---
title: "Set a custom field on an email contact"
method: PATCH
path: "/emails/contacts"
tags: ["Email campaigns (legacy)"]
deprecated: true
---

# Set a custom field on an email contact

`PATCH /emails/contacts`

## Request

- Base URL: `https://api.emelia.io`
- URL: `https://api.emelia.io/emails/contacts`
- Auth: API key in header `Authorization`

> **Deprecated.**

Sets or updates one field on the contact identified by email inside the campaign (campaignId). Known keys (firstName, lastName, phoneNumber...) update the field; any other name is stored under custom. Spaces in fieldName are removed. New integrations should use the multichannel /advanced campaign endpoints instead.

## Request body

- object
  - `campaignId` string, required
  - `email` string, email, required
  - `fieldName` string, required
  - `fieldValue` string, required

## Response `200`

Field set.

- object
  - `success` true, required

## Other responses

- `400`: Business or validation error. 400 by default; Joi validation errors carry code INVALID_REQUEST.

---

[API](https://skmtc.dev/emelia/apis/emelia-api.md) · [All operations](https://skmtc.dev/emelia/apis/emelia-api/llms.txt) · [OpenAPI document](https://skmtc.dev/emelia/apis/emelia-api/revisions/8c0cb435f2c4?raw)