---
title: "Generative UI... in Python?"
category: "talks"
date: "2026-06-30"
time: "3:20pm-3:40pm"
track: "Design Engineering"
room: "Track 6"
speakers: ["Jeremiah Lowin"]
sourceLabels: ["Official conference schedule", "Public YouTube metadata"]
scheduleTrack: "Design Engineering"
scheduleRoom: "Track 6"
scheduleLabels: ["Design Engineering", "Track 6", "session", "confirmed"]
---
# Generative UI... in Python?

## Conference Context
- Date/time: 2026-06-30 · 3:20pm-3:40pm
- Track/room: Design Engineering · Track 6
- Speaker(s): Jeremiah Lowin
- Session type/status: session · confirmed

- Track: Design Engineering
- Room: Track 6
- Session type: session
- Status: confirmed

## Session Description
MCP Apps are a big deal: tools can now return dashboards, forms, and visualizations directly in the conversation. But somebody (or their agent) has to write those UIs. Fortunately, most of those UIs don't need to be designed from scratch; they can be composed from existing components. In that case, what you really need is a DSL that's token-efficient, streaming-compatible, and has a shallow learning curve. Surprisingly, the best one turns out to be... Python. In this talk, I'll introduce Prefab, a generative UI library that uses Python to compose fully interactive React applications from production components, now natively integrated into FastMCP. I'll demo real use cases, walk through the design, and show where this approach works and where it doesn't. No JavaScript will be harmed.

## Media Evidence
[Your MCP Server is Bad (and you should feel bad) - Jeremiah Lowin, Prefect](https://www.youtube.com/watch?v=96G7FLab8xc) (speaker-match related prior/adjacent AI Engineer video; captions: English auto-captions).

- Source video: `youtube-96G7FLab8xc`
- Slide deck: [[youtube-96G7FLab8xc-dense-slides|Dense Slides: Your MCP Server is Bad (and you should feel bad) - Jeremiah Lowin, Prefect]] — 2 visible slide image(s); 2 HTML recreation(s).
![[assets/dense-slides/96G7FLab8xc/slide-001.jpg]]
![[assets/dense-slides/96G7FLab8xc/slide-002.jpg]]
- Additional slide evidence: [[youtube-96G7FLab8xc-slides|Slides: Your MCP Server is Bad (and you should feel bad) - Jeremiah Lowin, Prefect]], [[youtube-96G7FLab8xc-reconstructed-slides|Reconstructed Slides: Your MCP Server is Bad (and you should feel bad) - Jeremiah Lowin, Prefect]]
- Slide-derived themes for `youtube-96G7FLab8xc`: prefect, list, server, should, feel, engineer, code, summit.

## Evidence Graph
This evidence graph is generated from currently linked source material: official schedule text, related video pages, cached transcripts, visible slide text, dense/reconstructed slide pages, and AI slide-classification audits.

### Media Signals
- `youtube-96G7FLab8xc` — 10 slide-derived text signals
- Slide-derived themes for `youtube-96G7FLab8xc`: prefect, list, server, should, feel, engineer, code, summit.
- Evidence links for `youtube-96G7FLab8xc`: [[youtube-96G7FLab8xc]], [[youtube-96G7FLab8xc-slides]], [[youtube-96G7FLab8xc-dense-slides]], [[youtube-96G7FLab8xc-reconstructed-slides]]

### Agent Reading Notes
Use these signals to refine the synopsis, topic links, people/company context, and method notes. If a source is a related external video rather than an exact official recording, keep it framed as supporting evidence.

## Transcript Status
Related video transcript availability: English auto-captions. Treat this as supporting context, not a recording of this exact scheduled session unless later confirmed. Not fetched yet.

## People
- [[jeremiah-lowin]]

## Supporting Slides
- [[youtube-96G7FLab8xc-slides]] — extracted from the related public AI Engineer video.

## Slide Evidence
- Slide-only cropped deck: [[youtube-96G7FLab8xc-dense-slides]] (2 viable slide images).
- Related slide/OCR pages:
- [[youtube-96G7FLab8xc-dense-slides]]
- [[youtube-96G7FLab8xc-reconstructed-slides]]
- [[youtube-96G7FLab8xc-slides]]
- Slide-derived terms: `fastmcp`, `fivetran`, `server`, `prefect`, `mep.tool`, `bool`, `servers`, `dict`, `tools`, `email`, `user`, `mcps`, `product`, `b1.302`, `operations`, `tool`, `literal`, `track_latest_order`

## Synthesis
### Synthesized Breakdown
The session explains MCP Apps as a way to add interactive UI to MCP-based workflows. It treats the MCP host as the place where tool data, model reasoning, and human controls meet.

### Speaker And Company Context
- [[jeremiah-lowin|Jeremiah Lowin]] — Founder & CEO at [[prefect|Prefect]].

### Topics Covered
- [[agent-security]]
- [[coding-agents]]
- [[mcp]]
- [[mcp-apps]]

### Derived Links And Source Material
- [[youtube-96G7FLab8xc]] — related YouTube source page.
- [[youtube-96G7FLab8xc-slides]] — slide evidence.
- [[youtube-96G7FLab8xc-reconstructed-slides]] — slide evidence.
- [[youtube-96G7FLab8xc-dense-slides]] — slide evidence.

### Novel Concepts / Clever Methods
- [[mcp-app-runtime|MCP Apps As Agentic App Runtime]] — MCP Apps treats interactive UI returned from MCP servers as a runtime layer for agent-facing software.

### Evidence Boundary
This synthesis is based on the official schedule and linked source pages. It should be revisited when exact session recordings or transcript-backed secondary sources are available.