From 24a98062ee080e55478b92eed1a1865bf6ec1049 Mon Sep 17 00:00:00 2001
From: lobo <andreas.dahm@gmail.com>
Date: Tue, 29 Sep 2026 14:48:28 +0200
Subject: [PATCH] refactor(limits): server limits in one file, own texts for
 unknown errors

---
 src/components/AddGamePanel.jsx         |  4 ++--
 src/components/BacklogCard.jsx          |  9 ++++---
 src/components/GameCorrectionDialog.jsx | 11 ++++-----
 src/components/GameSearch.jsx           |  6 ++---
 src/components/ManualGameCard.jsx       |  3 ++-
 src/components/PileOfShameCard.jsx      |  3 ++-
 src/components/stats/OverviewStats.jsx  |  2 +-
 src/pages/AdminHintsPage.jsx            |  6 ++---
 src/pages/GameLibrary.jsx               |  5 ++--
 src/pages/ImportPage.jsx                |  6 ++---
 src/pages/PublicProfilePage.jsx         |  2 +-
 src/pages/RegistrationPage.jsx          |  5 ++--
 src/pages/RegistrationPage.test.jsx     | 13 ++++++++--
 src/pages/SettingsPage.jsx              |  5 ++--
 src/utils/backlog.js                    |  4 +---
 src/utils/imports.js                    | 14 ++++-------
 src/utils/limits.js                     | 32 +++++++++++++++++++++++++
 src/utils/manualGames.js                |  3 ---
 18 files changed, 84 insertions(+), 49 deletions(-)
 create mode 100644 src/utils/limits.js

diff --git a/src/components/AddGamePanel.jsx b/src/components/AddGamePanel.jsx
index 9755343..62d5a00 100644
--- a/src/components/AddGamePanel.jsx
+++ b/src/components/AddGamePanel.jsx
@@ -13,7 +13,7 @@ import GameCover from './GameCover.jsx';
 import GameSearch from './GameSearch.jsx';
 import useSessionExpired from '../hooks/useSessionExpired.js';
 import useStartImport from '../hooks/useStartImport.js';
-import {GAME_STATUSES} from '../utils/backlog.js';
+import {GAME_STATUSES, MAX_PLATFORM_LENGTH} from '../utils/limits.js';
 import {addGame, hoursToMinutes} from '../utils/manualGames.js';
 import {loadFavoritePlatform, preselectPlatform} from '../utils/platforms.js';
 
@@ -145,7 +145,7 @@ function AddForm({hit, favorite, onBack, navigate, expireSession}) {
                             </SelectContent>
                         </Select>
                     ) : (
-                        <Input id="add-platform" value={platform} maxLength={32} onChange={(e) => setPlatform(e.target.value)}/>
+                        <Input id="add-platform" value={platform} maxLength={MAX_PLATFORM_LENGTH} onChange={(e) => setPlatform(e.target.value)}/>
                     )}
                 </div>
                 <div className="space-y-2">
diff --git a/src/components/BacklogCard.jsx b/src/components/BacklogCard.jsx
index 4ae42fd..7d73e06 100644
--- a/src/components/BacklogCard.jsx
+++ b/src/components/BacklogCard.jsx
@@ -11,12 +11,11 @@ import {Select, SelectContent, SelectItem, SelectTrigger, SelectValue} from '@/c
 import {Textarea} from '@/components/ui/textarea';
 import {cn} from '@/lib/utils';
 import {STATUS_META} from './GameStatusBadge.jsx';
-import {GAME_PRIORITIES, GAME_STATUSES, NO_PRIORITY, saveBacklogEntry, toBacklogRequest} from '../utils/backlog.js';
+import {NO_PRIORITY, saveBacklogEntry, toBacklogRequest} from '../utils/backlog.js';
+import {GAME_PRIORITIES, GAME_STATUSES, MAX_NOTES_LENGTH} from '../utils/limits.js';
 import useSessionExpired from '../hooks/useSessionExpired.js';
 import {hasSession} from '../utils/auth.js';
 
-const NOTES_MAX = 2000;
-
 const toForm = (entry) => ({
     status: entry.status ?? 'BACKLOG',
     rating: entry.rating ?? 0,
@@ -133,12 +132,12 @@ export default function BacklogCard({game, onSaved}) {
             <div className="space-y-2">
                 <div className="flex items-baseline justify-between">
                     <Label htmlFor="backlog-notes">{t('BACKLOG.NOTES_LABEL')}</Label>
-                    <span className="text-xs text-muted-foreground tabular-nums">{form.notes.length} / {NOTES_MAX}</span>
+                    <span className="text-xs text-muted-foreground tabular-nums">{form.notes.length} / {MAX_NOTES_LENGTH}</span>
                 </div>
                 <Textarea
                     id="backlog-notes"
                     rows={3}
-                    maxLength={NOTES_MAX}
+                    maxLength={MAX_NOTES_LENGTH}
                     placeholder={t('BACKLOG.NOTES_PLACEHOLDER')}
                     value={form.notes}
                     onChange={(e) => set('notes')(e.target.value)}
diff --git a/src/components/GameCorrectionDialog.jsx b/src/components/GameCorrectionDialog.jsx
index 1257399..c55603a 100644
--- a/src/components/GameCorrectionDialog.jsx
+++ b/src/components/GameCorrectionDialog.jsx
@@ -11,10 +11,9 @@ import {Label} from '@/components/ui/label';
 import useSessionExpired from '../hooks/useSessionExpired.js';
 import {CORRECTABLE_MOODS, IGDB_GENRES, resetCorrection, saveCorrection} from '../utils/corrections.js';
 import {genreKey} from '../utils/stats.js';
+import {MAX_CORRECTION_GENRES, MAX_CORRECTION_LENGTH} from '../utils/limits.js';
 
 const ENDLESS_CHOICES = [[null, 'UNKNOWN'], [true, 'YES'], [false, 'NO']];
-// Core refuses more.
-const MAX_GENRES = 10;
 
 const initialValues = (game) => ({
     name: game.name ?? '',
@@ -129,12 +128,12 @@ export default function GameCorrectionDialog({game, open, onOpenChange, onChange
                     <DialogDescription>{t('CORRECTION.TEXT')}</DialogDescription>
                 </DialogHeader>
                 <div className="space-y-4">
-                    {row('name', <Input id="correction-name" value={values.name} maxLength={512}
+                    {row('name', <Input id="correction-name" value={values.name} maxLength={MAX_CORRECTION_LENGTH}
                                         onChange={(e) => set('name', e.target.value)}/>)}
-                    {row('image', <Input id="correction-image" value={values.image} maxLength={512}
+                    {row('image', <Input id="correction-image" value={values.image} maxLength={MAX_CORRECTION_LENGTH}
                                          placeholder={t('CORRECTION.IMAGE_HINT')}
                                          onChange={(e) => set('image', e.target.value)}/>)}
-                    {row('speedrun', <Input id="correction-speedrun" value={values.speedrun} maxLength={512}
+                    {row('speedrun', <Input id="correction-speedrun" value={values.speedrun} maxLength={MAX_CORRECTION_LENGTH}
                                             placeholder={t('CORRECTION.SPEEDRUN_HINT')}
                                             onChange={(e) => set('speedrun', e.target.value)}/>)}
                     {row('moods', choices('moods', CORRECTABLE_MOODS, (mood) => t(`PLAY_NEXT.MOOD.${mood}`)))}
@@ -150,7 +149,7 @@ export default function GameCorrectionDialog({game, open, onOpenChange, onChange
                         </div>
                     ))}
                     {row('genres', choices('genres', genreOptions,
-                        (genre) => t(`STATS.GENRE.${genreKey(genre)}`, {defaultValue: genre}), MAX_GENRES))}
+                        (genre) => t(`STATS.GENRE.${genreKey(genre)}`, {defaultValue: genre}), MAX_CORRECTION_GENRES))}
                 </div>
             </DialogContent>
         </Dialog>
diff --git a/src/components/GameSearch.jsx b/src/components/GameSearch.jsx
index 9b644ca..fdc07cd 100644
--- a/src/components/GameSearch.jsx
+++ b/src/components/GameSearch.jsx
@@ -7,9 +7,9 @@ import {Input} from '@/components/ui/input';
 import GameCover from './GameCover.jsx';
 import useSessionExpired from '../hooks/useSessionExpired.js';
 import {searchGames} from '../utils/manualGames.js';
+import {MAX_GAME_SEARCH_LENGTH, MIN_GAME_SEARCH_LENGTH} from '../utils/limits.js';
 
 const SEARCH_DEBOUNCE_MS = 400;
-const MIN_QUERY = 2;
 
 /**
  * The search field and the hits of Core's game search. The parent keeps the query, so it stays when the user goes
@@ -29,7 +29,7 @@ export default function GameSearch({query, onQueryChange, onPick, hide = () => f
         <>
             <div className="relative">
                 <Search className="pointer-events-none absolute left-2.5 top-1/2 size-4 -translate-y-1/2 text-muted-foreground"/>
-                <Input type="search" autoFocus value={query} maxLength={100} className="pl-8"
+                <Input type="search" autoFocus value={query} maxLength={MAX_GAME_SEARCH_LENGTH} className="pl-8"
                        placeholder={t('MANUAL_GAME.SEARCH_PLACEHOLDER')}
                        aria-label={t('MANUAL_GAME.SEARCH_PLACEHOLDER')}
                        onChange={(e) => onQueryChange(e.target.value)}/>
@@ -87,7 +87,7 @@ function useGameSearch(query) {
 
     useEffect(() => {
         const trimmed = query.trim();
-        if (trimmed.length < MIN_QUERY) {
+        if (trimmed.length < MIN_GAME_SEARCH_LENGTH) {
             setSearchState('idle');
             setResults([]);
             return undefined;
diff --git a/src/components/ManualGameCard.jsx b/src/components/ManualGameCard.jsx
index 37a124d..8fc3c79 100644
--- a/src/components/ManualGameCard.jsx
+++ b/src/components/ManualGameCard.jsx
@@ -10,6 +10,7 @@ import {Input} from '@/components/ui/input';
 import {Label} from '@/components/ui/label';
 import useSessionExpired from '../hooks/useSessionExpired.js';
 import {hoursToMinutes, removeGame, toHours, updateManualGame} from '../utils/manualGames.js';
+import {MAX_PLATFORM_LENGTH} from '../utils/limits.js';
 
 /**
  * Platform and hours of a game added by hand, and removing it. Steam games get both from the sync.
@@ -70,7 +71,7 @@ export default function ManualGameCard({game, onSaved}) {
             <div className="grid gap-5 sm:grid-cols-2">
                 <div className="space-y-2">
                     <Label htmlFor="manual-platform">{t('MANUAL_GAME.PLATFORM')}</Label>
-                    <Input id="manual-platform" value={platform} maxLength={32}
+                    <Input id="manual-platform" value={platform} maxLength={MAX_PLATFORM_LENGTH}
                            onChange={(e) => setPlatform(e.target.value)}/>
                 </div>
                 <div className="space-y-2">
diff --git a/src/components/PileOfShameCard.jsx b/src/components/PileOfShameCard.jsx
index ae36641..27820f5 100644
--- a/src/components/PileOfShameCard.jsx
+++ b/src/components/PileOfShameCard.jsx
@@ -7,7 +7,8 @@ import {Card} from '@/components/ui/card';
 import GameCover from './GameCover.jsx';
 import PileTrend from './stats/PileTrend.jsx';
 import {STATUS_META} from './GameStatusBadge.jsx';
-import {backlogShare, GAME_STATUSES} from '../utils/backlog.js';
+import {backlogShare} from '../utils/backlog.js';
+import {GAME_STATUSES} from '../utils/limits.js';
 import {formatPlaytime} from '../utils/games.js';
 
 /**
diff --git a/src/components/stats/OverviewStats.jsx b/src/components/stats/OverviewStats.jsx
index ad73173..e72bd0f 100644
--- a/src/components/stats/OverviewStats.jsx
+++ b/src/components/stats/OverviewStats.jsx
@@ -3,7 +3,7 @@ import {Gamepad2} from 'lucide-react';
 
 import StatsSection from './StatsSection.jsx';
 import StatTile from './StatTile.jsx';
-import {GAME_STATUSES} from '../../utils/backlog.js';
+import {GAME_STATUSES} from '../../utils/limits.js';
 import {formatPlaytime} from '../../utils/games.js';
 
 export default function OverviewStats({overview}) {
diff --git a/src/pages/AdminHintsPage.jsx b/src/pages/AdminHintsPage.jsx
index 8431aa5..9511a1b 100644
--- a/src/pages/AdminHintsPage.jsx
+++ b/src/pages/AdminHintsPage.jsx
@@ -15,8 +15,8 @@ import PageContainer from '../components/PageContainer.jsx';
 import useSessionExpired from '../hooks/useSessionExpired.js';
 import {hasSession} from '../utils/auth.js';
 import {createHint, endHint, fetchAdminHints} from '../utils/hints.js';
+import {MAX_HINT_LENGTH} from '../utils/limits.js';
 
-const MAX_TEXT = 500;
 const WEEK_MS = 7 * 24 * 60 * 60 * 1000;
 
 // The value of a datetime-local input: local time, no seconds.
@@ -129,11 +129,11 @@ export default function AdminHintsPage() {
                     <form onSubmit={submit} className="space-y-4">
                         <div className="space-y-2">
                             <Label htmlFor="hintTextEn">{t('ADMIN_HINTS.TEXT_EN')}</Label>
-                            <Textarea id="hintTextEn" required maxLength={MAX_TEXT} value={form.textEn} onChange={change('textEn')}/>
+                            <Textarea id="hintTextEn" required maxLength={MAX_HINT_LENGTH} value={form.textEn} onChange={change('textEn')}/>
                         </div>
                         <div className="space-y-2">
                             <Label htmlFor="hintTextDe">{t('ADMIN_HINTS.TEXT_DE')}</Label>
-                            <Textarea id="hintTextDe" maxLength={MAX_TEXT} value={form.textDe} onChange={change('textDe')}/>
+                            <Textarea id="hintTextDe" maxLength={MAX_HINT_LENGTH} value={form.textDe} onChange={change('textDe')}/>
                             <p className="text-xs text-muted-foreground">{t('ADMIN_HINTS.TEXT_HELP')}</p>
                         </div>
                         <fieldset className="space-y-2">
diff --git a/src/pages/GameLibrary.jsx b/src/pages/GameLibrary.jsx
index 5e1380b..b1b3b59 100644
--- a/src/pages/GameLibrary.jsx
+++ b/src/pages/GameLibrary.jsx
@@ -6,7 +6,8 @@ import SyncStatusBadge from '../components/SyncStatusBadge.jsx';
 import useForceSync from '../hooks/useForceSync.js';
 import useSessionExpired from '../hooks/useSessionExpired.js';
 import {formatPlaytime} from '../utils/games.js';
-import {GAME_STATUSES, libraryQuery, parseStatus} from '../utils/backlog.js';
+import {libraryQuery, parseStatus} from '../utils/backlog.js';
+import {GAME_STATUSES, MAX_LIBRARY_SEARCH_LENGTH} from '../utils/limits.js';
 import {ArrowUpDown, ChevronLeft, ChevronRight, Clock, EyeOff, Gamepad2, Library, Plus, RefreshCw, Search, SearchX, Timer, Trophy, Upload} from 'lucide-react';
 
 import {Badge} from '@/components/ui/badge';
@@ -269,7 +270,7 @@ export default function GameLibrary() {
                         onChange={(e) => setSearch(e.target.value)}
                         placeholder={t('LIBRARY.SEARCH_PLACEHOLDER')}
                         aria-label={t('LIBRARY.SEARCH_PLACEHOLDER')}
-                        maxLength={100}
+                        maxLength={MAX_LIBRARY_SEARCH_LENGTH}
                         className="pl-8"
                     />
                 </div>
diff --git a/src/pages/ImportPage.jsx b/src/pages/ImportPage.jsx
index 29f35c0..f35e717 100644
--- a/src/pages/ImportPage.jsx
+++ b/src/pages/ImportPage.jsx
@@ -15,11 +15,11 @@ import PageContainer from '../components/PageContainer.jsx';
 import useSessionExpired from '../hooks/useSessionExpired.js';
 import useStartImport from '../hooks/useStartImport.js';
 import {hasSession} from '../utils/auth.js';
-import {GAME_STATUSES} from '../utils/backlog.js';
 import {
-    checkUndo, getImport, listImports, MAX_IMPORT_ROWS, parseCsv, parseTextList, retryImport, saveImport, undoImport,
+    checkUndo, getImport, listImports, parseCsv, parseTextList, retryImport, saveImport, undoImport,
 } from '../utils/imports.js';
-import {hoursToMinutes, MAX_PLATFORM_LENGTH, toHours} from '../utils/manualGames.js';
+import {GAME_STATUSES, MAX_IMPORT_ROWS, MAX_PLATFORM_LENGTH} from '../utils/limits.js';
+import {hoursToMinutes, toHours} from '../utils/manualGames.js';
 import {loadFavoritePlatform, preselectPlatform} from '../utils/platforms.js';
 
 const POLL_MS = 2000;
diff --git a/src/pages/PublicProfilePage.jsx b/src/pages/PublicProfilePage.jsx
index 225554b..ce55d51 100644
--- a/src/pages/PublicProfilePage.jsx
+++ b/src/pages/PublicProfilePage.jsx
@@ -9,7 +9,7 @@ import {Skeleton} from '@/components/ui/skeleton';
 import {cn} from '@/lib/utils';
 import GameCover from '../components/GameCover.jsx';
 import GameStatusBadge, {STATUS_META} from '../components/GameStatusBadge.jsx';
-import {GAME_STATUSES} from '../utils/backlog.js';
+import {GAME_STATUSES} from '../utils/limits.js';
 import {formatPlaytime} from '../utils/games.js';
 import {hasSession} from '../utils/auth.js';
 import {normalizeProfileStyle} from '../utils/profileStyle.js';
diff --git a/src/pages/RegistrationPage.jsx b/src/pages/RegistrationPage.jsx
index ead87e3..9204c4d 100644
--- a/src/pages/RegistrationPage.jsx
+++ b/src/pages/RegistrationPage.jsx
@@ -13,6 +13,7 @@ import FeedbackAlert from '../components/FeedbackAlert.jsx';
 import FormField from '../components/FormField.jsx';
 import {registrationSchema} from '../utils/validation.js';
 import {clientFetch} from '../utils/api.js';
+import {MAX_DISPLAY_NAME_LENGTH} from '../utils/limits.js';
 
 const BACKEND_ERROR_KEY = {
     EMAIL_ALREADY_IN_USE: 'REGISTRATION.ERROR_EMAIL_IN_USE',
@@ -68,7 +69,7 @@ export default function RegistrationPage() {
                 ? {minutes: Math.ceil(Number(response.headers.get('Retry-After') ?? 900) / 60)}
                 : undefined;
             setFeedback({
-                message: mappedKey ? t(mappedKey, options) : data.message || t('REGISTRATION.ERROR_GENERIC'),
+                message: t(mappedKey ?? 'REGISTRATION.ERROR_GENERIC', options),
                 isError: true,
             });
         } catch (err) {
@@ -131,7 +132,7 @@ export default function RegistrationPage() {
                     <Input
                         id="displayName"
                         type="text"
-                        maxLength={24}
+                        maxLength={MAX_DISPLAY_NAME_LENGTH}
                         aria-invalid={!!errors.displayName}
                         {...register('displayName')}
                     />
diff --git a/src/pages/RegistrationPage.test.jsx b/src/pages/RegistrationPage.test.jsx
index ce8f779..eca6d32 100644
--- a/src/pages/RegistrationPage.test.jsx
+++ b/src/pages/RegistrationPage.test.jsx
@@ -12,12 +12,12 @@ vi.mock('react-i18next', () => ({
     }),
 }));
 
-function errorResponse(status, code, headers = {}) {
+function errorResponse(status, code, headers = {}, message = undefined) {
     return {
         ok: false,
         status,
         headers: new Headers(headers),
-        json: async () => ({code}),
+        json: async () => ({code, message}),
     };
 }
 
@@ -60,4 +60,13 @@ describe('RegistrationPage', () => {
 
         expect(await screen.findByText('REGISTRATION.ERROR_INVALID_INVITE_CODE')).toBeTruthy();
     });
+
+    it('shows its own text, not the English one of the server, for a refused input', async () => {
+        globalThis.fetch = vi.fn(async () => errorResponse(400, 'VALIDATION_FAILED', {}, 'The request is not valid'));
+
+        submitValidForm();
+
+        expect(await screen.findByText('REGISTRATION.ERROR_GENERIC')).toBeTruthy();
+        expect(screen.queryByText('The request is not valid')).toBeNull();
+    });
 });
diff --git a/src/pages/SettingsPage.jsx b/src/pages/SettingsPage.jsx
index bcabf72..8609741 100644
--- a/src/pages/SettingsPage.jsx
+++ b/src/pages/SettingsPage.jsx
@@ -32,6 +32,7 @@ import {apiFetch, refreshSession} from '../utils/api.js';
 import {hasSession, markSession} from '../utils/auth.js';
 import {FAVORITE_PLATFORMS, saveFavoritePlatform} from '../utils/platforms.js';
 import {LANGUAGES, saveSettings} from '../utils/settings.js';
+import {MAX_DISPLAY_NAME_LENGTH} from '../utils/limits.js';
 
 const BACKEND_ERROR_KEY = {
     DISPLAY_NAME_ALREADY_IN_USE: 'SETTINGS.ERROR_DISPLAY_NAME_IN_USE',
@@ -158,7 +159,7 @@ export default function SettingsPage() {
             if (!response.ok) {
                 const data = await response.json().catch(() => ({}));
                 const mappedKey = BACKEND_ERROR_KEY[data.code];
-                toast.error(mappedKey ? t(mappedKey) : data.message || t('SETTINGS.ERROR_SAVE'));
+                toast.error(t(mappedKey ?? 'SETTINGS.ERROR_SAVE'));
                 return {ok: false};
             }
 
@@ -393,7 +394,7 @@ export default function SettingsPage() {
                             <Input
                                 id="displayName"
                                 type="text"
-                                maxLength={24}
+                                maxLength={MAX_DISPLAY_NAME_LENGTH}
                                 placeholder={t('SETTINGS.DISPLAY_NAME_PLACEHOLDER')}
                                 aria-invalid={!!errors.displayName}
                                 {...register('displayName')}
diff --git a/src/utils/backlog.js b/src/utils/backlog.js
index a0775ec..4fe935d 100644
--- a/src/utils/backlog.js
+++ b/src/utils/backlog.js
@@ -1,7 +1,5 @@
 import {apiFetch} from './api.js';
-
-export const GAME_STATUSES = ['BACKLOG', 'PLAYING', 'FINISHED', 'COMPLETED', 'DROPPED'];
-export const GAME_PRIORITIES = ['HIGH', 'MEDIUM', 'LOW'];
+import {GAME_STATUSES} from './limits.js';
 
 // Radix Select has no empty value, so "no priority" needs its own value in the form.
 export const NO_PRIORITY = 'NONE';
diff --git a/src/utils/imports.js b/src/utils/imports.js
index 81c7c63..4fef954 100644
--- a/src/utils/imports.js
+++ b/src/utils/imports.js
@@ -1,15 +1,11 @@
 import {apiFetch} from './api.js';
 import {parseStatus} from './backlog.js';
-import {hoursToMinutes, MAX_PLATFORM_LENGTH} from './manualGames.js';
+import {MAX_IMPORT_TITLE_LENGTH, MAX_PLATFORM_LENGTH, MAX_PLAYTIME_MINUTES} from './limits.js';
+import {hoursToMinutes} from './manualGames.js';
 
 const IMPORTS_URL = () => `${import.meta.env.VITE_CORE_API_URL}/api/library/imports`;
 const JSON_HEADERS = {'Content-Type': 'application/json'};
 
-// Core's limits: lines per import, title length of the game search, playtime.
-export const MAX_IMPORT_ROWS = 1000;
-const MAX_TITLE = 100;
-const MAX_MINUTES = 6_000_000;
-
 // The calls return the raw response; the caller handles the status.
 export const createImport = (source, rows) =>
     apiFetch(IMPORTS_URL(), {method: 'POST', headers: JSON_HEADERS, body: JSON.stringify({source, rows})});
@@ -31,7 +27,7 @@ export const undoImport = (id) => apiFetch(`${IMPORTS_URL()}/${id}/games`, {meth
  * One title per line; empty lines are left out.
  */
 export const parseTextList = (text) => text.split(/\r?\n/).map((line) => line.trim()).filter(Boolean)
-    .map((line) => ({title: line.slice(0, MAX_TITLE)}));
+    .map((line) => ({title: line.slice(0, MAX_IMPORT_TITLE_LENGTH)}));
 
 // Header names, lower case, per field.
 const COLUMNS = {
@@ -65,9 +61,9 @@ export const parseCsv = (text) => {
         const minutes = at.minutes >= 0 ? Math.round(Number(value(record, 'minutes'))) || 0
             : hoursToMinutes(value(record, 'hours'));
         return {
-            title: value(record, 'title').slice(0, MAX_TITLE),
+            title: value(record, 'title').slice(0, MAX_IMPORT_TITLE_LENGTH),
             platform: platform && platform.length <= MAX_PLATFORM_LENGTH ? platform : null,
-            playtimeMinutes: minutes > 0 ? Math.min(minutes, MAX_MINUTES) : null,
+            playtimeMinutes: minutes > 0 ? Math.min(minutes, MAX_PLAYTIME_MINUTES) : null,
             status: parseStatus(value(record, 'status').toUpperCase()),
         };
     });
diff --git a/src/utils/limits.js b/src/utils/limits.js
new file mode 100644
index 0000000..2ffbb51
--- /dev/null
+++ b/src/utils/limits.js
@@ -0,0 +1,32 @@
+// Limits and enums that Core or Auth check. Each copy names its server source: change both together.
+
+// Core GameStatus
+export const GAME_STATUSES = ['BACKLOG', 'PLAYING', 'FINISHED', 'COMPLETED', 'DROPPED'];
+// Core GamePriority, in the order the UI shows it
+export const GAME_PRIORITIES = ['HIGH', 'MEDIUM', 'LOW'];
+
+// Core ManualGameUpdate.MAX_PLATFORM_LENGTH, Auth FavoritePlatformRequest @Size(max = 32)
+export const MAX_PLATFORM_LENGTH = 32;
+// Core ManualGameUpdate.MAX_MINUTES
+export const MAX_PLAYTIME_MINUTES = 6_000_000;
+// Core BacklogEntryDto.notes @Size(max = 2000)
+export const MAX_NOTES_LENGTH = 2000;
+
+// Core ImportRequest.MAX_ROWS
+export const MAX_IMPORT_ROWS = 1000;
+// Core ImportRequest.Row.title @Size(max = 100)
+export const MAX_IMPORT_TITLE_LENGTH = 100;
+// Core ManualGameController.search @Size(min = 2, max = 100)
+export const MIN_GAME_SEARCH_LENGTH = 2;
+export const MAX_GAME_SEARCH_LENGTH = 100;
+// Frontend only: Core's library search takes any length.
+export const MAX_LIBRARY_SEARCH_LENGTH = 100;
+// Core GameCorrectionService.MAX_TEXT
+export const MAX_CORRECTION_LENGTH = 512;
+// Core GameCorrectionService.MAX_GENRES
+export const MAX_CORRECTION_GENRES = 10;
+
+// Auth DisplayNameFormat.PATTERN (3 to 24 characters)
+export const MAX_DISPLAY_NAME_LENGTH = 24;
+// Auth CreateHintRequest @Size(max = 500)
+export const MAX_HINT_LENGTH = 500;
diff --git a/src/utils/manualGames.js b/src/utils/manualGames.js
index 887a0a2..cc53ebb 100644
--- a/src/utils/manualGames.js
+++ b/src/utils/manualGames.js
@@ -7,9 +7,6 @@ const JSON_HEADERS = {'Content-Type': 'application/json'};
 // positive keys; Auth also takes only those as background or banner.
 export const isSteamKey = (appid) => Number(appid) > 0;
 
-// Core's limit of a game's platform (ManualGameUpdate.MAX_PLATFORM_LENGTH).
-export const MAX_PLATFORM_LENGTH = 32;
-
 // Two decimals: then hoursToMinutes gives back the same minute.
 export const toHours = (minutes) => (minutes > 0 ? String(Math.round((minutes / 60) * 100) / 100) : '');