We’ve seen several discussions around developers receiving Error Code 226 in response to requests for tweet or direct message creation using the POST statuses/update, POST statuses/update_with_media and POST direct_messages/new endpoints. This previously undocumented error code has been added to our Error Codes & Responses list and is tied to our efforts to protect our users from spam and potentially malicious activity.
We constantly monitor and adjust our filters to block spam and malicious activity on the Twitter platform. These systems are tuned in real-time. If you get this response our systems have flagged the Tweet or DM as possibly fitting this profile. If you feel that the Tweet or DM you attempted to create was flagged in error, please report the details around that to us by filing a ticket at https://support.twitter.com/forms/platform.
Filing a ticket at the above URL is the best course of action to resolve any false positives we may be seeing in these detection efforts.
We’re working to improve our process in documenting new error codes for our devleoper community, ideally getting new codes on dev.twitter.com before they could start to show up in our responses to your API calls. We appreciate your patience as the team works towards this goal.