Accessing Accounts

Use ctx.accounts for typed fields, ctx.bumps for PDA seeds, and ctx.remaining_accounts for variable account lists passed after the fixed layout.

Recipe

pub fn route(ctx: Context<Route>) -> Result<()> {
    let bump = ctx.bumps.vault;
    let vault = &mut ctx.accounts.vault;
    for acc in ctx.remaining_accounts.iter() {
        require!(acc.owner == &crate::ID, MyError::BadRemaining);
    }
    Ok(())
}

When to reach for this: Handlers read or mutate validated accounts and optional extras.

Working Example

pub fn swap(ctx: Context<Swap>) -> Result<()> {
    let user = &ctx.accounts.user;
    let pool = &mut ctx.accounts.pool;
    let bump = ctx.bumps.pool;
 
    msg!("user: {}, pool bump: {}", user.key(), bump);
 
    for meta in ctx.remaining_accounts.iter() {
        let ai = meta.to_account_info();
        require!(ai.is_writable, SwapError::ReadonlyAccount);
    }
    Ok(())
}

What this demonstrates:

• Account fields are references with lifetimes tied to Context
• ctx.bumps.<name> matches seeds field name
• remaining_accounts is a slice of AccountInfo
• Use to_account_info() for CPI account metas

Deep Dive

Account Mutation

&mut Account<'info, T> serializes changes at end of instruction if the account was marked mut in constraints.

remaining_accounts

Clients append accounts after the IDL order. Document expected order and validate each entry.

Gotchas

• remaining_accounts unvalidated - Critical vulnerability. Fix: Check owner, discriminator, signer as needed.
• Wrong bump name in ctx.bumps - Field name must match seeds account field. Fix: Use exact struct field name.
• Cloning AccountInfo unnecessarily - CU waste. Fix: Pass references into CPI helpers.
• Assuming remaining order from IDL - Only fixed accounts are in IDL. Fix: Publish separate docs for extras.
• Reading data before validation in other crate - Only applies to unchecked paths. Fix: Keep validation in constraints first.

Alternatives

FAQs

Related

• remaining_accounts - dynamic sets
• Passing Remaining Accounts - CPI extras
• Instruction Handlers - Context overview

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.