## Reply to message

`POST /v1/mail/messages/:id/reply`

Sends a reply to a message: adds the In-Reply-To header, quotes the original message and carries over its attachments. Saved to the Sent folder. The message being replied to is specified in the path.

## Parameters

| Parameter | In | Type | Required | Description |
|----------|---|-----|:-----:|----------|
| `id` | path | integer | yes | Identifier of the message being replied to. List: `GET /v1/mail/messages` |

## Request fields (body)

| Field | Type | Required | Description |
|------|-----|:-----:|----------|
| `from` | string | yes | Sender address. Allowed values come from `GET /v1/mail/mailboxes/:id/senders` |
| `to` | array of strings | yes | Recipient addresses |
| `subject` | string | yes | Message subject |
| `body` | string | yes | Message body |
| `cc` | array of strings | no | Carbon copy addresses |
| `bcc` | array of strings | no | Blind carbon copy addresses |

## Examples

### curl — personal key

```bash
curl -X POST \
  -H "X-Api-Key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  https://vibecode.bitrix24.com/v1/mail/messages/1234/reply \
  -d '{
    "from": "sender@example.com",
    "to": ["recipient@example.com"],
    "subject": "Re: Message subject",
    "body": "Reply text"
  }'
```

### curl — OAuth application

```bash
curl -X POST \
  -H "X-Api-Key: YOUR_APP_KEY" \
  -H "Authorization: Bearer USER_SESSION_TOKEN" \
  -H "Content-Type: application/json" \
  https://vibecode.bitrix24.com/v1/mail/messages/1234/reply \
  -d '{
    "from": "sender@example.com",
    "to": ["recipient@example.com"],
    "subject": "Re: Message subject",
    "body": "Reply text"
  }'
```

### JavaScript — personal key

```javascript
const messageId = 1234
const res = await fetch(
  `https://vibecode.bitrix24.com/v1/mail/messages/${messageId}/reply`,
  {
    method: 'POST',
    headers: {
      'X-Api-Key': 'YOUR_API_KEY',
      'Content-Type': 'application/json',
    },
    body: JSON.stringify({
      from: 'sender@example.com',
      to: ['recipient@example.com'],
      subject: 'Re: Message subject',
      body: 'Reply text',
    }),
  }
)
const data = await res.json()
console.log(data.data.to)
```

### JavaScript — OAuth application

```javascript
const messageId = 1234
const res = await fetch(
  `https://vibecode.bitrix24.com/v1/mail/messages/${messageId}/reply`,
  {
    method: 'POST',
    headers: {
      'X-Api-Key': 'YOUR_APP_KEY',
      'Authorization': 'Bearer USER_SESSION_TOKEN',
      'Content-Type': 'application/json',
    },
    body: JSON.stringify({
      from: 'sender@example.com',
      to: ['recipient@example.com'],
      subject: 'Re: Message subject',
      body: 'Reply text',
    }),
  }
)
const data = await res.json()
```

## Response fields

| Field | Type | Description |
|------|-----|----------|
| `success` | boolean | `true` when the request succeeds |
| `data.success` | boolean | `true` when sending succeeds |
| `data.to` | array of strings | List of addresses the message was sent to |

## Response example

```json
{
  "success": true,
  "data": {
    "success": true,
    "to": ["recipient@example.com"]
  }
}
```

## Error response example

400 — no recipients passed:

```json
{
  "success": false,
  "error": {
    "code": "INVALID_PARAMS",
    "message": "Request object validation failed",
    "validation": [
      {
        "field": "MISSING_TO",
        "message": "Parameter \"to\" is required and must be a non-empty array."
      }
    ]
  }
}
```

## Errors

| HTTP | Code | Description |
|------|-----|----------|
| 400 | `INVALID_PARAMS` | The `id` path parameter is not a positive integer |
| 400 | `INVALID_PARAMS` | `to` is missing or the array is empty — `validation[].field` equals `MISSING_TO` |
| 400 | `INVALID_PARAMS` | The address in `from` is not available to the user — `validation[].field` equals `MESSAGE_REPLY_FAILED`. Allowed addresses: `GET /v1/mail/mailboxes/:id/senders` |
| 400 | `INVALID_PARAMS` | The message was deleted or moved to another folder. The reason is in the `validation` array |
| 403 | `SCOPE_DENIED` | The key lacks the `mail` scope |
| 401 | `TOKEN_MISSING` | The API key has no access tokens configured for the mailbox |
| 401 | `MISSING_API_KEY` | The `X-Api-Key` header is missing |
| 401 | `INVALID_API_KEY` | Invalid API key |
| 401 | `KEY_INACTIVE` | The API key is inactive |
| 401 | `KEY_EXPIRED` | The API key has expired |
| 422 | `BITRIX_ERROR` | Other Bitrix24 errors |
| 429 | `RATE_LIMITED` | The platform-wide request limit was exceeded |
| 502 | `BITRIX_UNAVAILABLE` | Bitrix24 is unavailable |

Full list of common API errors — [Errors](/docs/errors).

## See also

- [Send message](./send.md)
- [Forward message](./forward.md)
- [List messages](./list.md)
- [Mail messages](/docs/mail/messages)
- [Mail](/docs/mail)
- [Errors](/docs/errors)