ChatteriOS Developer Challenge

Build a WhatsApp-like iOS app on our hosted messaging API, and ship it to TestFlight. We test it on two real iPhones.

We provide the backend

A hosted messaging API with REST, WebSocket, media uploads and push notifications. You do not build a server.

API guide

Sign-up, friends, real-time 1:1 chat, delivery ticks, typing, presence and offline resilience.

Requirements

Publish through App Store Connect and invite infrastructure@chathealth.com.sg as a tester.

TestFlight guide

Qwen Code with Qwen3 Coder Next, paid by the gift card in your invitation.

Redeem your card

Layers, local store, outbox, sync engine and message status state machine.

App design

The exact script we run on two iPhones, step by step. No surprises.

Test plan