Today we are releasing an alpha version of Bitcoin DEX - a decentralised bitcoin exchange based on non-interactive atomic swaps. It allows you to swap bitcoins for stablecoins with a single bitcoin transaction, and without having to know your counterparty upfront. You can find the FAQ here. Here are some screenshots.
Your feedback is very welcome!

PS: you can use this faucet to receive some testnet Bitcoins to buy testnet Dollars on the DEX. Or you can receive testnet dollars by posting your address in this thread. Or you can receive testnet dollars in our Telegram group.


Edit: Here's a writeup of the protocol.

For fun I implemented OP_MUL using OP_ADD. You can find the code here on Github.

Feedback very appreciated!

And I have a question: do you guys know any good source for advanced bitcoin scripts? Is there something like a library for scripts?

I have been working on a protocol for stateless nodes. It is a simplified version of Utreexo. It does not require dedicated bridge nodes - only regular nodes serving regular blocks. Furthermore, nano nodes can serve each other. The protocol works on top of today's bitcoin. No consensus changes are required. All data structures emerge from the existing blockchain structure.

If there is at least one honest node available, the protocol provides full node security by downloading just about 150 MB.

Here is a straw-man proposal demonstrating the basic idea.

The detailed description can be found here.

Feedback is very welcome. Thanks for taking your time!

A flexible backend for browser-based Bitcoin clients. The in-official JavaScript library for Blockstream's Esplora API.
Find the code and a demo on Github

Feedback highly appreciated!

Hi all,

I've been working on a sidechain protocol with no trusted third party. You can find the whitepaper here.

Abstract. Coins is a Bitcoin extension designed for payments at scale.  We propose an efficient solution to the double-spending problem using a bitcoin-backed proof-of-stake.  Validators vote on sidechain blocks with one-time  signatures,  forming  a record that cannot be changed without destroying their collateral.  Every user can become a validator by locking bitcoins.  One-time signatures guarantee that validators lose their  stake  for  publishing  conflicting  histories.   Checkpoints  can  be  additionally secured with a bitcoin-backed proof-of-burn.  Assuming a rational majority of validators, the sidechain provides safety and liveness.  The sidechain’s footprint within bitcoin’s blockchain is minimal.  Spawning multiple, independent instances scales horizontally.

Your Feedback is highly appreciated!

Thanks!