⚙️ Programs

Programs on Solana are the equivalent of smart contracts: on-chain, immutable code that processes instructions and reads/writes accounts. They are compiled to BPF bytecode and deployed with a fixed program ID.

🎯 Key Ideas

Instructions — A single “method call”: program ID + list of accounts + instruction data (often serialized with Borsh ).
Program ID — The public key of the program; clients pass it in every instruction.
No internal storage — State lives in accounts owned by the program, not in the program binary.

📚 Development Options

Tool	Description
Native (C/Rust)	Solana SDK ; maximum control
Anchor	Anchor — Rust framework with IDL, macros, and client codegen
Seahorse	Python-like language that compiles to Solana programs

📝 Calling a Program (Client-Side)

You need: program ID, accounts required by the instruction, and instruction data (layout must match the program).


import {
  Connection,
  Keypair,
  PublicKey,
  Transaction,
  sendAndConfirmTransaction,
} from "@solana/web3.js";
 
const connection = new Connection("https://api.devnet.solana.com");
const programId = new PublicKey("YourProgramId...");
 
// Build instruction (accounts + data depend on the program)
const keys = [
  { pubkey: account1, isSigner: true, isWritable: true },
  { pubkey: account2, isSigner: false, isWritable: true },
];
 
const data = Buffer.alloc(8); // example: 8-byte instruction discriminator + args
// ... encode your instruction args (e.g. with borsh)
 
const ix = {
  programId,
  keys,
  data,
};
 
const tx = new Transaction().add(ix);
const sig = await sendAndConfirmTransaction(connection, tx, [payerKeypair]);
console.log("Signature:", sig);

With Anchor, you typically use the generated client and IDL so you don’t hand-build keys and data:


import { Program, AnchorProvider } from "@coral-xyz/anchor";
import idl from "./idl/my_program.json";
 
const provider = new AnchorProvider(connection, wallet, {});
const program = new Program(idl, programId, provider);
 
await program.methods
  .myInstruction(arg1, arg2)
  .accounts({ account1, account2 })
  .rpc();

⚙️ Programs

🎯 Key Ideas

📚 Development Options

📝 Calling a Program (Client-Side)

🔗 Resources