Apple Demonstrates Building a Local AI App on Mac in 13 Minutes with MLX and Xcode

At WWDC26 Apple released a 13‑minute technical video that demonstrates running "Agentic AI" directly on a Mac, enabling developers to create, modify, and debug applications entirely offline, preserving privacy and eliminating cloud‑API dependence.

What is Agentic AI? Unlike traditional chat‑based AI that only returns text, Agentic AI can decide its own next actions. In the demo, a natural‑language request such as "build a simple iPad drawing app" triggers the assistant to generate code, create project files, compile, run tests, and iteratively fix errors until the app builds successfully.

The demonstration builds a SwiftUI drawing app in minutes, even fine‑tuning details like stroke‑end effects, and shows the AI‑assistant operating within Xcode’s development environment.

Underlying architecture is broken into four layers:

1. MLX (core computation) – the low‑level neural‑network engine optimized for Apple silicon.

2. MLX‑LM (model loading) – loads and runs large language models on the device.

3. MLX‑LM Server (local server) – exposes the model as a locally hosted service.

4. Tool integration – Xcode or OpenCode connects to the local server via a configurable address (e.g., http://127.0.0.1:8080/v1).

Seamless Xcode integration is achieved by adding a "Locally Hosted provider" in Xcode’s Intelligence settings and specifying the server port (e.g., 8080). The IDE can then read the entire project, locate bugs, and automatically generate corrected code.

Performance breakthroughs stem from the M5 chip’s dedicated Neural Accelerators, delivering up to four‑times faster inference than the M4. Continuous batching allows parallel handling of tasks such as file search, code reading, and test generation.

If a single Mac is insufficient, Apple proposes distributed inference via Thunderbolt 5. Connecting multiple Macs (e.g., four M3 Ultra units) forms a cluster that boosts model throughput by nearly three‑fold and can run models with up to one trillion parameters locally.

Overall, Apple is not launching a new chat app but providing a complete local AI development toolchain that emphasizes privacy, low latency, and cost‑effective on‑device AI for enterprises, independent developers, and anyone wishing to avoid expensive cloud services.