What Nexview talks to, and how
Nexview downloads nothing and stores no movies. It talks to programs that do, and to services that pass word along. Here is what each of them needs, and what tends to go wrong.
Radarr and Sonarr
An address and an API key, nothing more. You find the key in Radarr and Sonarr under Settings → General → API Key.
Nexview reads the root folders and quality profiles from there and offers exactly those. Add a new profile in Radarr and it shows up here on the next visit.
The most common stumbling block is the address. If Nexview runs in a container, localhost is the container itself, not your computer. Use the address on your network, or the service name if both sit in the same Docker network.
Optionally a second instance for 4K can be entered for each. Only then does a 4K switch appear anywhere at all.
nexcrate
A single connection instead of Radarr and Sonarr, since Nexview 1.0.0. You enter the address; you do not have to copy the key: Nexview asks nexcrate for one, you confirm the request in nexcrate, and Nexview collects it.
Then Nexview reads the versions from nexcrate and checks whether this nexcrate will do. Whatever does not fit is shown in red and stops here, rather than surfacing with the first request. Which version everyone may request is set on the same page.
Root folders, quality profiles and naming do not exist here; they belong to nexcrate. And the same stumbling block as with Radarr: inside a container, localhost is the container itself. nexcrate listens on port 8390.
If Nexview already runs with Radarr and Sonarr, the assistant under Settings, Services switches it over. How that works is on the nexcrate page.
Media server
Nexview talks to Plex, Jellyfin and Emby, several at once if you like. A connected media server brings three things: signing in with the server's own account, the in library marker for titles that never came through Radarr, and the watched state.
Connecting differs. Plex goes through your Plex account: sign in, pick your own server from the list. Jellyfin and Emby take an address, a username and a password, they have no broker flow.
Nexview stores the first address the server actually answers on, the local one comes first in the list but is not always reachable from inside a container. If none answers, it is stored anyway and a notice appears: with Plex signing in keeps working, because it goes through plex.tv; only the library comparison needs a reachable address.
Only Plex has a watchlist , Jellyfin and Emby simply do not have one. All of it in detail on the media server page.
Notifications
After the wizard, under settings → notifications: ntfy, Gotify, Telegram, Discord, a plain webhook, Apprise or e-mail.
While setting up, Nexview sends a test message carrying a four-digit code you have to type back. That is not red tape: an “HTTP 200” from a push service only means accepted, never arrived, a wrong topic or an app with no subscription is answered just as politely.
How to build several inboxes with different events out of that is on the notifications page.
Three things to check first
Connection fails. Almost always the address as seen from the container. A quick test from inside the container settles it faster than any guess.
No profiles in the list. Then Radarr is answering but the key is wrong, with a wrong key Radarr returns no error, just an empty list.
Invitations never arrive. Usually the public address or the mail server is missing. Both live under settings → address and → SMTP settings; the log shows what it failed on.