> ## Documentation Index
> Fetch the complete documentation index at: https://replyke-feat-push-rich-payload-fields.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Check Username Availability

> Check if a username is available for use

Check if a given username is available for use.

## Query Parameters

<ParamField query="username" type="string" required>
  The username to check for availability
</ParamField>

## Response

<ResponseField name="available" type="boolean">
  `true` if the username is available, `false` if it's already taken
</ResponseField>

## Error Responses

<AccordionGroup>
  <Accordion title="Missing or Invalid Username - 400 Bad Request">
    ```json theme={null}
    {
      "error": "Username is required and must be a string.",
      "code": "username/invalid-input"
    }
    ```
  </Accordion>

  <Accordion title="Server Error - 500 Internal Server Error">
    ```json theme={null}
    {
      "error": "An error occurred while checking username availability.",
      "code": "username/server-error",
      "details": "<Error message>"
    }
    ```
  </Accordion>
</AccordionGroup>

***

## Notes

* This endpoint does **not** require authentication.
* Only exact matches are considered (case-sensitive).