diff --git a/config/scripts/verify-localization-catalog.mjs b/config/scripts/verify-localization-catalog.mjs
index a155e8741d3a..8d90a0b83b5d 100644
--- a/config/scripts/verify-localization-catalog.mjs
+++ b/config/scripts/verify-localization-catalog.mjs
@@ -151,6 +151,30 @@ function formatMissingKeys(label, keys) {
   return keys.map((key) => `${label}: ${key}`).join('\n')
 }
 
+// Language packs require nested names even though i18next also accepts flat keys.
+function collectDottedCatalogKeys(value, prefix = '') {
+  if (typeof value !== 'object' || value === null || Array.isArray(value)) {
+    return []
+  }
+  return Object.entries(value).flatMap(([key, child]) => {
+    const keyPath = prefix ? `${prefix}.${key}` : key
+    return [...(key.includes('.') ? [keyPath] : []), ...collectDottedCatalogKeys(child, keyPath)]
+  })
+}
+
+function reportDottedCatalogKeys(fileName, catalog) {
+  const dottedKeys = collectDottedCatalogKeys(catalog)
+  if (dottedKeys.length === 0) {
+    return 0
+  }
+  console.error(`${fileName} has keys with a dot in the name. Write them as nested objects.`)
+  console.error(formatMissingKeys('dotted', dottedKeys.slice(0, 20)))
+  if (dottedKeys.length > 20) {
+    console.error(`...and ${dottedKeys.length - 20} more dotted keys`)
+  }
+  return 1
+}
+
 function normalizeInterpolationVariables(value) {
   return collectInterpolationVariables(value)
     .map((variable) => variable.slice(2, -2))
@@ -480,6 +504,9 @@ export async function main(
     }
     return 0
   }
+  if (reportDottedCatalogKeys('en.json', catalog) !== 0) {
+    return 1
+  }
   let catalogKeys = new Set(flattenCatalogKeys(catalog))
   const references = sharedReferences ?? (await collectLocalizationReferences(root))
 
@@ -539,6 +566,9 @@ export async function main(
     const localeName = fileName.replace(/\.json$/, '')
     const localeCatalogPath = path.join(localesDir, fileName)
     const localeCatalog = JSON.parse(await fs.readFile(localeCatalogPath, 'utf8'))
+    if (reportDottedCatalogKeys(fileName, localeCatalog) !== 0) {
+      return 1
+    }
     const exitCode = verifyLocaleCatalog(catalog, localeName, localeCatalog)
     if (exitCode !== 0) {
       console.error('')
diff --git a/config/scripts/verify-localization-catalog.test.mjs b/config/scripts/verify-localization-catalog.test.mjs
index 4623f345b795..04ce129e17fc 100644
--- a/config/scripts/verify-localization-catalog.test.mjs
+++ b/config/scripts/verify-localization-catalog.test.mjs
@@ -65,6 +65,30 @@ describe('verify-localization-catalog', () => {
     })
   })
 
+  it.each([
+    ['en', false],
+    ['en', true],
+    ['es', false]
+  ])('rejects dotted %s keys without rewriting them (fix: %s)', async (locale, fix) => {
+    const nested = { auto: { example: { greeting: 'Hello.world' } } }
+    const { root, localesDir } = makeProject({
+      sourceText: 'export {}\n',
+      enCatalog: locale === 'en' ? { 'auto.example.greeting': 'Hello.world' } : nested,
+      esCatalog: locale === 'es' ? { auto: { 'example.greeting': 'Hola.world' } } : {}
+    })
+    const catalogPath = path.join(localesDir, `${locale}.json`)
+    const before = readFileSync(catalogPath, 'utf8')
+    const report = vi.spyOn(console, 'error').mockImplementation(() => undefined)
+    try {
+      await expect(verifyLocalizationCatalog(root, { fix })).resolves.toBe(1)
+      expect(report).toHaveBeenCalledWith(expect.stringContaining(`${locale}.json`))
+      expect(report).toHaveBeenCalledWith('dotted: auto.example.greeting')
+      expect(readFileSync(catalogPath, 'utf8')).toBe(before)
+    } finally {
+      report.mockRestore()
+    }
+  })
+
   it('never overwrites mismatched translations or removes target-only entries', async () => {
     const { root, localesDir } = makeProject({
       sourceText:
diff --git a/src/renderer/src/i18n/catalog-nested-settings.test.ts b/src/renderer/src/i18n/catalog-nested-settings.test.ts
new file mode 100644
index 000000000000..1d070a6a4ef3
--- /dev/null
+++ b/src/renderer/src/i18n/catalog-nested-settings.test.ts
@@ -0,0 +1,56 @@
+import i18next from 'i18next'
+import { expect, it } from 'vitest'
+import { parsePluginLanguagePackArtifact } from '../../../shared/plugins/plugin-language-pack-artifact'
+import en from './locales/en.json'
+import es from './locales/es.json'
+import fr from './locales/fr.json'
+import ja from './locales/ja.json'
+import ko from './locales/ko.json'
+import zh from './locales/zh.json'
+
+const AGENT_SETTINGS_KEYS = [
+  'environmentName',
+  'environmentValue',
+  'savedEnvironment',
+  'newEnvironment',
+  'removeEnvironment',
+  'loadingHost',
+  'updateHost',
+  'readFailed',
+  'saveFailed',
+  'hostDefaults',
+  'save'
+] as const
+
+it.each([
+  ['en', en],
+  ['es', es],
+  ['fr', fr],
+  ['ja', ja],
+  ['ko', ko],
+  ['zh', zh]
+] as const)(
+  'keeps %s agent settings usable as nested language-pack translations',
+  async (locale, catalog) => {
+    // Bundled security copy is intentionally unavailable to plugin language packs.
+    expect(
+      parsePluginLanguagePackArtifact(JSON.stringify({ settings: catalog.settings }))
+    ).toMatchObject({ ok: true })
+
+    const instance = i18next.createInstance()
+    await instance.init({
+      lng: locale,
+      fallbackLng: false,
+      resources: { [locale]: { translation: catalog } },
+      ignoreJSONStructure: false
+    })
+    for (const key of AGENT_SETTINGS_KEYS) {
+      expect(instance.t(`settings.agents.${key}`, { name: 'PATH' })).toBe(
+        catalog.settings.agents[key].replace('{{name}}', 'PATH')
+      )
+    }
+    expect(instance.t('settings.appearance.chat.title')).toBe(
+      catalog.settings.appearance.chat.title
+    )
+  }
+)
diff --git a/src/renderer/src/i18n/locales/en.json b/src/renderer/src/i18n/locales/en.json
index 88c89b90fb34..dd2a3b4eaaf6 100644
--- a/src/renderer/src/i18n/locales/en.json
+++ b/src/renderer/src/i18n/locales/en.json
@@ -319,7 +319,18 @@
       "codexSharedServerWarning": {
         "title": "Warn when a Codex tab shares a server",
         "description": "Shows a notice on a Codex you started yourself when it shares a server with other tabs, because its agent status may be wrong."
-      }
+      },
+      "environmentName": "Environment variable name",
+      "environmentValue": "Value for {{name}}",
+      "savedEnvironment": "Saved value · enter to replace",
+      "newEnvironment": "Value",
+      "removeEnvironment": "Remove",
+      "loadingHost": "Loading agent settings…",
+      "updateHost": "Update this server to edit its agent launch settings.",
+      "readFailed": "Couldn’t read agent settings. Check the host connection and try again.",
+      "saveFailed": "Couldn’t save agent settings. Check the host connection and try again.",
+      "hostDefaults": "Defaults for new agents on the selected host.",
+      "save": "Save"
     },
     "followSymlinkedDirectoriesKeywords": {
       "symlink": "symlink",
@@ -19791,7 +19802,6 @@
   "projectField": {
     "updateFailed": "Failed to update project field"
   },
-  "settings.appearance.chat.title": "Chat",
   "mediaPreview": {
     "unavailable": "Unable to play this media file. The file may be unavailable or use an unsupported codec.",
     "openFailed": "Could not open this file in the default app.",
@@ -19872,17 +19882,6 @@
       "updateRuntimeSafely": "Update the remote runtime to safely change workspace links"
     }
   },
-  "settings.agents.environmentName": "Environment variable name",
-  "settings.agents.environmentValue": "Value for {{name}}",
-  "settings.agents.savedEnvironment": "Saved value · enter to replace",
-  "settings.agents.newEnvironment": "Value",
-  "settings.agents.removeEnvironment": "Remove",
-  "settings.agents.loadingHost": "Loading agent settings…",
-  "settings.agents.updateHost": "Update this server to edit its agent launch settings.",
-  "settings.agents.readFailed": "Couldn’t read agent settings. Check the host connection and try again.",
-  "settings.agents.saveFailed": "Couldn’t save agent settings. Check the host connection and try again.",
-  "settings.agents.hostDefaults": "Defaults for new agents on the selected host.",
-  "settings.agents.save": "Save",
   "tabHoverCard": {
     "browser": "Browser",
     "editor": "Editor",
diff --git a/src/renderer/src/i18n/locales/es.json b/src/renderer/src/i18n/locales/es.json
index 546b6ea2152e..cf4c9694619c 100644
--- a/src/renderer/src/i18n/locales/es.json
+++ b/src/renderer/src/i18n/locales/es.json
@@ -151,7 +151,18 @@
       "codexSharedServerWarning": {
         "title": "Avisar cuando una pestaña de Codex comparte un servidor",
         "description": "Muestra un aviso en un Codex que usted mismo inició cuando comparte un servidor con otras pestañas, porque su estado de agente puede ser incorrecto."
-      }
+      },
+      "environmentName": "Nombre de la variable de entorno",
+      "environmentValue": "Valor de {{name}}",
+      "savedEnvironment": "Valor guardado · escribe para reemplazarlo",
+      "newEnvironment": "Valor",
+      "removeEnvironment": "Eliminar",
+      "loadingHost": "Cargando la configuración de agentes…",
+      "updateHost": "Actualiza este servidor para editar su configuración de inicio de agentes.",
+      "readFailed": "No se pudo leer la configuración de agentes. Comprueba la conexión con el host e inténtalo de nuevo.",
+      "saveFailed": "No se pudo guardar la configuración de agentes. Comprueba la conexión con el host e inténtalo de nuevo.",
+      "hostDefaults": "Valores predeterminados para nuevos agentes en el host seleccionado.",
+      "save": "Guardar"
     },
     "followSymlinkedDirectoriesKeywords": {
       "symlink": "enlace simbólico",
@@ -19536,16 +19547,5 @@
   },
   "projectField": {
     "updateFailed": "No se pudo actualizar el campo del proyecto"
-  },
-  "settings.agents.environmentName": "Nombre de la variable de entorno",
-  "settings.agents.environmentValue": "Valor de {{name}}",
-  "settings.agents.savedEnvironment": "Valor guardado · escribe para reemplazarlo",
-  "settings.agents.newEnvironment": "Valor",
-  "settings.agents.removeEnvironment": "Eliminar",
-  "settings.agents.loadingHost": "Cargando la configuración de agentes…",
-  "settings.agents.updateHost": "Actualiza este servidor para editar su configuración de inicio de agentes.",
-  "settings.agents.readFailed": "No se pudo leer la configuración de agentes. Comprueba la conexión con el host e inténtalo de nuevo.",
-  "settings.agents.saveFailed": "No se pudo guardar la configuración de agentes. Comprueba la conexión con el host e inténtalo de nuevo.",
-  "settings.agents.hostDefaults": "Valores predeterminados para nuevos agentes en el host seleccionado.",
-  "settings.agents.save": "Guardar"
+  }
 }
diff --git a/src/renderer/src/i18n/locales/fr.json b/src/renderer/src/i18n/locales/fr.json
index 9172662a3d52..4462703bfb44 100644
--- a/src/renderer/src/i18n/locales/fr.json
+++ b/src/renderer/src/i18n/locales/fr.json
@@ -252,7 +252,18 @@
       "codexSharedServerWarning": {
         "title": "Avertir lorsqu'un onglet Codex partage un serveur",
         "description": "Affiche un avis sur un Codex que vous avez démarré vous-même lorsqu'il partage un serveur avec d'autres onglets, car son statut d'agent peut être erroné."
-      }
+      },
+      "environmentName": "Nom de la variable d’environnement",
+      "environmentValue": "Valeur de {{name}}",
+      "savedEnvironment": "Valeur enregistrée · saisir pour remplacer",
+      "newEnvironment": "Valeur",
+      "removeEnvironment": "Supprimer",
+      "loadingHost": "Chargement des paramètres des agents…",
+      "updateHost": "Mettez ce serveur à jour pour modifier ses paramètres de lancement des agents.",
+      "readFailed": "Impossible de lire les paramètres des agents. Vérifiez la connexion à l’hôte et réessayez.",
+      "saveFailed": "Impossible d’enregistrer les paramètres des agents. Vérifiez la connexion à l’hôte et réessayez.",
+      "hostDefaults": "Paramètres par défaut des nouveaux agents sur l’hôte sélectionné.",
+      "save": "Enregistrer"
     },
     "followSymlinkedDirectoriesKeywords": {
       "symlink": "lien symbolique",
@@ -19537,16 +19548,5 @@
   },
   "projectField": {
     "updateFailed": "Échec de la mise à jour du champ du projet"
-  },
-  "settings.agents.environmentName": "Nom de la variable d’environnement",
-  "settings.agents.environmentValue": "Valeur de {{name}}",
-  "settings.agents.savedEnvironment": "Valeur enregistrée · saisir pour remplacer",
-  "settings.agents.newEnvironment": "Valeur",
-  "settings.agents.removeEnvironment": "Supprimer",
-  "settings.agents.loadingHost": "Chargement des paramètres des agents…",
-  "settings.agents.updateHost": "Mettez ce serveur à jour pour modifier ses paramètres de lancement des agents.",
-  "settings.agents.readFailed": "Impossible de lire les paramètres des agents. Vérifiez la connexion à l’hôte et réessayez.",
-  "settings.agents.saveFailed": "Impossible d’enregistrer les paramètres des agents. Vérifiez la connexion à l’hôte et réessayez.",
-  "settings.agents.hostDefaults": "Paramètres par défaut des nouveaux agents sur l’hôte sélectionné.",
-  "settings.agents.save": "Enregistrer"
+  }
 }
diff --git a/src/renderer/src/i18n/locales/ja.json b/src/renderer/src/i18n/locales/ja.json
index 8efe71d8eb08..a0647f056389 100644
--- a/src/renderer/src/i18n/locales/ja.json
+++ b/src/renderer/src/i18n/locales/ja.json
@@ -151,7 +151,18 @@
       "codexSharedServerWarning": {
         "title": "Codex タブがサーバーを共有する場合に警告する",
         "description": "自分で開始した Codex が他のタブとサーバーを共有している場合、Agent のステータスが間違っている可能性があるため、その Codex に関する通知が表示されます。"
-      }
+      },
+      "environmentName": "環境変数名",
+      "environmentValue": "{{name}} の値",
+      "savedEnvironment": "保存済みの値 · 置き換えるには入力",
+      "newEnvironment": "値",
+      "removeEnvironment": "削除",
+      "loadingHost": "Agent設定を読み込み中…",
+      "updateHost": "Agentの起動設定を編集するには、このサーバーを更新してください。",
+      "readFailed": "Agent設定を読み込めませんでした。ホストへの接続を確認して再試行してください。",
+      "saveFailed": "Agent設定を保存できませんでした。ホストへの接続を確認して再試行してください。",
+      "hostDefaults": "選択したホストで起動する新しいAgentの既定値。",
+      "save": "保存"
     },
     "followSymlinkedDirectoriesKeywords": {
       "symlink": "シンボリックリンク",
@@ -19536,16 +19547,5 @@
   },
   "projectField": {
     "updateFailed": "プロジェクトフィールドを更新できませんでした"
-  },
-  "settings.agents.environmentName": "環境変数名",
-  "settings.agents.environmentValue": "{{name}} の値",
-  "settings.agents.savedEnvironment": "保存済みの値 · 置き換えるには入力",
-  "settings.agents.newEnvironment": "値",
-  "settings.agents.removeEnvironment": "削除",
-  "settings.agents.loadingHost": "Agent設定を読み込み中…",
-  "settings.agents.updateHost": "Agentの起動設定を編集するには、このサーバーを更新してください。",
-  "settings.agents.readFailed": "Agent設定を読み込めませんでした。ホストへの接続を確認して再試行してください。",
-  "settings.agents.saveFailed": "Agent設定を保存できませんでした。ホストへの接続を確認して再試行してください。",
-  "settings.agents.hostDefaults": "選択したホストで起動する新しいAgentの既定値。",
-  "settings.agents.save": "保存"
+  }
 }
diff --git a/src/renderer/src/i18n/locales/ko.json b/src/renderer/src/i18n/locales/ko.json
index 649dd6709549..1b7a3692b4d6 100644
--- a/src/renderer/src/i18n/locales/ko.json
+++ b/src/renderer/src/i18n/locales/ko.json
@@ -151,7 +151,18 @@
       "codexSharedServerWarning": {
         "title": "Codex 탭이 서버를 공유할 때 경고",
         "description": "에이전트 상태가 잘못되었을 수 있으므로 서버를 다른 탭과 공유할 때 직접 시작한 Codex에 대한 알림을 표시합니다."
-      }
+      },
+      "environmentName": "환경 변수 이름",
+      "environmentValue": "{{name}} 값",
+      "savedEnvironment": "저장된 값 · 바꾸려면 입력",
+      "newEnvironment": "값",
+      "removeEnvironment": "삭제",
+      "loadingHost": "에이전트 설정 불러오는 중…",
+      "updateHost": "에이전트 실행 설정을 편집하려면 이 서버를 업데이트하세요.",
+      "readFailed": "에이전트 설정을 읽을 수 없습니다. 호스트 연결을 확인하고 다시 시도하세요.",
+      "saveFailed": "에이전트 설정을 저장할 수 없습니다. 호스트 연결을 확인하고 다시 시도하세요.",
+      "hostDefaults": "선택한 호스트의 새 에이전트 기본값입니다.",
+      "save": "저장"
     },
     "followSymlinkedDirectoriesKeywords": {
       "symlink": "심볼릭 링크",
@@ -19566,16 +19577,5 @@
   },
   "projectField": {
     "updateFailed": "프로젝트 필드를 업데이트하지 못했습니다"
-  },
-  "settings.agents.environmentName": "환경 변수 이름",
-  "settings.agents.environmentValue": "{{name}} 값",
-  "settings.agents.savedEnvironment": "저장된 값 · 바꾸려면 입력",
-  "settings.agents.newEnvironment": "값",
-  "settings.agents.removeEnvironment": "삭제",
-  "settings.agents.loadingHost": "에이전트 설정 불러오는 중…",
-  "settings.agents.updateHost": "에이전트 실행 설정을 편집하려면 이 서버를 업데이트하세요.",
-  "settings.agents.readFailed": "에이전트 설정을 읽을 수 없습니다. 호스트 연결을 확인하고 다시 시도하세요.",
-  "settings.agents.saveFailed": "에이전트 설정을 저장할 수 없습니다. 호스트 연결을 확인하고 다시 시도하세요.",
-  "settings.agents.hostDefaults": "선택한 호스트의 새 에이전트 기본값입니다.",
-  "settings.agents.save": "저장"
+  }
 }
diff --git a/src/renderer/src/i18n/locales/zh.json b/src/renderer/src/i18n/locales/zh.json
index a7734105c618..bbce2deb1286 100644
--- a/src/renderer/src/i18n/locales/zh.json
+++ b/src/renderer/src/i18n/locales/zh.json
@@ -151,7 +151,18 @@
       "codexSharedServerWarning": {
         "title": "当 Codex 选项卡共享服务器时发出警告",
         "description": "当您自己启动的 Codex 与其他选项卡共享服务器时，在您自己启动的 Codex 上显示一条通知，因为它的智能体状态可能是错误的。"
-      }
+      },
+      "environmentName": "环境变量名称",
+      "environmentValue": "{{name}} 的值",
+      "savedEnvironment": "已保存的值 · 输入以替换",
+      "newEnvironment": "值",
+      "removeEnvironment": "删除",
+      "loadingHost": "正在加载代理设置…",
+      "updateHost": "请更新此服务器以编辑其代理启动设置。",
+      "readFailed": "无法读取代理设置。请检查主机连接并重试。",
+      "saveFailed": "无法保存代理设置。请检查主机连接并重试。",
+      "hostDefaults": "所选主机上新代理的默认设置。",
+      "save": "保存"
     },
     "followSymlinkedDirectoriesKeywords": {
       "symlink": "符号链接",
@@ -19550,16 +19561,5 @@
   },
   "projectField": {
     "updateFailed": "无法更新项目字段"
-  },
-  "settings.agents.environmentName": "环境变量名称",
-  "settings.agents.environmentValue": "{{name}} 的值",
-  "settings.agents.savedEnvironment": "已保存的值 · 输入以替换",
-  "settings.agents.newEnvironment": "值",
-  "settings.agents.removeEnvironment": "删除",
-  "settings.agents.loadingHost": "正在加载代理设置…",
-  "settings.agents.updateHost": "请更新此服务器以编辑其代理启动设置。",
-  "settings.agents.readFailed": "无法读取代理设置。请检查主机连接并重试。",
-  "settings.agents.saveFailed": "无法保存代理设置。请检查主机连接并重试。",
-  "settings.agents.hostDefaults": "所选主机上新代理的默认设置。",
-  "settings.agents.save": "保存"
+  }
 }