Accustom Platform Architecture Diagram

App: Expo and React Native built for the web (Expo Router PWA) at my.accustom.app; desktop visitors are pointed to their phone
App sign-in is Google only: Privy runs the OAuth, and the Google token it returns opens the Firebase session. Password sign-in is switched off, except for the demo account
Landing: React and Vite. Challenges, blog and sign-up forms; Netlify edge and serverless functions build the sitemap, add share previews, record visits and pick the consent region
Landing also calls two functions to catch duplicate sign-ups, and sends consented page events to Firebase Analytics
The landing's buttons open the app; nothing else links the two
Admin: React and Vite. Staff and challenge hosts sign in through Firebase Auth, and each account has a role
DNS is on Cloudflare, which also proxies the app and admin; the landing goes straight to Netlify
Each site builds and deploys on push

Firestore rules keep the money collections backend-only
Scheduler: hourly reminders and a midnight close per timezone, hourly deposit reconciliation and ledger indexing, daily settlement upkeep
A new IP address gets an approximate location from ipapi.co once; the answer is cached in Firestore
GitHub Actions tests the app, backend and contract

A user's USDC sits in their own smart wallet on Base, created and signed for through Privy
Card payment runs in Privy's funding flow with Meld as provider; USDC lands in the user's wallet on Base
The wallet sends the deposit as a UserOp through Coinbase CDP's bundler; its paymaster covers the gas
Functions check the deposit on chain, then the escrow signer sends refunds and prizes to wallets, and fees and forfeits to the treasury. Those backend-signed sends pay gas in ETH from the signer
Grace days are paid from the wallet straight to the treasury and checked on chain by a function
Cash-out: a function opens a Meld session, the wallet sends USDC to Meld, and Meld's webhook reports progress
App and Functions reach Base through Alchemy; the admin console reads balances over the public Base RPC

Check-in photos and video upload to Cloud Storage
After a day closes, Claude looks at the photos on commits with automatic review on (the default unless Strict). It can only approve; anything else waits for a person in the admin console
Claude also checks a commit draft before payment: it can suggest changes or block a harmful one
SendGrid sends email; Firebase Cloud Messaging sends web push to the installed PWA
The app registers its push token with Cloud Messaging itself; pushes and emails go straight to the user, so neither is drawn as an arrow
Links and the header image in an email call two public functions, emailUnsubscribe and emailHero