### ❌ 📨 🆎 ✍

✋️ 🕐❔ 👆 📨 🎏 ❌ 🎚 👈 🚫 ☑ Pydantic 🆎 (✅ 💽 🎚) & 👆 ✍ ⚫️ 💖 👈 🔢, FastAPI 🔜 🔄 ✍ Pydantic 📨 🏷 ⚪️➡️ 👈 🆎 ✍, & 🔜 ❌.

🎏 🔜 🔨 🚥 👆 ✔️ 🕳 💖 <abbr title='A union between multiple types means "any of these types".'>🇪🇺</abbr> 🖖 🎏 🆎 🌐❔ 1️⃣ ⚖️ 🌅 👫 🚫 ☑ Pydantic 🆎, 🖼 👉 🔜 ❌ 👶:

=== "🐍 3️⃣.6️⃣ &amp; 🔛"

    ```Python hl_lines="10"
    {!> ../../../docs_src/response_model/tutorial003_04.py!}

    {!> ../../../docs_src/response_model/tutorial001_01.py!}
    ```

FastAPI will use this return type to:

* **Validate** the returned data.
    * If the data is invalid (e.g. you are missing a field), it means that *your* app code is broken, not returning what it should, and it will return a server error instead of returning incorrect data. This way you and your clients can be certain that they will receive the data and the data shape expected.