diff --git a/Dockerfile b/Dockerfile
index f056a8f..7794cde 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -16,4 +16,6 @@ WORKDIR /workspace
 COPY app/codex_account.js /usr/local/bin/codex-account
 RUN chmod +x /usr/local/bin/codex-account
 
-CMD ["codex-account"]
+ENV EXPECTED_CODEX_EMAIL=temp@gmail.com
+
+CMD ["sh", "-c", "email=\"$(codex-account)\"; if [ \"$email\" = \"$EXPECTED_CODEX_EMAIL\" ]; then printf 'Codex account email verified: %s\\n' \"$email\"; else printf 'Codex account email mismatch: expected %s, got %s\\n' \"$EXPECTED_CODEX_EMAIL\" \"${email:-<empty>}\" >&2; exit 1; fi"]
diff --git a/README.md b/README.md
index 11ef4f2..7a95dae 100644
--- a/README.md
+++ b/README.md
@@ -74,3 +74,12 @@ node app/codex_account.js
 docker build -t codex-account .
 docker run --rm -v "$HOME/.codex:/root/.codex:ro" codex-account
 ```
+
+容器啟動時會執行 `codex-account`，並確認取得的 email 是否等於 `EXPECTED_CODEX_EMAIL`。預設值為 `temp@gmail.com`，可用環境變數覆寫：
+
+```bash
+docker run --rm \
+  -e EXPECTED_CODEX_EMAIL='temp@gmail.com' \
+  -v "$HOME/.codex:/root/.codex:ro" \
+  codex-account
+```