diff --git a/apps/api/src/app.ts b/apps/api/src/app.ts
index 03eba80..f243879 100644
--- a/apps/api/src/app.ts
+++ b/apps/api/src/app.ts
@@ -2,6 +2,7 @@ import { Hono } from 'hono';
 import { cors } from 'hono/cors';
 import { healthRouter } from './routes/health';
 import { createAuthRouter } from './routes/auth/auth-router';
+import { createProbeRouter } from './routes/_probe/probe-router';
 import type { Db } from './infrastructure/db';
 import type { AppConfig } from './config';
 import type { Logger } from './lib/logger';
@@ -18,6 +19,7 @@ export function createApp(deps?: AppDeps): Hono {
   app.route('/', healthRouter);
   if (deps) {
     app.route('/', createAuthRouter(deps));
+    app.route('/api/_probe', createProbeRouter(deps));
   }
   return app;
 }
diff --git a/apps/api/src/index.ts b/apps/api/src/index.ts
index 6b25df1..8dbe0ba 100644
--- a/apps/api/src/index.ts
+++ b/apps/api/src/index.ts
@@ -1,3 +1,6 @@
+import { readFileSync, existsSync } from 'node:fs';
+import { resolve, dirname } from 'node:path';
+import { fileURLToPath } from 'node:url';
 import { serve } from '@hono/node-server';
 import { createApp } from './app';
 import { loadConfig } from './config';
@@ -5,6 +8,18 @@ import { checkEnv } from './lib/env-guard';
 import { createLogger } from './lib/logger';
 import { createDb } from './infrastructure/db';
 
+const rootEnv = resolve(dirname(fileURLToPath(import.meta.url)), '../../..', '.env');
+if (existsSync(rootEnv)) {
+  for (const line of readFileSync(rootEnv, 'utf-8').split('\n')) {
+    if (!line || line.startsWith('#')) continue;
+    const eq = line.indexOf('=');
+    if (eq === -1) continue;
+    const key = line.slice(0, eq).trim();
+    const val = line.slice(eq + 1).trim();
+    if (key && !(key in process.env)) process.env[key] = val;
+  }
+}
+
 checkEnv();
 const config = loadConfig();
 const logger = createLogger();
diff --git a/apps/api/src/middleware/require-auth.test.ts b/apps/api/src/middleware/require-auth.test.ts
new file mode 100644
index 0000000..9196393
--- /dev/null
+++ b/apps/api/src/middleware/require-auth.test.ts
@@ -0,0 +1,82 @@
+import { describe, it, expect } from 'vitest';
+import { Hono } from 'hono';
+import { requireRole } from './require-auth';
+import type { AppVariables, UserRole } from '../domain/auth/types';
+import type { Logger } from '../lib/logger';
+
+function makeLogger(): Logger & { warns: Array<[string, unknown?]> } {
+  const warns: Array<[string, unknown?]> = [];
+  return {
+    info: () => {},
+    warn: (event: string, ctx?: unknown) => warns.push([event, ctx]),
+    error: () => {},
+    warns,
+  };
+}
+
+function makeApp(
+  contextRole: string,
+  contextUserId: string,
+  allowedRoles: unknown[],
+  logger: Logger,
+) {
+  const app = new Hono<{ Variables: AppVariables }>();
+  app.get('/test', async (c, next) => {
+    c.set('userId', contextUserId);
+    c.set('userRole', contextRole as UserRole);
+    await next();
+  });
+  app.get('/test', requireRole(allowedRoles as UserRole[], { logger }), (c) =>
+    c.json({ ok: true }),
+  );
+  return app;
+}
+
+describe('requireRole middleware', () => {
+  it('allows a doctor when role is doctor', async () => {
+    const logger = makeLogger();
+    const app = makeApp('doctor', 'uid-1', ['doctor'], logger);
+    const res = await app.request('/test');
+    expect(res.status).toBe(200);
+    expect(await res.json()).toEqual({ ok: true });
+  });
+
+  it('returns 403 when patient hits a doctor-only route', async () => {
+    const logger = makeLogger();
+    const app = makeApp('patient', 'uid-2', ['doctor'], logger);
+    const res = await app.request('/test');
+    expect(res.status).toBe(403);
+    expect(await res.json()).toEqual({ error: 'Forbidden' });
+  });
+
+  it('allows a patient when role is patient', async () => {
+    const logger = makeLogger();
+    const app = makeApp('patient', 'uid-3', ['patient'], logger);
+    const res = await app.request('/test');
+    expect(res.status).toBe(200);
+  });
+
+  it('returns 403 when doctor hits a patient-only route', async () => {
+    const logger = makeLogger();
+    const app = makeApp('doctor', 'uid-4', ['patient'], logger);
+    const res = await app.request('/test');
+    expect(res.status).toBe(403);
+  });
+
+  it('logs auth.rbac.denied with user_id, role, and path on 403', async () => {
+    const logger = makeLogger();
+    const app = makeApp('patient', 'uid-5', ['doctor'], logger);
+    await app.request('/test');
+    expect(logger.warns).toHaveLength(1);
+    const [event, ctx] = logger.warns[0]!;
+    expect(event).toBe('auth.rbac.denied');
+    expect(ctx).toMatchObject({ user_id: 'uid-5', role: 'patient', path: '/test' });
+  });
+
+  it('rejects a junk role even when it appears in allowedRoles (defense-in-depth)', async () => {
+    const logger = makeLogger();
+    const app = makeApp('admin', 'uid-6', ['admin', 'doctor', 'patient'], logger);
+    const res = await app.request('/test');
+    expect(res.status).toBe(403);
+  });
+});
diff --git a/apps/api/src/middleware/require-auth.ts b/apps/api/src/middleware/require-auth.ts
index e0f93eb..f70c0fb 100644
--- a/apps/api/src/middleware/require-auth.ts
+++ b/apps/api/src/middleware/require-auth.ts
@@ -36,14 +36,20 @@ export function requireAuth(deps: {
   };
 }
 
+const VALID_ROLES = new Set<string>(['doctor', 'patient']);
+
 export function requireRole(
   roles: UserRole[],
   deps: { logger: Logger },
 ): MiddlewareHandler<Env> {
   return async (c, next) => {
-    const role = c.get('userRole');
-    if (!role || !roles.includes(role)) {
-      deps.logger.warn('auth.rbac.denied', { role, requiredRoles: roles });
+    const role = c.get('userRole') as string | undefined;
+    if (!role || !VALID_ROLES.has(role) || !roles.includes(role as UserRole)) {
+      deps.logger.warn('auth.rbac.denied', {
+        user_id: c.get('userId'),
+        role,
+        path: c.req.path,
+      });
       return c.json({ error: 'Forbidden' }, 403);
     }
     await next();
diff --git a/apps/api/src/routes/_probe/probe-router.test.ts b/apps/api/src/routes/_probe/probe-router.test.ts
new file mode 100644
index 0000000..4d1933c
--- /dev/null
+++ b/apps/api/src/routes/_probe/probe-router.test.ts
@@ -0,0 +1,55 @@
+import { describe, it, expect } from 'vitest';
+import { signJwt } from '../../lib/jwt';
+import { createProbeRouter } from './probe-router';
+
+const SECRET = 'test-secret-that-is-at-least-32-chars-long';
+
+function makeLogger() {
+  return { info: () => {}, warn: () => {}, error: () => {} };
+}
+
+function makeRouter() {
+  return createProbeRouter({ config: { JWT_SECRET: SECRET }, logger: makeLogger() });
+}
+
+function authHeader(role: 'doctor' | 'patient') {
+  return { Authorization: `Bearer ${signJwt({ sub: 'uid-probe', role }, SECRET)}` };
+}
+
+describe('GET /doctor-only probe route', () => {
+  it('returns 200 { ok: true } for a doctor', async () => {
+    const router = makeRouter();
+    const res = await router.request('/doctor-only', { headers: authHeader('doctor') });
+    expect(res.status).toBe(200);
+    expect(await res.json()).toEqual({ ok: true });
+  });
+
+  it('returns 403 for a patient', async () => {
+    const router = makeRouter();
+    const res = await router.request('/doctor-only', { headers: authHeader('patient') });
+    expect(res.status).toBe(403);
+    expect(await res.json()).toEqual({ error: 'Forbidden' });
+  });
+
+  it('returns 401 with no token', async () => {
+    const router = makeRouter();
+    const res = await router.request('/doctor-only');
+    expect(res.status).toBe(401);
+  });
+});
+
+describe('GET /patient-only probe route', () => {
+  it('returns 200 { ok: true } for a patient', async () => {
+    const router = makeRouter();
+    const res = await router.request('/patient-only', { headers: authHeader('patient') });
+    expect(res.status).toBe(200);
+    expect(await res.json()).toEqual({ ok: true });
+  });
+
+  it('returns 403 for a doctor', async () => {
+    const router = makeRouter();
+    const res = await router.request('/patient-only', { headers: authHeader('doctor') });
+    expect(res.status).toBe(403);
+    expect(await res.json()).toEqual({ error: 'Forbidden' });
+  });
+});
diff --git a/apps/api/src/routes/_probe/probe-router.ts b/apps/api/src/routes/_probe/probe-router.ts
new file mode 100644
index 0000000..8b52270
--- /dev/null
+++ b/apps/api/src/routes/_probe/probe-router.ts
@@ -0,0 +1,30 @@
+import { Hono } from 'hono';
+import type { AppConfig } from '../../config';
+import type { Logger } from '../../lib/logger';
+import type { AppVariables } from '../../domain/auth/types';
+import { requireAuth, requireRole } from '../../middleware/require-auth';
+
+export interface ProbeDeps {
+  config: Pick<AppConfig, 'JWT_SECRET'>;
+  logger: Logger;
+}
+
+export function createProbeRouter(deps: ProbeDeps): Hono<{ Variables: AppVariables }> {
+  const router = new Hono<{ Variables: AppVariables }>();
+
+  router.get(
+    '/doctor-only',
+    requireAuth(deps),
+    requireRole(['doctor'], deps),
+    (c) => c.json({ ok: true as const }),
+  );
+
+  router.get(
+    '/patient-only',
+    requireAuth(deps),
+    requireRole(['patient'], deps),
+    (c) => c.json({ ok: true as const }),
+  );
+
+  return router;
+}
diff --git a/apps/web/src/lib/api-client.ts b/apps/web/src/lib/api-client.ts
index 5294532..dc1f670 100644
--- a/apps/web/src/lib/api-client.ts
+++ b/apps/web/src/lib/api-client.ts
@@ -9,16 +9,15 @@ export const apiClient = initClient(apiContract, {
   baseHeaders: {},
   api: async ({ path, method, headers, body }) => {
     const token = getToken();
-    const response = await fetch(`${baseUrl}${path}`, {
+    const response = await fetch(path, {
       method,
       headers: {
-        'Content-Type': 'application/json',
         ...headers,
         ...(token ? { Authorization: `Bearer ${token}` } : {}),
       },
-      body: body !== null && body !== undefined ? JSON.stringify(body) : undefined,
+      body: body ?? undefined,
     });
-    const data = await response.json().catch(() => null) as unknown;
+    const data = (await response.json().catch(() => null)) as unknown;
     return { status: response.status, body: data, headers: response.headers };
   },
 });
diff --git a/apps/web/src/routes/login.tsx b/apps/web/src/routes/login.tsx
index bf70db2..0cab3df 100644
--- a/apps/web/src/routes/login.tsx
+++ b/apps/web/src/routes/login.tsx
@@ -1,5 +1,5 @@
 import { type FormEvent, useState } from 'react';
-import { createRoute, useNavigate } from '@tanstack/react-router';
+import { createRoute, useNavigate, redirect, isRedirect } from '@tanstack/react-router';
 import { useMutation, useQueryClient } from '@tanstack/react-query';
 import { rootRoute } from './__root';
 import { apiClient } from '../lib/api-client';
@@ -9,6 +9,14 @@ import { currentUserQueryOptions } from '../features/auth/queries';
 export const loginRoute = createRoute({
   getParentRoute: () => rootRoute,
   path: '/login',
+  beforeLoad: async ({ context: { queryClient } }) => {
+    try {
+      const user = await queryClient.ensureQueryData(currentUserQueryOptions);
+      throw redirect({ to: `/${user.role}` });
+    } catch (e) {
+      if (isRedirect(e)) throw e;
+    }
+  },
   component: LoginPage,
 });
 
diff --git a/packages/contracts/src/contract.ts b/packages/contracts/src/contract.ts
index 726c8cc..76e0956 100644
--- a/packages/contracts/src/contract.ts
+++ b/packages/contracts/src/contract.ts
@@ -6,6 +6,7 @@ import { documentsContract } from './documents';
 import { doctorContract } from './doctor';
 import { appointmentsContract } from './appointments';
 import { visitsContract } from './visits';
+import { probeContract } from './probe';
 
 const c = initContract();
 
@@ -20,6 +21,7 @@ export const apiContract = c.router({
   doctor: doctorContract,
   appointments: appointmentsContract,
   visits: visitsContract,
+  probe: probeContract,
 });
 
 export type ApiContract = typeof apiContract;
diff --git a/packages/contracts/src/probe.ts b/packages/contracts/src/probe.ts
new file mode 100644
index 0000000..ac63474
--- /dev/null
+++ b/packages/contracts/src/probe.ts
@@ -0,0 +1,28 @@
+import { initContract } from '@ts-rest/core';
+import { z } from 'zod';
+
+const c = initContract();
+
+const probeOkSchema = z.object({ ok: z.literal(true) });
+const errorResponseSchema = z.object({ error: z.string() });
+
+export const probeContract = c.router({
+  doctorOnly: {
+    method: 'GET',
+    path: '/api/_probe/doctor-only',
+    responses: {
+      200: probeOkSchema,
+      401: errorResponseSchema,
+      403: errorResponseSchema,
+    },
+  },
+  patientOnly: {
+    method: 'GET',
+    path: '/api/_probe/patient-only',
+    responses: {
+      200: probeOkSchema,
+      401: errorResponseSchema,
+      403: errorResponseSchema,
+    },
+  },
+});
diff --git a/test/e2e/auth.spec.ts b/test/e2e/auth.spec.ts
index 7f4a6bf..3dbbc2c 100644
--- a/test/e2e/auth.spec.ts
+++ b/test/e2e/auth.spec.ts
@@ -95,4 +95,28 @@ test.describe('Authentication', () => {
 
     await page.waitForURL('**/patient', { timeout: 5_000 });
   });
+
+  test('logged-in doctor visiting /login is redirected to /doctor', async ({ page }) => {
+    await page.goto('/login');
+    await page.getByLabel('Email').fill(DOCTOR_EMAIL);
+    await page.getByLabel('Password').fill(DOCTOR_PASSWORD);
+    await page.getByRole('button', { name: /sign in/i }).click();
+    await page.waitForURL('**/doctor');
+
+    await page.goto('/login');
+
+    await page.waitForURL('**/doctor', { timeout: 5_000 });
+  });
+
+  test('logged-in patient visiting /login is redirected to /patient', async ({ page }) => {
+    await page.goto('/login');
+    await page.getByLabel('Email').fill(PATIENT_EMAIL);
+    await page.getByLabel('Password').fill(PATIENT_PASSWORD);
+    await page.getByRole('button', { name: /sign in/i }).click();
+    await page.waitForURL('**/patient');
+
+    await page.goto('/login');
+
+    await page.waitForURL('**/patient', { timeout: 5_000 });
+  });
 });