# About

> Emin Mahrt is a journalist and publisher (proud magazine, Berlin) and builds Bitcoin self-custody and agent-payment infrastructure. This site is where it gets written down properly.

## Since 1999

German-Turkish IT guy since 1999, Berlin. I'm a product engineer and founder, shipping software since 1999. My work spans consumer apps, ad-tech, blockchain infrastructure and fintech.

In Berlin, I founded [proud magazine](https://proud.de), an independent socio-political publication recognized by the [DFJV](https://www.dfjv.de) and archived in the [German National Library](https://d-nb.info/992028108). I co-founded [abend.net](https://abend.net), an ML-driven ad optimization platform, and [abend.com](https://www.youtube.com/watch?v=NwmK8omRuok), a Facebook Events discovery app, together serving thousands of paying clients monthly.

After passing the technical engineering interview from Facebook I decided to pass on that and became COO and CPO of the newly founded [æternity Blockchain](https://aeternity.com) in 2017. I led product and operations, scaled the team to over 100 people, and contributed to Liechtenstein's Blockchain Act. In 2022 I served as Chief Product Officer at [Börse Stuttgart Digital Exchange](https://www.bsdex.com), leading product for one of Europe's first regulated crypto trading platforms.

I've been in Bitcoin since 2012: early mining, visiting [Room 77](https://www.coindesk.com/tech/2020/10/19/closing-time-for-bitcoins-iconic-room-77-and-thats-ok-says-owner), and contributing to different open source projects.

Now I'm building [nuri.com](https://nuri.com). We acquired the Nuri brand after its insolvency, rebuilt the product from scratch, and launched the first and only passkey-derived and owned self-custodial Bitcoin wallet with non-custodial Visa card and integrated banking, live on iOS and Android across Europe, expanding to 100+ countries with a stablecoin Visa/Mastercard, onchain Euro IBAN and USD ACH account.

## Journalist and publisher

The core rule of this site comes from proud magazine: free speech. Nothing here is censored.

> Saying you do not care about privacy because you have "nothing to hide" is like saying you do not care about free speech because you have "nothing to say".

Details: [Principles](https://emin.de/principles).

## Contact

emin@emin.de · [X](https://x.com/em) · [LinkedIn](https://www.linkedin.com/in/bitcoinlightning/) · [Signal](https://signal.me/#eu/_JNAHwkQcIQ4HU8MVuWrO_WTnBcEzq8OND-0DT5VF6Xr_Lq6jmVF4rH0sM4Oq671)

## What I work on

Wallets where the company holding the keys is not a dependency: passkeys carrying their own secret through the WebAuthn PRF extension, MuSig2 co-signing that decays to a single key on a Bitcoin timelock, and recovery tooling that works when the provider is gone.

Alongside that: x402 payments so software can pay for access without a signup flow, MCP servers so a model can call a system instead of scraping it, and making a website legible to both a search crawler and an agent.

## Topics

- journalism and publishing
- independent magazines
- Bitcoin self-custody
- passkeys and WebAuthn PRF
- MuSig2 co-signing
- x402 agent payments
- Model Context Protocol
- agent-readiness engineering
- SEO and generative engine optimization
- payment rails and SEPA

## How these articles get written

Long-form, one subject per piece, only about things actually built or measured. Every article opens with a TL;DR, carries a standalone takeaway per section, and ends with real sources. Every article is also published as clean Markdown, in a public JSON API, and through an MCP server.

## Elsewhere

- https://github.com/eminogrande
- https://www.linkedin.com/in/bitcoinlightning/
- https://x.com/em
- https://twitter.com/em
- https://medium.com/@em
- https://emin.substack.com
- https://proud.de

## Who else writes here

Some posts may come from the [AI desk](https://emin.de/author/ai-desk): an openly named AI writing desk, not a person, labelled "AI-written, human-supervised" on every post and in the metadata.

Contact: emin@emin.de