---
title: "Create AI custom field definition"
method: POST
path: "/accounts/self/ai/custom-fields"
tags: ["Fax AI"]
---

# Create AI custom field definition

`POST /accounts/self/ai/custom-fields`

Create a new custom field definition for AI field extraction. Admin-only. (Permitted scopes: **fax:all:edit**, **fax:ai_settings:edit**)

## Request body

- AiCustomFieldCreate — Request to create an AI custom field definition
  - `name` string, required — Display name of the custom field
  - `instructions` string, required — AI extraction instructions for this field
  - `enabled` boolean — Whether this custom field is active

## Response `200`

Response containing a single custom field definition

- AiCustomField — AI custom field definition
  - `id` string, required — Unique identifier for the custom field
  - `name` string, required — Display name of the custom field
  - `instructions` string, required — AI extraction instructions for this field
  - `enabled` boolean, required — Whether this custom field is active

## Other responses

- `400` — Error object in case there's a problem with given data
- `401` — Error object in case there's a problem with the authorization
- `500` — Error object in case there's a server error

---

[API](https://skmtc.net/fax/apis/fax-plus-rest-api.md) · [All operations](https://skmtc.net/fax/apis/fax-plus-rest-api/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/fax/fax-plus-rest-api/versions/c1afc85d2c15/schema)