WWDC Find My

A WWDC-week social map: developers sign in with Apple, set a bio + avatar, and see themselves and every other registered user as live pins on a map so they can find each other.

• iOS app (WWDCFindMy/) — SwiftUI, iOS 26, Sign in with Apple, always-on background location, MapKit.
• Backend (Server/) — Vapor + Fluent + Postgres, validates Apple identity tokens, issues session JWTs, stores profiles/locations, serves uploaded avatars.

Architecture

iOS app  ──Sign in with Apple──▶  POST /auth/apple   (verifies Apple token, issues session JWT)
         ──Bearer session JWT──▶  GET  /me            (validate token on launch)
                                  GET  /users         (everyone with a location → map pins)
                                  POST /location      (throttled background updates)
                                  PATCH /profile      (bio / name)
                                  POST /avatar        (multipart image → saved to disk)
                                  GET  /avatars/:file (public, served from disk)

The map refreshes by polling GET /users every ~15s while open; each device posts its own location on significant movement (> 25 m or > 30 s) via CLLocationUpdate.

Backend — local development

Requires Docker (for Postgres) and the Swift 6 toolchain.

cd Server
docker compose up -d                 # Postgres on :5432
APP_JWT_SECRET=dev-secret swift run App migrate --yes
APP_JWT_SECRET=dev-secret swift run App serve --hostname 0.0.0.0 --port 8080
swift test                           # route/auth tests (no DB needed)

The iOS app's ServerConfig points the simulator at http://localhost:8080.

Environment variables

Var	Purpose	Local default
DATABASE_URL	Postgres connection string	(falls back to local DATABASE_*)
APP_JWT_SECRET	HMAC secret for session JWTs	insecure dev default
APPLE_BUNDLE_ID	Audience for Apple token verification	com.kylebashour.WWDCFindMy
PUBLIC_BASE_URL	Base for avatar URLs	http://localhost:8080
AVATAR_DIR	Where avatars are written	Public/avatars

Backend — deploy to Fly.io

cd Server
fly launch --no-deploy                       # creates the app (or reuse fly.toml)
fly postgres create                          # managed Postgres; attach sets DATABASE_URL
fly postgres attach <pg-app-name>
fly volumes create avatars --size 1          # persistent disk for avatars (mounted at /data)
fly secrets set APP_JWT_SECRET="$(openssl rand -hex 32)"
fly deploy                                   # release_command runs migrations

fly.toml sets AVATAR_DIR=/data/avatars, PUBLIC_BASE_URL, and APPLE_BUNDLE_ID. After deploy, update ServerConfig.baseURL (device build) to the Fly host.

iOS app

Open WWDCFindMy.xcodeproj, build for an iOS 26 simulator or device.

• Capabilities: Sign in with Apple (WWDCFindMy/WWDCFindMy.entitlements), Background Modes → Location updates (Info.plist).
• Sign in with Apple requires the simulator/device to be signed into an Apple ID.
• Background location must be verified on a real iOS 26 device — the blue status indicator and true backgrounding don't fully reproduce in the simulator. Use Xcode's Debug → Simulate Location to feed movement.

Notes / future work

Out of scope for WWDC week (easy follow-ups): real-time push (APNs/websockets) instead of polling, a precise/approximate location toggle, account deletion, and moving avatars to object storage (S3/R2).