diff --git a/core/static/bundled/utils/api.ts b/core/static/bundled/utils/api.ts
index 95a86e1c..6ed4a53a 100644
--- a/core/static/bundled/utils/api.ts
+++ b/core/static/bundled/utils/api.ts
@@ -1,5 +1,5 @@
-import type { Client, Options, RequestResult, TDataShape } from "@hey-api/client-fetch";
-import { client } from "#openapi";
+import type { Client, RequestResult, TDataShape } from "#openapi:client";
+import { type Options, client } from "#openapi";
 
 export interface PaginatedResponse<T> {
   count: number;
diff --git a/counter/static/bundled/counter/counter-click-index.ts b/counter/static/bundled/counter/counter-click-index.ts
index 7a51344b..f594cdd8 100644
--- a/counter/static/bundled/counter/counter-click-index.ts
+++ b/counter/static/bundled/counter/counter-click-index.ts
@@ -1,7 +1,7 @@
+import { AlertMessage } from "#core:utils/alert-message";
 import { BasketItem } from "#counter:counter/basket";
 import type { CounterConfig, ErrorMessage } from "#counter:counter/types";
 import type { CounterProductSelect } from "./components/counter-product-select-index.ts";
-import { AlertMessage } from "#core:utils/alert-message";
 
 document.addEventListener("alpine:init", () => {
   Alpine.data("counter", (config: CounterConfig) => ({
diff --git a/counter/static/bundled/counter/product-list-index.ts b/counter/static/bundled/counter/product-list-index.ts
index a7cd3f86..de0381b9 100644
--- a/counter/static/bundled/counter/product-list-index.ts
+++ b/counter/static/bundled/counter/product-list-index.ts
@@ -167,7 +167,7 @@ document.addEventListener("alpine:init", () => {
       });
       // if products to download are already in-memory, directly take them.
       // If not, fetch them.
-      const products =
+      const products: ProductSchema[] =
         this.nbPages > 1
           ? await paginated(productSearchProductsDetailed, this.getQueryParams())
           : Object.values<ProductSchema[]>(this.products).flat();
diff --git a/counter/static/bundled/counter/product-type-index.ts b/counter/static/bundled/counter/product-type-index.ts
index e576a583..37de445d 100644
--- a/counter/static/bundled/counter/product-type-index.ts
+++ b/counter/static/bundled/counter/product-type-index.ts
@@ -1,6 +1,6 @@
+import { AlertMessage } from "#core:utils/alert-message";
 import Alpine from "alpinejs";
 import { producttypeReorder } from "#openapi";
-import { AlertMessage } from "#core:utils/alert-message";
 
 document.addEventListener("alpine:init", () => {
   Alpine.data("productTypesList", () => ({
diff --git a/counter/static/bundled/counter/types.d.ts b/counter/static/bundled/counter/types.d.ts
index 4a22a916..18fea258 100644
--- a/counter/static/bundled/counter/types.d.ts
+++ b/counter/static/bundled/counter/types.d.ts
@@ -1,4 +1,4 @@
-type ErrorMessage = string;
+export type ErrorMessage = string;
 
 export interface InitialFormData {
   /* Used to refill the form when the backend raises an error */
diff --git a/package-lock.json b/package-lock.json
index 5ab0eeb9..44e71934 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -48,6 +48,7 @@
         "@types/cytoscape-cxtmenu": "^3.4.4",
         "@types/cytoscape-klay": "^3.1.4",
         "@types/jquery": "^3.5.31",
+        "@types/js-cookie": "^3.0.6",
         "typescript": "^5.8.3",
         "vite": "^6.2.5",
         "vite-bundle-visualizer": "^1.2.1",
@@ -2865,6 +2866,13 @@
         "@types/sizzle": "*"
       }
     },
+    "node_modules/@types/js-cookie": {
+      "version": "3.0.6",
+      "resolved": "https://registry.npmjs.org/@types/js-cookie/-/js-cookie-3.0.6.tgz",
+      "integrity": "sha512-wkw9yd1kEXOPnvEeEV1Go1MmxtBJL0RR79aOTAApecWFVu7w0NNXNqhcWgvw2YgZDYadliXkl14pa3WXw5jlCQ==",
+      "dev": true,
+      "license": "MIT"
+    },
     "node_modules/@types/json-schema": {
       "version": "7.0.15",
       "resolved": "https://registry.npmjs.org/@types/json-schema/-/json-schema-7.0.15.tgz",
diff --git a/package.json b/package.json
index 3abaca2b..0e986ab9 100644
--- a/package.json
+++ b/package.json
@@ -10,7 +10,7 @@
     "openapi": "openapi-ts",
     "analyse-dev": "vite-bundle-visualizer --mode development",
     "analyse-prod": "vite-bundle-visualizer --mode production",
-    "check": "biome check --write"
+    "check": "tsc && biome check --write"
   },
   "keywords": [],
   "author": "",
@@ -30,9 +30,10 @@
     "@hey-api/openapi-ts": "^0.73.0",
     "@rollup/plugin-inject": "^5.0.5",
     "@types/alpinejs": "^3.13.10",
-    "@types/jquery": "^3.5.31",
     "@types/cytoscape-cxtmenu": "^3.4.4",
     "@types/cytoscape-klay": "^3.1.4",
+    "@types/jquery": "^3.5.31",
+    "@types/js-cookie": "^3.0.6",
     "typescript": "^5.8.3",
     "vite": "^6.2.5",
     "vite-bundle-visualizer": "^1.2.1",
diff --git a/sas/static/bundled/sas/album-index.ts b/sas/static/bundled/sas/album-index.ts
index 32f0f02f..b56b8e02 100644
--- a/sas/static/bundled/sas/album-index.ts
+++ b/sas/static/bundled/sas/album-index.ts
@@ -83,7 +83,6 @@ document.addEventListener("alpine:init", () => {
 
   Alpine.data("pictureUpload", (albumId: number) => ({
     errors: [] as string[],
-    pictures: [],
     sending: false,
     progress: null as HTMLProgressElement,
 
diff --git a/sas/static/bundled/sas/viewer-index.ts b/sas/static/bundled/sas/viewer-index.ts
index 59718b26..0eec9d36 100644
--- a/sas/static/bundled/sas/viewer-index.ts
+++ b/sas/static/bundled/sas/viewer-index.ts
@@ -1,3 +1,4 @@
+import type { UserAjaxSelect } from "#core:core/components/ajax-select-index";
 import { paginated } from "#core:utils/api";
 import { exportToHtml } from "#core:utils/globals";
 import { History } from "#core:utils/history";
@@ -130,7 +131,7 @@ exportToHtml("loadViewer", (config: ViewerConfig) => {
       currentPicture: {
         // biome-ignore lint/style/useNamingConvention: api is in snake_case
         is_moderated: true,
-        id: null,
+        id: null as number,
         name: "",
         // biome-ignore lint/style/useNamingConvention: api is in snake_case
         display_name: "",
@@ -142,7 +143,7 @@ exportToHtml("loadViewer", (config: ViewerConfig) => {
         full_size_url: "",
         owner: "",
         date: new Date(),
-        identifications: [],
+        identifications: [] as IdentifiedUserSchema[],
       },
       /**
        * The picture which will be displayed next if the user press the "next" button
@@ -155,7 +156,7 @@ exportToHtml("loadViewer", (config: ViewerConfig) => {
       /**
        * The select2 component used to identify users
        **/
-      selector: undefined,
+      selector: undefined as UserAjaxSelect,
       /**
        * Error message when a moderation operation fails
        **/
diff --git a/tsconfig.json b/tsconfig.json
index 1f47a39e..59a3642f 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -14,6 +14,7 @@
     "types": ["jquery", "alpinejs"],
     "paths": {
       "#openapi": ["./staticfiles/generated/openapi/client/index.ts"],
+      "#openapi:*": ["./staticfiles/generated/openapi/client/*"],
       "#core:*": ["./core/static/bundled/*"],
       "#pedagogy:*": ["./pedagogy/static/bundled/*"],
       "#counter:*": ["./counter/static/bundled/*"],