mailerpress/create-free-custom-field creates a contact custom-field definition via the free plugin’s POST /custom-field endpoint.
Use it on sites without MailerPress Pro.
At a glance
| Ability | mailerpress/create-free-custom-field |
| Toolset | MailerPress — toolset/mailerpress |
| Group | MailerPress › Contacts |
| Requires | AcrossAI Pro, plus MailerPress 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 |
How it works
It is distinct from mailerpress-pro/create-custom-field, which uses the Pro-only plural route. Both create custom fields; only one exists on any given site.
The field key is the storage key, and everything else references it: contact writes, segment conditions on Pro sites, and campaign personalisation tokens.
So it is worth choosing deliberately and keeping stable. Values are stored against the key rather than against the field record, which means changing it later orphans the data rather than renaming it.
The type governs what values are accepted. On Pro sites it also governs how segment conditions can compare the field, which is why a field stored as text cannot be compared numerically.
Not idempotent.
Input
| Name | Type | Required | What it is |
|---|---|---|---|
key | string | Yes | The storage key. Stable and referenced everywhere. |
label | string | Yes | The label shown to people. |
type | string | Yes | The field type. |
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 company field to contacts.
It resolves to one call:
{
"ability": "mailerpress/create-free-custom-field",
"parameters": {
"key": "company",
"label": "Company",
"type": "text"
}
}Worth knowing
- The free route; the Pro one is a different ability and a different endpoint.
- The key is the data’s identity — changing it orphans values.
- The type limits how segments can compare it on Pro sites.
- Not idempotent.
Related abilities
- MailerPress List Custom Fields (Free) — check it exists
- MailerPress Update Contact — write a value
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