BZA1 (BTX Artifacts standard)

BZA1 is a standard for issuing artifacts, on-chain collectible items, on the BTX blockchain. An artifact is created by an ordinary BTX transaction that carries a structured OP_RETURN payload, and ownership of the artifact follows the coin that carries it. Collections are recognized by indexers and a registry rather than by smart contracts. The specification is published at easybtx.com/nfts.

#How issuance works

A BZA1 issuance is a normal BTX transaction, valid under ordinary consensus rules. In addition to its spendable outputs, the transaction includes an OP_RETURN output with an 83-byte data lane holding the artifact payload. The payload is structured: a schema byte identifies the payload format, and a content commitment (a hash) binds the artifact to its content and metadata. The commitment is recorded on chain; the content itself is not.

Because issuance is just a transaction, no contract deployment, token mint call, or protocol change is involved. Full nodes validate the transaction like any other and do not interpret the artifact semantics.

#Ownership model

Each artifact is attached to a specific coin, a UTXO. Whoever can spend the coin owns the artifact, and transferring the artifact means spending the coin to the new owner, protected by the same post-quantum signatures (ML-DSA, SLH-DSA) as any BTX payment.

The payload format also includes a soulbound flag. A soulbound artifact is one intended to remain with its original recipient, and indexers that follow the standard treat it as non-transferable.

#Collections, indexers, and the registry

BTX has no smart contract layer, so BZA1 places collection logic off chain. Indexers scan the chain for well-formed BZA1 payloads and reconstruct artifact histories from transaction data, and a registry records recognized collections. A collection launches when the registry and indexers recognize its issuances, not when any code is deployed.

This division has direct consequences. On chain, an artifact inherits the guarantees of BTX itself: its content commitment and its ownership history are as durable as the chain. Off chain, the interpretation of artifacts, such as which issuances belong to which collection and which are canonical, depends on indexer rules and registry conventions rather than on consensus. Different indexers applying different rules could, in principle, disagree.

#Comparison with contract-based standards

Contract-based collectible standards on EVM chains implement ownership as mutable contract state. BZA1 instead reuses the transaction graph itself as the ownership record, similar in spirit to other UTXO-carried asset schemes. The trade is programmability for simplicity: BZA1 artifacts cannot execute logic, but there is also no contract to exploit, upgrade, or abandon.

Public collectible releases that use BZA1 are indexed at BTX drops, and issuance transactions can be inspected in BTXScan like any other BTX transaction.