sample-expo-kit-cause-pots

Cause Pots is a sample, not a template: a complete reference app to read, run, and copy the parts you need. Templates in this repository are starting points; this app shows what a finished feature set looks like on the expo-kit-anchor stack — collaborative savings pots on Solana, where contributors pool SOL into a shared vault that stays time-locked until enough of them sign off on releasing it.

Features

• Time-locked collaborative savings pots with an on-chain vault per pot
• Multi-signature release approval (M-of-N contributors)
• SOL amounts with an optional USD display currency (chain transfers are always SOL)
• Friend management by wallet address or .skr domain, resolved on mainnet with @solana-mobile/skr-domain
• Activity feed derived entirely from on-chain transaction history — no backend anywhere

Technologies

• Anchor (Solana program framework)
• Expo
• Uniwind (Tailwind CSS for React Native)
• @solana/kit
• @wallet-ui/react-native-kit

Get started

1. Install dependencies

   npm install
   

2. Start the app

This step builds the dependencies for the development client.

npm run android

The app connects to devnet by default, where the program is already deployed — you don't need the Rust toolchain to run it. Your wallet needs a small amount of devnet SOL for pot accounts and transaction fees; get some at faucet.solana.com.

The Anchor program

The anchor directory contains the cause_pots program, deployed on devnet at EvUrRjL2ZowK58ai87ztHmVXyTRNvGb6HCWQ2Feo9bNN. Five instructions cover the whole lifecycle:

Instruction	Behavior
create_pot	Creates the pot and its vault PDA; sets the target amount, unlock time, and signature threshold
add_contributor	Adds a wallet to the pot's contributor list (pot authority only)
contribute	Transfers SOL into the vault and tracks totals in a per-contributor account
sign_release	Records one contributor's approval for release, once the unlock time has passed
release_funds	Transfers the vault balance to a recipient once the signature threshold is met (pot authority only)

PDA seeds:

• Pot: ["pot", authority, name]
• Vault: ["vault", pot]
• Contributor: ["contributor", pot, contributor]

Rules enforced on-chain:

• The unlock time derives from Clock::get(), never from a client-supplied timestamp
• sign_release rejects non-contributors, double-signing, and signing before the unlock time
• release_funds rejects until the unlock time has passed and the signature count meets the threshold
• Signatures approve the release itself, not a destination: the pot authority picks the recipient at release time, so contributors trust the authority with the payout — the same model as the original app

Working on the program requires the Rust, Solana, and Anchor toolchains.

1. Generate a program keypair and sync the program ID

   This generates your own keypair, syncs it into Anchor.toml and declare_id!, rebuilds the program so the IDL carries the new address, and regenerates the TypeScript client from it:

   npm run anchor:setup
   

2. Build and test the program

   npm run anchor:test
   

   This builds the program, spins up a local validator, deploys, and runs the Vitest tests in anchor/tests, including the rejection paths: releasing before the unlock time, releasing below the signature threshold, and signing twice.

3. Deploy your own instance to devnet

   npm run anchor:deploy:devnet
   

The generated TypeScript client

The app talks to the program through a fully typed client generated by Codama from the program's IDL. It lives in anchor/src/client/js/generated and only depends on @solana/kit. Import it anywhere in the app via the @project/anchor alias:

import { fetchPot, findPotPda, getContributeInstructionAsync } from '@project/anchor'

After changing the program, rebuild the IDL and regenerate the client:

npm run anchor:build
npm run codama:js

Add hand-written wrappers around the generated code in anchor/src/client/js/index.ts — the generated directory is overwritten on every run.

How the app is put together

Everything the original three-tier version of this app kept on a server lives on chain or on the device here:

• Pots (src/features/pots) are read straight from the chain: the list is a getProgramAccounts scan decoded with the generated client (use-pots-query.ts), and every write is a generated instruction builder sent through Mobile Wallet Adapter (use-pot-program.ts). Pot metadata like the category and display currency are fields on the pot account.
• Friends (src/features/friends) are a local address book in expo-sqlite's key-value store. Adding a friend by .skr domain resolves it on mainnet with @solana-mobile/skr-domain (src/features/domains/resolve-address-or-domain.ts), and friends and pot contributors show a wallet's primary .skr name in place of its address when it has one.
• Activity (src/features/activity) is reconstructed from each pot's transaction history: getSignaturesForAddress gives the timeline and the generated identifyCausePotsInstruction and instruction data decoders identify what happened in each transaction.
• USD display (src/features/price) converts at the current CoinGecko rate. Contributions always move SOL on chain; a pot created in USD only renders its amounts differently.

Develop against localnet

For a faster loop you can run everything against a local validator, forwarded to your device over adb:

1. Start the localnet and keep it running: npx solana-mobile localnet
2. Deploy the program to it: npm run anchor:deploy:localnet
3. Switch the network to Localnet with the selector in the app
4. Connect your wallet and tap Request Airdrop to fund it

Two things to know: localnet needs a debug build — npm run android makes one, and Android debug builds allow the cleartext http://localhost endpoint while release builds only talk HTTPS. And the regular Seeker wallet only signs for public clusters, so signing on localnet requires a localnet-capable wallet such as fakewallet.

Learn more

To learn more about developing your project with Expo, look at the following resources:

• Expo documentation: Learn fundamentals, or go into advanced topics with our guides.
• Uniwind documentation: Learn how to style your app with Tailwind CSS.
• Anchor documentation: Learn how to build Solana programs with Anchor.
• Solana documentation: Learn how to build on Solana.