver`) always
+ * returns `[{ kind: 'unrestricted' }]` per ADR-0025 §331 — until
+ * the Prisma table lands the test tenant runs against a single
+ * "see everything" scope; the absence of fine-grained scoping is
+ * acceptable because guards consuming `@RequireScope` are not in
+ * the codebase yet.
+ */
+export abstract class ScopeResolver {
+  abstract resolve(input: { entraOid: string }): Promise<ReadonlyArray<Scope>>;
+}
+
+/**
+ * v1 stub — returns `unrestricted` for every user. Per ADR-0025
+ * §"Sources of truth — apf_portal-side `user_scopes` table" the
+ * real implementation queries `user_scopes WHERE userId = ?`; that
+ * lands with the `Person` + `User` schema (proposed ADR-0026) and
+ * the seed PR that follows.
+ *
+ * Deliberately not an in-memory hard-coded persona-keyed map: the
+ * 19 test personas have *intended* scopes (see
+ * `notes/test-tenant-role-assignments.md`) but those scopes have
+ * no guard consuming them yet, so per-persona stub data would be
+ * write-only documentation. When ADR-0026 lands, the seed PR
+ * populates `user_scopes`; this class is replaced by a
+ * Prisma-backed implementation in the same change.
+ */
+@Injectable()
+export class StubScopeResolver extends ScopeResolver {
+  override resolve(): Promise<ReadonlyArray<Scope>> {
+    return Promise.resolve([{ kind: 'unrestricted' }]);
+  }
+}

apps/portal-bff/src/auth/session-establisher.service.spec.ts

@@ -1,9 +1,11 @@
 import type { Request, Response } from 'express';
 import type { Logger } from 'nestjs-pino';
+import type { Principal } from 'shared-auth';
 import type { AuditWriter } from '../audit/audit.service';
 import type { UserSessionIndexService } from '../session/user-session-index.service';
 import type { UserDirectoryService } from '../users/user-directory.service';
 import type { AuthenticatedUser } from './auth.service';
+import type { PrincipalBuilder } from './principal-builder';
 import { SessionEstablisher } from './session-establisher.service';
 
 const USER: AuthenticatedUser = {
@@ -13,6 +15,7 @@ const USER: AuthenticatedUser = {
   displayName: 'Jane Doe',
   amr: ['pwd', 'mfa'],
   roles: [],
+  groups: [],
 };
 
 function makeReqStub(opts?: { sessionID?: string; sessionUser?: AuthenticatedUser }): Request {
@@ -53,8 +56,23 @@ interface Fixture {
   audit: { signIn: jest.Mock; signOut: jest.Mock };
   directory: { recordSignIn: jest.Mock };
   logger: ReturnType<typeof makeLoggerStub>;
+  principalBuilder: { build: jest.Mock };
 }
 
+const STUB_PRINCIPAL: Principal = {
+  user: {
+    id: USER.oid,
+    personId: USER.oid,
+    entraOid: USER.oid,
+    tenantId: USER.tid,
+    displayName: USER.displayName,
+  },
+  privileges: [],
+  roles: [],
+  scopes: [{ kind: 'unrestricted' }],
+  amr: USER.amr,
+};
+
 function makeFixture(): Fixture {
   const index = {
     add: jest.fn().mockResolvedValue(undefined),
@@ -69,13 +87,17 @@ function makeFixture(): Fixture {
     recordSignIn: jest.fn().mockResolvedValue(undefined),
   };
   const logger = makeLoggerStub();
+  const principalBuilder = {
+    build: jest.fn().mockResolvedValue(STUB_PRINCIPAL),
+  };
   const est = new SessionEstablisher(
     logger as unknown as Logger,
     index as unknown as UserSessionIndexService,
     audit as unknown as AuditWriter,
     directory as unknown as UserDirectoryService,
+    principalBuilder as unknown as PrincipalBuilder,
   );
-  return { est, index, audit, directory, logger };
+  return { est, index, audit, directory, logger, principalBuilder };
 }
 
 describe('SessionEstablisher.establish', () => {
@@ -97,6 +119,20 @@ describe('SessionEstablisher.establish', () => {
     expect((sess['csrfToken'] as string).length).toBeGreaterThan(20);
   });
 
+  it('builds the authorization principal and stamps mfaVerifiedAt on it (ADR-0025)', async () => {
+    const { est, principalBuilder } = makeFixture();
+    const req = makeReqStub();
+    const res = makeResStub();
+    await est.establish({ user: USER, req, res, surface: 'user' });
+    expect(principalBuilder.build).toHaveBeenCalledWith(USER);
+    const sess = (req as unknown as { session: Record<string, unknown> }).session;
+    const principal = sess['principal'] as Principal;
+    expect(principal).toBeDefined();
+    expect(principal.user.entraOid).toBe(USER.oid);
+    expect(principal.scopes).toEqual([{ kind: 'unrestricted' }]);
+    expect(principal.mfaVerifiedAt).toBe(sess['createdAt']);
+  });
+
   it('saves the session before returning (no race with the controller redirect)', async () => {
     const { est } = makeFixture();
     const req = makeReqStub();

apps/portal-bff/src/auth/session-establisher.service.ts

@@ -8,6 +8,7 @@ import { readSessionTimeouts } from '../session/session-cookie';
 import { UserSessionIndexService } from '../session/user-session-index.service';
 import { UserDirectoryService } from '../users/user-directory.service';
 import type { AuthenticatedUser } from './auth.service';
+import { PrincipalBuilder } from './principal-builder';
 
 export type AuthSurface = 'user' | 'admin';
 
@@ -47,6 +48,7 @@ export class SessionEstablisher {
     private readonly userSessionIndex: UserSessionIndexService,
     private readonly audit: AuditWriter,
     private readonly userDirectory: UserDirectoryService,
+    private readonly principalBuilder: PrincipalBuilder,
   ) {}
 
   async establish(opts: {
@@ -79,6 +81,14 @@ export class SessionEstablisher {
     // does not re-validate factors. Refreshed by future step-up
     // re-auth flows.
     req.session.mfaVerifiedAt = now;
+    // Authorization principal per ADR-0025: composes the three
+    // axes (privileges / functional roles / scopes) once at
+    // sign-in so guards read a single coherent shape instead of
+    // re-parsing claims on every request. Built before the
+    // session is persisted so a Redis hiccup either persists
+    // everything or nothing.
+    const principal = await this.principalBuilder.build(user);
+    req.session.principal = { ...principal, mfaVerifiedAt: now };
 
     await saveSession(req);
 

apps/portal-bff/src/config/load-entra-group-map.spec.ts

@@ -0,0 +1,93 @@
+import { mkdtempSync, writeFileSync } from 'node:fs';
+import { tmpdir } from 'node:os';
+import { join } from 'node:path';
+import { EntraGroupMapError } from 'shared-auth';
+import { loadEntraGroupToRoleResolver } from './load-entra-group-map';
+
+function tmpFile(name: string, contents: string): string {
+  const dir = mkdtempSync(join(tmpdir(), 'entra-map-'));
+  const path = join(dir, name);
+  writeFileSync(path, contents, 'utf8');
+  return path;
+}
+
+function noopWarn(): { onWarn: jest.Mock } {
+  return { onWarn: jest.fn() };
+}
+
+describe('loadEntraGroupToRoleResolver', () => {
+  it('returns an empty resolver and warns when ENTRA_GROUP_MAP_PATH is unset', () => {
+    const { onWarn } = noopWarn();
+    const { resolver, sourcePath } = loadEntraGroupToRoleResolver({
+      env: {},
+      onWarn,
+    });
+    expect(resolver.size).toBe(0);
+    expect(sourcePath).toBeNull();
+    expect(onWarn).toHaveBeenCalledWith('auth.entra_group_map_path_unset', expect.any(Object));
+  });
+
+  it('returns an empty resolver and warns when the file cannot be read', () => {
+    const { onWarn } = noopWarn();
+    const { resolver, sourcePath } = loadEntraGroupToRoleResolver({
+      env: { ENTRA_GROUP_MAP_PATH: '/tmp/definitely-not-a-real-path-xyz.json' },
+      onWarn,
+    });
+    expect(resolver.size).toBe(0);
+    expect(sourcePath).toBe('/tmp/definitely-not-a-real-path-xyz.json');
+    expect(onWarn).toHaveBeenCalledWith(
+      'auth.entra_group_map_file_unreadable',
+      expect.objectContaining({ path: '/tmp/definitely-not-a-real-path-xyz.json' }),
+    );
+  });
+
+  it('throws on malformed JSON', () => {
+    const path = tmpFile('bad.json', '{ not json');
+    expect(() =>
+      loadEntraGroupToRoleResolver({
+        env: { ENTRA_GROUP_MAP_PATH: path },
+        onWarn: jest.fn(),
+      }),
+    ).toThrow(EntraGroupMapError);
+  });
+
+  it('throws when the JSON is not an object', () => {
+    const path = tmpFile('arr.json', '["collaborateur"]');
+    expect(() =>
+      loadEntraGroupToRoleResolver({
+        env: { ENTRA_GROUP_MAP_PATH: path },
+        onWarn: jest.fn(),
+      }),
+    ).toThrow(EntraGroupMapError);
+  });
+
+  it('throws when a value is not a string', () => {
+    const path = tmpFile(
+      'bad-val.json',
+      JSON.stringify({ '11111111-1111-1111-1111-111111111111': 42 }),
+    );
+    expect(() =>
+      loadEntraGroupToRoleResolver({
+        env: { ENTRA_GROUP_MAP_PATH: path },
+        onWarn: jest.fn(),
+      }),
+    ).toThrow(EntraGroupMapError);
+  });
+
+  it('returns a populated resolver on a valid map', () => {
+    const path = tmpFile(
+      'good.json',
+      JSON.stringify({
+        '11111111-1111-1111-1111-111111111111': 'collaborateur',
+        '22222222-2222-2222-2222-222222222222': 'rh',
+      }),
+    );
+    const { resolver, sourcePath } = loadEntraGroupToRoleResolver({
+      env: { ENTRA_GROUP_MAP_PATH: path },
+      onWarn: jest.fn(),
+    });
+    expect(resolver.size).toBe(2);
+    expect(sourcePath).toBe(path);
+    expect(resolver.coveredRoles()).toEqual(['collaborateur', 'rh']);
+  });
+});

apps/portal-bff/src/config/load-entra-group-map.ts

@@ -0,0 +1,98 @@
+import { readFileSync } from 'node:fs';
+import { isAbsolute, resolve } from 'node:path';
+import { EntraGroupMapError, EntraGroupToRoleResolver, parseEntraGroupMap } from 'shared-auth';
+
+/**
+ * Outcome of `loadEntraGroupToRoleResolver` — paired with the
+ * source path (when set) so the boot log can name the file that
+ * was loaded, even when the resolver itself ends up empty.
+ */
+export interface EntraGroupResolverLoadResult {
+  readonly resolver: EntraGroupToRoleResolver;
+  /** `null` when no path was configured (env var unset). */
+  readonly sourcePath: string | null;
+}
+
+/**
+ * Loads the Entra group-GUID → role-slug map at BFF boot per
+ * [ADR-0025 §"Sources of truth — Entra-side configuration"](../../../../docs/decisions/0025-authorization-model-privileges-roles-scopes.md).
+ *
+ * Sourcing precedence:
+ *   1. `ENTRA_GROUP_MAP_PATH` env var → JSON file path (absolute,
+ *      or relative to `cwd`).
+ *   2. Unset → empty resolver, WARN logged at boot. Sign-in still
+ *      works but every user gets an empty `roles[]` until the
+ *      operator wires up the file. Acceptable for fresh dev
+ *      environments; production should always set the var.
+ *
+ * Failure modes:
+ *   - File configured but unreadable / missing → empty resolver,
+ *     WARN. Same fail-soft posture: an operator pointing at the
+ *     wrong path should not block every sign-in.
+ *   - File present but malformed (bad JSON, wrong shape, unknown
+ *     slug, duplicate GUID) → throws. A misconfigured map is a
+ *     hard-fail because the alternative is silently mis-resolving
+ *     a role.
+ *
+ * The function never reads `process.env` outside the documented
+ * key and never mutates it.
+ */
+export function loadEntraGroupToRoleResolver(opts: {
+  cwd?: string;
+  env?: NodeJS.ProcessEnv;
+  onWarn: (event: string, payload: Record<string, unknown>) => void;
+}): EntraGroupResolverLoadResult {
+  const env = opts.env ?? process.env;
+  const cwd = opts.cwd ?? process.cwd();
+  const rawPath = env['ENTRA_GROUP_MAP_PATH'];
+
+  if (typeof rawPath !== 'string' || rawPath === '') {
+    opts.onWarn('auth.entra_group_map_path_unset', {
+      hint: 'set ENTRA_GROUP_MAP_PATH to infra/<env>-tenant.entra.json — sign-in will succeed but resolve zero functional roles until configured',
+    });
+    return { resolver: new EntraGroupToRoleResolver(new Map()), sourcePath: null };
+  }
+
+  const absolutePath = isAbsolute(rawPath) ? rawPath : resolve(cwd, rawPath);
+
+  let raw: string;
+  try {
+    raw = readFileSync(absolutePath, 'utf8');
+  } catch (err) {
+    opts.onWarn('auth.entra_group_map_file_unreadable', {
+      path: absolutePath,
+      message: err instanceof Error ? err.message : String(err),
+    });
+    return { resolver: new EntraGroupToRoleResolver(new Map()), sourcePath: absolutePath };
+  }
+
+  let parsed: unknown;
+  try {
+    parsed = JSON.parse(raw);
+  } catch (err) {
+    throw new EntraGroupMapError(
+      `Entra group map at ${absolutePath} is not valid JSON: ${
+        err instanceof Error ? err.message : String(err)
+      }`,
+    );
+  }
+
+  if (parsed === null || typeof parsed !== 'object' || Array.isArray(parsed)) {
+    throw new EntraGroupMapError(
+      `Entra group map at ${absolutePath} must be a JSON object keyed on group GUID.`,
+    );
+  }
+
+  const stringified: Record<string, string> = {};
+  for (const [key, value] of Object.entries(parsed as Record<string, unknown>)) {
+    if (typeof value !== 'string') {
+      throw new EntraGroupMapError(
+        `Entra group map entry "${key}" in ${absolutePath} must be a string (the role slug); got ${typeof value}.`,
+      );
+    }
+    stringified[key] = value;
+  }
+
+  const map = parseEntraGroupMap(stringified);
+  return { resolver: new EntraGroupToRoleResolver(map), sourcePath: absolutePath };
+}

apps/portal-bff/src/grpc/ai-bridge/ai-bridge.controller.spec.ts

@@ -71,6 +71,7 @@ const USER: AuthenticatedUser = {
   displayName: 'Alice',
   amr: ['pwd', 'mfa'],
   roles: ['admin'],
+  groups: [],
 };
 
 // ---- Fake gRPC server (Chat + Rag + Models) -------------------

apps/portal-bff/src/session/session.types.ts

@@ -1,3 +1,4 @@
+import type { Principal } from 'shared-auth';
 import type { AuthenticatedUser } from '../auth/auth.service';
 
 /**
@@ -18,6 +19,26 @@ import type { AuthenticatedUser } from '../auth/auth.service';
 declare module 'express-session' {
   interface SessionData {
     user?: AuthenticatedUser;
+    /**
+     * Authorization principal per
+     * [ADR-0025 §"Principal shape"](../../../../docs/decisions/0025-authorization-model-privileges-roles-scopes.md).
+     * Built once at sign-in by `PrincipalBuilder` from the three
+     * source claims (Entra `roles` for privileges, Entra `groups`
+     * for functional roles, portal `user_scopes` for scopes) and
+     * read by the upcoming `@RequirePrivilege` / `@RequireRole` /
+     * `@RequireScope` guards on every request.
+     *
+     * Kept alongside `user` rather than replacing it: the audit
+     * module and the AI-bridge controller still key on
+     * `user.oid` / `user.tid` directly and would be churn-only
+     * to migrate. New consumers should reach for `principal`.
+     *
+     * Optional in the type — sessions persisted before this field
+     * existed will have it undefined. Guards must treat the
+     * missing-principal case the same as "no privileges, no roles,
+     * no scopes" rather than crashing.
+     */
+    principal?: Principal;
     /**
      * Epoch ms at which the BFF created this session. Posed by the
      * callback at the same time as `user`. Lets the absolute-timeout

apps/portal-bff/tsconfig.app.json

@@ -11,5 +11,10 @@
     "ignoreDeprecations": "5.0"
   },
   "include": ["src/**/*.ts"],
-  "exclude": ["jest.config.ts", "jest.config.cts", "src/**/*.spec.ts", "src/**/*.test.ts"]
+  "exclude": ["jest.config.ts", "jest.config.cts", "src/**/*.spec.ts", "src/**/*.test.ts"],
+  "references": [
+    {
+      "path": "../../libs/shared/auth"
+    }
+  ]
 }

docs/decisions/0025-authorization-model-privileges-roles-scopes.md

@@ -63,7 +63,7 @@ The four privileges above are the entire v1 catalogue. The last three were provi
 
 **Definition.** A _functional role_ is what someone does in APF. Multiple per user is the norm (a Directeur is also a Collaborateur; an RH-Aquitaine might also be a Bénévole de la Délégation 33). Functional roles carry **no** privilege flags and **no** scope by themselves — those live on the other axes.
 
-**Source of truth.** Entra security groups, named `apf-role-<role-slug>`. Memberships emitted in the `groups` claim. The BFF's OIDC callback resolves each Entra group GUID to a role slug via a static mapping (`libs/feature/auth/src/lib/entra-group-to-role.ts`) and populates `Principal.roles`.
+**Source of truth.** Entra security groups, named `apf-role-<role-slug>`. Memberships emitted in the `groups` claim. The BFF's OIDC callback resolves each Entra group GUID to a role slug via a static mapping (`libs/shared/auth/src/lib/entra-group-to-role.ts`) and populates `Principal.roles`.
 
 **v1 catalogue.** Grouped for readability; the slugs are kebab-case and intent-bearing.
 
@@ -234,18 +234,26 @@ Two configurations live on the Entra app registration:
 
    so the ID token includes the user's group GUIDs in the `groups` claim. The BFF's OIDC callback resolves group GUIDs to role slugs via a static map (committed to the repo). Unknown group GUIDs are logged at WARN and ignored — they do not break sign-in, but they signal a tenant misconfiguration that should be cleaned up.
 
-**The group GUIDs are tenant-specific.** The map file (`libs/feature/auth/src/lib/entra-group-to-role.ts`) keys the slug on the GUID _per environment_ — the dev/test/preprod/prod tenants all have distinct GUIDs for the same role slug. The map is structured as:
+**The group GUIDs are tenant-specific.** The map _data_ is keyed on Entra group GUID _per environment_ — the dev/test/preprod/prod tenants all have distinct GUIDs for the same role slug. The data lives in a gitignored `infra/<env>-tenant.entra.json` (see `infra/test-tenant.entra.example.json` for the schema). The BFF loads it at boot through the `EntraGroupToRoleResolver` exported from `libs/shared/auth/src/lib/entra-group-to-role.ts`:
 
-```ts
+```json
-export const ENTRA_GROUP_TO_ROLE: Record<string, FunctionalRole> = {
+{
-  // test tenant — sourced from `infra/test-tenant.entra.json`
+  "11111111-1111-1111-1111-111111111111": "collaborateur",
-  '11111111-1111-1111-1111-111111111111': 'collaborateur',
+  "22222222-2222-2222-2222-222222222222": "rh"
-  '22222222-2222-2222-2222-222222222222': 'rh',
+}
-  // …
-};
 ```
 
-A dedicated config file per environment (`apps/portal-bff/.env.*`) holds an override token if needed. The `groups`-claim overage scenario (Entra emits a `_claim_sources` hint instead of the full list when the user is in too many groups) is handled by the BFF calling Microsoft Graph at sign-in — out of scope for v1's small test tenant, lands when the production rollout brings real population in.
+```ts
+// libs/shared/auth/src/lib/entra-group-to-role.ts
+export class EntraGroupToRoleResolver {
+  resolve(
+    groupIds: ReadonlyArray<string>,
+    onUnknownGroup?: (groupId: string) => void,
+  ): ReadonlyArray<FunctionalRole>;
+}
+```
+
+The map file path is passed via `ENTRA_GROUP_MAP_PATH` (per-environment in `apps/portal-bff/.env.*`). The `groups`-claim overage scenario (Entra emits a `_claim_sources` hint instead of the full list when the user is in too many groups) is handled by the BFF calling Microsoft Graph at sign-in — out of scope for v1's small test tenant, lands when the production rollout brings real population in.
 
 ### Sources of truth — apf_portal-side `user_scopes` table
 
@@ -326,7 +334,7 @@ The four privileges live in the `apfrd.onmicrosoft.com` app registration with th
 | `Portal.SecurityOfficer` | `6f50ce58-a1e1-496b-a3c0-655559c66a28` |
 | `Portal.DPO`             | `39b8815f-b3fd-4597-9679-77dcbf788a07` |
 
-The 24 `apf-role-*` security groups were provisioned with the membership matrix above. Their GUIDs are tenant-specific and stay out of the repo; the implementation PR captures them in a gitignored `infra/test-tenant.entra.json` and references them by name in `libs/feature/auth/src/lib/entra-group-to-role.ts`.
+The 24 `apf-role-*` security groups were provisioned with the membership matrix above. Their GUIDs are tenant-specific and stay out of the repo; the implementation PR captures them in a gitignored `infra/test-tenant.entra.json` and references them by name in `libs/shared/auth/src/lib/entra-group-to-role.ts`.
 
 Scopes are **not** carried by Entra. They live in the portal-side `user_scopes` table, populated by `prisma/seed.ts` once the `Person` + `User` schema (proposed ADR-0026) lands. Until then the implementation skeleton honours the `unrestricted` default for testing.
 
@@ -343,7 +351,7 @@ Scopes are **not** carried by Entra. They live in the portal-side `user_scopes`
 ### Confirmation
 
 - **Schema test** in `apps/portal-bff/src/auth/principal.spec.ts` (lands with the auth wiring PR): every guard composition produces the expected allow/deny on each of the 10 test personas. Theory-style test matrix mirrors `apf-ai-service/tests/Apf.Ai.Tests/Rbac/RbacMatrix.cs`.
-- **Catalogue-vs-code drift check** in CI: a small ESLint custom rule (or a `pnpm run` script) greps every `@RequireRole('...')` / `@RequirePrivilege('...')` / scope literal in the codebase and asserts each one exists in the catalogue constants exported from `libs/feature/auth/src/lib/authorization.types.ts`. Fails the build on drift.
+- **Catalogue-vs-code drift check** in CI: a small ESLint custom rule (or a `pnpm run` script) greps every `@RequireRole('...')` / `@RequirePrivilege('...')` / scope literal in the codebase and asserts each one exists in the catalogue constants exported from `libs/shared/auth/src/lib/authorization.types.ts`. Fails the build on drift.
 - **Audit-event linkage**: every `403 Forbidden` from `@RequireRole` / `@RequireScope` writes an `admin.access_denied` row (per [ADR-0013](0013-audit-trail-separated-postgres-append-only.md) §"v1 events"), with the missing role/scope in the payload. Auditors can spot privilege-escalation attempts by pivoting on `outcome=denied`.
 - **PrincipalProjector test**: snapshot test asserting that the AI-service projection of a known persona produces a known flat-list output. Same fixture is reused on the AI service side as part of its RBAC matrix.
 
@@ -393,7 +401,7 @@ This door is recorded here so a future contributor does not feel they have to re
 ## More Information
 
 - **Phasing.** This ADR is decision-only. The implementation phasing is:
-  1. **PR — `Authorization` types + Principal builder + `entra-group-to-role` mapping skeleton.** Lands `libs/feature/auth/src/lib/authorization.types.ts` (the catalogues) and the OIDC callback hook that populates the new `privileges` / `roles` / `scopes` fields on the session principal. No new guards yet.
+  1. **PR — `Authorization` types + Principal builder + `entra-group-to-role` mapping skeleton.** Lands `libs/shared/auth/src/lib/authorization.types.ts` (the catalogues) and the OIDC callback hook that populates the new `privileges` / `roles` / `scopes` fields on the session principal. No new guards yet.
   2. **PR — `@RequireRole` + `@RequireScope` decorators + guard tests.** Adds the guards against a stubbed principal; integration with the actual session lands in the same PR.
   3. **PR — Drift CI gate.** ESLint rule (or `pnpm run` script) that asserts every role / privilege / scope literal in the codebase is in the catalogue.
   4. **PR — Test-tenant seed.** `prisma/seed.ts` populating the 10 test personas' `user_scopes` rows. Depends on the `Person` + `User` schema landing first (proposed ADR-0026).

infra/README.md

@@ -3,13 +3,14 @@
 Infrastructure-as-code artefacts for the project. Separate from application code and from documentation: this folder contains the recipes and configs that the team and ops use to stand up running infrastructure (CI runners, future local-dev databases, future on-prem deploy assets).
 
 | Subject                                | File / Folder                                                                                             | ADR / Reference                                                                                                                                                                                                                                                                               |
-| -------------------------------------- | -------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| -------------------------------------- | --------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
 | Self-hosted CI runners (Gitea Actions) | [`ci-runners.compose.yml`](ci-runners.compose.yml)                                                        | [ADR-0015 §"Runners"](../docs/decisions/0015-cicd-gitea-actions.md)                                                                                                                                                                                                                           |
 | Shared `act_runner` configuration      | [`runner-config.yaml`](runner-config.yaml)                                                                | [ADR-0015 §"Runners"](../docs/decisions/0015-cicd-gitea-actions.md)                                                                                                                                                                                                                           |
 | CI runners convenience script          | [`ci-runners.sh`](ci-runners.sh)                                                                          | See "Convenience script" below                                                                                                                                                                                                                                                                |
 | Runtime state of the runners           | `data/` (git-ignored after `.gitignore`)                                                                  | —                                                                                                                                                                                                                                                                                             |
 | Env-vars template for the runners      | `.env.example` (`.env` is git-ignored)                                                                    | —                                                                                                                                                                                                                                                                                             |
 | Local-dev runtime stack                | [`local/`](local/)                                                                                        | [ADR-0006](../docs/decisions/0006-persistence-postgresql-prisma.md), [ADR-0010](../docs/decisions/0010-session-management-redis.md), [ADR-0012](../docs/decisions/0012-observability-pino-opentelemetry.md), [ADR-0013](../docs/decisions/0013-audit-trail-separated-postgres-append-only.md) |
+| Entra group GUID → role slug map       | [`test-tenant.entra.example.json`](test-tenant.entra.example.json) (`*-tenant.entra.json` is git-ignored) | [ADR-0025 §"Sources of truth — Entra-side configuration"](../docs/decisions/0025-authorization-model-privileges-roles-scopes.md)                                                                                                                                                              |
 
 Future folders / files that will land here as the corresponding ADRs ship:
 
@@ -230,6 +231,38 @@ This stack is **dev-only**. The corresponding production layout (HA Postgres, Re
 
 ---
 
+## Entra group map — `test-tenant.entra.example.json`
+
+Pure JSON object keyed on Entra security-group GUID (lower-case), valued by an `apf-role-<slug>` slug from the ADR-0025 functional-role catalogue. The BFF loads it at boot through `EntraGroupToRoleResolver` (from `shared-auth`) and uses it on every sign-in to translate the `groups` claim into the 24-entry catalogue's role slugs.
+
+The 24 entries below cover the entire v1 catalogue — including `partenaire`, which ships empty in the test tenant by design but is kept in the schema so a typo or omission fails the parser at boot rather than silently dropping the role.
+
+### Provisioning a real file
+
+```bash
+cp infra/test-tenant.entra.example.json infra/test-tenant.entra.json
+
+# Then for each role replace the placeholder GUID with the real one
+# from Entra:
+#   Microsoft Entra admin centre → Groups → <apf-role-*> → Object ID.
+# Point the BFF at the file via apps/portal-bff/.env:
+#   ENTRA_GROUP_MAP_PATH=infra/test-tenant.entra.json
+```
+
+The real file (`infra/<env>-tenant.entra.json`) is git-ignored because the group GUIDs are tenant-private — leaking them does not authorize anything by itself, but it does reveal the tenant's internal authorization topology. Each environment (test / preprod / prod) carries its own file; the slugs are stable across environments, the GUIDs are not.
+
+If `ENTRA_GROUP_MAP_PATH` is unset, the resolver runs with an empty map: every user signs in successfully but receives an empty `roles[]` (and consequently no `apf-role-*` UI). The BFF logs a WARN at boot so an operator can spot the missing config; this is a deliberate fail-soft posture so a fresh dev environment is not blocked by an Entra-side dependency.
+
+Validation rules enforced at boot by `parseEntraGroupMap` (in `libs/shared/auth/`):
+
+- keys must look like a GUID (`8-4-4-4-12` hex);
+- values must be members of `FUNCTIONAL_ROLES`;
+- the same GUID cannot map to two different slugs (case-insensitive).
+
+A malformed file crashes the BFF at startup. The error message names the offending key / value.
+
+---
+
 ## Future infra concerns — placeholders
 
 These are listed here so a contributor knows where to expect related files; they don't exist yet.

infra/test-tenant.entra.example.json

@@ -0,0 +1,26 @@
+{
+  "00000000-0000-0000-0000-000000000001": "collaborateur",
+  "00000000-0000-0000-0000-000000000002": "chef-equipe",
+  "00000000-0000-0000-0000-000000000003": "chef-service",
+  "00000000-0000-0000-0000-000000000004": "directeur-etablissement",
+  "00000000-0000-0000-0000-000000000005": "directeur-territorial",
+  "00000000-0000-0000-0000-000000000006": "rh",
+  "00000000-0000-0000-0000-000000000007": "responsable-paie",
+  "00000000-0000-0000-0000-000000000008": "comptable",
+  "00000000-0000-0000-0000-000000000009": "juriste",
+  "00000000-0000-0000-0000-00000000000a": "dpo",
+  "00000000-0000-0000-0000-00000000000b": "rssi",
+  "00000000-0000-0000-0000-00000000000c": "it",
+  "00000000-0000-0000-0000-00000000000d": "formation",
+  "00000000-0000-0000-0000-00000000000e": "qualite",
+  "00000000-0000-0000-0000-00000000000f": "communication",
+  "00000000-0000-0000-0000-000000000010": "elu-ca",
+  "00000000-0000-0000-0000-000000000011": "elu-cd",
+  "00000000-0000-0000-0000-000000000012": "elu-cd-president",
+  "00000000-0000-0000-0000-000000000013": "elu-cd-tresorier",
+  "00000000-0000-0000-0000-000000000014": "elu-cd-secretaire",
+  "00000000-0000-0000-0000-000000000015": "delegue",
+  "00000000-0000-0000-0000-000000000016": "benevole",
+  "00000000-0000-0000-0000-000000000017": "benevole-responsable",
+  "00000000-0000-0000-0000-000000000018": "partenaire"
+}

libs/shared/auth/README.md

@@ -0,0 +1,24 @@
+# shared-auth
+
+Framework-agnostic authorization primitives shared across `portal-bff` and
+`portal-shell` per [ADR-0025](../../../docs/decisions/0025-authorization-model-privileges-roles-scopes.md):
+
+- **Catalogues** (`authorization.types.ts`) — closed-set lists of the four
+  privileges (`Portal.*` Entra app roles), the 24 functional roles
+  (`apf-role-*` Entra security groups), and the six scope kinds. Adding an
+  entry is an ADR amendment, not a code change in isolation.
+- **`Principal` type** — the session-resident shape consumed by route
+  guards (`@RequirePrivilege`, `@RequireRole`, `@RequireScope`) and projected
+  to the AI service's flat `roles[]` contract.
+- **`EntraGroupToRoleResolver`** — turns the tenant-specific Entra group
+  GUIDs carried in the OIDC `groups` claim into the catalogue's role slugs.
+  Configured at boot from `infra/<env>-tenant.entra.json` (gitignored —
+  GUIDs are tenant-private).
+
+## Building
+
+Run `pnpm nx build shared-auth` to build the library.
+
+## Running unit tests
+
+Run `pnpm nx test shared-auth` to execute the unit tests via [Vitest](https://vitest.dev/).

libs/shared/auth/eslint.config.mjs

@@ -0,0 +1,22 @@
+import baseConfig from '../../../eslint.config.mjs';
+
+export default [
+  ...baseConfig,
+  {
+    files: ['**/*.json'],
+    rules: {
+      '@nx/dependency-checks': [
+        'error',
+        {
+          ignoredFiles: [
+            '{projectRoot}/eslint.config.{js,cjs,mjs,ts,cts,mts}',
+            '{projectRoot}/vite.config.{js,ts,mjs,mts}',
+          ],
+        },
+      ],
+    },
+    languageOptions: {
+      parser: await import('jsonc-eslint-parser'),
+    },
+  },
+];

libs/shared/auth/package.json

@@ -0,0 +1,13 @@
+{
+  "name": "shared-auth",
+  "version": "0.0.1",
+  "private": true,
+  "type": "commonjs",
+  "main": "./src/index.js",
+  "types": "./src/index.d.ts",
+  "dependencies": {
+    "tslib": "^2.3.0",
+    "vitest": "^4.0.8",
+    "@nx/vite": "^22.7.1"
+  }
+}

libs/shared/auth/project.json

@@ -0,0 +1,19 @@
+{
+  "name": "shared-auth",
+  "$schema": "../../../node_modules/nx/schemas/project-schema.json",
+  "sourceRoot": "libs/shared/auth/src",
+  "projectType": "library",
+  "tags": ["scope:shared", "type:shared"],
+  "targets": {
+    "build": {
+      "executor": "@nx/js:tsc",
+      "outputs": ["{options.outputPath}"],
+      "options": {
+        "outputPath": "dist/libs/shared/auth",
+        "main": "libs/shared/auth/src/index.ts",
+        "tsConfig": "libs/shared/auth/tsconfig.lib.json",
+        "assets": ["libs/shared/auth/*.md"]
+      }
+    }
+  }
+}

libs/shared/auth/src/index.ts

@@ -0,0 +1,21 @@
+export {
+  PRIVILEGES,
+  FUNCTIONAL_ROLES,
+  SCOPE_KINDS,
+  isPrivilege,
+  isFunctionalRole,
+  isScopeKind,
+} from './lib/authorization.types';
+export type {
+  Privilege,
+  FunctionalRole,
+  ScopeKind,
+  Scope,
+  Principal,
+} from './lib/authorization.types';
+export {
+  EntraGroupToRoleResolver,
+  parseEntraGroupMap,
+  EntraGroupMapError,
+} from './lib/entra-group-to-role';
+export type { EntraGroupMap, EntraGroupMapEntry } from './lib/entra-group-to-role';

libs/shared/auth/src/lib/authorization.types.spec.ts

@@ -0,0 +1,55 @@
+import { describe, expect, it } from 'vitest';
+import {
+  FUNCTIONAL_ROLES,
+  PRIVILEGES,
+  SCOPE_KINDS,
+  isFunctionalRole,
+  isPrivilege,
+  isScopeKind,
+} from './authorization.types';
+
+describe('authorization catalogues', () => {
+  // ADR-0025 §"Decision Outcome" promises specific counts. Locking
+  // them down here makes a silent slug addition fail loudly — drift
+  // between ADR text and code would defeat the closed-set posture.
+  it('contains exactly 4 privileges, 24 functional roles, 6 scope kinds', () => {
+    expect(PRIVILEGES).toHaveLength(4);
+    expect(FUNCTIONAL_ROLES).toHaveLength(24);
+    expect(SCOPE_KINDS).toHaveLength(6);
+  });
+
+  it('catalogues are deduplicated', () => {
+    expect(new Set(PRIVILEGES).size).toBe(PRIVILEGES.length);
+    expect(new Set(FUNCTIONAL_ROLES).size).toBe(FUNCTIONAL_ROLES.length);
+    expect(new Set(SCOPE_KINDS).size).toBe(SCOPE_KINDS.length);
+  });
+
+  it('privilege entries are the 4 Portal.* values provisioned in the test tenant', () => {
+    expect([...PRIVILEGES]).toEqual([
+      'Portal.Admin',
+      'Portal.Auditor',
+      'Portal.SecurityOfficer',
+      'Portal.DPO',
+    ]);
+  });
+
+  it('isPrivilege narrows to known values, rejects unknown', () => {
+    expect(isPrivilege('Portal.Admin')).toBe(true);
+    expect(isPrivilege('Portal.RogueRole')).toBe(false);
+    // Case-sensitive — Entra claim values are exact.
+    expect(isPrivilege('portal.admin')).toBe(false);
+  });
+
+  it('isFunctionalRole narrows to known values, rejects unknown', () => {
+    expect(isFunctionalRole('collaborateur')).toBe(true);
+    expect(isFunctionalRole('directeur-etablissement')).toBe(true);
+    expect(isFunctionalRole('partenaire')).toBe(true);
+    expect(isFunctionalRole('unknown-role')).toBe(false);
+  });
+
+  it('isScopeKind narrows to known values, rejects unknown', () => {
+    expect(isScopeKind('etablissement')).toBe(true);
+    expect(isScopeKind('unrestricted')).toBe(true);
+    expect(isScopeKind('etablissement:0330800013')).toBe(false);
+  });
+});

libs/shared/auth/src/lib/authorization.types.ts

@@ -0,0 +1,176 @@
+/**
+ * Authorization catalogues + types per
+ * [ADR-0025](../../../../../docs/decisions/0025-authorization-model-privileges-roles-scopes.md).
+ *
+ * The three axes are independent: a `Principal` carries a list per
+ * axis, and guards consume the structured shape. Privileges gate
+ * portal *surfaces* (admin app, audit viewer); functional roles
+ * encode *what work the person does*; scopes encode *where the role
+ * applies*. Composition happens at guard time, not at sign-in —
+ * sign-in just builds the three lists.
+ *
+ * The catalogues are **closed**: every literal that appears in a
+ * `@RequirePrivilege` / `@RequireRole` / `@RequireScope` call must
+ * be a member of the corresponding constant array. A CI drift gate
+ * (next PR per ADR-0025 §"More Information") enforces that contract
+ * against the source tree.
+ */
+
+/**
+ * Portal-level capabilities, materialised as Entra app roles on the
+ * BFF's app registration. Each privilege gates a portal surface —
+ * never a business operation in isolation. The four entries here
+ * are the entire v1 set; adding a fifth is an ADR-0025 amendment.
+ *
+ * The exact strings are the `value` field of the Entra app-role
+ * manifest and are what Entra emits in the ID-token `roles` claim.
+ */
+export const PRIVILEGES = [
+  'Portal.Admin',
+  'Portal.Auditor',
+  'Portal.SecurityOfficer',
+  'Portal.DPO',
+] as const;
+
+export type Privilege = (typeof PRIVILEGES)[number];
+
+/**
+ * Functional roles, materialised as Entra security groups named
+ * `apf-role-<slug>`. The slug is what the BFF and SPA reason about;
+ * the Entra group GUID is tenant-private and resolved to a slug at
+ * the boundary (see `entra-group-to-role.ts`).
+ *
+ * Grouped here by APF org-chart category (workforce / governance /
+ * volunteer / external) for readability, but the union below is
+ * flat — guards don't care about the category.
+ */
+export const FUNCTIONAL_ROLES = [
+  // Workforce (15) — employees on payroll.
+  'collaborateur',
+  'chef-equipe',
+  'chef-service',
+  'directeur-etablissement',
+  'directeur-territorial',
+  'rh',
+  'responsable-paie',
+  'comptable',
+  'juriste',
+  'dpo',
+  'rssi',
+  'it',
+  'formation',
+  'qualite',
+  'communication',
+  // Governance (6) — élus + local delegates.
+  'elu-ca',
+  'elu-cd',
+  'elu-cd-president',
+  'elu-cd-tresorier',
+  'elu-cd-secretaire',
+  'delegue',
+  // Volunteer (2) — bénévoles with portal access.
+  'benevole',
+  'benevole-responsable',
+  // External (1) — placeholder, no consumer surface yet in v1.
+  'partenaire',
+] as const;
+
+export type FunctionalRole = (typeof FUNCTIONAL_ROLES)[number];
+
+/**
+ * Scope kinds — the six discriminants of `Scope`. Three carry a
+ * value (`etablissement:<finess>`, `delegation:<dept>`,
+ * `region:<insee>`); three are valueless (`self`, `siege`,
+ * `unrestricted`).
+ *
+ * Adding a kind is an ADR-0025 amendment. Adding a value (a new
+ * établissement opening, a new délégation) is a data operation and
+ * does not touch this file.
+ */
+export const SCOPE_KINDS = [
+  'self',
+  'etablissement',
+  'delegation',
+  'region',
+  'siege',
+  'unrestricted',
+] as const;
+
+export type ScopeKind = (typeof SCOPE_KINDS)[number];
+
+/**
+ * A scope on a principal. Three kinds carry a tenant-specific
+ * value, three do not. Discriminated union so consumers can
+ * exhaustively switch on `kind`.
+ *
+ * `value` semantics per kind:
+ *   - `etablissement`: APE / FINESS code (`9` characters, stable
+ *     across reorgs).
+ *   - `delegation`: French department code (`2` characters,
+ *     INSEE / postal — `'33'`, `'2A'`, `'971'`).
+ *   - `region`: INSEE region code (`2` characters).
+ */
+export type Scope =
+  | { readonly kind: 'self' }
+  | { readonly kind: 'etablissement'; readonly value: string }
+  | { readonly kind: 'delegation'; readonly value: string }
+  | { readonly kind: 'region'; readonly value: string }
+  | { readonly kind: 'siege' }
+  | { readonly kind: 'unrestricted' };
+
+/**
+ * The session-resident shape consumed by route guards. Built once
+ * at sign-in by the BFF's OIDC callback, persisted as part of the
+ * session payload, refreshed on every authenticated request from
+ * the session ID. Guards never re-derive it from claims at request
+ * time — that would re-do the Entra-group-to-slug mapping on every
+ * call.
+ *
+ * `amr` and `mfaVerifiedAt` live on the principal (not separately
+ * on the session) so the AI-service projector and any guard that
+ * wants to consult MFA freshness reads a single, coherent object.
+ *
+ * `user.id` and `user.personId` will become real portal UUIDs once
+ * the `User` + `Person` schema (proposed ADR-0026) lands. Until
+ * then the BFF-side builder populates both with the Entra `oid`
+ * as a stable placeholder so consumers can already key on a
+ * "portal identifier" without branching on availability.
+ */
+export interface Principal {
+  readonly user: {
+    readonly id: string;
+    readonly personId: string;
+    readonly entraOid: string;
+    readonly tenantId: string;
+    readonly displayName: string;
+  };
+  readonly privileges: ReadonlyArray<Privilege>;
+  readonly roles: ReadonlyArray<FunctionalRole>;
+  readonly scopes: ReadonlyArray<Scope>;
+  readonly amr: ReadonlyArray<string>;
+  readonly mfaVerifiedAt?: number;
+}
+
+/* ---------------------------------------------------------------- *
+ * Membership type-guards — runtime helpers callers use to validate
+ * arbitrary strings (claim values, config map values, drift-gate
+ * findings) against the closed catalogues. Returning a type
+ * predicate makes the post-check string narrow to the catalogue
+ * type, which keeps consumers honest about the closed-set rule.
+ * ---------------------------------------------------------------- */
+
+const PRIVILEGE_SET: ReadonlySet<string> = new Set(PRIVILEGES);
+const FUNCTIONAL_ROLE_SET: ReadonlySet<string> = new Set(FUNCTIONAL_ROLES);
+const SCOPE_KIND_SET: ReadonlySet<string> = new Set(SCOPE_KINDS);
+
+export function isPrivilege(value: string): value is Privilege {
+  return PRIVILEGE_SET.has(value);
+}
+
+export function isFunctionalRole(value: string): value is FunctionalRole {
+  return FUNCTIONAL_ROLE_SET.has(value);
+}
+
+export function isScopeKind(value: string): value is ScopeKind {
+  return SCOPE_KIND_SET.has(value);
+}

libs/shared/auth/src/lib/entra-group-to-role.spec.ts

@@ -0,0 +1,95 @@
+import { describe, expect, it, vi } from 'vitest';
+import {
+  EntraGroupMapError,
+  EntraGroupToRoleResolver,
+  parseEntraGroupMap,
+} from './entra-group-to-role';
+
+const GUID_A = '11111111-1111-1111-1111-111111111111';
+const GUID_B = '22222222-2222-2222-2222-222222222222';
+const GUID_C = '33333333-3333-3333-3333-333333333333';
+
+describe('parseEntraGroupMap', () => {
+  it('builds a frozen lower-cased map from a valid record', () => {
+    const map = parseEntraGroupMap({
+      [GUID_A]: 'collaborateur',
+      [GUID_B]: 'rh',
+    });
+    expect(map.get(GUID_A)).toBe('collaborateur');
+    expect(map.get(GUID_B)).toBe('rh');
+    expect(map.size).toBe(2);
+  });
+
+  it('lower-cases GUIDs so claim-side case variance does not miss', () => {
+    const upper = '11111111-1111-1111-1111-1111111111AB';
+    const map = parseEntraGroupMap({ [upper]: 'collaborateur' });
+    expect(map.get(upper.toLowerCase())).toBe('collaborateur');
+  });
+
+  it('rejects a value that is not in the closed catalogue', () => {
+    expect(() => parseEntraGroupMap({ [GUID_A]: 'rogue-role' })).toThrow(EntraGroupMapError);
+  });
+
+  it('rejects a key that does not look like a GUID', () => {
+    expect(() => parseEntraGroupMap({ 'not-a-guid': 'collaborateur' })).toThrow(EntraGroupMapError);
+  });
+
+  it('rejects a duplicate GUID (case-insensitive)', () => {
+    // Use a GUID containing hex letters so upper/lower casing
+    // produces two distinct strings (object literals dedup
+    // identical keys before iteration).
+    const lower = 'aaaabbbb-cccc-dddd-eeee-ffff00001111';
+    const upper = lower.toUpperCase();
+    expect(() =>
+      parseEntraGroupMap({
+        [lower]: 'collaborateur',
+        [upper]: 'rh',
+      }),
+    ).toThrow(EntraGroupMapError);
+  });
+});
+
+describe('EntraGroupToRoleResolver', () => {
+  const map = parseEntraGroupMap({
+    [GUID_A]: 'collaborateur',
+    [GUID_B]: 'directeur-etablissement',
+  });
+  const resolver = new EntraGroupToRoleResolver(map);
+
+  it('resolves known group GUIDs to catalogue role slugs', () => {
+    expect(resolver.resolve([GUID_A, GUID_B])).toEqual([
+      'collaborateur',
+      'directeur-etablissement',
+    ]);
+  });
+
+  it('orders the output by FUNCTIONAL_ROLES declaration, not claim order', () => {
+    // Claim order is `directeur-etablissement` first, then
+    // `collaborateur`. Resolver re-orders for deterministic logs
+    // and snapshot tests.
+    expect(resolver.resolve([GUID_B, GUID_A])).toEqual([
+      'collaborateur',
+      'directeur-etablissement',
+    ]);
+  });
+
+  it('deduplicates if the same GUID appears twice in the claim', () => {
+    expect(resolver.resolve([GUID_A, GUID_A])).toEqual(['collaborateur']);
+  });
+
+  it('skips unknown GUIDs and reports them via the optional callback', () => {
+    const onUnknown = vi.fn();
+    const out = resolver.resolve([GUID_A, GUID_C], onUnknown);
+    expect(out).toEqual(['collaborateur']);
+    expect(onUnknown).toHaveBeenCalledTimes(1);
+    expect(onUnknown).toHaveBeenCalledWith(GUID_C);
+  });
+
+  it('returns an empty list when the user has no groups', () => {
+    expect(resolver.resolve([])).toEqual([]);
+  });
+
+  it('coveredRoles() returns only mapped roles, in catalogue order', () => {
+    expect(resolver.coveredRoles()).toEqual(['collaborateur', 'directeur-etablissement']);
+  });
+});

libs/shared/auth/src/lib/entra-group-to-role.ts

@@ -0,0 +1,146 @@
+import { FUNCTIONAL_ROLES, isFunctionalRole, type FunctionalRole } from './authorization.types';
+
+/**
+ * One entry in the GUID → role-slug map. Surfaced as an explicit
+ * type so callers can build the map programmatically (e.g. tests,
+ * a future Microsoft Graph sync) without resorting to a bare
+ * `Record<string, string>` that loses the closed-set guarantee.
+ */
+export interface EntraGroupMapEntry {
+  readonly groupId: string;
+  readonly role: FunctionalRole;
+}
+
+/**
+ * The resolved map keyed on Entra group GUID. Frozen at parse time
+ * so the resolver cannot mutate it. Lookup is `O(1)`; the values
+ * are guaranteed to belong to the closed `FUNCTIONAL_ROLES`
+ * catalogue by the parser.
+ */
+export type EntraGroupMap = ReadonlyMap<string, FunctionalRole>;
+
+/**
+ * Thrown by `parseEntraGroupMap` when the operator-supplied
+ * configuration is malformed. The map is loaded once at BFF boot —
+ * a malformed file should crash the process, not silently degrade
+ * authorization. The error message points at the offending key /
+ * value so the runbook can fix the config without spelunking
+ * through stack traces.
+ */
+export class EntraGroupMapError extends Error {
+  override readonly name = 'EntraGroupMapError';
+  constructor(message: string) {
+    super(message);
+  }
+}
+
+/**
+ * Validates a raw `{ <guid>: <role-slug> }` mapping (as it would
+ * arrive from `JSON.parse` of an `infra/<env>-tenant.entra.json`
+ * file) into a frozen `EntraGroupMap`.
+ *
+ * Validation rules:
+ *   - keys must look like a GUID (8-4-4-4-12 hex pattern, case-
+ *     insensitive). Entra group GUIDs are stable; a typo here
+ *     would silently strip a role from every sign-in.
+ *   - values must be in `FUNCTIONAL_ROLES`. Catalogue drift is
+ *     caught at boot, not at the first user who happens to be in
+ *     the affected group.
+ *   - duplicate GUIDs (case-insensitive) are rejected. Two slugs
+ *     pointing at the same group would silently shadow one another
+ *     depending on the JS engine's object-key iteration order.
+ *
+ * The function deliberately does *not* require every role in the
+ * catalogue to have a GUID — `partenaire` ships empty in v1 by
+ * design (ADR-0025 §"Test-tenant personas"), and dev tenants may
+ * provision a subset for fast iteration. The BFF logs a one-line
+ * boot summary listing which roles are mapped so the operator can
+ * spot accidental omissions.
+ */
+export function parseEntraGroupMap(raw: Readonly<Record<string, string>>): EntraGroupMap {
+  const map = new Map<string, FunctionalRole>();
+  const lowercased = new Set<string>();
+
+  for (const [groupId, role] of Object.entries(raw)) {
+    if (!GUID_RE.test(groupId)) {
+      throw new EntraGroupMapError(
+        `Invalid GUID "${groupId}" in Entra group map (expected 8-4-4-4-12 hex).`,
+      );
+    }
+    if (!isFunctionalRole(role)) {
+      throw new EntraGroupMapError(
+        `Unknown role slug "${role}" for group "${groupId}". ` +
+          `Catalogue is closed; legal slugs are: ${FUNCTIONAL_ROLES.join(', ')}.`,
+      );
+    }
+    const lower = groupId.toLowerCase();
+    if (lowercased.has(lower)) {
+      throw new EntraGroupMapError(`Duplicate group GUID "${groupId}" in Entra group map.`);
+    }
+    lowercased.add(lower);
+    map.set(lower, role);
+  }
+
+  return map;
+}
+
+/**
+ * Resolves the `groups` claim from an Entra ID token (a list of
+ * group GUIDs the user belongs to) into a list of catalogue-valid
+ * `FunctionalRole` slugs. The OIDC callback (`session-establisher`)
+ * calls `resolve()` once per sign-in.
+ *
+ * Unknown GUIDs are ignored at the role level — `resolve()` simply
+ * skips them — but reported via the `onUnknownGroup` callback so
+ * the host application can log a WARN (per ADR-0025
+ * §"Sources of truth — Entra-side configuration": "Unknown group
+ * GUIDs are logged at WARN and ignored — they do not break sign-in,
+ * but they signal a tenant misconfiguration that should be cleaned
+ * up").
+ *
+ * Output is deduplicated and ordered to match the catalogue's
+ * declaration order (`FUNCTIONAL_ROLES`). Deterministic output
+ * keeps snapshot tests stable and makes log inspection easier.
+ */
+export class EntraGroupToRoleResolver {
+  constructor(private readonly map: EntraGroupMap) {}
+
+  /**
+   * Number of entries in the map. Surfaced for the boot-time log
+   * line the BFF emits ("resolver loaded with N mappings").
+   */
+  get size(): number {
+    return this.map.size;
+  }
+
+  /**
+   * Roles currently covered by the map. The BFF can log this set
+   * at boot to spot accidental omissions (e.g. a dev tenant that
+   * forgot to provision `dpo`). Returned sorted by catalogue order
+   * for stable logs.
+   */
+  coveredRoles(): ReadonlyArray<FunctionalRole> {
+    const covered = new Set(this.map.values());
+    return FUNCTIONAL_ROLES.filter((role) => covered.has(role));
+  }
+
+  resolve(
+    groupIds: ReadonlyArray<string>,
+    onUnknownGroup?: (groupId: string) => void,
+  ): ReadonlyArray<FunctionalRole> {
+    const matched = new Set<FunctionalRole>();
+    for (const raw of groupIds) {
+      const role = this.map.get(raw.toLowerCase());
+      if (role === undefined) {
+        if (onUnknownGroup) {
+          onUnknownGroup(raw);
+        }
+        continue;
+      }
+      matched.add(role);
+    }
+    return FUNCTIONAL_ROLES.filter((role) => matched.has(role));
+  }
+}
+
+const GUID_RE = /^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$/i;

libs/shared/auth/tsconfig.json

@@ -0,0 +1,23 @@
+{
+  "extends": "../../../tsconfig.base.json",
+  "compilerOptions": {
+    "module": "esnext",
+    "forceConsistentCasingInFileNames": true,
+    "strict": true,
+    "importHelpers": true,
+    "noImplicitOverride": true,
+    "noImplicitReturns": true,
+    "noFallthroughCasesInSwitch": true,
+    "noPropertyAccessFromIndexSignature": true
+  },
+  "files": [],
+  "include": [],
+  "references": [
+    {
+      "path": "./tsconfig.lib.json"
+    },
+    {
+      "path": "./tsconfig.spec.json"
+    }
+  ]
+}

libs/shared/auth/tsconfig.lib.json

@@ -0,0 +1,23 @@
+{
+  "extends": "./tsconfig.json",
+  "compilerOptions": {
+    "outDir": "../../../dist/out-tsc",
+    "declaration": true,
+    "types": ["node"]
+  },
+  "include": ["src/**/*.ts"],
+  "exclude": [
+    "vite.config.ts",
+    "vite.config.mts",
+    "vitest.config.ts",
+    "vitest.config.mts",
+    "src/**/*.test.ts",
+    "src/**/*.spec.ts",
+    "src/**/*.test.tsx",
+    "src/**/*.spec.tsx",
+    "src/**/*.test.js",
+    "src/**/*.spec.js",
+    "src/**/*.test.jsx",
+    "src/**/*.spec.jsx"
+  ]
+}

libs/shared/auth/tsconfig.spec.json

@@ -0,0 +1,22 @@
+{
+  "extends": "./tsconfig.json",
+  "compilerOptions": {
+    "outDir": "../../../dist/out-tsc",
+    "types": ["vitest/globals", "vitest/importMeta", "vite/client", "node", "vitest"]
+  },
+  "include": [
+    "vite.config.ts",
+    "vite.config.mts",
+    "vitest.config.ts",
+    "vitest.config.mts",
+    "src/**/*.test.ts",
+    "src/**/*.spec.ts",
+    "src/**/*.test.tsx",
+    "src/**/*.spec.tsx",
+    "src/**/*.test.js",
+    "src/**/*.spec.js",
+    "src/**/*.test.jsx",
+    "src/**/*.spec.jsx",
+    "src/**/*.d.ts"
+  ]
+}

libs/shared/auth/vitest.config.mts

@@ -0,0 +1,21 @@
+import { defineConfig } from 'vitest/config';
+import { nxViteTsPaths } from '@nx/vite/plugins/nx-tsconfig-paths.plugin';
+import { nxCopyAssetsPlugin } from '@nx/vite/plugins/nx-copy-assets.plugin';
+
+export default defineConfig(() => ({
+  root: __dirname,
+  cacheDir: '../../../node_modules/.vite/libs/shared/auth',
+  plugins: [nxViteTsPaths(), nxCopyAssetsPlugin(['*.md'])],
+  test: {
+    name: 'shared-auth',
+    watch: false,
+    globals: true,
+    environment: 'node',
+    include: ['{src,tests}/**/*.{test,spec}.{js,mjs,cjs,ts,mts,cts,jsx,tsx}'],
+    reporters: ['default'],
+    coverage: {
+      reportsDirectory: '../../../coverage/libs/shared/auth',
+      provider: 'v8' as const,
+    },
+  },
+}));

tsconfig.base.json

@@ -2,6 +2,7 @@
   "compilerOptions": {
     "rootDir": ".",
     "paths": {
+      "shared-auth": ["./libs/shared/auth/src/index.ts"],
       "shared-tokens": ["./libs/shared/tokens/src/index.ts"],
       "shared-util": ["./libs/shared/util/src/index.ts"],
       "shared-ui": ["./libs/shared/ui/src/index.ts"],