The CLI scaffolds a complete app — routing, theming, a tab layout and thirteen components already wired up. Pick a starting point below and copy one command.
Choose the setup that matches what you are building.
The components, theming and a tab layout. No backend.
Add BNA UI to an Expo app you already created.
A real-time backend with a schema and a live query. No sign-in.
Google, Apple, password and email OTP sign-in, pre-wired.
Postgres with row level security, realtime and storage. No sign-in.
Password, magic links, OTP, Google, Apple and GitHub, pre-wired.
Firestore, Cloud Storage and security rules with tests. No sign-in.
Password, Google and Apple sign-in, with owner-scoped rules.
Which one should I pick?
| You want to… | Start with |
|---|---|
| Build a UI and ship it, no server | Expo |
| Store data and sync it live across devices, no accounts | Convex, Supabase or Firebase |
| Have users sign in on day one | Convex + Auth, Supabase + Auth or Firebase + Auth |
Convex, Supabase or Firebase?
All three are real-time backends and all three starters give you the same app. They differ in where your logic lives and how authorization works.
| Convex | Supabase | Firebase | |
|---|---|---|---|
| Data model | Documents, schema in TypeScript | Postgres, schema in SQL migrations | Documents, no schema |
| Queries | TypeScript functions on the server | Direct from the client, plus edge functions | Direct from the client |
| Authorization | Checked inside each function | Row level security, enforced by Postgres | Security rules, evaluated against the query |
| Realtime | Every query is a live subscription | Opt in per table | Every listener is live |
| Search | Built-in full-text index | ilike, or a tsvector column | Whole-word tokens, or an extension |
| Offline cache | In-memory | In-memory | In-memory (no IndexedDB on RN) |
| Local dev | Cloud dev deployment | Cloud, or the whole stack in Docker | Emulator suite (needs a JDK) |
| Reach for it when | You want end-to-end TypeScript and no SQL | You want Postgres, SQL and a relational schema | You are already in the Google ecosystem |
Firestore evaluates a read rule against the query, not the documents it would return — it refuses any query it cannot prove is scoped to rows you are allowed to read. Postgres row level security does the opposite and silently narrows the result. Code that moves between the Supabase and Firebase starters has to account for that.
The Firebase auth starter also has no email OTP and no GitHub provider, and its Google and Apple buttons need a development build. The details are here.
Nothing in the component library depends on either, so you can start on the plain Expo path and add a backend later.
Existing project
Already have an Expo app? Don't run init over it. The manual guide adds the
theme system and hooks to a project you already have, then leaves you to pull in
components one at a time with bna-ui add.