Per-post (and per-feed) language: how far up the ladder is worth it?

[rmdes]

Hi Dave (and Dave's Claude) —

Second small Textcasting-alignment idea, filed as an issue to discuss before anyone writes code — and this one is genuinely a question as much as a proposal, so even if the answer is "not now," the thinking might be useful.

Today: one language for the whole server

The server declares a single language for every feed it generates. config.rssLanguage is "en-us" (server/code/rssnetwork.js:28), getDefaultHeadElements copies it onto every feed's head (rssnetwork.js:574), and daverss emits it as the channel <language> (daverss.js:265).

That means every user's feed claims en-us, regardless of what they actually write. A French or Portuguese writer on the server produces feeds that tell readers "this is English." Textcasting lists per-post language as a Tier 2 feature ("the web is multilingual"), but rss.chat isn't even at per-feed language yet — it's per-server.

I think there's a ladder here, and I'm genuinely unsure how far up it is worth climbing for a chat network. Laying out the rungs so you can say where (if anywhere) it fits.

Rung 1 — per-user feed language (cheap, no daverss change)

Let each user set their feed's language, the same way they already set myFeedTitle / myFeedDescription in prefs. buildFeedForUser would use the user's language for that feed's channel <language>, falling back to config.rssLanguage.

• No schema change beyond prefs (already a JSON blob on users).
• No daverss change — it already emits channel <language>; we'd just feed it a per-user value instead of the global constant.
• Fixes the "everyone is en-us" inaccuracy immediately.
• The everyone-feed stays on the server default (it's mixed-language by nature).

This feels like the 80% win: most people write in one language, and a correct per-feed language is what a feed reader actually keys off.

Rung 2 — per-post language (needs a daverss change)

A lang on individual items, for the genuinely bilingual writer who switches languages post to post.

• New nullable lang column on items; optional lang param on /newpost and /updatepost (which today take title / description / markdowntext / inReplyTo, rssnetwork.js:~32); pass it through buildFeedItems.
• daverss would need to emit it per item — RSS 2.0 has no per-item language element, so the options are the standard xml:lang attribute on <item>, or a source:lang element in your namespace. Your call, same as the modified-date question in Emit a per-item modified date in feeds (finishing edit-propagation for Textcasting) #4.
• JSON Feed 1.1 (if that ever lands — separate idea) has a native item-level language field, so per-post language maps cleanly there without any attribute question.

Rung 3 — resist for now

Auto-detection of a post's language, translation links (contentMap-style). Real Textcasting Tier-2 territory, but over-built for where rss.chat is today. Noting it only to say I'd leave it out.

What I'm actually asking

1. Does per-feed language (Rung 1) fit your view? It's cheap, needs no daverss change, and fixes a real inaccuracy — I'd happily send just that as a small PR if you want it.
2. Is per-post language (Rung 2) something you'd want in the product at all, or is per-feed enough for a chat network? If yes, that's another source: vs xml:lang naming decision for you.
3. Or is language something you'd rather not carry yet? Totally fine — this is a "think out loud together" issue, not a request.

No code until you weigh in. As with the modified-date issue, I'm bringing these one at a time so each stays easy to reason about.

Ricardo