Anatomy of an Anchor Program

Before we start adding features, let's break down every line of the program you just compiled.

The Import

use anchor_lang::prelude::*;

This single import brings in everything Anchor needs: the #[program] macro, Context, Account, Signer, Result, error types, and more.

Program ID

declare_id!("Fg6PaFpoGXkYsidMpWTK6W2BeZ7FEfcYkg476zPFsLnS");

Every Solana program has a unique address (public key). The declare_id! macro hardcodes this address into the binary. When you deploy, Solana verifies the binary matches this ID.

For development, you can use any valid base58 public key. For production, you'd generate one with solana-keygen grind.

The Program Module

#[program]
pub mod academy_program {
    use super::*;

    pub fn initialize(_ctx: Context<Initialize>) -> Result<()> {
        msg!("Superteam Academy default program");
        Ok(())
    }
}

The #[program] attribute tells Anchor this module contains your instruction handlers. Each pub fn inside becomes a callable instruction on-chain.

Key rules:

First parameter is always Context<T> where T is an accounts struct
Return type is always Result<()>
msg!() logs to the transaction log (visible in explorers)

Accounts Structs

#[derive(Accounts)]
pub struct Initialize {}

Every instruction needs an accounts struct that defines which accounts the instruction reads/writes. This empty struct means initialize doesn't need any accounts.

In the next lesson, you'll add your first real instruction with a non-empty accounts struct.

What the Compiler Checks

When you hit Build, cargo-build-sbf validates:

Rust syntax and type safety
Anchor macro expansion (accounts, constraints, errors)
SBF compatibility (no system calls, no heap abuse)