## Assign a role to a user in the merchant account

This endpoint allows you to assign an existing role to a user within your merchant account.

## Endpoint signature

```http
POST https://api.reservepay.com/merchants/assign-role HTTP/1.1
Content-Type: application/json
Accept: application/json
Authorization: Bearer <token>

{
  user_id: string,
  role_id: string?,
}
```

Returns: boolean

## Request arguments

### `user_id` (string)

**Required**. The ID of the user to whom the role will be assigned.
The user must already be a member of the merchant account

### `role_id` (string)

_Optional_. The ID of the role to assign to the user. This role must already exist in the merchant account. It will replace any existing role assigned to the user.

## Errors common to all endpoints

### `UNHANDLED_ERROR`

This error occurs when the server encounters an unexpected internal error that
it cannot handle gracefully. This typically happens due to bugs, infrastructure
issues, or edge cases that weren't anticipated during development.

### `INVALID_ARGUMENTS`

This error occurs when the request contains invalid or missing parameters.
Common cases include missing required fields, or values that don't match the
expected format or type.

### `BAD_VERSION`

This error occurs when making requests to an API version that does not exist.
This commonly happens when using an outdated SDK or when the API version
specified in the request URL is incorrect.