From Seerr to Nexview, in one pass
If you run Seerr, years of settings and accounts live there. So on the very first start Nexview offers a third way next to "Start fresh" and "From a backup": from a running Seerr installation. Nexview reads it through Seerr's API, shows area by area what it found, and at the end writes what you ticked, in one go. Twelve steps, most of them skippable.
Connect, read-only
The address and API key of your Seerr installation; the key sits under Settings, General over there. Nexview checks it with a second call, because Seerr's status address lets anyone in, and reports the version: the migration is vetted against Seerr 3.0 up to 3.4.1, and refuses anything newer rather than guessing.
The key is never stored. It lives for the duration of the wizard. Seerr's key acts as an administrator over there and could delete things; Nexview therefore calls only a fixed list of reading addresses and nothing else.
Radarr and Sonarr, one tick per slot
Addresses, keys, default folders and profiles come over in full. Nexview has four slots, films and series each in normal and 4K; Seerr can run any number of instances. Per slot the wizard takes the instance marked as default and names the one that stays behind.
After that it asks for the TMDB key, the one value Seerr does not have, and takes the mail server including its password, the notification channels for Discord, Telegram, Gotify, ntfy and webhooks, region and language, the house quota default and the block list. Nothing is preselected. An area without a tick is skipped.
Who comes along, and as what
One of Seerr's accounts becomes the owner, with a password you set here. For everyone else you tick who comes and pick a role per row. The default is user; what the person was in Seerr stands next to it as a hint. If you had two administrators, you can have two again, but you have to say so twice.
Each account brings its display name, a username shaped from it, its count quota, its personal region and language, its profile picture and its Plex, Jellyfin or Emby identity. The conversions stand on the row: Seerr's 0 means "do not count" and becomes an explicit "no limit"; Seerr counts seasons for series, Nexview counts requests.
Seerr does not hand out passwords. Plex accounts sign in through Plex as soon as the server is connected; everyone else gets one via "Forgot password" or from you.
Everything in one go, or not at all
Nothing has been written up to here. The summary shows per area whether it comes or is skipped. One click, and settings, block list, channels, owner and accounts land in a single transaction. If anything fails, the database stays empty and the wizard stays where it is.
After that the setup is complete and you are signed in as the owner. Nexview fetches the profile pictures once from plex.tv or Gravatar after writing and stores them as files; a picture that does not arrive is a missing picture, not a failed migration.
There is no way back after this. The wizard only appears in an empty installation. Whatever was not ticked you add in the settings; whatever was ticked stands.
The media server comes last
Connecting needs a signed-in account, and that only exists after writing. With Plex it runs through the usual code at plex.tv; the server Seerr used is marked in the list. With Jellyfin and Emby through address and administrator sign-in, the address prefilled from Seerr.
Seerr hands out the token for none of the three, and Nexview connects differently anyway. The step can be skipped and done later in the settings; until then, though, Plex accounts cannot get in.
The report at the end
What was written, how each person gets in, which rows were left out and why, and what remains by hand: which notifications go through which channel you set up afterwards, because Nexview knows different notifications than Seerr.
What the migration does not promise
The request history. What sits in Radarr and Sonarr, Nexview shows as present anyway. Only who asked would carry over, and Nexview would book no storage to anyone retroactively from that. Everything already there stays house stock.
Passwords, watch lists, per-person notification addresses, Seerr's override rules and discover sliders. None of them has a place in Nexview. The wizard says so where you would otherwise have noticed it later.
Seerr's own public address. It points at Seerr. Nexview asks for its own.
Moving into a running installation. It was planned and dropped: Nexview cannot merge two accounts of the same person, and that would have been the most common outcome there. The path only leads into an empty installation.