For web developers and founders shipping to phones

Expo App Builder From a Prompt to a Real Expo Project

Describe the app. Playcode builds an Expo project with file-based Expo Router screens, TypeScript, and an API client already pointed at a backend in the same project. Open the preview in a browser or on your phone, then let the agent run the cloud build.

No credit card required · No coding needed

Quick answer

Can AI build an Expo app for me?

Yes. Describe the app and Playcode builds a real Expo project - Expo Router screens, TypeScript, and an API client already wired to a backend and database in the same project. Preview it in a browser or on your phone, then ask the agent to run the cloud build for the stores.

1.1M+users
26M+projects
Since 2016

Used by people at

Counts registered accounts using corporate email domains from the companies above. Playcode is a self-serve product, not a contracted vendor to these brands.

How an Expo App Gets Built on Playcode

From the first sentence to a build you can install, in three steps

01

Describe the Screens, Not the Routing

Write what the app does: a workout tracker where you log a session, see your history, and sign in with the account you already use on the website. Playcode asks the questions a mobile engineer would - which screens sit behind sign-in, what has to be saved, what the phone needs when the signal drops.

Expo Router builds navigation from the files in the project, so a new screen is a new file. There is no route table to keep in sync and nothing to register by hand.

Preview
AI Chat
Publish
I'm a realtor in Miami. I need a website to show my listings and get buyer leads.
4 Questions
2 / 4
What's the main style for your real estate site?
AModern & minimal with clean lines
BLuxury feel with large property photos
CProfessional & corporate
DI'll describe my own style below
Or type your own answer...
Skip
Next
Describe what you want to change...
Economy
Build Progress
4/6
✓
Site layout & navigation
3s
✓
Hero section with CTA
5s
✓
Property listings grid
8s
Building contact form...
About page & bio
Footer & SEO meta
miami-homes.playcode.io
Miami Dream Homes
Your trusted partner in Miami real estate
Search by neighborhood...
Featured Listings
NEW
$1,250,000
Coral Gables Villa
4 bd|3 ba|2,400 sqft
OPEN
$890,000
Brickell Condo
2 bd|2 ba|1,200 sqft
Get in Touch
02

Watch It Run in the Browser and on Your Phone

The app renders in a browser preview while you iterate, which is the fast loop. When you want the real thing, open the same preview on your phone and use it with your thumbs.

Sign-in, sign-up, and a signed-in area come wired to the backend in the same project, so the first screen you add is already talking to real data instead of a mock.

03

Build for the Stores from the Cloud

When the app is ready, the agent sets up the build profile and the bundle identifiers, runs the build on Expo cloud infrastructure, and uploads it to App Store Connect or Google Play. No Mac and no local Android toolchain.

You bring your own Apple and Google developer accounts, and you click the final submit yourself. The app is listed under your account, not ours.

Your website is live!

https://
miami-homes.playcode.io
Site is secure - SSL certificate active
Or connect your domainmiami-dream-homes.com
Miami Dream Homes
Your trusted partner
Miami Dream Homes
Your trusted partner
The Expo setup math

Skip the Week Before the First Screen

What changes when the project, the backend, and the preview already exist

Starting an Expo app the usual way

  • Scaffold the project, then choose a router, a session approach, and a UI kit
  • Write auth twice, and find a server to host the half that matters
  • Wire secure token storage and a fetch client by hand
  • Learn signing, certificates, and store credentials before the first build
  • A week of setup before anyone can tap anything

Starting an Expo app on Playcode

  • Expo Router screens, TypeScript, and a shared UI kit are already in the project
  • Sign-in and sign-up already talk to a backend in the same project
  • The API client reads the public address of the project, so a phone can reach it
  • The agent prepares the build profile and drives the store upload
  • A screen running on your phone the same day
Read the files

What Your Expo Project Ships With

A normal Expo app in your workspace, not a web page in a shell

01

Expo Router, file-based

Screens live as files in the app directory, split into a signed-out group and a signed-in group. Adding a screen is adding a file, the router picks it up, and typed routes keep the links honest.

02

Sign-in wired to your own backend

A session provider owns who is signed in and the root layout swaps between the signed-out and signed-in screens, so no screen has to check auth itself. The account is the same one your website uses.

03

The session token in the device keychain

On a phone the access token is stored in the iOS Keychain or the Android Keystore and sent as a bearer header, which is the only correct place for a credential.

04

An API client a phone can actually reach

The client reads the public address of your project from an injected EXPO_PUBLIC_API_URL variable instead of localhost. A phone is a different machine from the server, and a hardcoded localhost is the classic bug that only appears on the device.

05

A shared UI kit and one theme

Screen, Heading, Body, Card, Field, and Button components read their colours and spacing from a single theme, so the tenth screen still looks like the first in light and dark.

06

Backend, database, and HTTPS included

The same project runs a real backend and database on a public HTTPS address, so the app has something real to call from its first request. No separate vendor to sign up for.

07

Real, exportable code

It is a standard Expo project in TypeScript. Open any file in the editor, change it yourself, or export the whole project and build it somewhere else.

A practical Expo implementation guide

Prove the Wiring Before You Build the Feature List

Pick libraries the preview can load, prove the app reaches its backend from a real phone, and only then add screens.

Before you build

Prerequisites

  • A project with a public address

    A phone is a different machine from the server, so the app needs the public address of the project rather than a local one. The platform injects it; nothing in the app should guess it.

    Ready when: Open the public link of the project in the browser on your phone and see the web side load over HTTPS.

  • A short list of the device features you actually need

    Only libraries the preview runtime already contains can load. A package with its own native code cannot run in the preview, so the list decides whether you stay in the fast loop or need a build of your own.

    Ready when: Every item on the list maps to an Expo SDK package or a JavaScript-only library, or you have accepted that it needs its own build.

Implementation sequence

Do, observe, verify
  1. 01
    Playcode AI prompt

    Ask for the screen, not the navigation

    Describe the screen, what it shows, and whether it sits before or after sign-in. Do not describe the routing: Expo Router turns a file in the app directory into a route, and the signed-out and signed-in groups already exist.

    Expected result

    A new screen file appears in the right group and is reachable from the screen that links to it.

    Verify

    Navigate to it from the previous screen in the preview, then close and reopen the app and reach it again.

  2. 02
    Playcode mobile preview

    Check the same screen in the browser and on the phone

    Open the preview in a browser for the fast loop, then open it on your phone and repeat the same actions on the device.

    Expected result

    The same screen, the same data, and the same states on both. The browser is a convenience surface, the phone is the truth.

    Verify

    A list that loads in the browser also loads on the phone. If it loads only in the browser, the request went to an address the phone cannot see.

  3. 03
    Playcode AI prompt and the project files

    Route every new call through the shared API client

    When you add an endpoint, ask for it to go through the API client the project already has, next to the existing auth and health calls, with its response type declared beside it.

    Expected result

    One file holds the backend address and the bearer header, and every screen inherits both.

    Verify

    Search the mobile app for a hardcoded host, port, or localhost and find none.

  4. 04
    Playcode chat plus your own Apple and Google accounts

    Run the store build from the cloud

    Create your own Apple and Google developer accounts, give the agent an Expo access token as a secret, and ask it to set the bundle identifiers, run the build, and upload the result.

    Expected result

    A signed build is produced on Expo cloud infrastructure and lands in App Store Connect or the Play Console under your account.

    Verify

    The build appears in your own developer console, and you install it on a phone from your test track before anyone else sees it.

Decisions that change the build

Do you need a library with its own native code?

  • Stay inside the Expo SDK and JavaScript-only libraries
  • Move to a build of your own that can carry any native module

Choose: Stay inside the Expo SDK while you are still deciding what the app is. Most first releases need camera, storage, notifications, and location, and the SDK covers those.

Tradeoff: Staying inside the SDK keeps the phone preview instant and the loop short, but rules out packages with custom native code. Moving to your own build unlocks every module and costs you the quick preview and a build step before each test.

Browser preview or phone for the daily loop?

  • The browser preview
  • A real phone

Choose: Iterate in the browser, and check on a phone before every milestone and before any release.

Tradeoff: The browser is always open and reloads instantly, but it is not a device: it does not show keychain-backed sessions surviving a cold start, real gestures, or the network view a phone has. The phone is slower to reach and is the only surface that tells the truth.

Before you share it

Test checklist

  • Happy path

    A new account signs up on the phone preview and the first signed-in screen loads data from the project backend.

    Expected: The account is created, the screen renders real data, and the session survives closing and reopening the app.

  • Invalid input

    Sign in on the phone with a wrong password, then submit the main form with a required field empty.

    Expected: Both are refused with a specific message, and no session or partial record is stored.

  • Duplicate or retry

    The main save button is tapped twice on a weak mobile connection, before the first response arrives.

    Expected: The retry behaviour you chose is visible on screen, and the backend does not end up with two records.

  • Published smoke test

    Install the build from your own developer console test track on a phone that has never opened the project, and complete the same flow against the published backend.

    Expected: The flow works over HTTPS against the live backend, with no development address left anywhere in the app.

If something goes wrong

Common failure cases

The app works in the browser preview and fails on the phone

Likely cause
A request went to a local address. The phone is a different machine from the server and cannot see localhost or any internal port, so this failure only ever shows up on the device.
Check
Open the same screen in the browser and on the phone. The phone shows a network error rather than an empty state.
Fix
Route the call through the project API client, which reads the public address from the injected variable, and delete the hardcoded host.

A library crashes the moment the screen imports it

Likely cause
The package contains its own native code. The preview runtime only carries the native modules it was built with, so nothing else can load there.
Check
Remove the import and confirm the screen renders again, then check whether the package ships native code.
Fix
Ask for an Expo SDK package or a JavaScript-only alternative. If the feature genuinely needs that native module, it needs a build of its own instead of the preview.

The phone preview goes blank or reports an incompatible version

Likely cause
The Expo version in the project moved past what the preview app understands. The version is pinned deliberately, because preview apps support one SDK at a time.
Check
The browser preview still works while the phone refuses to open the project.
Fix
Restore the project to the snapshot taken before the change, and treat an SDK move as its own decision with its own build rather than a casual upgrade.

The browser preview reports a cross-origin error the phone never shows

Likely cause
The browser preview is served from a different address than the API, so the browser needs the backend to allow it. A phone has no origin and never needs this.
Check
The same request succeeds on the device and fails only in the browser tab.
Fix
Restart the mobile preview so the backend picks the preview address back up. This is expected behaviour on the browser surface, not a defect in your screen.
What people ship first

Four Expo Apps Worth Building First

A first release only has to do one job well, on a real phone

The Companion App

Same account, two surfaces

You already have a web app on Playcode. Add the phone half: the same accounts, the same records, a handful of screens designed for a thumb instead of a mouse.

The Field App

Works where the desk is not

A crew that works away from a desk needs something small and fast: the day list, a form, a photo, a status change. It talks to the same backend the office dashboard uses.

The Store Listing

A listing under your name

Some buyers only trust a product that exists in the App Store or Google Play. A focused first version, built in the cloud and submitted under your own developer account, gets you there.

The Demo People Can Install

A build they can install

A build on somebody else's phone beats a slide deck. Send a test build from your developer console and let them tap through real data on their own device.

What the project actually contains

One Project, Three Parts That Already Know Each Other

Playcode has been building and running real projects since 2016

1 project
holds the site, the backend, and the phone app
1 account
signs in on the web and on the phone
0 Macs
store builds run on Expo cloud infrastructure
The engine

A software team in one agent

Playcode AI runs the same frontier models that power ChatGPT and Claude - and orchestrates them like a team: it plans the work, delegates to sub-agents, runs long jobs in the background, and reviews its own changes.

Every frontier model

The latest models from every major lab, in one picker. Switch anytime.

ClaudeGPTGeminiGrok

Sub-agents

Big jobs split across specialists - one explores your code, one writes, one audits - working in parallel.

Background tasks

Long builds and migrations keep running while you keep talking. They report back when done.

migration - running

It sees your designs

Have a design in Figma? Paste a screenshot - or a page you like, or a bug - and it builds from what it sees.

Tuned by years of iteration to write production software - structured, typed, maintainable - not throwaway prototypes.

Production code

Real code you can open, read, and edit

Under every project is a codebase the agent keeps production-grade. And you are never locked out of it: open the file explorer and edit any file yourself - server included. No AI required.

Quality is the default

Complete states, secure boundaries, structured code - the bar is what a professional agency would ship.

Every file is yours to open

Browse the whole project - frontend, backend, configuration - and edit directly in the built-in editor.

Developers are welcome

Invite your developer with the right role, or export the project code and files. Nothing is trapped in Playcode.

For teams and organizations

Share it like you share a doc

Playcode is built for organizations, not just solo builders. Workspaces hold your projects, people, and billing; roles and teams decide exactly who sees what.

Workspaces with their own billing

Create a workspace per company, client, or department - each with its own members, projects, and subscription.

Three clear roles

Admins manage, editors build, viewers watch. Set roles on the whole workspace, on a team, or on a single project.

Teams that scope access

Group people into teams and give each team its own projects - or a whole folder of them. Private projects stay private, even inside a shared workspace.

Share outside the workspace

Send a project to any email - a client, a contractor - with exactly the access you choose. No extra seat needed.

Share "Inventory tracker"
Acme Ops workspace
Private
client@partner.co
Editor Invite
Operations team
8 people
Editor
MK
Maya Kowalski
maya@acme.co
ADMIN
JR
Jon Reyes
jon@acme.co
EDITOR
LS
Lena Sato
lena@acme.co
VIEWER
Restricted - only people invited can open it
Real-time

Multiplayer by default

Work on one project together. Write in the same AI chat together. Every message, edit, and setting is fully synchronized - live, for everyone, on every device.

acme-launch · Playcode
MKJR
Maya's laptop
Maya
Add a 'Book a call' button to the hero
Jon
And link it to our calendar, please
Playcode AIDone - button added to the hero and linked to your calendar.Preview updated
Describe the next change...
Jon's phone
Maya
Add a 'Book a call' button to the hero
Jon
And link it to our calendar, please
Playcode AIDone - button added to the hero and linked to your calendar.
Message...
Already there. No refresh.

Same project, same moment

Everyone works in the project at the same time - even in the code editor - without lock-outs or "who has the latest version".

Every device

Start on the laptop, check from your phone: the same live state follows you everywhere you sign in.

Nothing to refresh

Changes arrive over a live connection the instant they happen. Reloading the page is a habit you can drop.

Feels instant

It never makes you wait

Instant

Every click applies immediately on your device. Syncing happens behind you, not in front of you.

Offline

Connection dropped? Your changes queue locally and replay the moment you are back.

Reload-proof

The queue survives closing the tab. Nothing you did is lost while you are away.

Your Options for Getting an Expo App

Four ways to reach a build you can install, compared

Set It Up Yourself

The Expo CLI plus a backend you host
$0 in toolsplus your time and a server to run
  • Scaffold first, then wire auth, storage, and the API client by hand
  • The backend and database are still your problem
  • Signing and store credentials to learn before the first build
  • Every screen is yours to write
Free, and slowest to a real app

No-Code Mobile Builder

Drag-and-drop app tools
$30 - $100+/monthacross several tools
  • Screens come fast, real logic does not
  • No Expo project to read, review, or hand over
  • Data lives in the vendor rather than in your database
  • Leaving means building it again
Fast start, hard ceiling

Mobile Dev Shop

An agency or a contract team
$15,000 - $50,000+typical quote
  • Weeks before anyone taps a screen
  • The spec is locked before you learn anything
  • Every change is a change order
  • The store paperwork is still yours
Slow and expensive

Playcode AI

From $21/monthwith annual billing - or $25 monthlyNo credit card required
  • An Expo Router project in your workspace from the first prompt
  • Backend, database, HTTPS, and a public address included
  • Preview in the browser, then on your phone
  • The agent drives the cloud build and the store upload
  • Real code you own and can export
Built for shipping, not scaffolding
Choose Playcode

Real People. Real Websites Built with AI.

"I built my entire portfolio site in 20 minutes. My clients think I hired a designer. Already got 3 new inquiries this month."
Marcus T. · Freelance Graphic Designer, Austin TX
"We switched from Wix to Playcode. The AI actually understands what we need instead of giving us cookie-cutter templates. Saved us thousands."
Sarah Chen · Owner, Bloom & Petal Floristry
"I update my property listings from my phone while showing apartments. Clients are impressed when I tell them I built the site myself."
David Morales · Real Estate Agent, Miami FL

Simple Pricing

Start small. Upgrade when you're ready.

Starter

$0to start

Try the AI website builder and see results

  • AI credits included to start
  • Publish your site instantly
  • Subdomain included
  • Website hosting included
  • No credit card required
Get Started

Pro

Most Popular
$25/month

Everything you need to build

  • 100 AI credits/month
  • All AI models (12+)
  • Visual editing
  • Custom domains
  • Website hosting included
  • Export your code anytime
  • Private projects
  • Unlimited collaborators
Start Building

Cancel anytime. No hidden fees.

How credits work

Credits are used when AI helps you. Simple edits cost less, complex features cost more.

  • "Change button color" ~0.3-0.5 credits
  • "Add a contact page" ~2-3 credits
  • "Build full landing page" ~5-10 credits

Most users never run out. 100 credits = lots of building.

Questions People Ask Before Building an Expo App

A real one. The project contains a standard Expo app: Expo Router screens as files, TypeScript with strict mode on, a normal package file with Expo dependencies, and an app config. Open the files in the editor, change them yourself, or export the project and build it elsewhere.

It arrives pinned to a version the phone preview understands, and the pin is deliberate: a preview app supports one SDK at a time. Upgrading on a whim breaks the phone preview, so the agent treats an SDK move as a real decision with a real cost instead of doing it quietly.

Not in the preview. The preview runtime only carries the native modules it was built with, so a package with its own native code fails at import there. Expo SDK packages and JavaScript-only libraries work. If a feature genuinely needs a custom native module, it needs a build of its own, and the agent will say so rather than pretending it works.

No. The build runs on Expo cloud infrastructure, driven by the agent with an Expo access token you provide as a secret. There is no simulator or emulator inside Playcode either: you test in the browser preview, on your own phone, and on a test build from your developer console.

Not for you, with you. The agent prepares the build, runs the upload, drafts the listing, and captures screenshots. You need your own Apple and Google developer accounts, each of which charges its own fee and takes time to approve, and the final submit is yours to click. Review takes days and can bounce.

It comes with one. The same project runs a real backend and database on a public HTTPS address, and the app arrives already wired to it, sign-in included. If you would rather call an API you already have, the agent can point the client at that instead.

Playcode is $25/month, or $21/month billed annually, with AI credits included and no credit card required to start. Apple and Google charge separately for their developer accounts. Look up their current fees before you plan a release, because they change.

Still have questions? Contact us

Where Expo builders go next

AI app builder The bigger picture: describe software, and Playcode builds and runs it.All Playcode builders Compare app, website, bot, and business-workflow paths.Playcode Cloud The backend, database, HTTPS, and snapshots your app calls.Build an MVP When the app is the first version of a product, not an add-on.How to build an iPhone app with AI The step-by-step version, from the first prompt to a build you install.

Your Expo app could be on your phone today.

Describe the screens. Open the preview on your own device this afternoon.

A workout tracker with sign-in and a history screen...Build My Expo App

No credit card required. AI credits included.