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Signing

Protostar offers two ways of providing the signature:

1. StarkCurveSigner​

By default, Protostar uses the StarkCurveSigner class from Starknet.py.

This way requires you to pass a private key (for signing) and account contract's address (to fetch the nonce). You can obtain the key and account address e.g. from Argentx or Braavos wallets.

2 options are used for this:

  • private-key-path - a path to the file containing private key in hex (prefixed with '0x') or decimal representation
  • account-address - your account contract's address on the appropriate network in hex (prefixed with '0x') or decimal representation

Alternatively, if you prefer not to store private key in a file, we check for PROTOSTAR_ACCOUNT_PRIVATE_KEY environment variable, and use it if it's available.
It should be in the same hex (prefixed with '0x') or decimal representation, like all the options above.

2. Using a custom signer class​

You can provide a custom signer class which inherits from BaseSigner abstract class. This way of signing requires you to write a class in Python, which signs the transaction in a way that is suitable to you. After writing such class, simply use signer_class argument in the CLI for declare-cairo0 command to use that class instead of the default one. Usage of this way of signing is exclusive with the default signer strategy.

caution

The custom signer class must not take any arguments in the constructor, since we don't pass any args on instantiation.

The Python file containing this class can be put next to Cairo source code. Protostar synchronizes PYTHONPATH with project's cairo_path. Modules that are dependencies of Protostar (like starknet_py or cairo-lang) should be available for importing by default. If you want to import other custom modules, you should extend PYTHONPATH yourself (https://docs.python.org/3/using/cmdline.html#envvar-PYTHONPATH), when running this command.