> For the complete documentation index, see [llms.txt](https://support.holidayhero.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://support.holidayhero.com/the-basics/reservations/metafields.md).

# Metafields

Metafields can be used within reservations. Overwrite a default value of an metafield and use this within the guest journey.

***

#### What are reservation metafields? <a href="#what-are-reservation-metafields" id="what-are-reservation-metafields"></a>

A **metafield** is a custom field defined once for your workspace. A metafield created with the `RESERVATION` resource is filled in per stay — this tab is where you set its value for *this* reservation. Use it for anything that differs per booking: an arrival time, a parking instruction, a rented extra, a special request.

A reservation metafield is its own field, not an override of a listing metafield. If nothing is filled in here, the metafield falls back to the **Default Value** set on its definition — not to a value from the listing or the brand.

For the broader concept, the field types and how metafields are defined at workspace level, see [Metafields](/the-basics/metafields.md).

#### What does the tab show? <a href="#what-does-the-tab-show" id="what-does-the-tab-show"></a>

The **Metafields** tab lists every metafield currently set on the reservation, with:

* The metafield **name**.
* The current **value** (as a badge).
* The **field type** — `TEXT`, `NUMBER`, `DATE`, `TIME` or `BOOLEAN`.
* An **AI** badge, when the guest-facing AI assistant is allowed to share the value. See [AI visibility](/the-basics/metafields.md#ai-visibility).
* The created and last-updated timestamps.

Only `RESERVATION` metafields appear here. A metafield that belongs to the property lives on the listing's tab, and one that belongs to the person lives on the guest's tab.

***

#### Frequently Asked Questions <a href="#frequently-asked-questions" id="frequently-asked-questions"></a>

<details open>

<summary>How do I add a metafield to a reservation?</summary>

1. Open the reservation.
2. Go to the **Metafields** tab.
3. Click **Add Metafield**.
4. Pick a metafield from the list and click **Add**. Metafields already on this reservation show as **(Already in use)** and cannot be picked twice.
5. The metafield appears in the table with its **Default Value**. Click **Edit** on its row, set the **Value**, and click **Save**.

Adding and setting the value are two separate steps — a metafield you add but never edit keeps its default.

</details>

<details open>

<summary>How do I change a metafield value?</summary>

Click **Edit** on the row to open the metafield's detail page. Update the value and save. The new value takes effect immediately for the guest app.

</details>

<details open>

<summary>How do I remove a metafield?</summary>

Open the metafield via **Edit** and click **Delete** on the detail page. That detaches it from this reservation only — the definition stays in the workspace and remains on other reservations. Any `{{ key }}` left in your content falls back to the metafield's **Default Value**.

</details>

<details open>

<summary>Can the AI assistant share a reservation metafield with the guest?</summary>

Only if the metafield's definition allows it. **AI visibility** is set once on the metafield itself and applies to every reservation using it — you cannot allow it for one stay and not another. The **AI** column on this tab shows which phase of the stay, if any, the assistant may share the value in. See [AI visibility](/the-basics/metafields.md#ai-visibility).

Note that a value you put into guest-facing content is readable by the assistant from that content regardless of the setting.

</details>

<details open>

<summary>Why can't I find a particular metafield in the dropdown?</summary>

Three common reasons:

* It was created for a different **Resource**. Only `RESERVATION` metafields appear here — a `LISTING` or `USER` metafield never will.
* It is already set on this reservation — it shows as **(Already in use)** and cannot be added twice.
* It has not been defined at workspace level yet. Define it first under [Metafields.](/the-basics/metafields.md)

</details>

***

## Agent Instructions: Querying This Documentation <a href="#agent-instructions-querying-this-documentation" id="agent-instructions-querying-this-documentation"></a>

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Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://support.holidayhero.com/the-basics/reservations/metafields.md?ask=<question>
```

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Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.