# POST /api/v1/tickets/{id}/messages

Append message (participant/admin)

Operation: `addTicketMessage`.

Append message (participant/admin)

The opener, the rental's host, or an admin (a support reply) may post to an OPEN case; anyone else gets 403 and a closed case 409.

## Endpoint

`POST https://amplerun-api.spiry.org/api/v1/tickets/{id}/messages`

## Authentication

Use the credential and scope required by this operation. For programmatic renter/host calls: `Authorization: Bearer $AMPLERUN_API_KEY`. A host-agent signature or other specialized proof is required where the description specifies it.

## Parameters

| Name | Location | Presence | Type | Description |
| --- | --- | --- | --- | --- |
| `id` | path | Required | UUID |  |
| `Idempotency-Key` | header | Required | UUID | UUID scoped to authenticated principal, route and canonical request hash. |

## Request body

Required body. 

### `application/json`

| Field | Type | Presence | Description |
| --- | --- | --- | --- |
| `text` | string | Required |  |

```json
{
  "type": "object",
  "additionalProperties": false,
  "required": [
    "text"
  ],
  "properties": {
    "text": {
      "type": "string",
      "minLength": 1
    }
  }
}
```

## Responses

### `201`

Message appended.

### `default`

Error envelope. 401 unauthenticated, 403/404 forbidden, 409 conflict, 422 invalid input, 429 rate limited (code UNAVAILABLE, retryable:true, no Retry-After header), 503 unavailable money/provider state with retryable:true.

`application/json`
| Field | Type | Presence | Description |
| --- | --- | --- | --- |
| `error` | object | Required |  |

```json
{
  "$ref": "#/components/schemas/ErrorEnvelope"
}
```

## Static request outline

Replace path/query placeholders and provide the required JSON body, headers and credential from the sections above. This is a request outline, not a command that chooses an amount or starts a rental for you.

```sh
curl --request POST 'https://amplerun-api.spiry.org/api/v1/tickets/{id}/messages' \
  --header "Authorization: Bearer $AMPLERUN_API_KEY"
```

[Schema definitions](https://docs.amplerun.com/reference/schemas.md) · [Download OpenAPI](/openapi.json) · [Authentication](https://docs.amplerun.com/agents/authentication.md) · [Errors and recovery](https://docs.amplerun.com/reference/errors.md)

---
Generated from the AmpleRun API contract.
Canonical: https://docs.amplerun.com/reference/api/add-ticket-message/