---
title: "Reply to a support ticket"
method: POST
path: "/api/v1/support/tickets/{id}/messages"
tags: ["Support"]
---

# Reply to a support ticket

`POST /api/v1/support/tickets/{id}/messages`

Adds a message to an existing support ticket.

## Path parameters

- `id` string, required

## Headers

- `Idempotency-Key` string

## Request body

- SupportMessageSubmission — Support submission containing a message body.
  - `body` string, required — Non-empty support message text.

## Response `200`

Original message replayed after a safe retry

- object
  - `publicId` string, required
  - `attachments` SupportAttachmentReceipt[], required
    - `publicId` string, required
    - `status` 'pending' | 'ready' | 'failed', required

## Other responses

- `201` — Message added
- `400` — Invalid input
- `401` — Unauthenticated
- `404` — Not found
- `409` — Reply key was reused with different message content.
- `429` — Xquik tier rate limit exceeded. The response includes a `Retry-After` header with the number of seconds to wait before retrying.
- `default` — Unexpected error.

## Changes

- **2026-08-20** `352bea67aca5` — 1 breaking, 2 warning, 2 info
  - removed `subschema #1, subschema #2` from the request body `anyOf` list (media type: multipart/form-data)
  - removed the request property `attachments` (media type: multipart/form-data)
  - removed the request property `body` (media type: multipart/form-data)
  - added `#/components/schemas/SupportMessageSubmission, #/components/schemas/SupportAttachmentSubmission` to the request body `anyOf` list (media type: multipart/form-data)
  - …1 more
- **2026-08-12** `5d4938bb7de3` — 108 warning
  - added the new `closed` enum value to the `allOf[#/components/schemas/Error]/error/oneOf[subschema #1: LegacyErrorCode]/` response property for the response status `429`
  - added the new `closed` enum value to the `allOf[#/components/schemas/Error]/error/oneOf[subschema #2: StructuredError]/code` response property for the response status `429`
  - added the new `closed` enum value to the `error/oneOf[subschema #1: LegacyErrorCode]/` response property for the response status `400`
  - added the new `closed` enum value to the `error/oneOf[subschema #1: LegacyErrorCode]/` response property for the response status `401`
  - …104 more
- …earlier changes not shown

[Full history](https://skmtc.dev/xquik-dev/apis/xquik-api-2/changes/api/v1/support/tickets/:id/messages/post.md)

---

[API](https://skmtc.dev/xquik-dev/apis/xquik-api-2.md) · [All operations](https://skmtc.dev/xquik-dev/apis/xquik-api-2/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/xquik-dev/xquik-api-2/revisions/73f46a2af801/schema)