Foreign Variables & Hashes

Foreign storage gives one contract read-only access to another contract's state.

Declaration

token_balances = ForeignHash(
    foreign_contract="currency",
    foreign_name="balances",
)

token_owner = ForeignVariable(
    foreign_contract="currency",
    foreign_name="owner",
)

Behavior

• reads behave like the underlying local primitive
• writes are rejected
• this is for composition, not shared mutable state

Why It Exists

Foreign storage is useful when:

• a contract needs to inspect canonical token balances
• governance logic depends on another contract's stored state
• you want to avoid copying state into a second contract

For behavior changes, use exported functions and explicit cross-contract calls.