The same language, spoken differently

Comments here are replies to a toot, and GoToSocial speaks Mastodon's API — so comments on a GTS instance should have simply worked. They did not, not once, and nobody saw it fail: arch-linux.cz, the first site to pair this engine with its own GTS instance, had never shown a single comment under any post. My own tests had Mastodon on both ends, so they could never have caught it.

Dialect is not language

Two accents were in the way. GoToSocial writes a status address in its own shape, and the engine's pattern insisted on Mastodon's — a numeric id where GTS answers with a 26-character ULID. And GTS requires a token even to read a public thread, where Mastodon hands it to anyone who asks. The first accent broke the address parsing; the second broke the entire idea of live comments, which is a visitor's browser fetching the thread — a browser you cannot give a token to.

Moderation is the door in

So on GoToSocial, comments are the moderated kind by construction: comments.approval: fav, and the cron reads the thread with the token, server-side, publishing the replies you star. The side effect is one Mastodon sites choose deliberately: visitors' browsers stop contacting your instance at all.

doctor --online now tests the capability, not the brand — can an anonymous request read the thread? — so a Mastodon instance in secure mode gets the same honest answer. And the fix was confirmed where the bug was found: the first starred reply on arch-linux.cz appeared under its post the same day 1.4 landed there.