Marcin Sadowski, Co-Founder and CTO of Mobile Reality, will introduce MDMA, an open-source generative UI engine that uses Markdown and YAML to give large language models a deterministic grammar for building reliable interfaces at a WarsawJS developer event.
WARSAW, Poland — August 12, 2026 — Marcin Sadowski, Co-Founder and Chief Technology Officer of Mobile Reality, will present "MDMA - Generative UI for your next application" at WarsawJS Meetup #141 on August 12 at Paramount in Warsaw. The talk will debut MDMA, an open-source engine that replaces fragile JSON and HTML outputs with a deterministic Markdown and YAML grammar, enabling large language models to reliably generate interactive forms, tables, and components at significantly lower operational cost.
Traditional generative user interface approaches require large language models to produce complex JSON or HTML structures. These outputs frequently corrupt when processed by smaller or less expensive models, pushing development teams toward premium services to maintain basic stability. MDMA, which stands for Markdown Document with Mounted Applications, addresses this by extending standard Markdown with YAML inside fenced code blocks. This structure provides LLMs with a strict, deterministic grammar for generating forms, tables, approval gates, charts, and webhooks, eliminating the structural ambiguity that causes conventional methods to fail.
The MDMA engine is published under the @mobile-reality npm organization as a suite of ten MIT-licensed packages. It functions as a fully headless state engine, allowing developers to integrate their own React, Next.js, or React Native components and design systems. A built-in deterministic validator and automatic fixer enable the system to achieve predictable results across diverse models, including GPT, Claude, Gemini, and Llama. The framework also includes out-of-the-box PII protection that automatically masks and hashes sensitive data entered into generated forms. Additionally, the @mobile-reality/mdma-mcp package provides a Model Context Protocol server, enabling direct integration with modern development environments such as Claude Desktop, Cursor, and VS Code.
Sadowski brings a background in robotics and automation to his software architecture practice. An alumnus of SGH Warsaw School of Economics, he delivered a TEDxWarsaw talk in 2017 on pushing boundaries through robotics, and has since focused on practical LLM engineering and bridging the gap between experimental AI and deterministic production stability.
Powered by MDMA, Mobile Reality has developed AI Headless Forms, a commercial solution that converts multi-step static forms into adaptive, conversational interfaces. The technology is already deployed in production environments within the FinTech and PropTech sectors, where it has reduced development timelines and costs. WarsawJS Meetup #141 begins at 6:30 PM at Paramount on Mokotowska 19. The event is sponsored by Dropbox, Paramount, Nord Security, and Xfaang, with media support from K MAG and partnerships from JetBrains, Webellian, and Tech Race Summit 2026.
"We built MDMA because production systems cannot tolerate the uncertainty of LLMs guessing HTML structures," said Marcin Sadowski, Co-Founder and CTO of Mobile Reality. "By constraining the output to a predictable Markdown and YAML grammar, we give developers reliability on cheap, fast models without sacrificing flexibility. The deterministic validator ensures that even if a model drifts, the system catches and fixes it before it reaches the user."
About Mobile Reality
Mobile Reality sp. z o.o. is an AI automation agency and end-to-end product software development company headquartered at Grzybowska 62 in Warsaw, Poland. Founded in 2016 by brothers Matt and Marcin Sadowski, the company builds intelligent systems ranging from AI agents and automation pipelines to full-stack digital products. As certified Make.com partners with more than seventy-five deployments, Mobile Reality serves clients across sectors including FinTech and PropTech. More information is available at https://themobilereality.com/.
