Macro jiminy_interface 

macro_rules! jiminy_interface {
    (
        $(#[$meta:meta])*
        $vis:vis struct $name:ident for $owner:path {
            $( $(#[$fmeta:meta])* $field:ident : $fty:ident = $fsize:expr ),+ $(,)?
        }
    ) => { ... };
    (
        $(#[$meta:meta])*
        $vis:vis struct $name:ident for $owner:path, version = $ver:literal {
            $( $(#[$fmeta:meta])* $field:ident : $fty:ident = $fsize:expr ),+ $(,)?
        }
    ) => { ... };
    (
        @impl version = $ver:literal,
        $(#[$meta:meta])*
        $vis:vis struct $name:ident for $owner:path {
            $( $(#[$fmeta:meta])* $field:ident : $fty:ident = $fsize:expr ),+ $(,)?
        }
    ) => { ... };
}

Declare a read-only interface for a foreign program’s account layout.

Generates a #[repr(C)] struct with the same LAYOUT_ID as the foreign program’s zero_copy_layout! definition, plus a load_foreign method that validates owner + layout_id.

The struct name must match the original account name for the LAYOUT_ID hash to agree. If you want a local alias, use type VaultView = Vault; after the macro invocation.

Version

By default, the interface assumes the foreign program uses version = 1. If the foreign layout uses a different version, specify it explicitly so the LAYOUT_ID hash matches:

jiminy_interface! {
    pub struct PoolV2 for PROGRAM_A, version = 2 {
        header:    AccountHeader = 16,
        authority: Address       = 32,
        reserve:   LeU64         = 8,
        fee_bps:   LeU16         = 2,
    }
}