---
title: "Changes to Preview First Messages"
method: POST
path: "/campaigns/audience-builds/{build_id}/preview-messages"
---

# Changes to Preview First Messages

`POST /campaigns/audience-builds/{build_id}/preview-messages`

> Every recorded change to this operation, newest first.

## Timeline

Changed in 5 of 23 revisions.

- **2026-09-24** `c714e58b5156`: 1 warning, 1 info
- **2026-09-18** `40ae92592bd0`: 1 info
- **2026-09-16** `c14a8fc770d0`: 1 info
- **2026-09-10** `8eb1d6b3ce25`: 2 breaking, 1 info
- **2026-09-02** `d96feef8e2ef`: 1 info

## Changes

- **2026-09-24** `c714e58b5156`: 1 warning, 1 info
  - removed the optional property `messages/items/fallback_reason` from the response with the `200` status
  - added the optional property `messages/items/write_error` to the response with the `200` status
- **2026-09-18** `40ae92592bd0`: 1 info
  - added the new optional request property `sender_name`
- **2026-09-16** `c14a8fc770d0`: 1 info
  - added the new optional request property `booking`
- **2026-09-10** `8eb1d6b3ce25`: 2 breaking, 1 info
  - the response property `messages/items/st_customer_id` became optional for the status `200`
  - response property `messages/items/st_customer_id` list-of-types was widened by adding types `null` to media type `application/json` of response `200`
  - added the optional property `messages/items/member_key` to the response with the `200` status
- **2026-09-02** `d96feef8e2ef`: 1 info
  - endpoint added

---

[Operation](https://skmtc.dev/noso/apis/crucible-backend-api/docs/campaigns/audience-builds/:build_id/preview-messages/post.md) - [API](https://skmtc.dev/noso/apis/crucible-backend-api.md) - [Page](https://skmtc.dev/noso/apis/crucible-backend-api/changes/campaigns/audience-builds/:build_id/preview-messages/post)