Disabling caching on JSON API endpoints doesnt seem possible with using just below in your sevices file
services: cache.backend.null: class: Drupal\Core\Cache\NullBackendFactory
so I found a hackish solution to use while I test the endpoints. Find flattenResponse method that is in ResourceResponseSubscriber class in Drupal\jsonapi\EventSubscriber and add to bottom of it
$disable_cache = new CacheableMetadata(); $disable_cache->setCacheMaxAge(0); $final_response->addCacheableDependency($disable_cache); return $final_response;
and this will add meta tag that will force this responses to be uncached. Also add to top of the file use Drupal\Core\Cache\CacheableMetadata; so method cand be found. This will help you have JSON file uncached all the time.