People hear "onchain" and reach for the word "permanent," as if everything a token touches turns to stone. It is a useful instinct, but it hides a split that trips up a lot of collectors. A second on this project is really two things bolted together: a token that does not move, and a link that you can rewrite whenever you feel like it. They have completely different lifespans, and it helps to keep them straight in your head.
The first part is the durable one. When a second is minted, it becomes an ERC-721 token on Base, recorded against a wallet address in the project's contract. That record does not depend on this website. It does not depend on us paying a hosting bill. Anyone can read it from the public contract, and it keeps answering long after any of us stop looking. That is the part that earns the word "permanent," and it is a narrow, honest kind of permanent: the ledger remembers that this second exists and who holds it.
The second part is softer, and on purpose. Every second carries a URL that the owner attaches, and the contract has a write function, updateUrl, that lets that owner replace the link any time they hold the token. Point second 43,200 at your portfolio today, at a friend's fundraiser next month, at nothing at all the month after. The token stays put. The pointer drifts.
Here is the distinction worth internalizing. The token is durable because the ledger keeps it. The link is only as durable as the page at the far end of it, which the contract never touches. The contract stores your URL as an exact string and hands it back faithfully; it does not visit the page, check that it loads, or keep it alive. If the domain lapses or the site moves, the contract will still return the old link, pointing confidently at a place that no longer exists.
That failure has a name from the wider web: link rot. Anyone who has clicked a citation from 2011 knows the feeling. Onchain does not fix it, and it would be dishonest to pretend otherwise. What onchain changes is only the token itself. The clock, the ownership, the fact that this exact second was claimed by this exact wallet: those are the permanent facts. The link riding on top is a normal web link with all of a web link's mortality.
Because that URL is set by whoever owns the second, it is untrusted input in the strictest sense. Someone could store anything in that string, so the front end treats every stored link as hostile until proven otherwise. Two habits in the code do the work. Before any stored text is shown on the page, it is escaped, so a link cannot smuggle in markup that runs as part of the site. And before any link becomes clickable, it is checked against a plain rule: only http and https addresses are allowed through. Anything else, including the old javascript: trick that tries to run code when you click, is refused and never becomes a live link.
Outbound links also carry rel="noopener nofollow", which keeps the page you open from reaching back into this one and tells search engines not to treat an owner's link as an endorsement from us. None of this makes a stranger's URL safe to click. It means the site itself will not be the thing that hurts you, and the judgment about whether to follow someone's link stays with you, where it belongs.
If you own a second, treat the link as a living field, not a set-and-forget engraving. Point it at something you control, like a domain or profile you expect to keep, rather than a URL that will expire the moment a campaign ends. Check it once in a while. When it rots, rewrite it. The token does not care how many times you change your mind, and neither does the contract.
And when you are the one clicking a stranger's second, remember what the green light does and does not tell you. The site confirming that a link is a valid https address is a syntax check, not a character reference. Where it goes and whether you trust it is your call. If you want to see the raw stored string without any of the site's rendering in the way, you can read it straight off the contract, which is the whole point of reading your second off Base without this site.
This is not financial advice, and being editable does not make a second worth anything in particular. Transactions on Base are irreversible and carry network fees, keys can be lost, and links, onchain or not, break. The thing worth holding onto is the split itself: the second is a permanent fact, the link is a temporary decision, and knowing which is which is most of what it means to actually own one of these.
→ Pick a second on the clock · What happens when you mint a second · Read your second off Base