Conference Kickoff

Be a helping hand

Since I have been active as an open source contributor and received funding for the first time in 2019, I have been asked by many people how to get started and get on the same path. While there are programs like BOSS that help with this (and I frequently recommend checking these out) I have found the most success with a different kind of advice. I find that specifically with experienced developers that have looked into Bitcoin for a while as well, they just want to get their hands dirty and are mostly looking for a place to start. This is where this talk comes in: I give people the advice to look for a project/feature that experienced people are already working on and offer support for them. The common conception often is that they don't need much help and that a new person should bring their own new ideas or pick up an abandoned project. However, this often sets people up for failure because there is usually not enough attention on these projects. Joining a project with traction guarantees feedback from experienced people on their work, there is usually more than enough stuff to do which then receives quicker review and also the attention that is already on the project makes is easier to raise funding without bringing a long track record. The talk would give lots of practical advice around this as well as real life examples.

Reviewing PRS

Why reviewing is a bottleneck and how to become better at it

Hackable by Default: Software that's Really Open Source

Open source software gives you the legal right to modify software - but how often do users actually do this? Can we find something better than the status quo? Could hacking the program happen within the program? This talk aims to answer these questions. Hackability should be a core design philosophy of an open source product, not an afterthought. Modern users have come to expect apps that behave like appliances, and this leaves them locked out of getting the maximum out of their software. With the help of modern tools and AI flattening the learning curve, we have an opportunity to rethink what user-modifiable software looks like. The talk explores Nostr as a distribution layer for software and includes a demo of a Nostr micro-app framework around this philosophy as a proof-of-concept.

Don't Trust Your Node: Policy-Based Signing for Secure Lightning Infrastructure

Lightning nodes are hot wallets by design, signing keys live alongside routing logic, creating a real attack surface for anyone running serious Lightning infrastructure. As a BTrust grantee contributing to Validating Lightning Signer (VLS), this talk breaks down the problem of blind signing, how VLS separates the signer from the node, and how policy rules are enforced before any signature is produced, making it especially relevant for LSPs and Lightning operators scaling across Africa. The presentation will provide a clear picture of the problem VLS solves, how it works in practice, and where the open challenges still are.

Anti-Fee-Sniping and Privacy for Taproot Transactions

BIP326 closes Bitcoin's on-chain privacy gap by normalizing nSequence across Taproot transactions — making Lightning channel closures indistinguishable from regular wallet payments. This talk covers the full specification: MAST, HTLCs vs PTLCs, fee sniping, and absolute vs relative locktimes, culminating in a production Rust implementation using the bdk_tx crate.

The 256 Foundation's Open-Source Mining Stack

In almost every layer of Bitcoin, open source is the default. Mining is the exception: one company dominates ASIC hardware and firmware, four pools direct ~75% of global hashrate, and miners hand multimillion-dollar operations to black-box hardware and software. The 256 Foundation is working to fix that. We'll walk the four pillars of the open-source mining stack end to end: Ember One (hash board), Libre Board (control board), Mujina (firmware), and Hydrapool (pool software). See the hardware in person: a sous vide cooker built from all four. We'll cover how to plug in: solo-mine sovereignly, test new hardware, file issues, contribute code, or show up on the forum. Mining is the last closed layer of Bitcoin. The 256 Foundation is opening it.

Don't Trust, Attest: Enclaves as a Trust-Minimization Tool for Bitcoin Apps

The rise of trust-minimized Bitcoin solutions is enhancing both the capabilities and user experience of Bitcoin, but these systems still often rely on cloud-hosted services. This creates a key requirement: ensuring those services are actually running the intended code, otherwise the model collapses back into blind trust in the operator. Secure enclaves and remote attestation directly close this gap by enabling verifiable execution, protecting sensitive key material, and shifting trust from "trust the operator" to "verify the code." I'll share my experience building an enclave framework with reproducible Nix builds, explain the architecture, and show how an MPC wallet cosigner leverages it in practice. I'll also explore how the Ark Labs Introspector intends to build on the same framework, alongside an honest discussion of the trust assumptions secure enclaves still cannot remove.

Your Bitcoin Address Is Leaking: Building a Privacy-First BIP-353 Resolver in Go

Bitcoin addresses are permanent public records. Every one you share becomes a window into your transaction history, and if any address ever gets linked to your identity, chain analysis can work backwards and forwards from there. BIP-353 doesn't just solve the UX problem of ugly addresses. It opens the door to payment types like Silent Payments and BOLT-12 that are private by design, not as an afterthought. BIP-353 maps human-readable handles like ₿[email protected] to payment instructions stored in DNSSEC-signed DNS TXT records. No custodian, no registry, just DNS. But the way you resolve a BIP-353 address determines whether you're actually private, or just using a nicer-looking string. This talk walks through bip353-go, an open-source Go library implementing BIP-353, built around a three-layer privacy threat model. 1. Who sees your query? A standard DNS lookup exposes the payment address you're resolving to your ISP and every on-path observer. bip353-go ships DNS-over-HTTPS (RFC 8484) to encrypt query names in transit, and Tor routing via SOCKS5 to strip your IP from the DoH server entirely. The privacy tradeoffs of each transport are explicit and configurable. 2. Can the resolver lie to you? Trusting a remote server to validate DNSSEC on your behalf means trusting it not to forge a payment address and steal your funds. bip353-go integrates dnssec-prover, the reference Rust implementation by the BIP-353 author, and performs full local DNSSEC chain validation on every resolution. The remote resolver is used only as a dumb relay. Its response cannot be forged without breaking the DNSSEC chain. 3. What does your payment method reveal? BIP-353 records can carry Silent Payment addresses (BIP-352) and BOLT-12 offers, both designed from the inception for receiver privacy. We'll look at how the library decodes and prioritizes them, and why "BOLT-12 > Silent Payment > BOLT-11 > on-chain" is a privacy ordering, not just a feature ranking. This is also a talk about building Bitcoin open-source software as a newcomer learning in public. Shipping something real, a well-structured Go library with typed error sentinels, integration tests against live DNS records, and Rust FFI bindings via UniFFI, taught me more about Bitcoin's privacy model than any blog post did. If you're early in your Bitcoin dev journey, this talk is proof that you can build something meaningful while still figuring things out. Attendees will leave with a concrete threat model for payment address privacy, a working understanding of how BIP-353 + Silent Payments + BOLT-12 compose into a genuinely private payment stack, and a Go library they can drop into their own projects today. github.com/btc-go/bip353

Can AI Help Bitcoin? Responsible Practices for Open-Source Development

AI tools are rapidly reshaping how developers write, review, and ship code but how should Bitcoin open-source contributors approach them? This talk explores the opportunities and risks of integrating AI into Bitcoin development workflows. We'll examine where AI genuinely adds value, where it introduces risk, and the responsible practices every contributor should adopt to maintain the security, rigour, and trust that Bitcoin demands. Whether you are a first-time contributor or a seasoned maintainer, you will leave with a practical framework for using AI as a tool that supports rather than compromises the integrity of open-source Bitcoin development.

Nostr, an open source database?

I'll talk about how nostr is a decentralised open source database - emphasing how (and why) to best make use of it in projects.

Workshop: Building Nostr apps with open source AI tools

In this workshop I will show participants how to use open source AI tools to build open source, decentralized, apps on Nostr. We cover how to use open source at every level of the stack, from the models to the frameworks and tools like Shakespeare and Opencode, to finally how to publish and share your open source app on Nostr with tools like Nsite and Ngit. The workshop will include a presentation portion, setup walkthrough/guide, collaborative building, and time for questions. The workshop will be at an intermediate level, with the expectation that participants are already familiar with the basics of working in the terminal, using git, etc. We will provide AI tokens for the workshop.

The Cognitive Cost of AI-Assisted Open Source

AI has dramatically lowered the barrier to contributing to open source. Pull requests can now be generated in seconds, code explanations are instant, and contribution speed has accelerated across the ecosystem. But as code generation becomes easier, a deeper question emerges: are contributors still developing the understanding required to maintain critical systems like Bitcoin? This talk explores the growing cognitive cost of AI-assisted development, from shallow review culture and low-context contributions to the erosion of systems thinking and technical intuition. Rather than arguing against AI, the session examines how contributors can use these tools without outsourcing the reasoning, verification, and responsibility that meaningful open-source work requires. In Bitcoin, where review quality, caution, and long-term thinking matter more than velocity, contribution integrity becomes essential. This session is a reflection on what it means to remain a thoughtful contributor in an era where generating code is no longer the hard part.

Onion Messages: How Lightning Learned to Talk Beyond Payments

Lightning Network is best known for routing payments, but a quieter revolution has been happening in the open: onion messages. Built on the same onion routing primitives that move sats, onion messages give Lightning a general-purpose, privacy-preserving communication layer — no payment required. This talk walks through the journey from problem to protocol. We'll start with how onion routing works for payments, then explore why the network needed a messaging layer beyond HTLCs — and how the open spec process produced one. We'll cover the core mechanism (how onion messages reuse Sphinx routing for arbitrary data), what they unlock (BOLT12 offers, blinded paths, async payments), and the privacy tradeoffs involved.

Open Source is Dead

AI is changing the tech landscape fast, causing previously devout open source advocates to already start talking about jumping ship. In this talk, I will lay out the threats to open source by AI, and advocate for why it still matters anyways.

Modern Testing and Fuzzing in Bitcoin Core

Bitcoin is a multi-billion dollar open-source protocol that remains exposed to good and bad actors in equal measure. The purpose of this talk is to try and shed light into how various teams try to revamp its resilience against edge cases and malicious inputs. Bitcoin Core testing suite has continued to evolve to multilayered efforts, from standard unit and functional tests to fuzzing and mutation testing. This talk also aims to dive into technicalities of Core Fuzzing, using tools like LibFuzzer to discover vulnerabilities that traditional testing cannot reach.

Implementing Replace-By-Fee (BIP 125) in LDK Node

A walk-through of the implementation of Replace-By-Fee (BIP 125) in LDK Node, a Lightning node library built on top of BDK. Beyond just enabling fee bumping on the onchain wallet, look at maintaining a consistent payment state when a transaction is replaced in the payment store, since a bump produces a new txid, the old one becomes conflicting. The required design for a new store to track and handle these conflicts correctly. The talk covers the design decisions made.

Hackathon Kickoff

Hacking Time

Lightning as Bitcoin’s Translation Layer

This talk explores how Lightning transforms Bitcoin from a settlement network into a usable payments system. Drawing from the experience of building Tando, we will look at what it actually means to build on Lightning Network and bring Bitcoin into everyday commerce.

Lightning Education as Infrastructure: Scaling Technical Capacity Across Multiple Countries

Lightning adoption depends not only on infrastructure and liquidity, but also on the availability of skilled developers capable of building and maintaining the ecosystem. This talk explores how treating developer education as infrastructure can rapidly scale Lightning capacity across multiple countries, sharing practical lessons from organizing hands-on Lightning bootcamps and building sustainable developer pipelines that continue producing active builders long after training ends.

AI-Powered Product Design for Bitcoin Experiences

Bitcoin is growing fast, but the products built around it haven't always kept up with the people using them. Gaps in user research, unclear journeys and rushed interfaces quietly push users away before they ever see the value. In this workshop, you'll see what a modern AI-powered design process looks like from start to finish. We'll cover prompt engineering for UX research, so you know exactly how to get useful, contextual insights out of AI tools rather than generic outputs. Using tools like Notion, Figma, claude and Cursor, we'll run a design sprint accelerated by AI agents. Whether you're a designer, developer, or product builder, you'll leave with a practical workflow you can apply to your next Bitcoin product immediately.

Bark in production: Implementing a moving spec in public

What it's like contributing in the open to a relatively new, fast-moving bitcoin project, and how to ensure we stick with rigor and pragmatism as much as possible.

"Beyond the Barrier: Female African Developers Reimagining Bitcoin Innovation"

Bitcoin doesn’t scale through marketing. It scales through builders. For too long, Bitcoin development has remained concentrated within a small demographic while massive technical talent across emerging markets remained untapped. Dada Devs was built to change that. Through focused pathways in Programming Bitcoin, Lightning, UX, and open-source collaboration, we have trained female African developers to move from first principles to shipping real Bitcoin products and contributing to the ecosystem. This keynote explores how emerging technologies, Bitcoin education, and frontier-market builders are reshaping Bitcoin development from the ground up, not through narratives, but through proof of work.

Cross-Platform Bitcoin Wallets with Flutter & BDK-Dart

Flutter developers can now build bitcoin apps on iOS and Android using bdk-dart. Dart bindings for the Bitcoin Dev Kit. In this lightning talk, I'll show you how to integrate bdk-dart into your Flutter project and walk through the developer reference app, bdk-dart Wallet, which showcases core wallet features including wallet creation (P2WPKH/P2TR), Electrum/Esplora sync, send & receive, and transaction history. Leave with a working mental model of BDK's API surface and a scannable link to run the app yourself.

Bitcoin Transfer

It will presenting first MVP website of a crypto app that will help most South Sudanese change bitcoin to local currency using lightning

Mining Illustrated feat. Mujina Open-Source Firmware

A guided walk through the full data path of Bitcoin mining, from the network down to the silicon and back. We'll trace exactly what moves between the Bitcoin network, a pool, and a miner, then dig into what each side does with it. We'll cover: What a pool receives from the Bitcoin network What a miner receives from a pool What a miner does on the inside What a miner returns to the pool What the pool sends back to the Bitcoin network To make it real, we'll run a complete Bitcoin network in the room and mine against it using Mujina Open-Source Mining Firmware on your laptop, with provided Bitaxe Gammas serving as hashboards. You'll see every layer of the stack running on hardware in front of you.

The Future of Bitcoin Mining is Open

Open source is becoming unstoppable in the age of AI: when intelligence is shared, innovation compounds. The same force that is transforming software will soon reshape Bitcoin mining from the inside out. Closed systems will give way to open infrastructure, faster experimentation, and a new generation of builders. This shift will disrupt operations, energy optimization, automation, and hardware integration across the entire industry. And that disruption is exactly what Bitcoin mining needs: more innovation, more decentralization, stronger security, and a more resilient network.

Why African Designers +Bitcoin = The Future

Bitcoin adoption in Africa isn't bottlenecked by technology. It's bottlenecked by design. 400 million unbanked adults across Sub-Saharan Africa stand to benefit from Bitcoin, but the tools they encounter are built by engineers, for engineers. Confusing onboarding flows, unexplained self-custody, and jargon-heavy interfaces are silently killing adoption before it starts. This talk makes the case that designers, specifically African designers, are the missing layer in Bitcoin's growth story on the continent. Drawing from BitDesigners Africa's experience running community meetups and workshops across Nigerian cities, I'll break down how UX decisions make or break real-world Bitcoin adoption, what happens when you put designers and developers in the same room solving onboarding problems, and the concrete path from curious designer to open-source Bitcoin contributor. This isn't a theoretical pitch. It's a field report from the people building the bridge between Bitcoin and the next hundred million users, and a call to take design as seriously as we take code.

Edge Liquidity Bridges: Connecting African Fiat to Lightning via Taproot Assets

Cross-border payments in Africa suffer from fragmented fiat rails, limited interoperability, and high settlement friction. Emerging Bitcoin-native protocols offer a new space such as multi-asset issuance on Bitcoin with instant settlement over Lightning. This talk presents a PoC for bridging African fiat currencies (NGN, GHS) into Bitcoin using Taproot Assets. We will look into the mechanics of Edge-Node Liquidity Bridges covering asset minting, channel liquidity management (addressing rebalancing without Splicing), routing constraints, and "Proof-of-Burn" settlement flows across multiple currency zones.

Plugins, Not Forks: Extending BTCPay Server Without Compromising the Core

BTCPay Server's plugin system turns a self-hosted payment processor into a platform. This workshop walks through the plugin architecture — how it's structured, how plugins hook into the core, and what it takes to build one from scratch. If you run BTCPay or build on it, this is the layer you should understand.

Hackathon Expo

Working on Bitcoin

We invite contributors to bitcoin-core to tell us about their journey working in public.

Cashu ecash protocol

A deep walk into the adoption and use of ecash wallets and development of the cashu protocal

Gating APIs with Lightning: A Hands-On L402 Workshop Using Aperture

L402 is an open standard that turns Lightning into an authentication and payment layer for APIs. Instead of API keys and subscription plans, your service issues a Lightning invoice — the client pays, gets a macaroon, and gains access. It's permissionless, programmable, and built on open-source tooling. In this hands-on workshop, we'll build an L402-gated API from scratch using Aperture, the open-source reverse proxy from the LND ecosystem. Participants will work in a pre-configured regtest environment (Docker-based, no mainnet sats needed) and walk through the full cycle: setting up a backend service, placing it behind Aperture, configuring macaroon-based access, and testing the 402 Payment Required flow from the client side.

The Open Source Privacy Gap

The Open Source Privacy Gap Bitcoin is often described as private but in reality it is pseudonymous not anonymous. Leaking even small pieces of information can expose a user’s identity or enable long term tracking. Yet privacy is rarely broken by a single catastrophic failure. More often it degrades gradually as information from different sources is combined over time. This talk explores how modern chain analysis works from clustering heuristics and wallet fingerprinting to intersection attacks and metadata leakage and examines how privacy assumptions can break down in subtle and unexpected ways. Even strong guarantees made within one model may fail to generalize once additional information becomes available to an adversary. Rather than treating privacy as a binary property the talk frames it as a spectrum shaped by assumptions, adversaries, and observable leaks that compound over time. Drawing parallels to side channel attacks, it argues that small leaks can accumulate into significant privacy failures even when individual components appear secure in isolation. The goal is not to argue that privacy is impossible, nor to present a single “magic bullet” solution. Instead the talk encourages more rigorous and holistic thinking about how privacy systems behave in the real world and why small improvements across wallets, protocols, infrastructure and user behavior can meaningfully strengthen privacy over time.

Bearer Tokens for Bitcoin: A Look at Cashu

Cashu is a Chaumian ecash protocol built on Bitcoin and Lightning, it's a precise cryptographic protocol with a clean spec and growing reference implementations. This talk goes inside the machinery: the Blind Diffie-Hellman Key Exchange that makes mint-side unlinkability possible, how the NUT specifications translate that into a concrete mint/wallet API and why a string of characters can be money.

Refactoring Bitcoin Core Consensus Code: Safe or Risky?

Bitcoin's consensus rules are the most critical code in Bitcoin Core. libbitcoinkernel has been exposed, but it's not enough — it ships with Bitcoin Core quirks tightly coupled to it. Block validity unit tests don't exist. Fuzz harnesses for block validation don't exist. Can we safely refactor consensus logic and separate it from those quirks without changing or introducing new behaviour? Not yet. Right now, every refactor is a high-stakes gamble with chainsplits and consensus failures on the line. This talk walks through the test gap, shows why it makes consensus decoupling so risky, and makes the case for the specific infrastructure that needs to be built before we can answer "do" with any confidence — and why writing those tests is one of the highest-value open source contributions you can make to Bitcoin Core today.

The Last Mile — Bridging Legacy Mobile Money to Bitcoin Liquidity

While global discourse focuses on L2 scaling and institutional ETFs, the African frontier faces a more immediate technical hurdle: The On-Ramp Gap. In a market where 95% of liquidity is locked in mobile money silos like M-Pesa, true Bitcoin adoption isn’t a lack of interest—it’s a lack of programmatic access. This session, hosted by Bitika(Satsoko), moves beyond the "Why" of Bitcoin to the "How" of building production-ready infrastructure. We will dive into the architectural challenges of abstracting legacy mobile money APIs into seamless Bitcoin settlement layers, managing liquidity in volatile fiat environments, and navigating Kenya’s 2026 VASP regulatory landscape. Designed for builders and investors, this discussion highlights how Bitika is "working in public" to turn fragmented local rails into high-velocity Bitcoin gateways. Attendees will gain a technical roadmap for connecting legacy finance to the Bitcoin protocol, identifying the "picks and shovels" necessary to scale across the continent. We aren't just building a wallet; we are building the processing layer for the next billion users.

Sending and Receiving silent payment transactions with bdk-sp

In this workshop participants will be able to send and receive silent payment transactions using the experimental repository bdk-sp. Participants will also be able to get an overview about what are silent payment and how they improve privacy.

MDK: The Open Standard for Mining Software Infrastructure

This workshop introduces MDK by Tether (Mining Development Kit), an open-source initiative designed to make Bitcoin mining infrastructure easier to build, integrate, and extend. Today, mining sites are often held together by fragmented systems, custom scripts, vendor-specific tools, and disconnected interfaces for machines, power systems, cooling, telemetry, and automation. MDK aims to provide a shared, modular foundation that developers, operators, and companies can build on together. This session will present the vision behind MDK, the problem it solves, the principles guiding its design, and the opportunity for the broader Bitcoin ecosystem to contribute to an open standard for mining software and infrastructure.

Don’t Trust, Verify. Reproducible Builds in Bitcoin

Bitcoin is built on the principle of "don’t trust, verify" , yet in practice, most users and even many developers cannot independently verify that released binaries correspond to the published source code. This talk will introduce reproducible builds from a developer’s perspective - what they are - why they matter for Bitcoin software, - how to implement them in their projects ( environment isolation, dependency pinning, deterministic toolchains, and independent verification workflows and a checklist developers can apply to make their own software reproducible.)

"Where Did My Money Go?" What Lightning Can Fix About Payments in Africa

I build payment systems for a living. Every day, I integrate mobile money providers, Airtel, MTN, Vodacom, Orange, M-Pesa etc across eight African countries, and every day, something breaks. Callbacks arrive hours late, or never at all. Customers get debited but never credited. Reconciliation jobs catch transactions that the real-time flow silently dropped. A provider goes down with no notice, and suddenly thousands of people are asking: "where did my money go?" This talk is about that question, and about what the Lightning Network offers as an answer. I'll share real stories from building and maintaining mobile money integrations across the continent: the callback failure rates, the reconciliation delays, the provider outages you can't do anything about because you don't control the infrastructure. Then I'll walk through how Lightning's design, instant finality, cryptographic proof of payment, no middleman holding your funds in limbo, addresses these exact pain points. This isn't a talk about replacing mobile money tomorrow. It's about understanding why payments break the way they do in Africa, what Lightning gets right at a protocol level, and where the real opportunities are for developers building at this intersection. If you've ever waited for a callback that never came, this one's for you.

Hackathon Finals

Panel

Hackathon Awards

Hackathon Awards