Solana DApp Learning

Learn Solana by building small, readable DApps.
Wallet connections, SOL transfers, Anchor counters, on-chain data stores, and Pyth-priced payments.

Quick start · Examples · Programs · Contributing

What this project teaches

This repository began as my first Solana DApp and live-coding learning project. It now uses Solana Kit and Wallet Standard for the browser examples, with buildable Anchor sources alongside them. Each lesson exposes the underlying instructions instead of hiding the transaction flow behind a large framework.

This is an educational project. The wallet actions target Devnet. Jupiter quotes use Mainnet market data and do not execute trades.

Quick start

Requirements: Node.js 24, npm, and a Wallet Standard wallet set to Devnet.

git clone https://github.com/SebastianBoehler/solana-dapp-learning.git
cd solana-dapp-learning
npm ci
cp .env.example .env.local
npm run dev

Open localhost:3000. Connect your wallet and obtain Devnet SOL through the Solana faucet. The SOL transfer lesson works without deploying a custom program.

Counter, oracle, and USD payments require your own matching programs deployed on Devnet. Enter their public addresses in .env.local, then restart Next.js. See program setup.

Variable	Required for
NEXT_PUBLIC_COUNTER_PROGRAM_ID	Counter actions
NEXT_PUBLIC_ORACLE_PROGRAM_ID	Exchange data store actions
NEXT_PUBLIC_PAY_USD_PROGRAM_ID	Pyth-priced SOL payments
NEXT_PUBLIC_SOL_USD_PRICE_ACCOUNT	A fresh Pyth SOL/USD price update account on Devnet
PYTH_API_KEY	Server-side Hermes price preview
JUPITER_API_KEY	Server-side Jupiter V2 quotes

API keys stay on the server. Do not prefix them with NEXT_PUBLIC_. Missing configuration and upstream failures are shown as errors.

Examples

Lesson	Where to start	What happens
Wallet connection	wallet-button.tsx	Discovers Wallet Standard wallets and connects a Devnet signer
SOL transfer	sendLamports.tsx	Builds a System Program transfer to a recipient you enter
Counter	counter.tsx, counter/src/lib.rs	Derives a wallet PDA, initializes, changes by four, reads, and closes it
Exchange data store	oracle.tsx, oracle/src/lib.rs	Reads BTC/USDT from Binance and lets your wallet write one scaled value
Pyth-priced payment	pyth_send_usd.tsx, pyth-pay-usd/src/lib.rs	Sends SOL for a USD amount in cents, using a verified Pyth pull-oracle price
SPL token minting	spl_token.tsx	Callable helper creates a fresh mint and associated token account, then mints 200 tokens
Round-trip quotes	/arbitrage, jupiter.ts	Compares SOL → USDC → SOL quotes from Jupiter V2

The main page contains SOL transfers, payments, the counter, and the exchange data store. Dedicated pages are available at /oracle, /sendUsd, and /arbitrage. The token helper is a source example without a dedicated UI: call mintToken(client, connected.signer) from a connected-wallet component.

The exchange data store is user-controlled data, not a verified oracle. The Binance stream closes when the component unmounts. Every write needs wallet approval; the example does not use a shared signing key or an automated writer.

Pyth prices

The payment program uses pyth-solana-receiver-sdk, validates the SOL/USD feed and full verification through get_price_no_older_than, and rejects prices more than 60 seconds old or dated in the future. It uses checked integer arithmetic and rounds up to the next lamport. Only system-owned recipient accounts are accepted.

Configure a current Pyth Devnet pull-oracle account. Publishing and refreshing that account is a separate prerequisite; the UI does not publish price updates. The Hermes button previews an off-chain price through the current Hermes SDK and a server-only key. That preview is not the payment program's price source.

See Pyth's Solana integration guide and Hermes authentication.

Jupiter quotes

Get an API key from the Jupiter developer portal. The example calls /swap/v2/order without a taker, so it receives quotes without transactions. Sequential quotes are not atomic. Their difference excludes execution costs and does not demonstrate profitable arbitrage. See Jupiter V2.

Building and deploying programs

The Cargo workspace contains three separate Anchor programs under contract/. It pins Anchor 1.2.1 and Pyth's receiver SDK 2.0.0.

Host compilation and arithmetic tests require stable Rust:

cargo test --workspace --locked

For deployable Solana binaries, install Anchor CLI 1.2.1 and its supported Solana/Agave SBF toolchain. Follow the current Anchor installation instructions. The original public program addresses remain in the sources to preserve project history; this repository does not contain their deployment keys.

For your own deployments:

1. Generate local program keypairs with your Solana CLI in target/deploy/, named my_counter-keypair.json, my_oracle-keypair.json, and pyth_program-keypair.json.
2. Run anchor keys sync to update declare_id! and Anchor.toml to those addresses.
3. Run anchor build with the matching current toolchain.
4. Deploy to Devnet with anchor deploy --provider.cluster devnet using your funded local wallet.
5. Put the deployed addresses into .env.local. Configure the Pyth Devnet account separately.

Keep your local wallet and deployment keypairs out of Git. Keys previously published with the historical demos have been removed from the current tree; they remain in Git history and must not be reused.

Development and verification

npm run typecheck
npm test
npm run build
cargo test --workspace --locked

The JavaScript tests cover exact amount parsing and instruction encoding, including the counter's u8 step and the oracle's name/data signatures. Rust tests cover counter overflow/underflow and USD-to-lamport conversion. GitHub Actions runs these checks for pushes and pull requests.

These checks validate local compilation and selected behavior. They do not validate deployed programs, SBF binaries, wallet approvals, live Pyth publishing, or authenticated Jupiter requests. See manual checks for the remaining integration steps.

Project layout

src/components/     Lesson UI and shared wallet/status components
src/hooks/          Instruction builders and token example
src/lib/            Solana client, amount parsing, and Jupiter requests
src/pages/          Next.js pages and server-only API routes
contract/           Anchor program sources and Cargo manifests
tests/              JavaScript regression tests

Learning together

The original learning sessions are on my YouTube channel. Questions, corrections, and focused example improvements are welcome through GitHub issues and pull requests. See CONTRIBUTING.md.

License

MIT.