diff --git a/custom-api_v2.md b/custom-api_v2.md
index 55b9374..32a06c6 100644
--- a/custom-api_v2.md
+++ b/custom-api_v2.md
@@ -99,7 +99,7 @@ async (args) => {
       {
         role: "user",
         content: JSON.stringify({
-          targetLanguage: args.to,
+          targetLanguage: args.toLang,
           segments: args.texts.map((text, id) => ({ id, text })),
           glossary: {},
         }),
@@ -132,7 +132,7 @@ async (args) => {
       {
         role: "user",
         content: JSON.stringify({
-          targetLanguage: args.to,
+          targetLanguage: args.toLang,
           segments: args.texts.map((text, id) => ({ id, text })),
           glossary: {},
         }),
diff --git a/src/apis/trans.js b/src/apis/trans.js
index 7b09740..56d9b70 100644
--- a/src/apis/trans.js
+++ b/src/apis/trans.js
@@ -74,12 +74,13 @@ const genUserPrompt = ({
   glossary = {},
   from,
   to,
+  toLang,
   texts,
   docInfo,
 }) => {
   if (useBatchFetch) {
     return JSON.stringify({
-      targetLanguage: to,
+      targetLanguage: toLang,
       title: docInfo.title,
       description: docInfo.description,
       segments: texts.map((text, i) => ({ id: i, text })),
@@ -557,8 +558,8 @@ const genCloudflareAI = ({ texts, from, to, url, key }) => {
   return { url, body, headers };
 };
 
-const genCustom = ({ texts, from, to, url, key }) => {
-  const body = { texts, from, to };
+const genCustom = ({ texts, fromLang, toLang, url, key }) => {
+  const body = { texts, from: fromLang, to: toLang };
   const headers = {
     "Content-type": "application/json",
     Authorization: `Bearer ${key}`,
@@ -638,6 +639,8 @@ export const genTransReq = async ({ reqHook, ...args }) => {
     useBatchFetch,
     from,
     to,
+    fromLang,
+    toLang,
     texts,
     docInfo,
     glossary,
@@ -667,6 +670,8 @@ export const genTransReq = async ({ reqHook, ...args }) => {
           useBatchFetch,
           from,
           to,
+          fromLang,
+          toLang,
           texts,
           docInfo,
           glossary,
diff --git a/src/config/api.js b/src/config/api.js
index 4761340..49e170b 100644
--- a/src/config/api.js
+++ b/src/config/api.js
@@ -312,14 +312,14 @@ export const OPT_LANGS_TO_SPEC = {
     ["id", "id"],
     ["vi", "vi"],
   ]),
-  [OPT_TRANS_OPENAI]: OPT_LANGS_SPEC_DEFAULT,
-  [OPT_TRANS_GEMINI]: OPT_LANGS_SPEC_DEFAULT,
-  [OPT_TRANS_GEMINI_2]: OPT_LANGS_SPEC_DEFAULT,
-  [OPT_TRANS_CLAUDE]: OPT_LANGS_SPEC_DEFAULT,
-  [OPT_TRANS_OLLAMA]: OPT_LANGS_SPEC_DEFAULT,
-  [OPT_TRANS_OPENROUTER]: OPT_LANGS_SPEC_DEFAULT,
-  [OPT_TRANS_CLOUDFLAREAI]: OPT_LANGS_SPEC_DEFAULT,
-  [OPT_TRANS_CUSTOMIZE]: OPT_LANGS_SPEC_DEFAULT,
+  [OPT_TRANS_OPENAI]: OPT_LANGS_SPEC_NAME,
+  [OPT_TRANS_GEMINI]: OPT_LANGS_SPEC_NAME,
+  [OPT_TRANS_GEMINI_2]: OPT_LANGS_SPEC_NAME,
+  [OPT_TRANS_CLAUDE]: OPT_LANGS_SPEC_NAME,
+  [OPT_TRANS_OLLAMA]: OPT_LANGS_SPEC_NAME,
+  [OPT_TRANS_OPENROUTER]: OPT_LANGS_SPEC_NAME,
+  [OPT_TRANS_CLOUDFLAREAI]: OPT_LANGS_SPEC_NAME,
+  [OPT_TRANS_CUSTOMIZE]: OPT_LANGS_SPEC_NAME,
 };
 
 const specToCode = (m) =>
@@ -342,7 +342,7 @@ Object.entries(OPT_LANGS_TO_SPEC).forEach(([t, m]) => {
 });
 
 export const defaultNobatchPrompt = `You are a professional, authentic machine translation engine.`;
-export const defaultNobatchUserPrompt = `Translate the following source text from ${INPUT_PLACE_FROM} to ${INPUT_PLACE_TO}. Output translation directly without any additional text.\n\nSource Text: ${INPUT_PLACE_TEXT}\n\nTranslated Text:`;
+export const defaultNobatchUserPrompt = `Translate the following source text to ${INPUT_PLACE_TO}. Output translation directly without any additional text.\n\nSource Text: ${INPUT_PLACE_TEXT}\n\nTranslated Text:`;
 
 export const defaultSystemPrompt = `Act as a translation API. Output a single raw JSON object only. No extra text or fences.