## Bulk message load

`POST /v1/chats/messages/bulk`

Loads messages from several dialogs in a single request. Use it to sync multiple chats without extra API calls.

## Request body fields

| Field | Type | Req. | Description |
|------|-----|:-----:|---------|
| `dialogs` | array | yes | Array of dialogs to load. From 1 to 50 items |
| `dialogs[].dialogId` | string | yes | Dialog ID: numeric user ID, `chatXXX`, or the literal `me`. In the response the result arrives under the value passed in the request — for `me` the key is `"me"` |
| `dialogs[].lastId` | number | no | Cursor to load older messages |
| `dialogs[].firstId` | number | no | Cursor to load newer messages |
| `dialogs[].limit` | number | no | Number of messages for this dialog (no more than 200) |

## Examples

### curl — personal key

```bash
curl -X POST "https://vibecode.bitrix24.com/v1/chats/messages/bulk" \
  -H "X-Api-Key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "dialogs": [
      { "dialogId": "chat42", "limit": 20 },
      { "dialogId": "chat99", "lastId": 5000 }
    ]
  }'
```

### curl — OAuth application

```bash
curl -X POST "https://vibecode.bitrix24.com/v1/chats/messages/bulk" \
  -H "X-Api-Key: YOUR_APP_KEY" \
  -H "Authorization: Bearer USER_SESSION_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "dialogs": [
      { "dialogId": "chat42", "limit": 20 },
      { "dialogId": "chat99", "lastId": 5000 }
    ]
  }'
```

### JavaScript — personal key

```javascript
const res = await fetch('https://vibecode.bitrix24.com/v1/chats/messages/bulk', {
  method: 'POST',
  headers: {
    'X-Api-Key': 'YOUR_API_KEY',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    dialogs: [
      { dialogId: 'chat42', limit: 20 },
      { dialogId: 'chat99', lastId: 5000 },
    ],
  }),
})

const { success, data } = await res.json()
console.log('Summary:', data.summary)
for (const [key, result] of Object.entries(data.results)) {
  console.log(`Dialog ${key}:`, result.messages.length, 'messages')
}
```

### JavaScript — OAuth application

```javascript
const res = await fetch('https://vibecode.bitrix24.com/v1/chats/messages/bulk', {
  method: 'POST',
  headers: {
    'X-Api-Key': 'YOUR_APP_KEY',
    'Authorization': 'Bearer USER_SESSION_TOKEN',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    dialogs: [
      { dialogId: 'chat42', limit: 20 },
      { dialogId: 'chat99', lastId: 5000 },
    ],
  }),
})

const { success, data } = await res.json()
```

## Response fields

| Field | Type | Description |
|------|-----|---------|
| `success` | boolean | Always `true` on success |
| `data.results` | object | Map of results: key is the `dialogId` from the request, value is an object with messages |
| `data.results.<dialogId>.chatId` | number | Numeric chat ID |
| `data.results.<dialogId>.messages` | array | Array of dialog messages (fields as in [Read messages](/docs/chats/messages/list)) |
| `data.results.<dialogId>.users` | array | Dialog participants with profiles |
| `data.errors` | object | Map of errors: key is the `dialogId`, value is an object with a `code` field |
| `data.summary.total` | number | Total number of requested dialogs |
| `data.summary.succeeded` | number | Number of successfully loaded dialogs |
| `data.summary.failed` | number | Number of dialogs that failed |

## Response example

```json
{
  "success": true,
  "data": {
    "results": {
      "chat42": {
        "chatId": 42,
        "messages": [
          {
            "id": 1001,
            "chatId": 42,
            "authorId": 5,
            "date": "2026-06-05T10:00:00+00:00",
            "text": "Hello, team!",
            "unread": false,
            "uuid": null,
            "replaces": [],
            "params": [],
            "disappearingDate": null
          }
        ],
        "users": [
          {
            "id": 5,
            "active": true,
            "name": "John Brown",
            "firstName": "John",
            "lastName": "Brown",
            "bot": false,
            "type": "user"
          }
        ],
        "files": []
      }
    },
    "errors": {},
    "summary": {
      "total": 1,
      "succeeded": 1,
      "failed": 0
    }
  }
}
```

## Error response example

400 — the `dialogs` array is missing or empty:

```json
{
  "success": false,
  "error": {
    "code": "INVALID_REQUEST",
    "message": "Body must contain \"dialogs\" array with at least 1 item. Each item: { dialogId, lastId?, firstId?, limit? }"
  }
}
```

## Errors

| HTTP | Code | Description |
|------|-----|---------|
| 400 | `INVALID_REQUEST` | The `dialogs` field is missing, empty, or an item has no `dialogId` |
| 400 | `BATCH_LIMIT_EXCEEDED` | Limit exceeded: more than 50 dialogs in a single request |
| 422 | `BITRIX_ERROR` | Bitrix24 returned an error while processing the whole batch request |
| 502 | `ME_ALIAS_RESOLUTION_FAILED` | Failed to resolve the current user for the `me` literal. The whole batch is rejected |
| 502 | `BITRIX_UNAVAILABLE` | Bitrix24 is unavailable or returned a server error |
| 403 | `SCOPE_DENIED` | The key is missing the `im` scope |
| 401 | `TOKEN_MISSING` | No `X-Api-Key` was passed or tokens are not configured |

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

## Known specifics

**Partial success.** An error for one dialog does not stop processing of the rest. Check `data.errors` and `data.summary.failed` to detect partial failures.

**50-dialog limit.** Set by the Bitrix24 batch-request limit. If you need to process more dialogs, split the request into several parts.

**Result keys.** The keys in `data.results` and `data.errors` match the `dialogId` field from the request. If you passed several entries with the same `dialogId`, only the last match has a result.

## See also

- [Messages](/docs/chats/messages)
- [Read messages](/docs/chats/messages/list)
- [Chat discovery](/docs/chats/discovery/get)