diff --git a/.github/workflows/translate-i18n-claude.yml b/.github/workflows/translate-i18n-claude.yml
index 50a03bb7ab8..aaf51aa6064 100644
--- a/.github/workflows/translate-i18n-claude.yml
+++ b/.github/workflows/translate-i18n-claude.yml
@@ -8,11 +8,11 @@ on:
   workflow_dispatch:
     inputs:
       files:
-        description: 'Specific files to translate (space-separated, e.g., "app common"). Leave empty for all files.'
+        description: 'Specific files to translate (space-separated, e.g., "app common"). Required for full mode; leave empty in incremental mode to use en-US files changed since HEAD~1.'
         required: false
         type: string
       languages:
-        description: 'Specific languages to translate (space-separated, e.g., "zh-Hans ja-JP"). Leave empty for all supported languages.'
+        description: 'Specific languages to translate (space-separated, e.g., "zh-Hans ja-JP"). Leave empty for all supported target languages except en-US.'
         required: false
         type: string
       mode:
@@ -29,14 +29,14 @@ permissions:
   pull-requests: write
 
 concurrency:
-  group: translate-i18n-${{ github.ref }}
-  cancel-in-progress: true
+  group: translate-i18n-${{ github.event_name }}-${{ github.ref }}
+  cancel-in-progress: ${{ github.event_name == 'push' }}
 
 jobs:
   translate:
     if: github.repository == 'langgenius/dify'
     runs-on: ubuntu-latest
-    timeout-minutes: 60
+    timeout-minutes: 120
 
     steps:
       - name: Checkout repository
@@ -57,28 +57,52 @@ jobs:
         id: context
         shell: bash
         run: |
+          DEFAULT_TARGET_LANGS=$(awk "
+            /value: '/ {
+              value=\$2
+              gsub(/[',]/, \"\", value)
+            }
+            /supported: true/ && value != \"en-US\" {
+              printf \"%s \", value
+            }
+          " web/i18n-config/languages.ts | sed 's/[[:space:]]*$//')
+
           if [ "${{ github.event_name }}" = "push" ]; then
             BASE_SHA="${{ github.event.before }}"
             if [ -z "$BASE_SHA" ] || [ "$BASE_SHA" = "0000000000000000000000000000000000000000" ]; then
               BASE_SHA=$(git rev-parse HEAD~1 2>/dev/null || true)
             fi
             HEAD_SHA="${{ github.sha }}"
-            CHANGED_FILES=$(git diff --name-only "$BASE_SHA" "$HEAD_SHA" -- 'web/i18n/en-US/*.json' 2>/dev/null | sed -n 's@^.*/@@p' | sed 's/\.json$//' | tr '\n' ' ' | sed 's/[[:space:]]*$//')
-            TARGET_LANGS=""
-            SYNC_MODE="incremental"
-          else
-            HEAD_SHA=$(git rev-parse HEAD)
-            TARGET_LANGS="${{ github.event.inputs.languages }}"
-            SYNC_MODE="${{ github.event.inputs.mode || 'incremental' }}"
-            if [ -n "${{ github.event.inputs.files }}" ]; then
-              CHANGED_FILES="${{ github.event.inputs.files }}"
+            if [ -n "$BASE_SHA" ]; then
+              CHANGED_FILES=$(git diff --name-only "$BASE_SHA" "$HEAD_SHA" -- 'web/i18n/en-US/*.json' 2>/dev/null | sed -n 's@^.*/@@p' | sed 's/\.json$//' | tr '\n' ' ' | sed 's/[[:space:]]*$//')
             else
               CHANGED_FILES=$(find web/i18n/en-US -maxdepth 1 -type f -name '*.json' -print | sed -n 's@^.*/@@p' | sed 's/\.json$//' | sort | tr '\n' ' ' | sed 's/[[:space:]]*$//')
             fi
-            if [ "$SYNC_MODE" = "incremental" ]; then
-              BASE_SHA=$(git rev-parse HEAD~1 2>/dev/null || true)
+            TARGET_LANGS="$DEFAULT_TARGET_LANGS"
+            SYNC_MODE="incremental"
+          else
+            BASE_SHA=""
+            HEAD_SHA=$(git rev-parse HEAD)
+            if [ -n "${{ github.event.inputs.languages }}" ]; then
+              TARGET_LANGS="${{ github.event.inputs.languages }}"
             else
-              BASE_SHA=""
+              TARGET_LANGS="$DEFAULT_TARGET_LANGS"
+            fi
+            SYNC_MODE="${{ github.event.inputs.mode || 'incremental' }}"
+            if [ -n "${{ github.event.inputs.files }}" ]; then
+              CHANGED_FILES="${{ github.event.inputs.files }}"
+            elif [ "$SYNC_MODE" = "incremental" ]; then
+              BASE_SHA=$(git rev-parse HEAD~1 2>/dev/null || true)
+              if [ -n "$BASE_SHA" ]; then
+                CHANGED_FILES=$(git diff --name-only "$BASE_SHA" "$HEAD_SHA" -- 'web/i18n/en-US/*.json' 2>/dev/null | sed -n 's@^.*/@@p' | sed 's/\.json$//' | tr '\n' ' ' | sed 's/[[:space:]]*$//')
+              else
+                CHANGED_FILES=$(find web/i18n/en-US -maxdepth 1 -type f -name '*.json' -print | sed -n 's@^.*/@@p' | sed 's/\.json$//' | sort | tr '\n' ' ' | sed 's/[[:space:]]*$//')
+              fi
+            elif [ "$SYNC_MODE" = "full" ]; then
+              echo "workflow_dispatch full mode requires the files input to stay within CI limits." >&2
+              exit 1
+            else
+              CHANGED_FILES=""
             fi
           fi
 
@@ -93,6 +117,7 @@ jobs:
           fi
 
           {
+            echo "DEFAULT_TARGET_LANGS=$DEFAULT_TARGET_LANGS"
             echo "BASE_SHA=$BASE_SHA"
             echo "HEAD_SHA=$HEAD_SHA"
             echo "CHANGED_FILES=$CHANGED_FILES"
@@ -103,7 +128,7 @@ jobs:
           } >> "$GITHUB_OUTPUT"
 
           echo "Files: ${CHANGED_FILES:-<none>}"
-          echo "Languages: ${TARGET_LANGS:-<all supported>}"
+          echo "Languages: ${TARGET_LANGS:-<none>}"
           echo "Mode: $SYNC_MODE"
 
       - name: Run Claude Code for Translation Sync
@@ -113,6 +138,7 @@ jobs:
           anthropic_api_key: ${{ secrets.ANTHROPIC_API_KEY }}
           github_token: ${{ secrets.GITHUB_TOKEN }}
           allowed_bots: 'github-actions[bot]'
+          show_full_output: ${{ github.event_name == 'workflow_dispatch' }}
           prompt: |
             You are the i18n sync agent for the Dify repository.
             Your job is to keep translations synchronized with the English source files under `${{ github.workspace }}/web/i18n/en-US/`, then open a PR with the result.
@@ -139,11 +165,13 @@ jobs:
 
             Required execution plan:
             1. Resolve target languages.
-               - If no target languages were provided, read `${{ github.workspace }}/web/i18n-config/languages.ts` and use every language with `supported: true`.
+               - Use the provided `Target languages` value as the source of truth.
+               - If it is unexpectedly empty, read `${{ github.workspace }}/web/i18n-config/languages.ts` and use every language with `supported: true` except `en-US`.
             2. Stay strictly in scope.
                - Only process the files listed in `Files in scope`.
-               - Only process the resolved target languages.
+               - Only process the resolved target languages, never `en-US`.
                - Do not touch unrelated i18n files.
+               - Do not modify `${{ github.workspace }}/web/i18n/en-US/`.
             3. Detect English changes per file.
                - Read the current English JSON file for each file in scope.
                - If sync mode is `incremental` and `Base SHA` is not empty, run:
@@ -160,6 +188,7 @@ jobs:
                - Use this command as the source of truth for missing and extra keys inside the current scope.
             5. Apply translations.
                - For every target language and scoped file:
+                 - If the locale file does not exist yet, create it with `Write` and then continue with `Edit` as needed.
                  - ADD missing keys.
                  - UPDATE stale translations when the English value changed.
                  - DELETE removed keys. Prefer `pnpm --dir ${{ github.workspace }}/web run i18n:check ${{ steps.context.outputs.FILE_ARGS }} ${{ steps.context.outputs.LANG_ARGS }} --auto-remove` for extra keys so deletions stay in scope.
@@ -181,4 +210,4 @@ jobs:
             8. If there are no translation changes after verification, do not create a branch, commit, or PR.
           claude_args: |
             --max-turns 80
-            --allowedTools "Read,Edit,Bash(git *),Bash(git:*),Bash(gh *),Bash(gh:*),Bash(pnpm *),Bash(pnpm:*),Bash(date *),Bash(date:*),Glob,Grep"
+            --allowedTools "Read,Write,Edit,Bash(git *),Bash(git:*),Bash(gh *),Bash(gh:*),Bash(pnpm *),Bash(pnpm:*),Bash(date *),Bash(date:*),Glob,Grep"