Account Constraints

#[derive(Accounts)]
#[instruction(...)]
pub struct Initialize<'info> {
  ...
}

Github Solpg

You can access the instruction’s arguments with the #[instruction(..)] attribute. You have to list them in the same order as in the instruction but you can omit all arguments after the last one you need.

#[account(signer)]
#[account(signer @ <custom_error>)]

Github Solpg

Checks the given account signed the transaction. Custom errors are supported via @. Consider using the Signer type if you would only have this constraint on the account.

#[account(mut)]
#[account(mut @ <custom_error>)]

Github Solpg

Checks the given account is mutable. Makes anchor persist any state changes. Custom errors are supported via @.

#[account(
  init,
  payer = <target_account>,
  space = <num_bytes>
)]

Github Solpg

Creates the account via a CPI to the system program and initializes it (sets its account discriminator).

#[account(
  init_if_needed,
  payer = <target_account>
)]


#[account(
  init_if_needed,
  payer = <target_account>,
  space = <num_bytes>
)]

Github Solpg

Exact same functionality as the init constraint but only runs if the account does not exist yet.

This feature should be used with care and is therefore behind a feature flag. You can enable it by importing anchor-lang with the init-if-needed cargo feature. When using init_if_needed, you need to make sure you properly protect yourself against re-initialization attacks.

#[account(
  seeds = <seeds>,
  bump
)]


#[account(
  seeds = <seeds>,
  bump,
  seeds::program = <expr>
)]


#[account(
  seeds = <seeds>,
  bump = <expr>
)]


#[account(
  seeds = <seeds>,
  bump = <expr>,
  seeds::program = <expr>
)]

Github Solpg

Checks that given account is a PDA derived from the currently executing program, the seeds, and if provided, the bump. If not provided, anchor uses the canonical bump. Add seeds::program = <expr> to derive the PDA from a different program than the currently executing one.

#[account(
  has_one = <target_account>
)]


#[account(
  has_one = <target_account> @ <custom_error>
)]

Github Solpg

Checks the target_account field on the account matches the key of the target_account field in the Accounts struct. Custom errors are supported via @.

#[account(address = <expr>)]
#[account(address = <expr> @ <custom_error>)]

Github Solpg

Checks the account key matches the pubkey. Custom errors are supported via @.

#[account(owner = <expr>)]
#[account(owner = <expr> @ <custom_error>)]

Github Solpg

Checks the account owner matches expr. Custom errors are supported via @.

#[account(executable)]

Github Solpg

Checks the account is executable (i.e. the account is a program). You may want to use the Program type instead.

#[account(rent_exempt = skip)]
#[account(rent_exempt = enforce)]

Github Solpg

Enforces rent exemption with = enforce. Skips rent exemption check that would normally be done through other constraints with = skip, e.g. when used with the zero constraint

#[account(zero)]

Github Solpg

Checks the account discriminator is zero.

Use this constraint if you want to create an account in a previous instruction and then initialize it in your instruction instead of using init. This is necessary for accounts that are larger than 10 Kibibyte because those accounts cannot be created via a CPI (which is what init would do).

#[account(close = <target_account>)]

Github Solpg

Closes the account by:

• Sending the lamports to the specified account
• Assigning the owner to the System Program
• Resetting the data of the account

Requires mut to exist on the account.

#[account(constraint = <expr>)]
#[account(
  constraint = <expr> @ <custom_error>
)]

Github Solpg

Constraint that checks whether the given expression evaluates to true. Use this when no other constraint fits your use case.

#[account(
  realloc = <space>,
  realloc::payer = <target>,
  realloc::zero = <bool>
)]

Github Solpg

Used to realloc program account space at the beginning of an instruction.

#[account(
  token::mint = <target_account>,
  token::authority = <target_account>
)]


#[account(
  token::mint = <target_account>,
  token::authority = <target_account>,
  token::token_program = <target_account>
)]

Github Solpg

Can be used as a check or with init to create a token account with the given mint address and authority. When used as a check, it's possible to only specify a subset of the constraints.

#[account(
  mint::authority = <target_account>,
  mint::decimals = <expr>
)]


#[account(
  mint::authority = <target_account>,
  mint::decimals = <expr>,
  mint::freeze_authority = <target_account>
)]

Github Solpg

Can be used as a check or with init to create a mint account with the given mint decimals and mint authority. The freeze authority is optional when used with init. When used as a check, it's possible to only specify a subset of the constraints.

#[account(
  associated_token::mint = <target_account>,
  associated_token::authority = <target_account>
)]


#[account(
  associated_token::mint = <target_account>,
  associated_token::authority = <target_account>,
  associated_token::token_program = <target_account>
)]

Github Solpg

Can be used as a standalone as a check or with init to create an associated token account with the given mint address and authority.

#[account(*::token_program = <target_account>)]

Github Solpg

The token_program can optionally be overridden.