- Overall winner 1st place
cashu player
#6
a web podcast player where listeners can stream cashu over a spilman channel
Status · Submissions closed
Event timeline ·View schedule →
Hackathon control board
Berlin, payments edition
money in movement
Build something real. Find collaborators, choose a challenge, ship your project, and put it in front of the bitcoin++ community.
§ Featured builds
Built in public.
Winning and featured projects from this hackathon. Explore the full gallery →
- Overall winner 3rd place
Will I make my boat?
#29
Check whether unilateral exit of your VTXOs will succeed before VTXO expiry, given current mempool conditions.
§ More winning builds
Honorable mentions & sponsor prizes
- Award winner Honorable Mentions
barkmesh
#1
Meshcore transportation layer for ark-to-ark payments using bark
- Award winner Honorable Mentions
eNFT
#18
Privacy-preserving bearer collectibles built on Cashu – the JPG *is* the NFT
- Award winner Honorable Mentions
DropShop
#24
Lightning for anything fiat
- Sponsor award Build on Flame
- Sponsor award Best use of Bark
- Sponsor award Trustless Bets
Bark Dice
#19
Roll the dice. Verify the odds. Get paid in Bitcoin. Bark Dice brings provably verifiable dice games to Ark, with fast payouts straight to your wallet.
- Sponsor award Build on Flame
Firebreak
#13
Chain-enforced spending allowances for apps and AI agents
- Sponsor award Build on Flame
Flame toolbox and smart contract
#14
A wallet, block explorer and a smart contract proof of concept for Flame
- Sponsor award Best use of Bark
barkade
#31
script emulation with bark
- Sponsor award Most useful Electrum plugin
LowTide
#20
LowTide is an Electrum plugin that forecasts the weekly fee tide and lets you send, consolidate and migrate at rates below 1 sat/vB. If a transaction gets stuck, it compares Wait, RBF, CPFP and the mempool.space accelerator side by side with real costs and recommends the cheapest option that meets your deadline
- Sponsor award Most Based Payment Protocol
NWC Commission Payments
#17
A Nostr Wallet Connect extension that lets a marketplace take its cut on a Lightning sale without ever holding funds or a spending key to the vendor's wallet. The customer pays one ordinary invoice. The vendor's wallet acts as a forwarding hop: it holds the sale, pays the commission to the platform under a policy the vendor set, and settles both with one preimage. All or nothing by HTLCs, not by trust. Idempotent requests, peer to peer between vendor and platform, no changes to customer wallets. Submitted as an issue and PR to the NWC spec repo.
- Sponsor award Ain’t nobody got time for that
Barkauf
#10
Open software for open technology - Bark SDK based Bitcoin wallet for Sailfish OS
§ Prizes
Prize pool.
Ranked rewards for the top projects. Challenges can stack on top.
[ Award ]
Honorable Mentions
These projects deserved recognition for being outstanding.
Prizes
Tickets 🎫
1.6M satoshis
Ain’t nobody got time for that
Does your project involve an onchain bitcoin transaction that needs to confirm promptly? If so, your project is a contender for this prize, which will be awarded for the project which most creatively integrates mempool’s transaction accelerator via the public API as an option for getting a stuck transaction confirmed.
Prizes
Mempool Enterprise Silver Subscription + 500k sats in accelerator credit
21M satoshis
DM x.com/orangesurfbtc or signal orangesurf.01 to receive prize
Build on Flame
Build a project on Flame, a new electronic cash network protocol based on Bitcoin. Flame offers modern features such as confidentiality, powerful programming environment, low latency and higher throughput based on a decentralized proof-of-burn consensus. The network continuously burns bitcoins as a means to timestamp blocks of transactions. As an incentive, network issues new units of flames.
Prizes
3.5M sats pool
3.5M satoshis
Best use of Bark
Build something that moves bitcoin with Bark, Second‘s implementation of the Ark protocol, which is live on mainnet.
We want to see wallets, payment flows, merchant tools, payouts, P2P, or infrastructure where Bark does the real work of moving money. Use whatever fits your project: the bark CLI, the bark daemon’s REST API, the Rust library, or the FFI bindings.
Prizes
1500000 sats pool
1.5M satoshis
The Second team is at btc++ all week to help with Bark setup, signet funds and questions.
Most useful Electrum plugin
The Electrum Wallet is extensible through external plugins. Build the most useful plugin for day-to-day use cases to help real users improve their Bitcoin experience. The plugin can be for a desktop, Android or daemon (headless) instance. See https://plugins.electrum.org.
Prizes
1000000 sats per winner
1M satoshis
You receive 1_000_000 sat to a BOLT11 or BOLT12 Lightning invoice.
See the Future
Build a Bitcoin price forecast people can trust, using Glimpse prediction market data. Use the Glimpse API or the glimpse-markets Python package to make a visualization, app, bot, or alert that turns market probabilities into a forecast anyone can read.
API docs: https://docs.glimpse.markets/index Python package: https://pypi.org/project/glimpse-markets/ LLMs: https://docs.glimpse.markets/llms.txt
Prizes
1000000 sats per winner
1M satoshis
Paid in Bitcoin to the address or Lightning destination the winning team provides after the announcement.
Trustless Bets
Build a non-custodial betting or gaming application on Bitcoin. Poker, roulette, blackjack, sports betting, or any conditional payment game is welcome. It must use peer-to-peer, self-custodial infrastructure such as Arkade, Bark, or another Bitcoin L2, and it must run in production with real sats. Testnet and signet entries are ineligible.
Prizes
750000 sats per winner
750k satoshis
Paid in Bitcoin via Lightning to the winning team.
Most Based Payment Protocol
Best proposal for improving payment protocols in the bitcoin ecosystem. Think big, think idempotent, think peer to peer.
Prizes
500k sats
500k satoshis
§ The judges
8 judges.
Scoring is handled by the assigned hackathon judges.
