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Imports Overview ​

Contracts can depend on other deployed contracts.

Two Patterns ​

  • static import: import currency
  • dynamic import: importlib.import_module("con_example")
  • dynamic function call: importlib.call("con_example", "transfer", {"amount": 10, "to": "bob"})
  • dynamic probes: importlib.exists("con_example"), importlib.has_export("con_example", "transfer")
  • flexible targets: importlib.owner_of(...) and importlib.enforce_interface(...) accept either a contract name string or an imported contract module
  • contract metadata: importlib.contract_info(...) returns canonical runtime metadata for a deployed contract
  • code verification: importlib.code_hash(...) returns the canonical SHA3-256 hash of stored contract source or the stored Xian VM IR artifact

How A Cross-Contract Call Behaves ​

When contract A calls into contract B, the runtime keeps the original signer stable while moving the immediate caller along the call chain:

That is why token contracts check ctx.caller: when another contract calls transfer, the spender is the calling contract, not the human signer. See Context Variables for the full rules.

Important Restriction ​

This is contract import resolution, not Python package importing. Imports are resolved against deployed contracts in state.

  • importlib.import_module(...)
  • importlib.exists(...)
  • importlib.has_export(...)
  • importlib.call(...)
  • importlib.enforce_interface(...)
  • importlib.owner_of(...)
  • importlib.contract_info(...)
  • importlib.code_hash(...)