Projects

A list of the Bitcoin and Lightning projects I created, worked on or contributed to in the last years. This list might not be exhaustive.

Donations, Support, and Grants

Over the past years, I’ve received support and funding from the following organizations for my open-source work. Without this support, I wouldn’t have had the time and freedom to work on the projects listed below. I publish this for transparency and to give credit. This support is no-strings-attached, and I’m not affiliated with the supporters in any other way.

OpenSats

OpenSats LTS grant
announcement

opensats.org

HRF

Bitcoin Development Fund 2023
announcement

hrf.org

Spiral

Spiral developer grant 2023
announcement

spiral.xyz

Brink

full year 2022 (exclusive)
announcement

brink.dev

Bitcoin Suisse

one-time donation* (2022)
announcement

bitcoinsuisse.com

Coinbase Giving

full year 2021 (exclusive)
announcement (PDF archive)

coinbase.com

Samourai Wallet

one-time donation
mempool.observer (2020)

samouraiwallet.com

Shift Crypto

supported my work on
mempool.observer (2019)

shiftcrypto.ch

Bitrefill

supported my work on
transactionfee.info

bitrefill.com

*forwarded to Brink due to exclusivity agreement with Brink

November 29, 2023

CPU usage of Bitcoin Core peers

To help improve partition resistance, a medium-term goal is to increase the number block relay connections a Bitcoin Core node has (see #28462). However, how much resources do block-relay connections use? Surely they are cheaper than full-relay connections? This blog-post focuses on the CPU usage of …

October 7, 2023

bitcoin++23 Workshop: Writing a NixOS Module for your_app

Instructions for my Writing a NixOS Module for your_app workshop. Slides can be found here.

August 10, 2023

GitHub Metadata Backup and Mirror

This year, the Bitcoin Core project will have its 13th anniversary being hosted on GitHub. 13 years of issues and pull requests with critical design decisions and nuanced discussions hosted with a US-based company known for shutting down open-source software repositories when needing to follow DMCA …

June 8, 2022

bitcoin++ workshop: Tracing Bitcoin Core v23.0

These are the tasks of my “Tracing Bitcoin Core v23.0” workshop for bitcoin++ 2022. They might not make much sense on their own as participants used a pre-setup VPS. The workshop slides can be found here. This branch was used during the workshop.

November 14, 2021

Monitoring Taproot Activation

In November 2021, the Taproot soft-fork activated on the Bitcoin network. I streamed my activation monitoring and helped pools not mining P2TR spends to fix their issues.

July 28, 2021

Contribution: Bitcoin Core Project

I list my contributions to the Bitcoin Core project and detail their context and background. Of course, not all contributions are worth mentioning here.

June 28, 2021

Summer of Bitcoin 2021

This is a placeholder for the Summer of Bitcoin mentoring I did. I plan to fill this in, once I get the time to do so.

June 27, 2021

bitcoind-observer

My experimental bitcoind-observer tool is a Bitcoin Core Prometheus metrics exporter utilizing and demonstrating the newly added tracepoints in Bitcoin Core.

May 6, 2021

miningpool-observer: Observing Bitcoin Mining Pools

My miningpool-observer project aims to bring transparency to mining pool transaction selection. The tool can detect missing and extra transactions in blocks. One goal is to detect censorship by mining pools.

January 31, 2020

transactionfee.info (2020 version)

The website transactionfee.info shows Bitcoin protocol layer statistics. This includes statistics about Bitcoin transactions, their in- and outputs, about blocks and Bitcoin scripts. The project is a joint effort with Bitrefill CEO @ziggamon.

November 27, 2019

Contribution: Colab version of the Optech Schnorr / Taproot Workshop

Bitcoin Optech created a workshop explaining the Schnorr and Taproot upgrade to engineers. However, users needed to compile a patched version of Bitcoin Core with Taproot support and download and set up the Jupyter notebooks.

October 10, 2019

Bitcoin Transaction Monitor

Whenever you, an exchange or somebody else sends a Bitcoin transaction, it gets broadcast to all nodes in the Bitcoin network. Each broadcast transaction is represented by a dot on the Bitcoin Transaction Monitor scatterplot. The transactions are arranged by the time of arrival at my Bitcoin node …

September 28, 2019

rawtx library

The rawtx Golang module helps you (and me) to answer questions about raw Bitcoin transactions, their inputs, outputs, and scripts. I use the rawtx package for example in my Bitcoin Transaction Monitor and transactionfee.info projects.

August 4, 2019

Timeline: Historical events in the development of Bitcoin

To fully understand the rationale behind the current state of Bitcoin development, knowledge about historical events is essential. I created an open-source project containing the data for a timeline of historical developments in Bitcoin. Most data points are adopted from a talk John Newbery gave on …

June 1, 2019

mempool.observer (2019 version)

The mempool.observer website displays visualizations about my Bitcoin mempool. For example, a visualization of my current mempool and the historical mempool of my node is shown. The idea is to provide information about the current mempool state to a Bitcoin user with a seemingly stuck and …

May 16, 2019

mempool-dat

A Golang package that can deserialize Bitcoin Core’s mempool.dat files. This is a toy project. I developed this to learn more about Golang and the mempool.dat file format by Bitcoin Core.

March 2, 2019

c-lightning plugin: csvexportpays

A toy plugin for c-lightning to export all payments made with a c-lightning node to a .csv file. I build this a few days after Blockstream released the plugin support in c-lightning v0.7 to showcase how simple it is to build plugins.

June 23, 2018

lnplays.com

Konstantin Nick (@sputn1ck) and I build lnplays.com for the Lighting Hackday in June 2018. You could play Pokémon via the Lightning Network build. Pressing the buttons of the GameBoy to move the player and to interact with the world would generate a lightning invoice. Paying that invoice would send …

January 22, 2018

transactionfee.info (2018 version)

We build transactionfee.info in 2018 to raise awareness about the inefficient use of block space by exchanges, services, and wallets. The project is a joint effort with Bitrefill CEO @ziggamon.

October 7, 2017

mempool.observer (2017 version)

The mempool.observer website displays statistics about my Bitcoin mempool. This covers the 2017 version which I iterated on in 2019.