Are you talking about outgoing API calls from your application to external API or incoming calls to your application API? If the second one then yes, you can make middleware and add to api group checking for obligatory fields and validating them.
If you application makes API calls to external API then you should make/use API client which handles this every request. Like:
public function getUsers()
{
return $this->get('/users');
}
protected function get($endpoint)
{
return $this->httpClient->get($this->getFullUrl($endpoint), [
'headers' => $this->getHeaders(),
]);
}
protected function getHeaders()
{
return [
'Authorization' => 'Basic ' . $this->authHash,
'X-Requested-With' => 'XMLHttpRequest',
];
}