Zerdinals

You will get from this page: what a Zerdinal is, what is actually guaranteed about one, and the boundaries to know before you hold or make one.

Plain language

Zerdinals are digital artifacts inscribed through Zcash transparent transactions. An inscription writes your content (an image, text, JSON, or other supported types) into the Zcash chain through a commit and reveal pair of transactions. The content lives on chain. Ownership is the ownership of one specific transparent output, and it moves with ordinary Zcash transactions signed in a wallet.

Its number

Every completed inscription is given a number in the order the chain completed it, and that number is how the product names it: No. 087871. Most inscriptions carry no title, so the number is the thing that is genuinely unique about one. There is exactly one No. 87871 and there always will be.

Why it matters

An inscription is the most durable kind of publication most people will ever make: reconstructing the content needs only a Zcash node, and no company, server, or website has to survive for it to exist. The trade is permanence in both directions; nothing published this way can be unpublished.

What you can rely on

Content is on chain. The bytes live in reveal transaction scripts, in 240-byte pieces. No Universe server has to exist for an inscription to survive.
Provenance is verifiable. Ownership is a chain of transparent transactions from the genesis inscription to the current owner. Every artifact page shows that chain in full: where it was inscribed, every hand it passed through, and the transaction behind each step.
Universe v1 inscriptions carry a content commitment. The commit transaction’s address is derived from a hash of the exact content and content type, so the chain committed to your content before any content byte was broadcast. Anything that does not match the commitment is simply not your inscription, and you can verify this yourself with a node and the specification.

Safety boundary

Zerdinals use transparent Zcash data. Addresses, content, and activity are publicly visible forever.
Ownership lives on an output that ordinary wallets can spend by accident. Safety in sixty seconds covers the two habits that prevent it.
Sending an inscription-bearing output entirely into a shielded pool ends protocol tracking permanently. The product marks such artifacts as untrackable and never guesses a shielded owner.

Technical detail

A Zerdinal is created by a commit transaction (a P2SH output whose redeem script commits to the reveal key and a hash of the content) and one or more reveal transactions carrying the content in their input scripts, up to 4 pieces of 240 bytes per transaction and up to 255 pieces total (61,200 bytes). When the carrying output is spent, the inscription moves to the first transparent non-data output of the spending transaction.

Zerdinals deliberately do not number individual zatoshis. The ordinality decision explains why that theory cannot be honest on Zcash.