# Send surveys after events

Send a Pristo CX survey automatically after an event, such as a purchase or a support call, with an event-based distribution and sending windows.

An **Event-Based Questionnaire** distribution in Pristo CX sends a questionnaire to a contact automatically after an activity of a chosen event type is recorded, such as a purchase. You set it up in **Management** > **Distributions**, and activities reach Pristo CX from an import or from the API.

## Before you start

- Role: account admin or program admin. See [roles and permissions](https://docs.pristo.io/cx/users/roles-and-permissions).
- Plan: the **Distributions** page appears under **Management** on the Pro plan.
- Setup: the event types you want to react to, defined in the population under **Events attributes**. See [Populations overview](https://docs.pristo.io/cx/populations/overview).
- A way to report activities: a file with **Import activities** in the population, or your systems calling the API. See [Import activities](https://docs.pristo.io/cx/populations/import-activities) and [Send an event](https://docs.pristo.io/cx/api/send-an-event).

## Steps

![Sketch of the main tab of a new event-based distribution. Marker 2 is on the event-based type option. Marker 3 is on the list of event types. Marker 4 is on the button that adds a filter on event attributes. Marker 5 is on the line that sets how long to wait after the event. Marker 6 is on the sending days and hours. Marker 7 is on the button that goes to the next tab, at the bottom right.](https://docs.pristo.io/_astro/distribution-main-event-based.D2CJxQ2_.webp)

1. Start a new distribution and choose the questionnaire, as described in [Create a distribution](https://docs.pristo.io/cx/distributions/create-a-distribution).

2. On the **Main** tab, enter a **Description** and select **Event-Based Questionnaire**.

3. Under **Trigger events**, open **Choose events** and select one or more event types.

4. Optionally filter by event attributes: select **Add**, choose an attribute, a comparison and a value, and select **Save**. Select **And** to add another condition.

5. On the line that starts with **Send**, set how long to wait after the activity in days, hours or minutes.

6. Under **Schedule Delivery**, select the days on which questionnaires may go out and set **From** and **To** for each, or select **Every day 08:00-20:00**.

7. Choose the **Anonymity Level** and select **Next**.

8. On the **Samples** tab, optionally limit the contacts by attribute and set the **Distribution Rules**, then select **Next**.

9. Write the message on the **Wording** tab, select **Next** to save, and activate the distribution from the menu in its row.

## Result

The status shows **Active**. Each time an activity of a chosen type arrives for a contact who passes the filters and rules, Pristo CX schedules the questionnaire for that contact. The contact's page lists the activity under **Events** and the message under **Sends**.

Pristo CX picks the send time like this: it adds the delay to the time it processes the activity. If that time falls inside a sending window, the questionnaire goes out then. Otherwise it goes out when the next window opens, within the next 7 days. Windows use the questionnaire's time zone.

When an activity arrives for a contact who is not in the population yet, Pristo CX adds the contact from the activity's contact details. For a contact who exists, it updates the details the activity carries.

## Limits

- Delay: 0 to 9 days, 0 to 23 hours or 0 to 59 minutes. Pristo CX applies only the largest unit you set, so 1 day and 2 hours waits 1 day.
- Sending windows: one window per day, in 15-minute steps. At least one day is required.
- Filters: up to 5 conditions on event attributes, and the activity must match all of them. An activity without the filtered attribute does not match.
- Send spacing: up to 180 days. With 0, sends to the same contact are still at least 10 minutes apart.
- The event type in an API call is the event type's **Unique Identifier**, not its name.

## Troubleshooting

**No questionnaire was sent after an activity.** Check that the distribution is active and that the activity's event type is selected under **Trigger events**. The contact must be subscribed and active, have a usable phone number or email for the channel, and pass the filters, the segment and the spacing rules.

**The questionnaire went out later than the delay.** The delayed time fell outside the sending windows, so it waited for the next window.

**The event types list is empty.** The population has no event types yet. Define them under **Events attributes** first.

## Related

- [Create a distribution](https://docs.pristo.io/cx/distributions/create-a-distribution)
- [Send an event with the API](https://docs.pristo.io/cx/api/send-an-event)
- [Populations overview](https://docs.pristo.io/cx/populations/overview)
- [Distributions overview](https://docs.pristo.io/cx/distributions/overview)