diff --git a/action.yml b/action.yml
index 028357c..b9358ab 100644
--- a/action.yml
+++ b/action.yml
@@ -15,17 +15,39 @@ outputs:
 runs:
   using: 'composite'
   steps:
-  - name: 顯示資訊
-    id: display
+  - name: 取得專案
+    uses: actions/checkout@v6
+  - name: 產生 AI 回覆
+    id: response
+    uses: https://gitea.jsc.idv.tw/actions/codex@v0.0.2
+    with:
+      OAUTH: ${{ secrets.CODEX_OAUTH }}
+      MODEL: gpt-5.4-mini
+      PROMPT: |
+        請根據以下 Gitea issue 資訊，以繁體中文回覆使用者。
+        請只輸出要張貼到 issue 留言中的內容，不要包含額外前言。
+
+        ## 問題標題
+        ${{ github.event.issue.title }}
+
+        ## 問題描述
+        ${{ github.event.issue.body }}
+
+        ## 使用者留言
+        ${{ github.event.comment.body }}
+  - name: 留言 AI 回覆
     env:
       GITEA_SERVER_URL: ${{ gitea.server_url }}
       GITEA_REPOSITORY: ${{ gitea.repository }}
-      RUNNER_TOKEN: ${{ inputs.runner_token }}
-      TEXT: ${{ inputs.text }}
+      ISSUE_NUMBER: ${{ github.event.issue.number }}
+      RUNNER_TOKEN: ${{ secrets.RUNNER_TOKEN }}
     run: |
-      echo "Gitea Server Url: $GITEA_SERVER_URL"
-      echo "Gitea Repository: $GITEA_REPOSITORY"
-      echo "Gitea Runner Token: $RUNNER_TOKEN"
-      echo "Input Text: $TEXT"
-      echo "text=$TEXT" >> "$GITHUB_OUTPUT"
+      jq -n --rawfile body response.md '{body: $body}' > comment.json
+
+      curl --fail-with-body \
+        -X POST \
+        -H "Authorization: token $RUNNER_TOKEN" \
+        -H "Content-Type: application/json" \
+        --data @comment.json \
+        "$GITEA_SERVER_URL/api/v1/repos/$GITEA_REPOSITORY/issues/$ISSUE_NUMBER/comments"
     shell: bash
\ No newline at end of file