Languages

Entries are stored in whatever AMS_TMDB_LANGUAGE is set to. If you want your stack in French, set that — it is what every client gets by default, and it is almost certainly the setting you want:

AMS_TMDB_LANGUAGE=fr-FR

The variable gives the setting tmdb.language its first value, at the first start. After that, the language of the answers is changed under Settings › Answering, without a restart, and it can be set for one key or one address rule too — which is how one Radarr answers in French while everything else answers in English. See tmdb.language.

Any other language is fetched the first time something asks for it and kept from then on:

curl 'http://localhost:8080/v1/tvdb/shows/fr/81189'       # the Skyhook form
curl 'http://localhost:8080/api/v1/items/{id}?language=ja'

One caveat worth knowing before you rely on the per-request form: Sonarr v4 does not use it. Its request builder sets the language segment to en once and never changes it, so every request from a Sonarr v4 arrives as English whatever its own UI language says, and AMS_TMDB_LANGUAGE — the setting tmdb.language, which it seeds — is the knob for it. Sonarr v5 does. It asks /v2/tvdb/shows/{language}/{id}/{seasonType} in the language a person set for the series, as three letters (eng, fra, deu…), and is answered in that language when the catalogue holds the series in it; when it does not, in the language of the answers for that caller (tmdb.language, on its key or on its address’s rule); then in English; then as the series is stored. A code that names no language is read as eng, as Skyhook reads it, rather than refused. Every language the series is named in travels with the answer too (translations), the series’ own among them, which is where a Sonarr v5 reads the original title from. Per-request language is otherwise for the web UI, for anything calling this server directly, and for TMDB clients — which do send language= and get it forwarded.

A translation never overwrites a field someone locked. That would undo a rename the moment a client asked in another language, which is the one thing locking exists to prevent. Lock a field per language if you want different text in each (Locking a text for one language).

What the relays write into the answers of TMDB clients, by the language they ask in, is in A note on languages.