> For the complete documentation index, see [llms.txt](https://painor.gitbook.io/gramjs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://painor.gitbook.io/gramjs/working-with-usernames/channels.checkusername.md).

# channels.checkUsername

Check if a username is free and can be assigned to a channel/supergroup

## Example

{% tabs %}
{% tab title="Javascript" %}

```javascript
const {Api, TelegramClient} = require('telegram');
const {StringSession} = require('telegram/sessions');

const session = new StringSession('');
const client = new TelegramClient(session, apiId, apiHash, {});

(async function run() {
    const result = await client.invoke(new Api.channels.checkUsername({
        channel: new Api.InputChannel({...}),
        username: 'random string here',
        }));
    console.log(result); // prints the result
})();
```

{% endtab %}

{% tab title="TypeScript" %}

```typescript
import {Api, TelegramClient} from 'telegram';
import {StringSession} from 'telegram/sessions';

const session = new StringSession('');
const client = new TelegramClient(session, apiId, apiHash, {});

(async function run() {
    const result: Api.Bool = await client.invoke(new Api.channels.checkUsername({
        channel: new Api.InputChannel({...}),
        username: 'random string here',
        }));
    console.log(result); // prints the result
})();
```

{% endtab %}
{% endtabs %}

## TL schema

```
boolFalse#bc799737 = Bool;
boolTrue#997275b5 = Bool;
---functions---
channels.checkUsername#10e6bd2c channel:InputChannel username:string = Bool;
```

## Parameters

|     Name     | Type                                                        | Description                                                                                               |
| :----------: | ----------------------------------------------------------- | --------------------------------------------------------------------------------------------------------- |
|  **channel** | [InputChannel](https://core.telegram.org/type/InputChannel) | The [channel/supergroup](https://core.telegram.org/api/channel) that will assigned the specified username |
| **username** | [string](https://core.telegram.org/type/string)             | The username to check                                                                                     |

## Result

[Bool](https://core.telegram.org/type/Bool)

## Possible errors

| Code | Type                               | Description                                                                                                 |
| :--: | ---------------------------------- | ----------------------------------------------------------------------------------------------------------- |
|  400 | CHANNELS\_ADMIN\_PUBLIC\_TOO\_MUCH | You're admin of too many public channels, make some channels private to change the username of this channel |
|  400 | CHANNEL\_INVALID                   | The provided channel is invalid                                                                             |
|  400 | CHAT\_ID\_INVALID                  | The provided chat id is invalid                                                                             |
|  400 | USERNAME\_INVALID                  | The provided username is not valid                                                                          |

## Can bots use this methd ?

### yes

## Related pages

### [Channels](https://core.telegram.org/api/channel)

How to handle channels, supergroups, groups, and what's the difference between them.