Saving a player's progress

By default every game keeps its progress in the visitor's own browser, and that progress does not follow them between sites. A streak built inside an embed on your site is a different streak from the one on unlatchgames.com and from every other publisher's.

This is not a bug and there is no flag for it. Browsers partition storage by top-level site precisely so that an embedded frame cannot be used to follow someone around the web.

What to do about it

Identify the player. Put your own user id on the embed URL — the same uid rewards use:

<iframe src="https://unlatchgames.com/play/solitaire/?pub=YOUR_CODE&uid=USER_ID"></iframe>

With a uid present, the game keeps a second copy of its save on our server, keyed to your code and that user. When they come back — same browser or not, same device or not — they get their streak.

Nothing else changes. There is no account to make, no login, no cookie banner: you already know who they are, and we only need the opaque id you already gave them.

What is actually stored

The game's own save blob: a streak, which levels are finished, settings. A few hundred bytes, capped at 16 KB, opaque to us, kept for a year after their last play.

No personal data. A uid with an @ in it is refused outright. Do not put an email address, a name or anything else identifying in it — that is in the terms, and it is also the thing that keeps this simple for both of us.

Two devices at once

Last write wins. If somebody plays on a phone and a laptop in the same minute, one of those saves will be overwritten. The game is told when that happened, so it is not silent, but there is no merge — merging streaks is a judgement only the game can make and the server does not try.