Create purchase request

ExchangeRequest::create(User::find(1), 'purchase', 'stb', 10, .5);

Create sale request

ExchangeRequest::create(User::find(1), 'sale', 'stb', 10, .5);

Approve request

ExchangeRequest::find(1)->approve(User::find(2));

Delete request

ExchangeRequest::find(1)->delete();

Getting requests

$userFrom = User::find(1);

$userFrom->exchangeRequests(); //All user requests
$userFrom->pendingExchangeRequests(); //Pending user requests
$userFrom->approvedExchangeRequests(); //Approved user requests