The latest implementation of bitcoin (BTC) on the Ethereum blockchain quietly went live this week.

There are 1.24 renBTC live on the Ethereum mainnet now, according to Etherscan. Three sources with knowledge of the project have confirmed this is the Ren smart contract, live ahead of its launch announcement.

Kain Warwick of Synthetix tweeted Wednesday he was the first person to hold a full bitcoin in renBTC.

However, there’s no way yet for members of the public to mint additional renBTC, the CEO of the company behind the project told CoinDesk in an email.

“While the smart contracts have been deployed on Ethereum, RenVM itself is not actually on mainnet. This is because RenVM is a distinct network separate to Ethereum. The final mainnet subzero version of RenVM won’t be deployed until later,” Taiyang Zhang wrote. “The minted renBTC so far has been from our own internal testing [and] Kain from Synthetix testing the system. The public hasn’t been able to mint renBTC thus far.”

RenBTC becomes the latest in a rash of products built to expose bitcoin-backed assets to the benefits of Ethereum’s various decentralized finance (DeFi) platforms.

Here’s a succinct description of the system from a Medium post by the company’s CTO, Loong Wang:

"Any asset minted on Ethereum by RenVM is a 1:1 backed ERC-20. This means that if you have 1 renBTC (an ERC-20), you can always redeem it for 1 BTC. It's a direct supply peg. renBTC isn't a synthetic, it doesn't rely on a liquidation mechanism, and it's not the price of Bitcoin on Ethereum. It is a one to one representation of Bitcoin on Ethereum that can be redeemed for BTC at any time, in any amount."

The contracts for the three new tokens are already published in Ren’s documentation. There are also already 1.12 renZEC minted and a negligible amount of renBCH.

Ren is a project that grew out of the $30 million initial coin offering (ICO) for the Republic Protocol, originally envisioned as a way to run dark pools – privacy-preserving trading venues where the order book is kept secret. According to Crunchbase, its backers included Polychain Capital and FBG Capital.

Read more: Into the Dark Pool: $30 Million ICO Could Pave Way for Huge Crypto Trades

But in a recent issue of The Defiant newsletter, Wang explained his firm’s pivot away from dark pools. 

The big trades were on chains that weren’t Ethereum, he said. “ETH had a lot of liquidity, but it was predominantly Bitcoin and USDT. So we would had to leverage things like atomic swaps, and they’re just too painful,” Wang told The Defiant’s Cami Russo. “And so we kind of turned around to say, well, we need to solve this interoperability problem before large liquidity is actually truly accessible in this space.”

The RenVM is a way to hold a cryptocurrency in a multi-signature wallet controlled by nodes in the RenVM and mint a representation of that asset as an ERC-20 token for use on Ethereum. Unlike other projects, RenVM is bringing more than bitcoin to Ethereum (see bitcoin cash (BCH) and zcach (ZEC) above), with other assets to follow.