Function assert_pda 

pub fn assert_pda(
    account: &AccountView,
    seeds: &[&[u8]],
    program_id: &Address,
) -> Result<u8, ProgramError>

Derive a PDA from the given seeds and program id, verify it matches the account’s address, and return the bump.

Uses find_program_address under the hood (syscall on-chain). Returns the canonical bump if the derived address matches. Errors with InvalidSeeds if no bump produces a match.

This is the pinocchio equivalent of Anchor’s seeds + bump constraint but you get the bump back for storage or CPI signing.

let bump = assert_pda(vault, &[b"vault", authority.as_ref()], program_id)?;