Nowadays such clients are effectively impossible, because the XTwitter API pricing is designed for business users only. Some bigger services can afford to pay for the privilege to post via the API (e.g. Buffer I think?), which can work for corporate communications. The prices are such that often it's cheaper to pay a person to do the crossposting manually and do it properly while at it.
Yes, it's because of the XTwitter API changes (mostly between February 2023 and February 2024).
People have been crossposting to Mastodon and the fediverse for many years.
In the old days you would do it with a desktop or mobile client for Twitter and Identi.ca. In the 2020s there were many server-side crossposters like moa.party. https://wiert.me/2025/05/19/moa-link-your-mastodon-account-t...
Nowadays such clients are effectively impossible, because the XTwitter API pricing is designed for business users only. Some bigger services can afford to pay for the privilege to post via the API (e.g. Buffer I think?), which can work for corporate communications. The prices are such that often it's cheaper to pay a person to do the crossposting manually and do it properly while at it.
Because mastadon is not relevant to anybody but the people on HN. It's 2026, I really can't believe HN is still stuck on mastadon.