Building Smart Contracts on Solana

Why Solana Over Ethereum?

Ethereum is the most established smart contract platform, but its throughput limitations and high gas fees make it impractical for many consumer applications. Solana addresses these constraints through a combination of innovations: Proof of History (PoH) as a cryptographic clock, parallel transaction processing, and a tower BFT consensus mechanism.

The practical result: Solana transactions typically cost less than $0.001 and confirm in under 400 milliseconds. For applications where users transact frequently or where micropayments matter, these are not trivial advantages.

The trade-off is complexity. Solana's programming model is fundamentally different from Ethereum's Solidity-based contracts. Solana programs (the Solana term for smart contracts) are stateless — they do not store data themselves. All state is stored in separate accounts that the program operates on. This is unintuitive at first but makes Solana's parallel execution model possible.

Understanding the Solana Account Model

Before writing any code, you need to understand the account model, because everything in Solana revolves around it:

• Programs — Executable code stored on-chain. These are stateless and immutable (unless the upgrade authority updates them).
• Accounts — Data storage on-chain. Every piece of state (a user's token balance, a game character's stats, a DAO proposal) is stored in a separate account.
• Program Derived Addresses (PDAs) — Deterministic account addresses derived from a program ID and "seeds". These are how programs own and manage accounts without a private key.
• Signers — Accounts that have signed a transaction, authorizing changes to their state.

When you call a Solana program, you pass it a list of accounts it is allowed to read from or write to. This explicit account listing is what enables Solana to process non-conflicting transactions in parallel.

Setting Up Your Development Environment

You will need the following tools installed:

• Rust — Solana programs are written in Rust. Install via rustup.
• Solana CLI — Command-line tools for deploying programs and managing accounts (sh -c "$(curl -sSfL https://release.solana.com/stable/install)").
• Anchor CLI — The Anchor framework dramatically simplifies Solana program development (cargo install --git https://github.com/coral-xyz/anchor avm).
• Node.js — For writing tests and client-side code using the @coral-xyz/anchor TypeScript SDK.

After installation, configure your Solana CLI to use the devnet for development: solana config set --url devnet. Generate a keypair: solana-keygen new and airdrop some test SOL: solana airdrop 2.

Your First Anchor Program

Anchor is the standard framework for Solana development. It handles the boilerplate of account validation, serialization, and error handling, letting you focus on your program logic. Create a new project with anchor init my_program.

A minimal Anchor program that stores and increments a counter looks like this (in programs/my_program/src/lib.rs):

The key concepts Anchor introduces: #[program] marks your instruction handlers, #[derive(Accounts)] defines which accounts each instruction expects, and Account<Counter> tells Anchor to deserialize and validate the account automatically. The init constraint in the account struct tells Anchor to create the account if it does not exist.

Writing Tests

Anchor generates a TypeScript test suite in the tests/ directory. Tests run against a local validator or devnet. The SDK's program.methods.initialize().accounts({...}).rpc() pattern maps directly to your Rust instruction handlers, making the client code extremely readable.

Always test on localnet first (anchor test spins one up automatically), then devnet, and never skip the testing step before mainnet deployment. On-chain programs cannot be easily patched after deployment unless you maintain an upgrade authority.

Program Deployment

Deploying a Solana program involves compiling the Rust code to a BPF (Berkeley Packet Filter) bytecode and uploading it to a program account. The command anchor deploy --provider.cluster devnet handles this end to end. Your program ID is the public key of the program account, which you use in all client-side calls.

For production deployments, consider using a multi-sig upgrade authority with Squads Protocol to require multiple team members to approve program upgrades. This is an essential security measure for programs handling real funds.

Key Security Considerations

Solana program security is a deep topic, but here are the most critical issues beginners overlook:

• Signer checks — Always verify that accounts with authority over funds have actually signed the transaction.
• Account ownership checks — Verify that the accounts passed to your program are owned by the expected program, not by an attacker's program.
• Arithmetic overflow — Use Rust's checked_add, checked_mul etc. or the checked_math crate to prevent integer overflow bugs.
• Reentrancy — While Solana does not have the same reentrancy risk as Ethereum due to its execution model, cross-program invocations (CPI) still require careful state management.

Consider getting your program audited by a professional security firm (such as Neodyme, OtterSec, or Sec3) before deploying to mainnet, especially if it will handle significant value.

Back to all articles