PHP sample code

channels.php

//Initiation code (should be in 1 file)
$json = $_POST['payload']
$secret = "your_secret_key_in_the_settings_page"
$obj = json_decode($json)

if(sha1($json+$secret) == $_POST['signature']) {
  if(some_function_that_checks_if_a_uid_is_valid_by_checking_your_database($obj['uid'])) {
    $conversion_id = some_function_that_generates_and_stores_a_conversion_id_with_the_amount($obj['amount'])
    echo $conversion_id
  } else {
    http_response_code(401);
  }
} else {
  http_response_code(401);
}


//Completion code (should be in another file)
$json = $_POST['payload']
$secret = "your_secret_key_in_the_settings_page"
$obj = json_decode($json)

if(sha1($json+$secret) == $_POST['signature']) {
  if(some_function_that_asks_your_database_if_a_conversion_id_is_valid($obj['conversion_id'])) {
    some_function_that_records_a_completed_conversion_in_your_database($obj['conversion_id'])
    echo "OK"
  } else {
    http_response_code(401);
  }
} else {
  http_response_code(401);
}