diff --git a/bun.lockb b/bun.lockb
index caf76b7..a887a6d 100755
Binary files a/bun.lockb and b/bun.lockb differ
diff --git a/package.json b/package.json
index caa0599..e4f2fc7 100644
--- a/package.json
+++ b/package.json
@@ -5,8 +5,7 @@
     "prisma"
   ],
   "devDependencies": {
-    "@sveltejs/adapter-auto": "^3.0.1",
-    "@sveltejs/adapter-node": "^2.0.1",
+    "@sveltejs/adapter-node": "^2.0.2",
     "@sveltejs/enhanced-img": "^0.1.7",
     "@sveltejs/vite-plugin-svelte": "^3.0.1",
     "@tailwindcss/forms": "^0.5.7",
diff --git a/src/app.d.ts b/src/app.d.ts
index 7f3235d..aed052f 100644
--- a/src/app.d.ts
+++ b/src/app.d.ts
@@ -1,9 +1,17 @@
+import type { Auth as AuthType } from '$lib/server/auth';
+import type { PrismaClient } from '@prisma/client';
+import type { AuthRequest, Session } from 'lucia';
+
 // See https://kit.svelte.dev/docs/types#app
 // for information about these interfaces
 declare global {
   namespace App {
     // interface Error {}
-    // interface Locals {}
+    interface Locals {
+      db: PrismaClient;
+      auth: AuthRequest;
+      session: Session | null;
+    }
     interface PageData {
       seo?: {
         title?: string;
@@ -16,6 +24,16 @@ declare global {
     // interface PageState {}
     // interface Platform {}
   }
+
+  namespace Lucia {
+    type Auth = AuthType;
+    type DatabaseUserAttributes = {
+      username: string;
+      disallowedIngredients: string | null;
+    };
+    // eslint-disable-next-line @typescript-eslint/ban-types
+    type DatabaseSessionAttributes = {};
+  }
 }
 
 export {};
diff --git a/src/hooks.server.ts b/src/hooks.server.ts
new file mode 100644
index 0000000..12484db
--- /dev/null
+++ b/src/hooks.server.ts
@@ -0,0 +1,12 @@
+import { auth } from '$lib/server/auth';
+import { db } from '$lib/server/db';
+
+import type { Handle } from '@sveltejs/kit';
+
+export const handle: Handle = async ({ event, resolve }) => {
+  event.locals.db = db;
+  event.locals.auth = auth.handleRequest(event);
+  event.locals.session = await event.locals.auth.validate();
+
+  return resolve(event);
+};
diff --git a/src/routes/+layout.server.ts b/src/routes/+layout.server.ts
index f9639fa..6fb6d79 100644
--- a/src/routes/+layout.server.ts
+++ b/src/routes/+layout.server.ts
@@ -1,11 +1,8 @@
 import type { LayoutServerLoad } from './$types';
 
-export const load = (async () => {
+export const load = (async ({ locals }) => {
   return {
-    user: {
-      username: 'Carlos',
-      disallowedIngredients: ['chocolat'],
-    },
+    user: locals.session?.user,
     seo: {
       title: 'CookConnect',
       meta: {
diff --git a/src/routes/+layout.svelte b/src/routes/+layout.svelte
index 97c1d9c..7420903 100644
--- a/src/routes/+layout.svelte
+++ b/src/routes/+layout.svelte
@@ -7,6 +7,7 @@
 
   import type { LayoutData } from './$types';
 
+  import { enhance } from '$app/forms';
   import { page } from '$app/stores';
 
   export let data: LayoutData;
@@ -49,15 +50,17 @@
       <nav class="flex items-center lg:order-2 sm:mx-0 mx-auto">
         <ul class="contents">
           <li>
-            <button
-              type="button"
-              class="
+            <form method="POST" action="/?/logout" use:enhance>
+              <button
+                type="submit"
+                class="
                 text-gray-800 hover:bg-gray-50 focus:ring-4 focus:ring-gray-300 font-medium
                 rounded-lg text-sm px-4 lg:px-5 py-2 lg:py-2.5 mr-2 focus:outline-none
               "
-            >
-              Se déconnecter
-            </button>
+              >
+                Se déconnecter
+              </button>
+            </form>
           </li>
           <li>
             <a
diff --git a/src/routes/+page.server.ts b/src/routes/+page.server.ts
index 9051dc4..5b271a8 100644
--- a/src/routes/+page.server.ts
+++ b/src/routes/+page.server.ts
@@ -1,6 +1,16 @@
-import type { PageServerLoad } from './$types';
+import { fail, redirect } from '@sveltejs/kit';
+
+import { auth } from '$lib/server/auth';
+
+import type { Actions, PageServerLoad } from './$types';
+
+export const load = (async ({ locals }) => {
+  const { session } = locals;
+
+  if (!session) {
+    redirect(303, '/login');
+  }
 
-export const load = (async () => {
   return {
     seo: {
       title: 'CookConnect',
@@ -11,3 +21,24 @@ export const load = (async () => {
     },
   };
 }) satisfies PageServerLoad;
+
+export const actions = {
+  logout: async ({ locals, cookies }) => {
+    const { session } = locals;
+
+    if (!session) {
+      return fail(401, { error: "Vous n'êtes pas connecté." });
+    }
+
+    await auth.invalidateSession(session.sessionId);
+
+    const sessionCookie = auth.createSessionCookie(null);
+
+    cookies.set(sessionCookie.name, sessionCookie.value, {
+      ...sessionCookie.attributes,
+      path: sessionCookie.attributes.path ?? '/',
+    });
+
+    redirect(303, '/');
+  },
+} satisfies Actions;
diff --git a/src/routes/account/+page.server.ts b/src/routes/account/+page.server.ts
index 3443497..d35e077 100644
--- a/src/routes/account/+page.server.ts
+++ b/src/routes/account/+page.server.ts
@@ -1,11 +1,17 @@
-import type { PageServerLoad } from './$types';
+import { PrismaClientKnownRequestError } from '@prisma/client/runtime/library';
+import { fail, redirect } from '@sveltejs/kit';
+
+import type { Actions, PageServerLoad } from './$types';
+
+export const load = (async ({ locals }) => {
+  const { session } = locals;
+
+  if (!session) {
+    redirect(303, '/login');
+  }
 
-export const load = (async () => {
   return {
-    user: {
-      username: 'Carlos',
-      disallowedIngredients: 'chocolat',
-    },
+    user: session.user,
     seo: {
       title: 'Mon profil',
       meta: {
@@ -14,3 +20,68 @@ export const load = (async () => {
     },
   };
 }) satisfies PageServerLoad;
+
+export const actions = {
+  default: async ({ locals, request }) => {
+    const { db, session } = locals;
+    const data = await request.formData();
+
+    if (!session) {
+      redirect(303, '/login');
+    }
+
+    const username = data.get('username') as string;
+    const disallowedIngredients = data.get('disallowedIngredients') as string;
+
+    if (!username) {
+      return fail(422, { error: "Le nom d'utilisateur ne peut pas être vide." });
+    }
+
+    if (!/^[A-Za-z]+$/g.test(username)) {
+      return fail(422, {
+        error: "Le nom d'utilisateur ne doit contenir que des lettres.",
+      });
+    }
+
+    if (username.length < 3 || username.length > 20) {
+      return fail(400, {
+        error: "Le nom d'utilisateur doit être compris entre 3 et 20 caractères.",
+      });
+    }
+
+    if (disallowedIngredients) {
+      if (!/[a-zA-Z,]/.test(disallowedIngredients)) {
+        return fail(422, {
+          error: 'Les ingrédients ne doivent contenir que des lettres et des virgules.',
+        });
+      }
+    }
+
+    if (disallowedIngredients.length > 255) {
+      return fail(400, {
+        error: 'La liste des ingrédients à éviter ne peut pas dépasser 255 caractères.',
+      });
+    }
+
+    try {
+      await db.user.update({
+        where: { id: session.user.userId },
+        data: {
+          username,
+          disallowedIngredients,
+        },
+      });
+    } catch (e) {
+      if (e instanceof PrismaClientKnownRequestError && e.code === 'P2002') {
+        return fail(400, { error: "le nom d'utilisateur est déjà utilisé." });
+      }
+
+      // eslint-disable-next-line no-console
+      console.error('Error while updating user:', e);
+
+      return fail(500, {
+        error: "Oops... Quelque chose s'est mal passé. Veuillez réessayer plus tard.",
+      });
+    }
+  },
+} satisfies Actions;
diff --git a/src/routes/account/+page.svelte b/src/routes/account/+page.svelte
index f7d1dae..952c382 100644
--- a/src/routes/account/+page.svelte
+++ b/src/routes/account/+page.svelte
@@ -5,11 +5,16 @@
   import { prefersReducedMotion } from '$lib/utils/preferences';
   import { toasts } from '$lib/utils/toats';
 
-  import type { PageData } from './$types';
+  import type { ActionData, PageData } from './$types';
 
   import { enhance } from '$app/forms';
 
   export let data: PageData;
+  export let form: ActionData;
+
+  $: if (form?.error) {
+    toasts.error(form.error);
+  }
 </script>
 
 <h1 class="h1">Profil</h1>
diff --git a/src/routes/account/favourites/+page.server.ts b/src/routes/account/favourites/+page.server.ts
index 25c56ed..d46799f 100644
--- a/src/routes/account/favourites/+page.server.ts
+++ b/src/routes/account/favourites/+page.server.ts
@@ -1,12 +1,35 @@
+import { redirect } from '@sveltejs/kit';
+
 import type { PageServerLoad } from './$types';
-import type { Favourite, Recipe } from '@prisma/client';
 
 const ALLOWED_PER_PAGE = [10, 25, 50, 100];
 
-export const load = (async () => {
+export const load = (async ({ locals }) => {
+  const { session, db } = locals;
+
+  if (!session) {
+    redirect(303, '/login');
+  }
+
+  const [favourites, count] = await Promise.all([
+    db.favourite.findMany({
+      where: {
+        userId: session.user.userId,
+      },
+      include: {
+        recipe: true,
+      },
+    }),
+    db.favourite.count({
+      where: {
+        userId: session.user.userId,
+      },
+    }),
+  ]);
+
   return {
-    count: 0,
-    favourites: [] as (Favourite & { recipe: Recipe })[],
+    favourites,
+    count,
     allowedPerPage: ALLOWED_PER_PAGE,
     perPage: ALLOWED_PER_PAGE[0],
     totalPages: 1,
diff --git a/src/routes/login/+page.server.ts b/src/routes/login/+page.server.ts
index 18c68a8..866d7fe 100644
--- a/src/routes/login/+page.server.ts
+++ b/src/routes/login/+page.server.ts
@@ -5,7 +5,13 @@ import { auth } from '$lib/server/auth';
 
 import type { Actions, PageServerLoad } from './$types';
 
-export const load = (async () => {
+export const load = (async ({ locals }) => {
+  const { session } = locals;
+
+  if (session) {
+    redirect(303, '/');
+  }
+
   return {
     seo: {
       title: 'Se connecter',
@@ -18,7 +24,13 @@ export const load = (async () => {
 }) satisfies PageServerLoad;
 
 export const actions = {
-  login: async ({ request, cookies }) => {
+  login: async ({ request, cookies, locals }) => {
+    const { session } = locals;
+
+    if (session) {
+      redirect(303, '/');
+    }
+
     const data = await request.formData();
     const username = (data.get('username') ?? '') as string;
     const password = (data.get('password') ?? '') as string;
diff --git a/src/routes/recipes/[slug]/+layout.server.ts b/src/routes/recipes/[slug]/+layout.server.ts
index a691878..1c13e67 100644
--- a/src/routes/recipes/[slug]/+layout.server.ts
+++ b/src/routes/recipes/[slug]/+layout.server.ts
@@ -1,11 +1,11 @@
 import { PrismaClientKnownRequestError } from '@prisma/client/runtime/library';
 import { error } from '@sveltejs/kit';
 
-import { db } from '$lib/server/db';
-
 import type { LayoutServerLoad } from './$types';
 
-export const load = (async ({ params }) => {
+export const load = (async ({ params, locals }) => {
+  const { db } = locals;
+
   try {
     const recipe = await db.recipe.findUniqueOrThrow({
       where: {
diff --git a/src/routes/recipes/[slug]/+page.server.ts b/src/routes/recipes/[slug]/+page.server.ts
index f84107b..dbbb472 100644
--- a/src/routes/recipes/[slug]/+page.server.ts
+++ b/src/routes/recipes/[slug]/+page.server.ts
@@ -1,19 +1,68 @@
-import { db } from '$lib/server/db';
+import { redirect } from '@sveltejs/kit';
+
+import { openai } from '$lib/server/GPT';
 import { jsonValueToArray } from '$lib/utils/json';
 
 import type { PageServerLoad } from './$types';
 
-export const load = (async ({ parent }) => {
+export const load = (async ({ parent, locals }) => {
+  const { session, db } = locals;
+
+  if (!session) {
+    redirect(303, '/login');
+  }
+
   const { recipe } = await parent();
+  const favourite = await db.favourite.findFirst({
+    where: {
+      recipeId: recipe.id,
+      userId: locals.session?.user.userId,
+    },
+  });
+
+  const checkDisallowedIngredients = async (): Promise<string[] | null> => {
+    if (session.user.disallowedIngredients && recipe.ingredients) {
+      const result = await openai.chat.completions.create({
+        model: 'gpt-3.5-turbo',
+        stream: false,
+        messages: [
+          {
+            role: 'system',
+            content: `
+                Voici une liste d'ingrédients à éviter: ${session.user.disallowedIngredients}.
+                Les ingrédients à éviter sont séparés par une virgule. Si une valeur n'est pas un ingrédient valide, tu peux l'ignorer.
+                Si dans la recette que je te donne, il y a au moins un ingrédient de cette liste ou du même genre, tu me renvoies un objet JSON avec le format suivant :
+                {
+                  "disallowedIngredients": string[],
+                },
+                où "disallowedIngredients" contiendra la liste des ingrédients à éviter que tu as trouvé dans la recette.
+                Si tu ne trouves pas d'ingrédients à éviter, "disallowedIngredients" sera un tableau vide.
+              `,
+          },
+          {
+            role: 'user',
+            content: recipe.ingredients.toString(),
+          },
+        ],
+      });
+
+      const { disallowedIngredients } = JSON.parse(result.choices[0].message.content ?? '');
+
+      return disallowedIngredients.length > 0 ? disallowedIngredients : null;
+    }
+
+    return null;
+  };
 
   return {
+    disallowedIngredients: checkDisallowedIngredients(),
     recipe: {
       ...recipe,
       ingredients: jsonValueToArray(recipe.ingredients),
       steps: jsonValueToArray(recipe.steps),
       shoppingList: jsonValueToArray(recipe.shoppingList),
     },
-    isFavourite: false,
+    isFavourite: !!favourite,
     seo: {
       title: recipe.dish,
       meta: {
@@ -24,14 +73,20 @@ export const load = (async ({ parent }) => {
 }) satisfies PageServerLoad;
 
 export const actions = {
-  favourite: async ({ params }) => {
+  favourite: async ({ params, locals }) => {
+    const { session, db } = locals;
+
+    if (!session) {
+      redirect(303, '/login');
+    }
+
     // Get favourite
     const favourite = await db.favourite.findFirst({
       where: {
         recipe: {
           slug: params.slug,
         },
-        userId: '1',
+        userId: session.user.userId,
       },
       include: {
         recipe: true,
@@ -54,7 +109,7 @@ export const actions = {
       data: {
         user: {
           connect: {
-            id: '1',
+            id: session.user.userId,
           },
         },
         recipe: {
diff --git a/src/routes/recipes/[slug]/+page.svelte b/src/routes/recipes/[slug]/+page.svelte
index ac45396..9558b0b 100644
--- a/src/routes/recipes/[slug]/+page.svelte
+++ b/src/routes/recipes/[slug]/+page.svelte
@@ -1,14 +1,17 @@
 <script lang="ts">
   import { quintOut } from 'svelte/easing';
-  import { crossfade } from 'svelte/transition';
+  import { crossfade, fade } from 'svelte/transition';
 
   import Clipboard from '$lib/svg/Clipboard.svelte';
+  import Close from '$lib/svg/Close.svelte';
   import Facebook from '$lib/svg/Facebook.svelte';
   import Reddit from '$lib/svg/Reddit.svelte';
   import StarEmpty from '$lib/svg/StarEmpty.svelte';
   import StarFull from '$lib/svg/StarFull.svelte';
   import Twitter from '$lib/svg/Twitter.svelte';
+  import Warning from '$lib/svg/Warning.svelte';
   import { copyToClipboard } from '$lib/utils/clipboard';
+  import { prefersReducedMotion } from '$lib/utils/preferences';
 
   import type { PageData } from './$types';
 
@@ -16,6 +19,8 @@
 
   export let data: PageData;
 
+  let isIngredientsWarningOpen = true;
+
   const [send, receive] = crossfade({
     duration: 700,
     easing: quintOut,
@@ -25,8 +30,51 @@
   const twitter = encodeURI(`https://twitter.com/intent/tweet`);
 
   $: starKey = data.isFavourite ? 'full' : 'empty';
+
+  const closeIngredientsWarning = () => {
+    isIngredientsWarningOpen = false;
+  };
 </script>
 
+<div class="mb-4" role="alert">
+  {#await data.disallowedIngredients then disallowedIngredients}
+    {#if disallowedIngredients && isIngredientsWarningOpen}
+      <div
+        class="flex items-center rounded-lg gap-2 p-3 bg-amber-600/30 border-2 border-amber-600/75 text-amber-600 max-w-[106.25rem] mx-auto"
+        transition:fade={{ duration: prefersReducedMotion() ? 0 : 250 }}
+      >
+        <Warning class="w-7 h-7 flex-shrink-0" />
+        <div class="flex-grow">
+          <p>Contient des ingrédients à éviter, indiqués dans votre profil :</p>
+          <ul class="list-disc list-inside capitalize ml-4">
+            {#each disallowedIngredients as ingredient}
+              <li>{ingredient}</li>
+            {/each}
+          </ul>
+        </div>
+        <button type="button" aria-label="Fermer cette alerte" on:click={closeIngredientsWarning}>
+          <Close />
+        </button>
+      </div>
+    {/if}
+  {:catch}
+    {#if isIngredientsWarningOpen}
+      <div
+        class="flex items-center rounded-lg gap-2 p-3 bg-amber-600/30 border-2 border-amber-600/75 text-amber-600 max-w-[106.25rem] mx-auto"
+        transition:fade={{ duration: prefersReducedMotion() ? 0 : 250 }}
+      >
+        <Warning class="w-7 h-7 flex-shrink-0" />
+        <p class="flex-grow">
+          Impossible de vérifier si la recette contient des ingrédients à ne pas utiliser...
+        </p>
+        <button type="button" aria-label="Fermer cette alerte" on:click={closeIngredientsWarning}>
+          <Close />
+        </button>
+      </div>
+    {/if}
+  {/await}
+</div>
+
 <div class="flex gap-2 items-center justify-center">
   <form method="POST" action="?/favourite" class="relative" use:enhance>
     <h1 class="h1 first-letter:capitalize" style="view-transition-name: {data.recipe.slug};">
diff --git a/src/routes/recipes/[slug]/accompaniments/+page.server.ts b/src/routes/recipes/[slug]/accompaniments/+page.server.ts
index 947acf3..271dacd 100644
--- a/src/routes/recipes/[slug]/accompaniments/+page.server.ts
+++ b/src/routes/recipes/[slug]/accompaniments/+page.server.ts
@@ -1,9 +1,17 @@
+import { redirect } from '@sveltejs/kit';
+
 import { openai } from '$lib/server/GPT';
 import { jsonValueToArray } from '$lib/utils/json';
 
 import type { PageServerLoad } from './$types';
 
-export const load = (async ({ parent }) => {
+export const load = (async ({ parent, locals }) => {
+  const { session } = locals;
+
+  if (!session) {
+    redirect(303, '/login');
+  }
+
   const { recipe } = await parent();
 
   const getAccompaniments = async () => {
diff --git a/src/routes/recipes/[slug]/similar/+page.server.ts b/src/routes/recipes/[slug]/similar/+page.server.ts
index 4e45e63..aefe550 100644
--- a/src/routes/recipes/[slug]/similar/+page.server.ts
+++ b/src/routes/recipes/[slug]/similar/+page.server.ts
@@ -1,10 +1,17 @@
+import { redirect } from '@sveltejs/kit';
+
 import { openai } from '$lib/server/GPT';
-import { db } from '$lib/server/db';
 import { jsonValueToArray } from '$lib/utils/json';
 
 import type { PageServerLoad } from './$types';
 
-export const load = (async ({ parent }) => {
+export const load = (async ({ parent, locals }) => {
+  const { session, db } = locals;
+
+  if (!session) {
+    redirect(303, '/login');
+  }
+
   const { recipe } = await parent();
 
   const getSimilarRecipes = async () => {
diff --git a/src/routes/register/+page.server.ts b/src/routes/register/+page.server.ts
index 896c3e1..57c7320 100644
--- a/src/routes/register/+page.server.ts
+++ b/src/routes/register/+page.server.ts
@@ -6,7 +6,13 @@ import { auth } from '$lib/server/auth';
 
 import type { Actions, PageServerLoad } from './$types';
 
-export const load = (async () => {
+export const load = (async ({ locals }) => {
+  const { session } = locals;
+
+  if (session) {
+    redirect(303, '/login');
+  }
+
   return {
     seo: {
       title: 'Créer un compte',
@@ -19,7 +25,13 @@ export const load = (async () => {
 }) satisfies PageServerLoad;
 
 export const actions = {
-  register: async ({ request, cookies }) => {
+  register: async ({ request, cookies, locals }) => {
+    const { session } = locals;
+
+    if (session) {
+      redirect(303, '/login');
+    }
+
     const data = await request.formData();
     const username = (data.get('username') ?? '') as string;
     const password = (data.get('password') ?? '') as string;
diff --git a/src/routes/search/+page.server.ts b/src/routes/search/+page.server.ts
index 5404bfe..a267a11 100644
--- a/src/routes/search/+page.server.ts
+++ b/src/routes/search/+page.server.ts
@@ -2,7 +2,6 @@ import { PrismaClientKnownRequestError } from '@prisma/client/runtime/library';
 import { fail, redirect } from '@sveltejs/kit';
 
 import { openai } from '$lib/server/GPT';
-import { db } from '$lib/server/db';
 import { slugify } from '$lib/utils/slug';
 
 import type { PageServerLoad } from './$types';
@@ -12,7 +11,13 @@ type Dish = {
   slug: string;
 };
 
-export const load = (async ({ url }) => {
+export const load = (async ({ url, locals }) => {
+  const { session, db } = locals;
+
+  if (!session) {
+    redirect(303, '/login');
+  }
+
   const query = url.searchParams.get('q') ?? '';
 
   const getResult = async (): Promise<{ recipe: null | Dish; suggestions: Dish[] }> => {
@@ -106,7 +111,13 @@ export const load = (async ({ url }) => {
 }) satisfies PageServerLoad;
 
 export const actions = {
-  generate: async ({ request }) => {
+  generate: async ({ request, locals }) => {
+    const { session, db } = locals;
+
+    if (!session) {
+      redirect(303, '/login');
+    }
+
     const data = await request.formData();
     const dish = (data.get('dish') ?? '') as string;
     const result = await openai.chat.completions.create({
diff --git a/svelte.config.js b/svelte.config.js
index 3ca6f06..23a8b9e 100644
--- a/svelte.config.js
+++ b/svelte.config.js
@@ -1,4 +1,4 @@
-import adapter from '@sveltejs/adapter-auto';
+import adapter from '@sveltejs/adapter-node';
 import { vitePreprocess } from '@sveltejs/vite-plugin-svelte';
 
 /** @type {import('@sveltejs/kit').Config} */