anchor-lang & anchor-spl

anchor-lang 0.32.1 provides macros, account validation, and IDL generation for on-chain programs. anchor-spl wraps SPL Token, Associated Token, and related programs with typed CPI helpers. This pair is the default Rust framework on Agave 4.1.1 when teams want IDL-driven clients in TypeScript (@solana/kit 7.0.0 via Codama) and Python (AnchorPy).

Recipe

Quick-reference recipe card - copy-paste ready.

[dependencies]
anchor-lang = "0.32.1"
anchor-spl = "0.32.1"

use anchor_lang::prelude::*;
use anchor_spl::token::{self, Token, TokenAccount, Transfer};
 
declare_id!("<PROGRAM_ID>");
 
#[program]
pub mod my_program {
    use super::*;
    pub fn transfer_tokens(ctx: Context<TransferTokens>, amount: u64) -> Result<()> {
        token::transfer(ctx.accounts.transfer_ctx(), amount)?;
        Ok(())
    }
}

When to reach for this:

• Greenfield product programs with frequent instruction changes.
• Teams wanting Anchor IDL + TypeScript/Python clients.
• SPL Token CPIs without hand-packing instruction data.
• Standard account constraints (signer, mut, seeds, init).

Working Example

use anchor_lang::prelude::*;
use anchor_spl::{
    associated_token::AssociatedToken,
    token::{Mint, Token, TokenAccount, Transfer},
};
 
declare_id!("Fg6PaFpoGXkYsidMpWTK6W2BeZ7FEfcYkg476zPFsLnS");
 
#[program]
pub mod token_vault {
    use super::*;
 
    pub fn deposit(ctx: Context<Deposit>, amount: u64) -> Result<()> {
        let cpi_accounts = Transfer {
            from: ctx.accounts.user_ata.to_account_info(),
            to: ctx.accounts.vault_ata.to_account_info(),
            authority: ctx.accounts.user.to_account_info(),
        };
        let cpi_ctx = CpiContext::new(ctx.accounts.token_program.to_account_info(), cpi_accounts);
        anchor_spl::token::transfer(cpi_ctx, amount)?;
        Ok(())
    }
}
 
#[derive(Accounts)]
pub struct Deposit<'info> {
    #[account(mut)]
    pub user: Signer<'info>,
    #[account(mut)]
    pub user_ata: Account<'info, TokenAccount>,
    #[account(mut)]
    pub vault_ata: Account<'info, TokenAccount>,
    pub token_program: Program<'info, Token>,
}

What this demonstrates:

• #[program] dispatches instructions with generated discriminator.
• #[derive(Accounts)] encodes validation and metas.
• anchor_spl::token::transfer performs CPI to SPL Token program.
• Signer, Account, and Program types enforce ownership.

Deep Dive

How It Works

• Proc macros expand to solana-program entrypoints and account iterators.
• anchor build emits IDL JSON and TypeScript types (legacy) or feeds Codama.
• anchor-spl maps SPL layouts to Account<'info, T> with owner checks.
• Feature flags (init-if-needed, idl-build) tune codegen and IDL contents.

Rust Crate Table

TypeScript / NPM Table

Rust Notes

// Match CLI and crate versions exactly
// Anchor.toml: anchor_version = "0.32.1"
 
// Space for init accounts
#[account(init, payer = user, space = 8 + MyState::INIT_SPACE)]
pub state: Account<'info, MyState>,

Gotchas

• CLI vs crate version mismatch - obscure IDL errors. Fix: avm use 0.32.1 and anchor-lang = "0.32.1".
• Missing token_program account in CPI - runtime failure. Fix: include all SPL required accounts in struct.
• Overusing UncheckedAccount - security holes. Fix: typed accounts or explicit owner checks.
• IDL not checked in - client drift. Fix: commit target/idl/*.json or regenerate in CI.
• Init without rent calculation - insufficient lamports. Fix: use space macro + Rent sysvar helpers.

Alternatives

FAQs

Related

• solana-program & solana-sdk - underlying primitives
• Anchor Basics - accounts model
• spl-token & spl-associated-token-account - token crates
• Codama - client generation

Stack versions: This page was written for Agave 4.1.1, Solana CLI 3.0.10, Anchor 0.32.1, anchor-lang 0.32.1, Rust 1.91.1, @solana/kit 7.0.0, Surfpool 0.12.0, and LiteSVM 0.6.x.