Build mobile apps faster with Expo and Thirdweb

This is a guest post from Joaquim Verges - Joaquim has 10+ years of experience building consumer applications, he built the mobile teams and Twitter and Twitch. He fell in love with web3 technology and now leads client engineering at thirdweb. His passion is to push the boundaries of what consumer onchain apps and games can do through open source libraries and tools.

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I don’t think people fully realize that Blockchain technology is useful for many applications and industries beyond the financial world.

Blockchains are essentially public servers, where all the data is available to everyone to read. Smart contracts are programs that run on those servers with a public API that anyone can deploy and call. Wallets are user accounts that can authenticate on those public servers to access their own data.

These public servers come with primitives built in, like authentication, identity, payments and user data. All things that every app needs and you usually build yourself every time. On top of that, it standardizes how to read and write data, so that apps can talk to each other with a common API.

By using open source libraries like thirdweb and public servers as your backend, apps can be built much faster than previously possible because all the complexity of authentication, identity, payments, security, scaling and user data comes out of the box!

We’re starting to see the rise of “onchain apps” which take advantage of these public servers to unlock new features that were not previously available or prohibitively difficult to build:

• Peer to peer payments and digital marketplaces with security/consistency/scaling built in
• Micro payments with extremely low fees
• Payment automation, splitting and distribution back to users
• Cross app authentication and data sharing
• Apps with open APIs allowing communities to form and build third party experiences
• Readable user history, attestations and credentials from other platforms

So far most of the successful onchain apps have been web based, but we’re starting to see more and more mobile apps come online. Mobile adoption means orders of magnitude more users and apps than the web, massively expanding the activity on public servers with a large network of apps and users contributing to them.

As an example, the decentralized social network Farcaster is now bringing to life a new wave of applications that can read the profile and social graph of their users immediately on sign up, solving the bootstrap problem and offering personalized experiences as soon as a new user signs up. And all that’s needed for that is a wallet address.

Imagine signing up to a brand new app with one click, and immediately seeing your profile picture, username, bio, all your friends that also use that app and recommendations based on activity you’ve done on other apps, like your past purchases or onchain activity. This is possible today by building on top of these public servers with open standards, and it's making onchain apps better than traditional, closed ecosystem apps.

Most of the onchain apps today are built on React Native, using expo and thirdweb.

The new generation of onchain apps are getting built faster than ever thanks to an ever growing ecosystem of open standards, tools and open source libraries.

Thirdweb is a full stack, open source development platform that spans across frontend, backend and onchain, and is available on web, react native, unity, and unreal platforms.

The thirdweb React Native SDK is built for Expo, and allows you to:

• Authenticate users with standard login methods (email, phone, passkey, socials, etc..)
• Create wallets and smart accounts for every user automatically
• Connect and link external wallets (Metamask, Coinbase, Rainbow, etc)
• Authenticate with your server using the Sign In With Ethereum standard
• Collect analytics to monitor the activity and growth of your app
• Read data from any blockchain
• Write data to any blockchain on behalf of the connected user
• Download / upload files to IPFS
• Generate type safe APIs for any deployed smart contract
• React Hooks for connection, wallet management, transactions, and more
• React UI components for connection, wallet management, transactions, and more
• Facilitate payments with fiat or crypto
• And much more

Along with the SDK comes a management dashboard for analytics, configuration, and a large collection of smart contracts to deploy directly from UI.

You can think of it as a modern Firebase, covering all the essentials from authentication to infra to analytics, so you can focus on just building your app at record speed.

The thirdweb SDK is built for Expo, using standard Expo modules and native cryptography modules for best performance. It has minimal footprint thanks to named exports and tree shaking.

Using the react-native export directive, the SDK maintains the same imports and same API between React Web and React Native, making it easy to write common business logic between apps and websites.

Developer experience is the biggest focus of the SDK, aiming to simplify all aspects of working with blockchains. Here’s a very high level view of connecting, reading data and sending a transaction:

Try out all the features on the thirdweb expo starter by cloning it on github and running it for yourself, and check out the thirdweb developer portal for more information.

The thirdweb SDK itself uses expo modules like expo-web-browser, and expo-linking, as well as expo modules for native cryptography, which greatly improves performance. We saw a massive improvement in encryption benchmarks compared to using JS libraries. This results in mobile apps performing better than websites in most of the heavy workload scenarios.

We also use EAS Build to distribute builds internally and externally. Internally, we release new versions of our demo apps weekly for everyone to try, report bugs and show early features to partners. Externally to submit to the stores. EAS Submit helped us manage all the app store complexities. We also plan to use EAS Update for our upcoming demo apps to distribute updates faster.

Our favorite thing about building our SDK on top of Expo is how simplified the setup is for our developers. Previously we had to spend hours debugging environment setups and nuances for our developers using bare workflows. By going Expo only, we reduced that pain to almost zero and our developers are really happy with it.

Here are a few examples of successful apps built with Expo and thirdweb:

Kontigo is popular micro banking app in Latin America that lets you pay, save, and earn interest using stablecoins (USDC). Think Venmo, but with more banking features - they even have credit loans and their own debit cards.

They let the blockchain do all the heavy lifting of securing assets, p2p payments, yield earning and more. They use thirdweb’s react native SDK, in-app wallets with smart accounts, thirdweb engine to automate transactions and more. Their users simply log in with Google, all the blockchain interactions happen under the hood and are invisible to users.

Fame is an MMA loyalty and fandom app, which lets users follow all the latest MMA news and events, but also earn loyalty points through mini games which unlock perks, passes, and cosmetics for MMA fans.

They used thirdweb to handle all the user authentication and wallet management, with all the loyalty points and assets attributed onchain.

Blue Social aims to gamify networking and meeting people by using a clever system to reward real life interactions using bluetooth and geolocation.

They use thirdweb for their login and user system across the mobile app and their website, and to publish their proofs of interaction onchain as well as their blue points reward system.

The next Uber, Airbnb, and Twitter are being built right now and are all leveraging public servers to tap into an ever growing network of interconnected users and applications. At thirdweb we’re on a mission to make those apps insanely easy and fast to build with our full stack platform and Expo.

We’re continuously improving our platform React Native SDK with new functionality, follow the updates on our changelog and connect with the thirdweb community on X or Farcaster.