Cryptocurrency developer Unwriter is making good on his promise “to build everything on top of Bitcoin”—Bitcoin SV (BSV) to be specific.
On January 3rd, the eve of the 10th anniversary of the Bitcoin genesis block, Unwriter announced on Twitter the launch of Datapay, the “simplest” JavaScript library for building and broadcasting data transactions to the BSV blockchain.
It’s so simple, according to the developer, that “all it takes is four lines (of code) to start writing data” to the BSV chain.

Source: Datapay GitHub
Forked from Datacash, the library Unwriter wrote for the BCH, Datapay uses BSV Explorer as its default RPC.
It’s also powered by bsv, a library for cryptography, key management and transaction building for Bitcoin SV. But unlike the conventional Bitcoin transaction libraries, which focus on sending money, Datapay is designed with a different philosophy—send data as simple as possible.
To do this, the Datapay library only has two methods: build, for building a transaction but not broadcasting it to the network; and send, for sending a transaction.
Unwriter explained on GitHub, “Datapay was created in order to make it dead simple to construct OP_RETURN related transactions, but you can even use it to build regular transactions. Also Datapay exposes datapay.bsv endpoint which you can use to access the underlying bsv library.”