---
title: "POST (Create) an A/B Test for an Email Campaign Activity"
method: POST
path: "/emails/activities/{campaign_activity_id}/abtest"
tags: ["Email Campaigns AB Tests"]
---

# POST (Create) an A/B Test for an Email Campaign Activity

`POST /emails/activities/{campaign_activity_id}/abtest`

Use this method to create a new A/B test for a primary email campaign activity. You must specify an alternative subject line, the percentage of contact to use for the A/B test, and the number of hours to wait after the A/B test is sent before determining the winning subject line. To create an A/B test, the campaign must have a `current_status` of `DRAFT`. When you create an A/B test, the `type` changes from Newsletter (code= `10`) to A/B Test (code= `57`).

## Path parameters

- `campaign_activity_id` string, required

## Request body

- ABTestData
  - `alternative_subject` string, required — The alternate email subject line to use for A/B testing.
  - `test_size` integer, required — The percentage of contact recipients to participate in the A/B Test. For example, if the value is 30, then 30% of contacts will receive the email campaign with subject line A, and 30% of contacts will receive the email campaign with subject line B. Valid values include <code>5</code> to <code>50</code> percent. Currently, A/B tests support subject line only.
  - `winner_wait_duration` integer, required — The number of hours Constant Contact waits after the A/B test is sent before determining the winning subject line. The winner is the subject line with the highest number of contact opens. Valid values include <code>6</code>, <code>12</code>, <code>24</code>, and <code>48</code>. After the winner is determined, Constant Contact automatically sends the email campaign with the winning subject line to all the remaining contacts, which did not participate in the A/B test.

## Response `201`

Request successful.

- ABTestData
  - `alternative_subject` string, required — The alternate email subject line to use for A/B testing.
  - `test_size` integer, required — The percentage of contact recipients to participate in the A/B Test. For example, if the value is 30, then 30% of contacts will receive the email campaign with subject line A, and 30% of contacts will receive the email campaign with subject line B. Valid values include <code>5</code> to <code>50</code> percent. Currently, A/B tests support subject line only.
  - `winner_wait_duration` integer, required — The number of hours Constant Contact waits after the A/B test is sent before determining the winning subject line. The winner is the subject line with the highest number of contact opens. Valid values include <code>6</code>, <code>12</code>, <code>24</code>, and <code>48</code>. After the winner is determined, Constant Contact automatically sends the email campaign with the winning subject line to all the remaining contacts, which did not participate in the A/B test.

## Other responses

- `400` — Bad request. Either the JSON was malformed or there was a data validation error.
- `401` — The Access Token used is invalid.
- `403` — Forbidden request. You lack the necessary scopes, you lack the necessary user privileges, or the application is deactivated.
- `404` — The requested resource was not found.
- `409` — Conflict. The resource you are creating or updating conflicts with an existing resource.
- `429` — Too many requests. You exceeded the request rate limit.
- `500` — There was a problem with our internal service.

---

[API](https://skmtc.net/cc/apis/appconnect-v3.md) · [All operations](https://skmtc.net/cc/apis/appconnect-v3/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/cc/appconnect-v3/revisions/4b4a534c818d/schema)