diff --git a/.gitea/workflows/response.yaml b/.gitea/workflows/response.yaml
new file mode 100644
index 0000000..cbe4d4e
--- /dev/null
+++ b/.gitea/workflows/response.yaml
@@ -0,0 +1,51 @@
+name: AI Response
+
+on:
+  issue_comment:
+    types:
+    - created
+
+jobs:
+  response:
+    name: 回覆問題留言
+    runs-on: ubuntu
+    if: ${{ contains(github.event.comment.body, '@opencode') }}
+    steps:
+    - name: 安裝 OpenCode
+      run: npm install -g opencode-ai
+
+    - name: 產生 AI 回覆
+      env:
+        COMMENT_BODY: ${{ github.event.comment.body }}
+        ISSUE_BODY: ${{ github.event.issue.body }}
+        ISSUE_TITLE: ${{ github.event.issue.title }}
+        NO_COLOR: "1"
+        TERM: dumb
+      run: |
+        clean_comment="$(printf '%s' "$COMMENT_BODY" | sed -E 's/@opencode[[:space:]]*//g')"
+
+        {
+          printf '請根據以下 Gitea issue 資訊，以繁體中文回覆使用者。\n'
+          printf '請只輸出要張貼到 issue 留言中的內容，不要包含額外前言。\n\n'
+          printf '## 問題標題\n%s\n\n' "$ISSUE_TITLE"
+          printf '## 問題描述\n%s\n\n' "$ISSUE_BODY"
+          printf '## 使用者留言\n%s\n' "$clean_comment"
+        } > prompt.md
+
+        opencode run --agent plan "$(cat prompt.md)" > response.md
+
+    - name: 留言到問題
+      env:
+        GITEA_REPOSITORY: ${{ gitea.repository }}
+        GITEA_SERVER_URL: ${{ gitea.server_url }}
+        ISSUE_NUMBER: ${{ github.event.issue.number }}
+        RUNNER_TOKEN: ${{ secrets.RUNNER_TOKEN }}
+      run: |
+        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"