> ## Documentation Index
> Fetch the complete documentation index at: https://docs.mailerpath.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Workflow customization fields

> Reference for the timing and priority fields clients can set to adjust workflow behavior.

MailerPath controls workflow logic and execution. Clients can adjust a limited set of approved fields to tune timing and delivery priority without changing the workflow's core behavior.

Use `PATCH /client/workflows/{workflow_id}/customization` to apply these fields.

## Timing fields

### `delay_minutes`

**Type:** integer

The number of minutes to wait after a contact triggers the workflow before the email is scheduled.

This is a minimum wait — not necessarily the final send time. After the delay elapses, the scheduler applies `send_time_mode` to find the next valid send window.

**Example:** `delay_minutes = 120`, `send_time_mode = 1` — contact triggers at 9:00 AM → earliest scheduling attempt is 11:00 AM → scheduler picks the next valid window at or after 11:00 AM.

If not set, the workflow's system default is used.

***

### `send_time_mode`

**Type:** integer (enum)

Controls exactly when the email is sent once the delay has elapsed.

| Value | Mode            | Behavior                                                                                                                                                                         |
| ----- | --------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `1`   | `window_start`  | Send at the start of the next valid send window, on an allowed weekday, in the contact's timezone. This is the default.                                                          |
| `2`   | `immediate`     | Bypass send windows entirely. Send exactly at `now + delay_minutes`, regardless of timezone or business hours.                                                                   |
| `3`   | `specific_time` | Send at the exact hour and minute defined by `preferred_send_hour` and `preferred_send_minute`, on the next allowed weekday in the contact's timezone. Both fields are required. |
| `4`   | `morning`       | Send at the morning slot configured in client settings, on the next allowed weekday.                                                                                             |
| `5`   | `afternoon`     | Send at the afternoon slot configured in client settings, on the next allowed weekday.                                                                                           |

For send windows and allowed weekday configuration, see [Send windows and timezones](/documentation/settings/send-windows-and-timezones).

***

### `preferred_send_hour`

**Type:** integer (0–23)

Hour of day in the contact's local timezone to send the email.

Only used when `send_time_mode = 3`. Must be set together with `preferred_send_minute`.

***

### `preferred_send_minute`

**Type:** integer (0–59)

Minute within the hour to send the email.

Only used when `send_time_mode = 3`. Must be set together with `preferred_send_hour`.

***

## Priority field

### `priority_score`

**Type:** integer (1–100)

Controls queue processing order for this workflow relative to others. Higher score means the workflow's emails are processed sooner when multiple sends are queued at the same time.

Overrides the workflow's system default priority score.

***

## Full customization request example

```json theme={null}
{
  "timing": {
    "delay_minutes": 60,
    "send_time_mode": 3,
    "preferred_send_hour": 10,
    "preferred_send_minute": 30
  },
  "priority": {
    "priority_score": 80
  }
}
```

This configuration: wait 60 minutes after trigger, then send at 10:30 AM in the contact's timezone on the next allowed weekday.

***

## What you cannot change

MailerPath controls the following and they are not client-customizable:

* Entry and exit conditions
* Suppression and conflict rules
* Workflow step sequence and logic
* Template structure and copy (except through template editing)

## Related pages

* [Workflows overview](/documentation/core-functionalities/workflows/overview)
* [Send windows and timezones](/documentation/settings/send-windows-and-timezones)
* [Workflow Library by State](/documentation/core-functionalities/workflows/predefined-workflows-by-state)