diff --git a/gui/src/i18n/interpolate.ts b/gui/src/i18n/interpolate.ts
new file mode 100644
index 000000000..ccb979b61
--- /dev/null
+++ b/gui/src/i18n/interpolate.ts
@@ -0,0 +1,11 @@
+import type { TKey } from "./en";
+
+export type Vars = Record<string, string | number>;
+export type TFn = (key: TKey, vars?: Vars) => string;
+
+export function interpolate(s: string, vars?: Vars): string {
+  if (!vars) return s;
+  let out = s;
+  for (const k of Object.keys(vars)) out = out.split(`{${k}}`).join(String(vars[k]));
+  return out;
+}
diff --git a/gui/src/i18n/shared.ts b/gui/src/i18n/shared.ts
index 982dd9f9d..ec53d1ab7 100644
--- a/gui/src/i18n/shared.ts
+++ b/gui/src/i18n/shared.ts
@@ -5,6 +5,9 @@ import { ko } from "./ko";
 import { zh } from "./zh";
 import { ru } from "./ru";
 import { ja } from "./ja";
+import type { TFn } from "./interpolate";
+
+export { interpolate, type TFn, type Vars } from "./interpolate";
 
 export type Locale = "en" | "de" | "ko" | "zh" | "ru" | "ja";
 export type { TKey };
@@ -47,20 +50,10 @@ export function setActiveLocale(locale: Locale): void {
   activeLocale = locale;
 }
 
-export type Vars = Record<string, string | number>;
-export type TFn = (key: TKey, vars?: Vars) => string;
-
 export interface I18nContextValue { locale: Locale; setLocale: (l: Locale) => void; t: TFn }
 
 export const I18nContext = createContext<I18nContextValue | null>(null);
 
-export function interpolate(s: string, vars?: Vars): string {
-  if (!vars) return s;
-  let out = s;
-  for (const k of Object.keys(vars)) out = out.split(`{${k}}`).join(String(vars[k]));
-  return out;
-}
-
 export function useI18n(): I18nContextValue {
   const ctx = useContext(I18nContext);
   if (!ctx) throw new Error("useI18n must be used within LanguageProvider");
diff --git a/tests/provider-workspace-data.test.ts b/tests/provider-workspace-data.test.ts
index a17b6e872..8cc979e19 100644
--- a/tests/provider-workspace-data.test.ts
+++ b/tests/provider-workspace-data.test.ts
@@ -29,7 +29,7 @@ import {
   providerIconSrc,
 } from "../gui/src/provider-icons";
 import { en } from "../gui/src/i18n/en";
-import { interpolate, type TFn } from "../gui/src/i18n/shared";
+import { interpolate, type TFn } from "../gui/src/i18n/interpolate";
 import {
   bucketPresets,
   filterPresets,
diff --git a/tests/tencent-siliconflow-providers.test.ts b/tests/tencent-siliconflow-providers.test.ts
index 966918073..7a3242aa5 100644
--- a/tests/tencent-siliconflow-providers.test.ts
+++ b/tests/tencent-siliconflow-providers.test.ts
@@ -5,7 +5,7 @@ import { PROVIDER_REGISTRY } from "../src/providers/registry";
 import { routeModel } from "../src/router";
 import type { OcxConfig } from "../src/types";
 import { en } from "../gui/src/i18n/en";
-import { interpolate, type TFn } from "../gui/src/i18n/shared";
+import { interpolate, type TFn } from "../gui/src/i18n/interpolate";
 import { formatProviderDisplayName, isCatalogProviderId } from "../gui/src/provider-icons";
 
 const englishT: TFn = (key, vars) => interpolate(en[key], vars);
diff --git a/tests/volcengine-providers.test.ts b/tests/volcengine-providers.test.ts
index 93c7bf415..f2e4526d6 100644
--- a/tests/volcengine-providers.test.ts
+++ b/tests/volcengine-providers.test.ts
@@ -10,7 +10,7 @@ import { routeModel } from "../src/router";
 import type { OcxConfig } from "../src/types";
 import { buildProviderPostBody } from "../gui/src/provider-payload";
 import { en } from "../gui/src/i18n/en";
-import { interpolate, type TFn } from "../gui/src/i18n/shared";
+import { interpolate, type TFn } from "../gui/src/i18n/interpolate";
 import { formatProviderDisplayName, isCatalogProviderId } from "../gui/src/provider-icons";
 import { withTestTranslatorBudget } from "./helpers/translator-budget";