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Release 15.10.2024: migration guide

This release of =nil; adds support of the onlyResponse modifier, changes currency IDs to be of the address type and launches the currency faucet service.

Summary of key changes​

  • The newly added currency faucet service makes it easy to transfer the default token (NIL) as well as various pre-set currencies (e.g., 'mock' implementations BTC or USDT) to any address
  • The onlyResponse modifier limits access to callback functions used in sendRequest(), making sure they can only be called by the response to a given request
  • CurrencyId is a new alias for the address type, fully replacing the previous currency IDs which were of the uin256 type
info

Read this tutorial to learn more about the currency faucet service.

Migration of smart contracts​

  • Replace usage of uint256 in currency IDs with CurrencyId

CurrencyId is an alias for the address type which fully replaces the previous system where currency IDs were of the uint256 type. To cast a contract address to a CurrencyId:

CurrencyId id = CurrencyId.wrap(address(this));

This change simplifies the management of custom currencies as there is no longer a need to keep track of separate currency addresses and their IDs.

  • Mark callback functions with the onlyResponse modifier

The Nil.sol library now includes the onlyResponse modifier. After this modifier is applied to a function, said function can only be called by responses that arrive to the requests sent via sendRequest(). The modifier protects callback functions from being unfairly executed by malicious parties.

Migration of the =nil; CLI​

No specific changes have to be made to the =nil; CLI commands.

Migration of Nil.js scripts​

The Nil.js client library now supports several useful 'wrappers' designed to simplify work with the faucet service.

Read this tutorial to learn more or access the references for Nil.js to learn more..

Migration of Hardhat scripts​

No specific changes have to be made to existing Hardhat scripts.