## Membership records

`GET /v1/chats/:dialogId/users/relations`

Returns the membership records of the named users: which of them are in the chat and with what role — owner, manager or member. Useful for checking the result of [adding members](/docs/chats/members/add) or [adding managers](/docs/chats/members/managers-add) without fetching all members.

## Parameters

| Parameter | Type | Required | Description |
|----------|-----|:-----:|---------|
| `dialogId` (path) | string | yes | Dialog identifier: `chatXXX` for a group chat, a user ID for the personal dialog with that user, or the alias `me` for the personal dialog with yourself |
| `userIds` (query) | string | yes | From 1 to 50 user IDs separated by commas, for example `5,7`. Each is a positive integer without spaces or leading zeros. A repeated ID is allowed and counts toward the 50 |

Other parameters and repeated ones are rejected with `400 INVALID_PARAMS`.

## Examples

### curl — personal key

```bash
curl "https://vibecode.bitrix24.com/v1/chats/chat42/users/relations?userIds=5,7,12" \
  -H "X-Api-Key: YOUR_API_KEY"
```

### curl — OAuth application

```bash
curl "https://vibecode.bitrix24.com/v1/chats/chat42/users/relations?userIds=5,7,12" \
  -H "X-Api-Key: YOUR_APP_KEY" \
  -H "Authorization: Bearer USER_SESSION_TOKEN"
```

### JavaScript — personal key

```javascript
const res = await fetch('https://vibecode.bitrix24.com/v1/chats/chat42/users/relations?userIds=5,7,12', {
  headers: { 'X-Api-Key': 'YOUR_API_KEY' },
})

const { data } = await res.json()
const inChat = new Set(data.relations.map((r) => r.userId))
```

### JavaScript — OAuth application

```javascript
const res = await fetch('https://vibecode.bitrix24.com/v1/chats/chat42/users/relations?userIds=5,7,12', {
  headers: {
    'X-Api-Key': 'YOUR_APP_KEY',
    'Authorization': 'Bearer USER_SESSION_TOKEN',
  },
})

const { data } = await res.json()
const inChat = new Set(data.relations.map((r) => r.userId))
```

## Response fields

| Field | Type | Description |
|------|-----|---------|
| `success` | boolean | Always `true` on success |
| `data.relations` | array | The membership records of the named users who are in the chat. A user outside the chat is not listed |
| `data.relations[].id` | number | Membership record ID |
| `data.relations[].userId` | number | User ID |
| `data.relations[].chatId` | number | Chat ID |
| `data.relations[].role` | string | The role: `owner`, `manager` or `member` |
| `data.relations[].isHidden` | boolean | Whether the membership is hidden |

## Response example

```json
{
  "success": true,
  "data": {
    "relations": [
      {
        "id": 71,
        "userId": 5,
        "chatId": 42,
        "isHidden": false,
        "role": "owner"
      },
      {
        "id": 77,
        "userId": 7,
        "chatId": 42,
        "isHidden": false,
        "role": "member"
      }
    ]
  }
}
```

## Error response example

400 — no `userIds`:

```json
{
  "success": false,
  "error": {
    "code": "INVALID_PARAMS",
    "message": "`userIds` is required: 1-50 Bitrix24 user ids separated by commas (4,7), each a positive integer without spaces or leading zeros."
  }
}
```

## Errors

| HTTP | Code | Description |
|------|-----|---------|
| 400 | `INVALID_PARAMS` | `userIds` is absent, holds more than 50 IDs or an ID that is not a positive integer; another parameter or a repeated parameter. Checked before any call to Bitrix24 |
| 403 | `SCOPE_DENIED` | The API key does not have the `im` scope |
| 401 | `TOKEN_MISSING` | The API key has no Bitrix24 tokens configured |
| 404 | `ENTITY_NOT_FOUND` | Bitrix24 returned "not found"; the portal code is in `error.b24Code` |
| 422 | `BITRIX_ERROR` | Bitrix24 returned an error; the portal code is in `error.b24Code`. A missing chat lands here with the code `CHAT_NOT_FOUND` |
| 502 | `ME_ALIAS_RESOLUTION_FAILED` | The user could not be resolved for the `me` alias |

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

## Known specifics

**Reading may make you a member.** If the chat allows auto-join, Bitrix24 may add the caller as a member. A `READONLY` key may use this read operation under the narrow exception; it does not mark messages read. The user's Bitrix24 access and the `im` scope still apply.

## See also

- [List members](/docs/chats/members/list)
- [Add managers](/docs/chats/members/managers-add)
- [Chat members](/docs/chats/members)