Merge pull request 'feat(auth): P5-004 Authentik OIDC adapter via Better Auth genericOAuth' (#97) from feat/p5-sso-authentik into main

apps/gateway/src/main.ts

@@ -12,6 +12,15 @@ async function bootstrap(): Promise<void> {
     throw new Error('BETTER_AUTH_SECRET is required');
   }
 
+  if (
+    process.env['AUTHENTIK_CLIENT_ID'] &&
+    (!process.env['AUTHENTIK_CLIENT_SECRET'] || !process.env['AUTHENTIK_ISSUER'])
+  ) {
+    console.warn(
+      '[warn] AUTHENTIK_CLIENT_ID is set but AUTHENTIK_CLIENT_SECRET or AUTHENTIK_ISSUER is missing — Authentik SSO will not work',
+    );
+  }
+
   const logger = new Logger('Bootstrap');
   const app = await NestFactory.create<NestFastifyApplication>(
     AppModule,

docs/plans/authentik-sso-setup.md

@@ -0,0 +1,40 @@
+# Authentik SSO Setup
+
+## Create the Authentik application
+
+1. In Authentik, create an OAuth2/OpenID Provider.
+2. Create an Application and link it to that provider.
+3. Copy the generated client ID and client secret.
+
+## Required environment variables
+
+Set these values for the gateway/auth runtime:
+
+```bash
+AUTHENTIK_CLIENT_ID=your-client-id
+AUTHENTIK_CLIENT_SECRET=your-client-secret
+AUTHENTIK_ISSUER=https://authentik.example.com
+```
+
+`AUTHENTIK_ISSUER` should be the Authentik base URL, for example `https://authentik.example.com`.
+
+## Redirect URI
+
+Configure this redirect URI in the Authentik provider/application:
+
+```text
+{BETTER_AUTH_URL}/api/auth/callback/authentik
+```
+
+Example:
+
+```text
+https://mosaic.example.com/api/auth/callback/authentik
+```
+
+## Test the flow
+
+1. Start the gateway with `BETTER_AUTH_URL` and the Authentik environment variables set.
+2. Open the Mosaic login flow and choose the Authentik provider.
+3. Complete the Authentik login.
+4. Confirm the browser returns to Mosaic and a session is created successfully.

docs/scratchpads/p5-004-authentik-sso.md

@@ -0,0 +1,44 @@
+# P5-004 Scratchpad
+
+- Objective: Add optional Authentik OIDC SSO adapter via Better Auth genericOAuth.
+- Task ref: P5-004
+- Issue ref: #96
+- Plan:
+  1. Inspect auth/gateway surfaces and Better Auth plugin shape.
+  2. Add failing coverage for auth config/startup validation where feasible.
+  3. Implement adapter, docs, and warnings.
+  4. Run targeted typechecks, lint, and review.
+
+- TDD note: no low-friction auth plugin or bootstrap-env test seam exists for `packages/auth/src/auth.ts` or `apps/gateway/src/main.ts`. This change is configuration-oriented and does not alter an existing behavioral contract with a current test harness. I skipped new tests for this pass and relied on exact typecheck/lint/test commands plus manual review.
+
+- Changes:
+  1. Added conditional Better Auth `genericOAuth` plugin registration for the `authentik` provider in `packages/auth/src/auth.ts`.
+  2. Added a soft startup warning in `apps/gateway/src/main.ts` for incomplete Authentik env configuration.
+  3. Added `docs/plans/authentik-sso-setup.md` with env, redirect URI, and test-flow guidance.
+  4. Confirmed `packages/auth/src/index.ts` already exports `AuthConfig`; no change required there.
+
+- Verification:
+  1. `pnpm --filter @mosaic/db build`
+  2. `pnpm --filter @mosaic/auth typecheck`
+  3. `pnpm --filter @mosaic/gateway typecheck`
+  4. `pnpm lint`
+  5. `pnpm format:check`
+  6. `pnpm --filter @mosaic/auth test`
+  7. `pnpm --filter @mosaic/gateway test`
+
+- Results:
+  1. `@mosaic/auth` typecheck passed after replacing the non-existent `enabled` field with conditional plugin registration.
+  2. `@mosaic/gateway` typecheck passed.
+  3. Repo lint passed.
+  4. Prettier check passed after formatting `apps/gateway/src/main.ts`.
+  5. `@mosaic/auth` tests reported `No test files found, exiting with code 0`.
+  6. `@mosaic/gateway` tests passed: `3` files, `20` tests.
+
+- Review:
+  1. Manual review of the diff found no blocker issues.
+  2. External `codex-code-review.sh --uncommitted` was attempted but did not return a usable verdict in-session; no automated review findings were available from that run.
+
+- Situational evidence:
+  1. Provider activation is env-gated by `AUTHENTIK_CLIENT_ID`.
+  2. Misconfigured optional SSO surfaces a warning instead of crashing gateway startup.
+  3. Setup doc records the expected redirect path: `{BETTER_AUTH_URL}/api/auth/callback/authentik`.

packages/auth/src/auth.ts

@@ -1,5 +1,6 @@
 import { betterAuth } from 'better-auth';
 import { drizzleAdapter } from 'better-auth/adapters/drizzle';
+import { genericOAuth } from 'better-auth/plugins';
 import type { Db } from '@mosaic/db';
 
 export interface AuthConfig {
@@ -10,6 +11,33 @@ export interface AuthConfig {
 
 export function createAuth(config: AuthConfig) {
   const { db, baseURL, secret } = config;
+  const authentikIssuer = process.env['AUTHENTIK_ISSUER'];
+  const authentikClientId = process.env['AUTHENTIK_CLIENT_ID'];
+  const authentikClientSecret = process.env['AUTHENTIK_CLIENT_SECRET'];
+  const plugins = authentikClientId
+    ? [
+        genericOAuth({
+          config: [
+            {
+              providerId: 'authentik',
+              clientId: authentikClientId,
+              clientSecret: authentikClientSecret ?? '',
+              discoveryUrl: authentikIssuer
+                ? `${authentikIssuer}/.well-known/openid-configuration`
+                : undefined,
+              authorizationUrl: authentikIssuer
+                ? `${authentikIssuer}/application/o/authorize/`
+                : undefined,
+              tokenUrl: authentikIssuer ? `${authentikIssuer}/application/o/token/` : undefined,
+              userInfoUrl: authentikIssuer
+                ? `${authentikIssuer}/application/o/userinfo/`
+                : undefined,
+              scopes: ['openid', 'email', 'profile'],
+            },
+          ],
+        }),
+      ]
+    : undefined;
 
   return betterAuth({
     database: drizzleAdapter(db, {
@@ -36,6 +64,7 @@ export function createAuth(config: AuthConfig) {
       expiresIn: 60 * 60 * 24 * 7, // 7 days
       updateAge: 60 * 60 * 24, // refresh daily
     },
+    plugins,
   });
 }