Inscribing Mainnet
art · bitcoin · ordinals

ord version 0.4.0 has been released. Inscriptions are finally ready for Bitcoin mainnet.


Inscriptions are digital artifacts native to the Bitcoin blockchain. They are created by inscribing sats with content using ord, and can be viewed with the ordinals explorer. They do not require a separate token, a side chain, or changing Bitcoin.

Inscriptions are created by including content, like an image, text, SVG, or HTML, in an inscription transaction. The content is included in the transaction witness, which normally contains signatures and other data proving that a transaction is authorized.

Along with the content, the inscription transaction contains a content type, also known as a MIME type, identifying the type of content to be inscribed.

When mined, the inscription is made on the first sat of the first output of the transaction, permanently and inexorably marking it, distinguishing it from its fellows. It is no longer just a sat, it is an intertwined component of the long and confusing tale that is human art and culture.

Using ordinal theory, the unspent output containing an inscribed sat can be found, and its movements and ownership tracked across time and transactions, allowing inscriptions to traded, gifted, bought, and sold.

This allows inscriptions quite native to Bitcoin. They can be sent to normal bitcoin addresses, in normal bitcoin transactions, and benefit from timelocks, multisig, and all the rest of Bitcoin's infrastructure. To avoid losing them, a wallet that holds inscriptions must perform sat control, the sizing and alignment of transaction inputs and outputs that controls the destination of individual sats, but aside from that, transactions that transfer inscriptions are quite mundane.

Digital Artifacts

Inscriptions are digital artifacts, and digital artifacts are NFTs, but not all NFTs are digital artifacts. Digital artifacts are NFTs held to a higher standard, closer to their ideal. For an NFT to be a digital artifact, it must be decentralized, immutable, on-chain, and unrestricted. The vast majority of NFTs are not digital artifacts. Their content is stored off-chain and can be lost, they are on centralized chains, and they have back-door admin keys. What's worse, because they are smart contracts, they must be audited on a case-by-case basis to determine their properties.

Inscriptions are unplagued by such flaws. Inscriptions are immutable and on-chain, on the oldest, most decentralized, most secure blockchain in the world. They are not smart contracts, and do not need to be examined individually to determine their properties. They are true digital artifacts.

ord 0.4.0

ord is an open-source binary written in Rust, and developed on GitHub. It implements an ordinal wallet, which can create and transfer inscriptions, and a block explorer. There are public mainnet, signet, and testnet instances.

ord is experimental software, and comes with no warranty or guarantees. ord 0.4.0, the latest release, has been tested carefully, and can now be used to make inscriptions on mainnet, and that those inscriptions will not break due to a future protocol change.

Three mechanisms exist to introduce opt-in changes to the protocol, without breaking existing inscriptions: Versioning, optional fields, and mandatory fields.

Inscriptions can contain a version field. The inscription parser will ignore inscriptions with an unrecognized version. This allows introducing fundamental changes to inscriptions, without disrupting existing inscriptions.

Additionally, fields can be marked as optional or mandatory, which determines how an inscription parser treats an unrecognized field. Unrecognized optional fields are ignored but the inscription is normally, while unrecognized mandatory fields render the whole inscription invalid.

Individual features that can be safely ignored if unsupported can be introduced as optional fields, while features that must be supported in order in order to understand an inscription can be introduced as mandatory fields.

Inscriptions are not finished, but this flexibility gives us confidence that future improvements can be made opt-in and non-disruptive.

Let markets and bazaars where rare sats and inscriptions are traded grow and flourish, and may their wares never crack or vanish.

What's missing?

Inscriptions have many unique benefits and features, but they have not yet reached feature parity with other NFT implementations.

Two key features are missing: provenance and decentralized markets.

Provenance is the ability to determine the author of an inscription, or its membership in a set of inscriptions all created by the same person. We have a design that accomplishes this, and its implementation is tracked in issue #783. A transaction creating a new inscription, X, may include an existing inscription, P, in its inputs, which is returned back to the owner in its outputs. Since only the owner of P could have made this transaction, this identifies P as the parent of X. This mechanism is flexible, and can be used to identify an inscription as being created by an individual, or to identify an inscription as being a member of a larger collection. Furthermore, this mechanism is recursive. You can create in inscription that represents your identity, and use that inscription as the parent of an inscription that itself is used as the parent inscription for a collection.

For inscriptions be valuable, there must be venues where they can be bought and sold. We have a sketch for decentralized and trustless offers to buy and sell using partially-signed transactions, and its implementation is tracked in issue #802. The owner of an inscription may offer it for sale by publishing a transaction that includes it as an input, and containing an output that pays to them the sale price. Any third party can take such a transaction, add their own input of at least the sale price, add an output sending the inscription to themselves, and finalize it by broadcasting it to be mined. Offers to buy are similar.

What's next?

Inscriptions have been designed to be native to the web. Inscriptions are byte strings, identified with a content type, and so can be displayed in a browser. HTML, CSS, JavaScript, SVG, MP3, PNG, and JPEG, are supported by the ordinals explorer.

Inscription content is sandboxed so that it cannot make outgoing web requests. However, in the future, this sandboxing will be relaxed to allow inscriptions to use the content of other inscriptions. This will allow for the development of an a modular, on-chain ecosystem of remixing and composition. This is tracked in issue #1082.

Inscriptions are unnamed and untitled, but we hope to give artificers the ability to give their inscriptions globally unique, human-readable names. This is tracked in issue #794.

The future of inscriptions is bright. We hope not only to reach feature parity with other NFT implementations, but to surpass them.