The Anchor framework is the dominant development framework for building programs on Solana. It provides a set of Rust macros and abstractions that handle boilerplate tasks like account deserialization, ownership checks, and PDA validation, allowing developers to focus on business logic. Anchor has become the de facto "standard library" of the Solana ecosystem, similar to how Hardhat and Foundry serve the Ethereum development workflow.

Core features

Declarative account validation: Anchor's #[derive(Accounts)] macro generates account validation logic from struct-level attributes. Constraints like has_one, seeds, and constraint are checked before the instruction handler executes.

1#[derive(Accounts)]
2pub struct Initialize<'info> {
3    #[account(
4        init,
5        payer = authority,
6        space = 8 + 32 + 8,
7        seeds = [b"vault", authority.key().as_ref()],
8        bump
9    )]
10    pub vault: Account<'info, Vault>,
11    #[account(mut)]
12    pub authority: Signer<'info>,
13    pub system_program: Program<'info, System>,
14}

Automatic discriminators: Anchor prepends an 8-byte discriminator (SHA-256 hash of the account type name) to all account data. This prevents type cosplay attacks where a Borsh-deserialized account of one type is misinterpreted as another.

IDL generation: Anchor automatically generates an Interface Description Language (IDL) file that describes the program's instructions and accounts, enabling client-side SDK generation.

Security constraints reference

Audit considerations

While Anchor eliminates entire classes of vulnerabilities through its constraint system, auditors should still verify:

• Custom constraint expressions cover all edge cases
• remaining_accounts (unvalidated accounts passed outside the struct) are properly checked in the instruction handler
• CPI calls within Anchor programs correctly propagate signer seeds
• Account close operations handle the rent-refund vulnerability (account can be reopened in the same transaction)

Anchor significantly raises the security baseline for Solana programs, but its abstractions can also hide subtle vulnerabilities from developers who do not understand the underlying native mechanics.