mailerpress-pro/create-custom-field registers a new contact custom-field definition.
The field_key must be a stable machine slug — alphanumerics with underscores or hyphens — because MailerPress uses it as the storage key.
At a glance
| Ability | mailerpress-pro/create-custom-field |
| Toolset | MailerPress Pro — toolset/mailerpress-pro |
| Group | MailerPress Pro › Contact Custom Fields |
| Requires | AcrossAI Pro, plus MailerPress with its Pro add-on active on the site |
| Capability | manage_options |
| Safety | Writes data |
| Repeatable | Not idempotent — each call changes the row set, so re-running is not a no-op |
| Ships in | AcrossAI Pro 0.9.16 and later |
The key is permanent in practice
Values are stored against the key rather than against the field record, which means the key is the identity of the data. Changing it later is not a rename — it is a new field, with the old values still filed under the old key and invisible to the new one.
So the key is worth choosing carefully at creation and worth keeping boring: lowercase, descriptive, unlikely to need changing when the label does.
The label is what people see and is safe to change.
The type governs both what values are accepted and how segments can compare them. Getting it wrong is recoverable only by creating a new field of the right type and migrating the values, since a type change on an existing field does not convert the stored data.
Not idempotent.
Input
| Name | Type | Required | What it is |
|---|---|---|---|
field_key | string | Yes | Stable machine slug: alphanumerics, underscores and hyphens. The storage key. |
label | string | Yes | The label shown to people. |
type | string | Yes | The field type. Governs accepted values and segment comparison. |
options | array | No | Choices, for the types that take them. |
What comes back
| Name | Type | What it is |
|---|---|---|
field | object | The created definition. |
success | boolean | Whether the call completed. |
message | string | A one-line summary of what happened, suitable for showing a human. |
error_code | string | Present only on failure — a stable machine-readable reason, such as a missing field, a wrong field type or an unmet confirmation. |
Example
Ask your assistant:
Add a plan-tier field to contacts.
It resolves to one call:
{
"ability": "mailerpress-pro/create-custom-field",
"parameters": {
"field_key": "plan_tier",
"label": "Plan tier",
"type": "select",
"options": ["Free", "Standard", "Enterprise"]
}
}Worth knowing
- The key is the data’s identity. Changing it orphans existing values.
- The label is safe to change; the key is not.
- A wrong type means creating a new field and migrating.
- Not idempotent.
Related abilities
- MailerPress Pro List Custom Fields — check it does not exist
- MailerPress Pro Update Custom Field — change the label
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